GRDC GrowNotes Northern Peanuts December 2014

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December 2014

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planning/paddock preparation • pre-planting • planting •

plant growth and physiology • nutrition and fertiliser •

weed control • insect control • nematode control •

diseases • harvest • post harvest handling and storage •

environmental responses • marketing • current research

December 2014

Peanuts

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PEANUTS - Contents

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Table of Contents

A Introduction

A.1 Agronomy at a glance ..................................................................................... viii

A.2 Crop overview .................................................................................................. ix

A.3 Executive summary ........................................................................................... x

A.4 Keywords ......................................................................................................... xi

1 Planning/Paddock preparation

1.1.1 Peanut production season plan ...............................................................1

Pre-season.................................................................................................................. 2

Ground preparation ..................................................................................................... 2

Week 0: planting ......................................................................................................... 2

Week 1: cracking ......................................................................................................... 3

Weeks 2 and 3: crop establishment............................................................................. 3

Weeks 4 and 5: flowering ............................................................................................ 3

Weeks 6 and 7: main flowering .................................................................................... 3

Weeks 8 and 9: pegging ............................................................................................. 4

Weeks 10 and 11: pegging and pod-setting ................................................................ 4

Weeks 12 and 13: canopy closure and pod-setting ..................................................... 4

Weeks 14 and 15: Pod-filling ....................................................................................... 4

Weeks 16 and 17: pod-filling and early maturity........................................................... 4

Weeks 18 and 19: maturity and digging ...................................................................... 4

Weeks 20 and 21 ........................................................................................................ 5

Harvest ....................................................................................................................... 5

Pre-cleaning ................................................................................................................ 5

Curing ......................................................................................................................... 5

1.2 Paddock selection .............................................................................................6

1.2.1 Rotations ................................................................................................6

1.2.2 Soils ........................................................................................................6

1.3 Paddock history ................................................................................................7

1.3.1 Paddock history trials ..............................................................................8

1.3.2 Pesticide history ....................................................................................12

1.4 Benefitsofpeanutsasarotationcrop .............................................................12

1.5 Disadvantagesofpeanutsasarotationcrop .................................................13

1.6 Pre-plant weed control ....................................................................................13

1.7 Potential crop contaminants ............................................................................13

1.8 Seedbed requirements ....................................................................................13

1.9 Soil moisture ..................................................................................................14

1.9.1 Dryland .................................................................................................15

1.9.2 Irrigation ...............................................................................................15

What will Irrigation do? .............................................................................................. 15

Irrigation systems ...................................................................................................... 17

1.10 Yield and targets .............................................................................................18

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1.10.1 Seasonal outlook...................................................................................19

1.10.2 Fallow moisture and double-cropping ....................................................19

1.10.3 Water-useefficiency ..............................................................................20

1.10.4 Nitrogen-useefficiency ..........................................................................22

1.11 Diseasestatusofpaddock ..............................................................................22

1.12 Insectstatusofpaddock .................................................................................23

2 Pre-planting

2.1 Varietalperformanceandratingsyield ...............................................................1

2.1.1 Hi Oleic varieties ......................................................................................3

2.1.2 Yielding ability .........................................................................................3

2.2 Qualityofplantingseed ....................................................................................5

2.2.1 Growingpeanutsforseed .......................................................................5

Clean land ................................................................................................................... 6

Clean machinery ......................................................................................................... 6

Irrigation ...................................................................................................................... 6

Supplementary calcium ............................................................................................... 6

Maturity ....................................................................................................................... 6

Digging and threshing ................................................................................................. 7

Drying ......................................................................................................................... 7

Peanut seed contracts ................................................................................................ 7

3 Planting

3.1 Seed dressings .................................................................................................1

3.2 Inoculation ........................................................................................................2

3.3 Germination ......................................................................................................2

3.4 Reduced tillage .................................................................................................2

3.5 Timeofplanting ................................................................................................3

3.6 Seeding rate ......................................................................................................3

3.7 Sowing depth ....................................................................................................4

3.8 Rowconfiguration .............................................................................................5

3.9 Sowing equipment ............................................................................................7

3.9.1 Press-wheels ..........................................................................................8

3.9.2 Planters ...................................................................................................9

4 Plant growth and physiology

4.1 Botanical types .................................................................................................2

4.2 Growth and development ..................................................................................3

4.2.1 Germination and emergence ...................................................................3

4.2.2 Vegetative growth ....................................................................................4

4.2.3 Flowering ................................................................................................5

4.2.4 Pegging ..................................................................................................6

4.2.5 Pod development ....................................................................................7


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4.2.6 Podfill ......................................................................................................7

4.2.7 Maturity ...................................................................................................7

4.3 Seed dormancy .................................................................................................8

5 Nutrition and fertiliser

5.1 Nutritional requirements.....................................................................................1

5.2 Soilfertility .........................................................................................................4

5.3 Crop removal rates ............................................................................................4

5.4 Soil testing ........................................................................................................5

5.5 Nutrient availability and soil pH ..........................................................................5

5.6 Calcium .............................................................................................................6

5.7 Nitrogen ...........................................................................................................9

5.8 Phosphorus ....................................................................................................11

5.9 Sulfur .............................................................................................................13

5.10 Potassium .......................................................................................................14

5.11 Boron ..............................................................................................................16

5.12 Copper ...........................................................................................................17

5.13 Iron .................................................................................................................18

5.14 Magnesium .....................................................................................................19

5.15 Manganese .....................................................................................................20

5.16 Molybdenum ...................................................................................................21

5.17 Zinc .................................................................................................................22

5.18 Cadmium management ...................................................................................23

6 Weed control

6.1 Digging .............................................................................................................3

6.2 Threshing ..........................................................................................................3

6.3 Drying ...............................................................................................................4

6.4 Management options ........................................................................................4

6.4.1 Cultivation ...............................................................................................4

6.4.2 Herbicides ...............................................................................................4

Grass weeds ............................................................................................................... 4

Broadleaf weeds ......................................................................................................... 5

Weed peanuts ............................................................................................................. 5

7 Insect control

7.1 Typesofinsectpests .........................................................................................1

Foliage feeders ............................................................................................................ 1

Sucking insects ........................................................................................................... 2

7.2 Growth stages ..................................................................................................2

7.2.1 Pre-emergence .......................................................................................2

7.2.2 Emergencetofirstflowering ...................................................................2

7.2.3 Flowering,peggingandpodfill .................................................................3


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7.2.4 Mature crops ...........................................................................................4

7.3 Damage caused by pests ..................................................................................4

Soil insects and pod damage ..................................................................................... 4

7.4 Managementofinsectpests ............................................................................4

7.5 Majorinsectpestsofpeanuts............................................................................5

7.5.1 Aphids (Aphididae) ..................................................................................5

7.5.2 Cluster caterpillar (Spodoptera litura) .......................................................6

7.5.3 Cutworms (Agrotis spp.) ..........................................................................7

7.5.4 Lucerne seed web moth (Etiella behrii).....................................................7

7.5.5 False wireworms (Gonocephalum spp. and Pterohelaeus spp.) ...............9

7.5.6 Helicoverpa punctigera and H. armigera ................................................10

7.5.7 Lucerneleafhopper(Austroasca alfalfae) ...............................................11

7.5.8 Vegetableleafhopper(Austroasca viridigrisea) .......................................12

7.5.9 Pineapple mealybug ................................................................................................. 13

7.5.10 Mirids (Miridae), green and brown (Creontiades sp.) ..............................14

7.5.11 Peanut mite (Paraplonobia spp.) ............................................................15

7.5.12 Two-spotted mite (Tetranychus urticae) .................................................16

7.5.13 Redshoulderedleafbeetle(Monolepta australis) ...................................17

7.5.14 Silverleafwhitefly(Bemisia tabaci, type B) ..............................................18

7.5.15 Storage insects .....................................................................................19

7.5.16 Thrips (Thysanoptera) ............................................................................20

7.5.17 Whitefringedweevil(Graphognathus leucoloma) ....................................21

7.5.18 Cane whitegrubs (Lepidiota spp.) ..........................................................22

7.5.19 Peanut whitegrubs (Heteronyx piceus) ...................................................23

7.5.20 Wireworms (click beetles, Elateridae ) ....................................................24

8 Nematode control

8.1 Typesofnematodes ..........................................................................................2

8.1.1 Root-lesion nematodes (Pratylenchus brachyurus) ..................................2

8.1.2 Root-knot nematodes (Meloidogyne hapla) .............................................3

8.2 Effectsofcroppinghistoryonnematodestatus .................................................3

9 Diseases

9.1 Damage caused by disease ..............................................................................2

9.2 Managementofdisease ...................................................................................2

9.2.1 Crop rotation ...........................................................................................3

9.2.2 Fungicideprogramforhighriskareas ................................................................... 3

9.3 Disease symptoms ............................................................................................4

9.3.1 Causesofseedlingsdying(orpooremergence) ......................................4

Soil-borne fungi including Aspergillus niger (Aspergillus crown rot)

and Rhizopus arrhizus ................................................................................................. 4


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Damaged seed............................................................................................................ 5

9.3.2 Causesofleaveswithbrownspots .........................................................6

Early and late leaf spot (caused by Cercospora arachidicola

and Cercosporidium personatum) ............................................................................... 6

Rust (caused by Puccinia arachidis) ............................................................................ 8

Net (or web) blotch (caused by Didymosphaeria arachidicola) ................................... 10

Pepper spot and scorch (caused by Leptosphaerulina arachidicola) .......................... 11

Physiological spotting ................................................................................................ 11

9.3.3 Leaves with colour variations .................................................................12

Capsicum chlorosis virus (CaCV) ............................................................................... 12

Peanut mottle virus (PMV) ......................................................................................... 13

Tomato spotted wilt virus (TSWV) .............................................................................. 14

Verticillium wilt (caused by Verticillium dahliae) ........................................................... 15

9.3.4 Branch wilting or plant death .................................................................17

Sclerotinia blight (caused by Sclerotinia sclerotiorum and S. minor) ........................... 17

Cylindrocladium black rot (CBR) (caused by Cylindrocladium crotalaria) .................... 18

White mould (caused by Sclerotium rolfsii) ................................................................. 21

Collar rot (caused by Lasiodiplodia theobromae) ....................................................... 22

Aspergillus crown rot (caused by Aspergillus niger).................................................... 23

Charcoal rot (caused by Macrophomina phaseolina) ................................................. 25

Rhizoctonia stem rot (caused by Rhizoctonia solani) .................................................. 26

9.3.5 Ill-thrift ...................................................................................................26

Root-lesion nematodes (Pratylenchus brachyurus) .................................................... 26

Root-knot nematodes (Meloidogyne hapla) ............................................................... 27

9.3.6 Pods damaged at harvest .....................................................................28

Soil insects ................................................................................................................ 28

Pod-rotting fungi, including Lasiodiplodia theobromae, Pythium spp.

and Rhizoctonia solani ............................................................................................... 28

Aflatoxin-producing fungi (Aspergillus flavus and A. parasiticus) ................................. 28

9.4 Soil-borne diseases ........................................................................................30

9.4.1 Neocosmospora vasinfecta ...................................................................31

10 Plant growth regulators and canopy management

11 Crop desiccation/spray out

12 Harvest

12.1 Hull scrape test ...............................................................................................1

12.2 When to dig .....................................................................................................3

12.2.1 Peg strength ...........................................................................................3

12.2.2 Disease ...................................................................................................4

12.2.3 Weather conditions .................................................................................4

12.2.4 Soil conditions .........................................................................................4

12.2.5 Area to be harvested ...............................................................................4

12.3 Digging and inverting .........................................................................................4


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12.4 Windrowing .......................................................................................................6

12.5 Threshing ..........................................................................................................6

12.6 Wet harvest issues and management ................................................................7

13 Post harvest handling and storage

13.1 Howtodryandstorepeanutson-farm ..............................................................1

13.1.1 Aflatoxin ..................................................................................................2

13.1.2 Off-flavourcontamination .......................................................................2

13.2 Pre-cleaning ......................................................................................................3

14 Environmental responses

14.1 Climate .............................................................................................................1

14.2 Temperature ......................................................................................................1

14.3 Rainfall ..............................................................................................................3

14.4 Daylength ..........................................................................................................4

14.5 Soils ..................................................................................................................4

15 Marketing

15.1 Consumption ....................................................................................................1

15.1.1 Food value ..............................................................................................2

15.2 World production ..............................................................................................3

15.3 Contract options ...............................................................................................3

16 Current research

17 Key contacts

18 References


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FeedbackTable of Contents Section A PEANUTS - Introduction

SECTION A

Introduction

A.1 Agronomy at a glance

• Returnsforpeanutsdependonyieldandquality.Bestreturnsareobtainedunder

reliablerainfallorirrigationwithintensivemanagement.Mosttypesofirrigationcan

beused,includingsprinklersystemsandfurrowirrigation.Successfulfurrowirrigation

requires good land levels and raised beds.

• Peanutsprefersands,sandyloamsandlightclayloams(Figure1);podlossescanbe

high in heavy or sticky soils.

• Inhighriskareas,allnewpaddocksmustbeassessedforpesticideandheavymetal

residues prior to planting.

• PlantingusuallyoccursfromOctobertoJanuaryinQueenslandandNewSouthWales

(NSW). In the Northern Territory, winter plantings occur in March–April, while summer

plantingsarealsopossiblefromOctober-January.Cropstakeabout5months

togrow;however,early-maturingvarietiestakingabout4monthstogrowarealso

available. Planting should be timed so that harvesting is conducted in relatively dry

conditions.

• Theminimumsoiltemperaturerequiredforgerminationis18°C,measuredat50mm

depth at 09:00 (9am).

• The crop’s maturity is assessed to determine harvesting time. Harvesting is a two-part

operation. First, the taproot is cut and the plant shoots and peanut pods are inverted to

partiallydryinthefieldforseveraldaysbeforeaseparatethreshingoperationisdone.

• Optimumthreshingoccursatapodmoisturecontentof16–18%.Controlleddrying

bringsthepeanutsslowlytoasafestoragemoisturecontentandensuresoptimum

quality.Extendedperiodsofpaddockdryingcancausehigherlosses,moresplits,

poorerqualityandincreasedriskofraindamage.

• Peanutsshouldformpartofasustainablefarmingsysteminrotationwithagrassor

cereal crop. 1

1 PCA.Areyouinterestedingrowingpeanuts?PeanutCompanyofAustralia,http://www.pca.com.au/growing-peanuts.php


http://www.pca.com.au/growing-peanuts.php


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Figure 1: Growers are advised to research best practice management to maximise peanut production. (Photo: Graeme Wright, PCA)

A.2 Crop overview

The peanut or groundnut (Arachis hypogaea)isanannuallegumecroporiginatingfrom

South America. Peanuts grow on a small bush or vine. The crop takes 4–6 months to grow,

depending on the variety and region planted.

The Australian peanut industry has about 160 growers including North, Central and

southern Queensland, and northern NSW (Figure 2).

Australiaproducesabout40,000tonnes(t)offarmerstockpeanutsannually,which

representsonlyabout0.2%oftheworld’speanutproduction.Morethan90%ofAustralia’s

peanuts are grown in Queensland. The industry is based on the large-seeded Virginia

varieties and medium to large seeded Runner varieties. Plantings are ~one-third Virginia and

two-thirds Runner types. Some new ultra-early varieties with runner-type kernels are also

planted.

Thesizeofthedomesticmarketforpeanutsis~50,000tofpodsannually.

Australiaisoneofthefewpeanut-producingcountrieswhereimportsarefreelypermitted.

Thepricethatgrowersreceivefortheircropisthereforesignificantlyinfluencedbyworld

prices. 2

An‘off’flavourproblemwasdetectedinpeanutsfromNorthQueensland’sTolgaregion

in 2008 and 2009. The cost to the Australian peanut industry was more than $1 million

2 PHarden,LWieck,GWright,,(2014)Peanutproductionguide,August2014.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf

i More information

Are you interested in

growing peanuts?

Section A PEANUTS - Introduction


http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf



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in downgraded product. This musty, earthy taste had never been detected in peanuts

anywhere,andAustralianpeanutexportswereaffected.

Theexactcauseofthetastehasyettobeconfirmed,butchangesresultingfromresearch

supported by the Grains Research and Development Corporation (GRDC) to the way

peanuts are delivered, shelled and stored appear to have largely resolved the issue.

Araftofchangeswereimplementedinresponsetotheproblem,includinga0.5%lower

kernelmoisturecontentatdelivery,andbetteroverallharvestingmanagementon-farmhave

reducedtheseverityoftheproblem.TheGRDC-fundedstudyhaswiderimplicationsfor

farmersinnorthernQueensland,becausethegrowingofpotatoesandpeanutsinrotation

couldalsobeafactor.3

Figure 2: Peanut production areas of Australia . (Note, there is no current production in the Ord region.)

A.3 Executive summary

Peanutsarearobustanddrought-tolerantplant,buttheywillnotreturnahealthyprofitto

thegrowerunlesstheyreceiveadequatewaterandnutrition,andprotectionfromweeds

anddiseases.Growersarepaidontheweightandqualityofpeanutkernels.

Peanutscanbegrownonawiderangeofsoils,providedthesurfacesoil(thetop15–20

cm)isreasonablyfriable.Suitablesoiltypesincludesands,sandyloamsandsiltyloams.In

Australia, peanuts have traditionally been grown as high-value crops on the red clay loams

(Krasnozems)oftheSouthBurnettandAthertonTablelandinQueensland.Peanutscanbe

3 CCollis(2012)Peanutsbackinflavourbutmysterylingers.GroundCover,Issue97,March–April2012,GRDC,http://www.grdc.com.au/Media-Centre/Ground-Cover/Ground-Cover-Issue-97-March-April-2012/Peanuts-back-in-flavour-but-mystery-lingers



http://www.grdc.com.au/Media-Centre/Ground-Cover/Ground-Cover-Issue-97-March-April-2012/Peanuts-back-in-flavour-but-mystery-lingers


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growninawiderangeoftropicalandsub-tropicalenvironmentsinAustralia,andcontribute

favorablyasanitrogen(N)-fixerinrotationwithsugarcane,cottonandcereals.

TheGRDCalsosupportsthepeanutindustrybyfundingresearchandextensionprojects.

A.4 Keywords

Actinomycetes

These micro-organisms can grow on stored peanuts. They produce volatile compounds

thatcontaminatestorednuts,andcausemusty,earthyoff-flavours.4

4 GRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March2013,GRDC http://www.grdc.com.au/Downloads.ashx?q=/~/media/07956E2C47544ED9BA2F677D6576C567.pdf



http://youtu.be/GEU3IJ2I9Z4?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7

http://www.grdc.com.au/Downloads.ashx?q=/~/media/07956E2C47544ED9BA2F677D6576C567.pdf

http://youtu.be/GEU3IJ2I9Z4?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7

Section 1 PEANUTS - Planning/Paddock preparation

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1.1.1 Peanut production season planAcropmanagementtableisavaluabletoolforplanningthepeanutcroppingseason

(Figure 1).

Crop stage-weeks 0 2 4 6 8 10 12 14 16 18 20 22Ground preparation Deep

Ripping

Fertiliser Soil Test Lime and/or Pre-plant fertiliser

Gypsum

Planting Plant

Weed control Pre-plant incorporated

Pre-emergent

Post-emergent Applications

Foliar disease control RegularscheduledapplicationsoffoliarfungicidesforLeafspot,Rust,NetBlotch

Sclerotinia control

Irrigation requirement HIGH LOW HIGH MODERATE

Digging Digging

Threshing Threshing

Growthstagefora20to 22 week variety

Emerge Vegetative Growth

Flowering and Pegging

Pod Development

Wheeler

Middleton

Menzies

Holt

Redvale Page

Figure 1: Peanut crop management table. (Source: PCA) 1

Usethefollowingchecklisttoensurethatyoucompleteeachoftheoperationsatthe

correct time.

1 PHarden,LWieck,GWright(2013)Peanutproductionguide,August2013.PeanutCompanyofAustraliahttp://www.pca.com.au/pdfs/growing-peanuts/ppg2013.pdf

SECTION 1

Planning/Paddock preparation





December 2014



Pre-season

• Carryoutsoiltestsandhaveresultsinterpretedbyaqualifiedagronomist.

• Determine whether a soil ameliorant such as gypsum or lime is required.

• Forecastlikelyinputrequirements(pesticides,fungicides,inoculants,seed)andplan

procurement.

• Determineyourdesiredplantingdatebasedontheseasonalforecastandrisk.

• Determineyourdeadlineforplanting.Ifthisdeadlineisreachedandithasnotrained,

pre-water your paddock.

• Plan and budget an irrigation schedule.

• Calculate and plan machinery requirements.

• Calibrateplanterandfertiliserequipmentandplanforrecalibrationbetweenpaddocks.

• Calibrate boom spray and check nozzles.

• Determine which variety best suits your conditions and order seed.

Ground preparation

• Deep-rip your paddock.

• Prepare an even seedbed to ensure that it has good tilth.

• Ifsoilameliorantsarerequired,theyshouldbeapplied1–3monthsbeforeplanting.

• Ifgranularmagnesiumorzincisrequired,applyatleast2weeksbeforeplanting.

Week 0: planting

• Ensuregoodmoistureforplantingandgermination.

• Ifusingpeatinoculants,ensurethattheyarekeptinacoolplace(Eskyorfridge).

• Ifusingdryinoculant,sprinklesomeintotheplanterbox.Half-filltheboxwithseed

(gently) and sprinkle some more inoculant over the seed. Fill the box with seed and

sprinkle with some more inoculant.

• Seed placement, depth and calibration should be checked at regular intervals during

planting.

• ApplicationsofS-metolachlor(Dual®) are recommended as a post-plant pre-emergent


http://youtu.be/izdE8gc89uE

http://youtu.be/xjwC_GeMtZM

http://youtu.be/RupuG5oQJhg

https://www.youtube.com/watch?v=izdE8gc89uE

https://www.youtube.com/watch?v=xjwC_GeMtZM

https://www.youtube.com/watch?v=RupuG5oQJhg



December 2014



herbicideinmostsituations.Applicationneedstobefinishedassoonaspossibleafter

planting (1–2 days) prior to seedling emergence.

• Inirrigationsystems,S-metolachlorneedstobewateredinwithin10daysof

application,although5daysispreferredtohelpensuregoodcropemergence.

• Irrigation scheduling plan should be in place.

Week 1: cracking

• Cracking describes when the peanuts are just about to emerge. They start to push

through the soil and the rows become visible.

• Ifthesoilisdryorthereisahardcrust,irrigationatthistimecanbebeneficialtoensure

good emergence.

• Ifweedshaveemergedbeforethepeanutsemerge,consideranapplicationofa

knockdown herbicide with no residual, such as paraquat.

Weeks 2 and 3: crop establishment

• Cropshouldbefullyemerged.

• Scoutforsoilinsectsandfoliarinsects,especiallyHelicoverpa.Scoutforcutworms

(Agrotis sp.)

• Generally,noirrigationisrecommendedatthisstage.Itmaybebeneficialtostressthe

crop.

Weeks 4 and 5: flowering

• Flowering has started.

• Spray any weeds with post-emergent herbicides as recommended by your agronomist.

• Donotirrigatewhentheveryfirstfewflowersappearbecauseitwillstressthecrop,

reducing potential yield.

• Applyprotectivefungicideapplicationsasrecommendedbyyouragronomist.

• Ifrequired,applyfoliarfertilisers,especiallycopper(onverysandysoils)andzinc.

• Ifrequired,applygypsumat1–2t/ha.Consultyouragronomistformoreinformation.

• Scoutforfoliarinsects,especiallyjassids,leafhoppers,mitesandHelicoverpa.

Weeks 6 and 7: main flowering

• Thisisthestartofthemainfloweringandthestartofthelogarithmic(fastest)growth

phase when the peanuts begin to grow very rapidly.

• In irrigation systems, irrigation is essential at this stage because it is when the crop’s

yield potential is set.

• Useyourirrigationtotrytofillthesoilprofile.Thismayinvolvetwowateringsinquick

succession.

• Scoutforfoliarinsectsandfoliardisease.

• Sprayappropriatefungicideasneeded.

• Ifinter-rowcultivationisneeded(e.g.hardsettingsoil,weeds),itisbestperformedno

later than at this stage.




December 2014



Weeks 8 and 9: pegging

• Ensurethatyoufollowyourirrigationschedule(cropstressduringpeggingandpodset

can be detrimental to yield).

• Pull up two or three bushes to check the pegging and development.

• Scoutforfoliarinsectsanddiseases.

• Sprayappropriatefungicideasneeded.

• Spraywithfoliarfertilisers.

• IfSclerotiniablightcouldbeaproblem,sprayaprotectantfungicideatthistime.

Weeks 10 and 11: pegging and pod-setting

• Checkscheduleifgrowingpeanutsunderirrigation.

• Pull up some bushes to check development.

• Scoutfordiseasesandinsects.

• Make sure harvesting equipment is properly repaired and maintained.

Weeks 12 and 13: canopy closure and pod-setting

• Thecropshouldreachfullcanopyclosurebyweek12,anditshouldnowbesettingits

peak yield potential.

• Thecropfactorinyourirrigationscheduleshouldnowincreaseto1.0(thismeansthe

cropwillloseasmuchwaterasanopenpanofwaterplacedinthesunandwind).

• Scoutfordiseasesandinsectsandsprayasnecessary.

• Spraywithfoliarfertilisersasrequired.

Weeks 14 and 15: Pod-filling

• Keep the water up to the crop. Check your irrigation schedule.

• Pull up some bushes to check pod development.

• Scoutforinsects,especiallyarmyworms(Spodoptera sp.), which stay at or just below

groundlevelduringthedaybutfeedonpegsduringthenight.

• Scoutfordisease,especiallyrust.Lookcarefullyforraisedcopperypustulesonthe

backofleaves.

Weeks 16 and 17: pod-filling and early maturity

• Keep the water up to the crop.

• Scoutfordisease.

• Attheendofweek17,checkforsignsofmaturity.Pullupsomebushesuptocheck

formaturity.

• Early-maturingvarietiesmaybefullymaturebythistimeinsomeenvironments.

Weeks 18 and 19: maturity and digging

• Wateruseofthecropmaystarttolessenduringthisphase,butdigaroundunder

some plants and check the moisture status.

• Youstillneedtokeepthecropmoisttoavoidaflatoxinandtohelpfilloutanylater

setting pods.




December 2014



• Checkformaturity.

• Scoutforanysignsofdisease.

Weeks 20 and 21

• Check maturity using the hull scrape test and double-check any pods you are unsure

ofbyusingtheshell-outtechnique.

• Testmaturityinthepaddockbyrunningsomestripswiththedigger.Checkforlosses

and maturity.

• Make sure the digger is working properly. The elevator chain speed should be slightly

fasterthantheforwardspeedofthedigger.

• Stepdownfromthetractorregularlytocheckunderthewindrowforlosses.Trytoget

good inversion.

• Ifyouaredealingwithlargeareas,itmaybebesttodiginitiallyaportionthatyoucan

comfortablyharvestwiththethresher.

Harvest

• Toavoidaflatoxincontamination,peanutsshouldremaininthewindrowfornomore

than 3 days.

• Idealmoisturecontentforthreshing,toavoidlossesanddamagetothekernels,is

~18%.

• Takesamplesfromthewindrowandcheckthemoisturecontent.

• Thespeedofthepickupheadshouldmatchtheforwardspeed.Thisallowsthe

windrow to be picked up without separating or over-running the inverted bushes.

• Checkcylinderspeedsregularly;theymayhavetobeadjustedaswindrowconditions

change during the day.

Pre-cleaning

• Pre-clean your peanuts to remove dirt, sticks, weeds and other extraneous matter.

• Pre-cleaning will also remove many loose shell kernels and immature pods and so

decreasetheriskofaflatoxincontamination.

Curing

• Ensure that peanuts are adequately pre-cleaned.

• Startdryingwithin3hofthreshingtopreventaflatoxindevelopment.

• Makesureairtemperatureintheplenumdoesnotexceed11°Caboveambient

temperatures(uptoamaximumof35°C).

• Checkthatthemoistureremovalratedoesnotexceed0.5%perh.

• Therelativehumidityofthedryingairshouldbe50–65%.

• Regularly check the temperature and relative humidity in the air tunnel.

• Regularlycheckthemoisturecontentofthepeanuts.2

2 PHarden,LWieck,GWright(2013)Peanutproductionguide,August2013.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2013.pdf

i More information

PCA. Peanut production

season plan—checklist.



http://www.pca.com.au/pdfs/growing-peanuts/checklist.pdf




December 2014



1.2 Paddock selection

1.2.1 RotationsWhenchoosingpaddocks,rotationspastandfutureshouldbeconsidered.Peanuts

preferablyshouldberotatedwithagrassorcerealcrop3 to increase sustainability, reduce

diseaseandmakethemostuseofexcessnitrogen(N).

A good crop rotation, avoiding a peanut monoculture, will lower disease levels, which can

increasedramaticallywhenpeanutsfollowpeanuts.Thereissomeevidencethatpeanuts

followingpotatoeshaveahigherriskofcontaminationwithoff-flavourvolatilecompounds.

Agenusofactinomycete,Streptomyces, is known to produce the volatile compounds

associatedwithoff-flavour;thesebacteriaarepresentinimmatureand/ordecomposing

potatoes,whichcanleadtoahighnumberofactinomycetesporesinthesoil.Immature

potatoesleftafterharvestcanberoughlythesamesizeasmaturepeanutpods,andare

sometimes harvested with the peanuts. Streptomyces on these immature potatoes can be

transferredtostoragebins,alongwiththepotatoes,duringharvesting.4

1.2.2 SoilsPeanutsrequirewell-drained,friablesoilssuchassandyloam,siltyloams,andfriableclay

loam.Thepreferredsoiltypesforgrowingpeanutsaresands,sandyloamsandlightclay

loams. Peanuts will grow on heavier soils, but harvest losses tend to be high in heavy or

sticky soils. 5

Thehistoryofallpaddocksnewtopeanutcroppingshouldbeconsidered;theremaybea

needtotestforheavymetalsandpesticidespriortoplanting(seePesticide history below).

InAustralia,peanutshavetraditionallybeengrownontheredclayloams(krasnozems)of

theSouthBurnettandAthertonTableland.Thesesoilsarenaturallyfriableandhaveagood

3 PeanutCompanyofAustralia,http://www.pca.com.au

4 GRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March2013,GRDC,http://www.grdc.com.au/Downloads.ashx?q=/~/media/07956E2C47544ED9BA2F677D6576C567.pdf

5 P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) Peanut CompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf


http://www.pca.com.au/bmp/bmp8.htm

http://www.pca.com.au







December 2014



water-holdingcapacity.However,peanutscanbegrownonawiderangeofsoils,provided

thesurfacesoil(top15–20cm)isreasonablyfriable.

Soils prone to waterlogging should be avoided because peanuts do not tolerate long

periodsofwaterlogging.Plantingonraisedbedscanhelptoalleviateminorwaterlogging

problems.

Heavy clay soils or hard-setting soils that break into large clods should be avoided because

podsmaybetornoffthebushatdigging.Theseloosepodscannotberecoveredbythe

harvester.Heavysoilconditionsmayleadtohighlevelsofextraneousmaterialintheload,

which will incur penalties.

Heavyclaysmayalsobecomenon-trafficableforlongperiodsbecauseofwetweather.This

can cause harvesting delays and potential yield losses. 6

1.3 Paddock history

Tobesuccessful,peanutsmustformpartofasustainablefarmingsystem.Newpaddocks

that have never grown peanuts may be able to produce two consecutive peanut crops.

However, the best system involves growing peanuts once every 2 or 3 years on the one

paddockwithagrassorcerealcropastherotationspecies.Goodrotationcropsfor

peanuts include sugarcane, maize, Rhodes grass (Chloris gayana) and sorghum. 7

Peanut yields are maximised by rotating with other crops over a 3-year period. Peanuts

fixNintothesoil;however,theyalsoremoveotheressentialnutrients,whichneedtobe

replaced to ensure that yield potential is achieved.

Somefarmersgrowpeanutsfortwoseasonsinonepaddockandthenrotateouttoother

cropsforthreetofiveseasons.

Anotherreasonwhygrowersareencouragedtoadoptaregularrotationofcropswith

peanutsistoavoidbuild-upofweed,diseaseandinsectproblems,whichoccurunderany

systemofmonoculture.

Crops such as potatoes, navy beans or soybeans are not ideal in long-term sustainable

rotationswithpeanutsbecausetheytendtohostmanyofthesamepestanddisease

problems.

6 P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) Peanut CompanyofAustraliahttp://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf

7 P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013, (Updated August 2014) Peanut CompanyofAustraliahttp://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf






December 2014



Research trial results

1.3.1 Paddock history trialsBetween1983and1996,atrialattheRedvale,intheKingaroyregion,examinedeffects

ofvariouscroprotationsandleypasturesonpeanutproductivityandcropvalue,andon

theincidenceofknownpeanutpathogens.Onaverage,peanutcropsyielded25%higher

inrotationsthaninamonoculture,butthequalityofharvestedpodswasunaffectedby

rotation. There was no additional yield response to rotation breaks longer than a single year,

andnoadditionalresponsetograssleysoveralternatecrops.Incidenceofknownpeanut

pathogenswassignificantlyaffectedbyrotation,buttheimpactofthesepathogensoncrop

yieldwasstronglyrelatedtoin-croprainfallandresultantseasonalyieldpotential.Gross

returnsfrompeanutcropsinamonoculturewere$177perhalowerpertonneofpotential

yieldthanincroprotations.Thefindingshavebeenusedasabasisforoptimisingrainfed

peanutfarmingsystemsforlong-termviabilityandsustainability.8

Therelativelyhighyieldpotentialofthecrop(upto5tdrypods/haingoodseasons)and

theexcellentpricesforqualityproduce(upto$850/tdrypods)havemadepeanutsvery

attractivetofarmmanagers.Often,however,thisresultsinthecropbeinggrowntoo

frequentlyinthecroprotationinanefforttomaximisereturns,withaconsequentincrease

insoil-bornepathogensandrelativelypoorcropperformance.

Severaloverseasstudieshavedemonstratedtheneedforsubstantialbreaksbetween

peanutcropsgrowninthesamefield.InGeorgia,USA,forexample,increasingperiods

withoutpeanutsfrom1to3yearsresultedincommercialpeanutyields11–25%(dryland)

and7–36%(irrigated)higherthanunderpeanutmonoculture.However,studieshavealso

shownthatrotations,particularlyunderirrigation,wereoftenshorterthanoptimalbecause

themostsuccessfulrotationcrops(e.g.cerealsandgrassleys)weregenerallyofmuch

lowereconomicvalue.AsAustralianfarmersfaceincreasingeconomicpressures,peanut

producersfacesimilartemptationstoshortenthepeanutrotation.

TheinitialstudyatRedvalecomparedapeanutmonoculturewithpeanutsgrownafter1or

2yearsofcroppingmaize,orafter1,2,3or4yearsofgrasspastureley(Rhodesgrass).

Tworeplicateplotsofeachtreatmentweresownineachofthreeconsecutiveseasons.

Therepeatedtreatmentserieswasusedtosampletheresponseacrossarangeof

climaticconditions.Intheinitialpeanutcropaftertherotationbreaks,plotsweresplitwith

treatmentsofeither0or4kgcarbofuran/hatoquantifytheroleofnematodes(Pratylenchus

brachyurus,root-lesionnematode;andMeloidogyne hapla, root-knot nematode) in crop

productivity responses. Soil was conventionally tilled prior to sowing each crop and basal

nutrients (N, phosphorus, potassium) were applied to meet crop requirements.

Oncereturnedtopeanuts,plotsweremaintainedinmonocultureforthreesuccessive

seasonstoquantifyresidualeffectsofbreaks.Afterthethirdpeanutcrop,subplotswere

either continued in peanut monoculture or sown to a crop rotation comprising soybeans,

maizeandpeanuts.Opportunitysowingsofwinteroats(Avena sativa)weremadeafter

eachlegumecropinthisrotationwheneverrainfallpermitted,withbiomassincorporated

as a green manure at the early boot stage. The peanut monoculture plots were split to

treatment with and without winter oats.

8 MBell,GHarch,JTatnell,KMiddleton(2003)Theimpactofcroprotationonpeanutproductivityinrainfedcroppingsystems.AustralianAgronomyConference,http://www.regional.org.au/au/asa/2003/c/5/bell.htm


http://www.regional.org.au/au/asa/2003/c/5/bell.htm



December 2014




Soil(0–30cm,in10-cmincrements)wascollectedfromsubsetsofplotsimmediatelyprior

to planting in each season, to assess nematode numbers and soil chemical properties.

Plant establishment and mortality data were recorded during most seasons, numbers

ofnematodesinpeanutrootsweredetermined~6weeksafterplanting,andplotswere

scoredfortheincidenceandseverityofsymptomscausedbyknownsoil-bornepathogens

midseasonandatmaturity.Grossreturnsfrompeanutcroppingweredeterminedusing

commercialgradingstandardsandcurrentcropvalues.Croprotations(peanutsfollowing1

or2yearsofgrassleyormaize,orfollowingarotationwithsoybeans,oatsandmaize)were

comparedwithmonoculturepeanutsintermsofpodyieldsandgrossmargins(derived

usingaveragecostsofproductionfromeachcropandcurrentinputcosts).

Peanut yields and crop value varied markedly between growing seasons (Figure 2).

Yield was more responsive than crop value to breaking the monoculture. The results

demonstratedthataveragegrossreturns($/ha)were30%higherinthebreaktreatments

thaninthepeanutmonoculture.Noaflatoxinwasrecordedinanyyear,andthiswas

reflectedinconsistentlyhighcropvalues.

Figure 2:

800ns

ns nsns ns

ns

ns

ns

*

700

600

500

550

650

750

450

4001 2 3 4 5 6 7 8 9

Cro

p v

alue

($/t

)

Crop year

Peanut monocultureRotation

a800

ns

nsns ns ns

ns

ns

ns

*

700

600

500

550

650

750

450

4001 2 3 4 5 6 7 8 9

Po

d y

ield

(t/h

a)

Crop year

Peanut monocultureRotation

b

(a) Crop value ($/t) and (b) pod yield (kg/ha) for peanut crops in the study at Redvale, Kingaroy. * Indicates statistical significance (P<0.05); ns, no significant differences.

Thisstudyproducednoevidencethatbreaksoflongerthanonesummerseason(i.e.

peanuts grown every second year) were necessary to maximise crop yields and crop

value(initialstudyphase,Table1,).Grassleyswerenomoreeffectiveinraisingpeanut

productivity than rotating to maize cropping. The alternate rotation in the second phase

ofthestudy(peanuts–oats–soybeans–oats–maize–fallow–peanuts)producedsignificant

increases in crop productivity compared with continuous peanut cropping (Table 1).

Comparisonswerelimitedbythewiderrangeofbreakdurationsintheleytreatmentsthan

in the maize cropping (1–4 years v. 1–2 years). However, this limited sampling indicated that

grassleys>2yearsproducednoadditionalbenefitsintermsofpeanutyieldorcropvalue.

Data clearly showed that introducing a winter green manure crop (oats) into a continuous

summerpeanutcroppingpattern,aspracticedinsomeofthenewerproductionareas

underirrigation,hadnopositiveeffectonyieldsorcropvalue.Yieldsweresignificantlylower

than in the peanuts–oats–soybeans–oats–maize rotation (Table 1).




December 2014




Table 1: Effect of break duration and break type on peanut yield (t pods/ha) and crop value ($/t)

Rotation Years out of peanuts

Peanut yield (kg/ha)

Crop quality ($/t)

Initial phase of study

Continuous peanut 0 1.53 $643.2

Maize 1 1.86 $630.0

Maize 2 1.98 $635.9

Grass ley 1 1.88 $648.2

Grass ley 2 1.84 $653.2

l.s.d. (P = 0.05) 0.21 ns

Second phase of study

Continuouspeanuts,winterfallow 0 2.28 $650.9

Continuous peanuts, winter oats 0 2.28 $659.7

Crop rotation (peanuts, oats, soybeans, oats, maize)

3 3.07 $670.4

l.s.d. (P = 0.05) 0.25 ns

Becausetherewasnodifferentiationbetweenbreaktypes(grassormaize)intermsof

subsequent peanut productivity, data were pooled within years and an assessment was

madeoftheresidualeffectofthebreaksuponreturntopeanutmonoculture.Thisisan

important issue, because growers recognise the need to grow break crops but also want to

maximisethefrequencyofthehigh-valuepeanutcropintherotation.Theanalysis(Figure

3)clearlyshowsthatthemaximumbenefitofabreakwascapturedinthefirstpeanutcrop,

withanaverageyieldincreaseof26%.Significantresidualbenefitspersistedforonlythe

secondandthirdpeanutcropsafterthebreak;thesebenefitswerereducedtolessthan

halfthoserecordedintheinitialpeanutcrop.

Figure 3:

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.61 2 3 4 5 6 7 8 9

Rel

ativ

e p

od

yie

lds

com

par

ed

to m

ono

cult

ure

pea

nuts

Consecutive peanut crops after break

Combined analysis of the residual effect of crop rotations on pod yields after a return to peanut monoculture. Length of capped line indicates significant differences (P < 0.05).

Relationships between the potential yields in each season (yields in rotated plots) and the

lossinyieldorgrossreturns(yield×cropvalue)resultingfromemployingamonoculture

were derived using regression techniques. These relationships suggested that 0.24 t pods/

haor$177grossreturn/hawouldbelostforeachtonneofpeanutyieldpotentialina

monoculture compared with adequate rotations (R2=0.81and0.80foryieldandgross

return loss relationships, respectively). Losses in gross returns would obviously increase

where crop values were greater than the average $640/t recorded during this study (e.g.

under irrigation).




December 2014




Therewasnoevidenceofanyrotationresponsesresultingfromchangesinsoilchemical

fertility,asevidencedbyplantnutrientstatus.Thiswasnotsurprisingconsideringthe

generousfertiliserapplicationsusedduringthestudy.Grassleyswereshowntoaffectsoil

physicalfertility,inparticulartheabilityofsoilstoresistcrustingandallowrainfalltoinfiltrate.

However, these changes had little impact on soil water during subsequent growing seasons

andresultantyieldsofthepeanutcrops.Thiswasduetoacombinationofintensivetillage

aftertheleyminimisingdifferencesinsoilstructure,andthehighratesofinternaldrainage

andlowplant-availablewaterstorageinthesesoils.Therefore,themeasuredpeanut

rotation responses were more likely due to impacts on soil health, in particular to the

incidenceofsoil-bornepeanutpathogens.

Several known soil-borne peanut pathogens were present at the experimental site during

the study, including root-lesion and root-knot nematodes, crown rot (causal organism

Aspergillus niger), Verticillium wilt (causal organism Verticillium dahliae), collar rot (causal

organism Lasiodiplodia theobromae) and Sclerotinia blight (causal organism Sclerotinia

minor).Theincidenceandseverityofalloftheseorganismsvariedwithseason(e.g.

Sclerotiniablightwasevidentonlyintherelativelywet1993–94season).Theincidenceof

severaloftheseorganismswasaffectedbycroprotation(e.g.Table2),andthecombined

contributionofalloftheknownpathogenstovariationinpeanutyieldwithinanyoneseason

rangedfrom5%to50%.Thesmallestcontributiontoyieldvariationbytheseorganisms

occurred in the poor seasons (years 2, 5 and 8 in Figure 2b), when the predominant yield-

limitingfactorwaswaterdeficit.

Table 2: Effect of crop rotation on the incidence of selected pathogens in the following peanut crop in crop years 7 and 9 (from Figure 2)

Betweenrotationsfortheparticularpathogenandgrowingseason,meansfollowedbythesamelettersarenotsignificantlydifferent

Pathogen or disease

Continuous peanut, winter

fallow

Continuous peanut, winter

oats

Peanut rotated with soybean,

oats, maize

Year 7 Year 9 Year 7 Year 9 Year 7 Year 9

Root-knot nematodes (/g DW root)

465a 1580a 690a 1775a 32b 29b

Root-lesion lesion nematode (/g DW root)

480 215 668 63 376 201

Verticillium wilt at harvest (%plants)

16.5a 47.8a 4.4b 37.8ab 3.7b 23.1b

Sclerotinia blight at harvest (%plants)

0 5.8a 0 3.6a 0 15.9b

Plant mortality due to crown rot (%plants)

23.7a 20.7a 24.6a 17.8a 1.6b 6.3b

Seasonalrainfallconditionshavethegreatestimpactonproductivityofrainfedpeanutcrops

intheinlandBurnett.However,croprotationsinvolvingayearwithoutpeanutsineachfield

will consistently result in greater peanut yields and gross returns than in peanut monocultures,

withresidualbenefitspersistingforafurthertwopeanutcrops.Rotationssignificantlyreduced

theincidenceofknownpeanutpathogens,withthegreatestbenefitsintermsofyieldand

returnsoccurringinhigh-yieldingseasons.Thesefindingswillformthebasisofeconomic

analysestodeterminetheoptimumpeanutfrequencyinthecroppingsystemsofthisregion.9

9 MBell,GHarch,JTatnell,KMiddleton(2003)Theimpactofcroprotationonpeanutproductivityinrainfedcroppingsystems.AustralianAgronomyConference,http://www.regional.org.au/au/asa/2003/c/5/bell.htm





December 2014



1.3.2 Pesticide historyOrganochlorideresiduesinthesoilandheavymetalscanbeamajorproblemforgrowing

peanuts.Thepeanutfruitorpodgrowsdirectlyinthesoilandtakesupmanyofitsown

nutrientsthroughthepodwall.Consequently,pesticideresiduesandheavymetalsareoften

takendirectlyintothepeanutasitgrows.Thismaythenrenderthepeanutunfitforhuman

consumption.Allnewpaddocksshouldbetestedforpesticideresiduespriortoplanting

peanuts. 10Formoreinformation,checkwithyourprocessor.

1.4 Benefits of peanuts as a rotation crop

Peanutshavebeenshowntohavebeneficialeffectsonfollow-upcropsofsugarcaneand

cotton.

Insugarcane,peanutscanprovideabreakincanemonoculture,resultinginareductionof

pathogensandhealthiercanestools,aswellasboostingNavailabletothefollow-upcrop

and improving soil structure. Peanuts also have the potential to lengthen ratoons in the

follow-upcanecrop.Accordingto2006datafromthe(then)QueenslandDepartmentof

PrimaryIndustriesandFisheries,caneyieldswereboostedbyatleast20%overthewhole

crop cycle. 11

In2005–06,peanutswerefoundtofix60–90kgN/hainarotationthatincludedcottonand

wheat, at Bonshaw in northern NSW. Peanuts were also thought to assist with control of

nutgrass. 12


11 PCA.Benefitsofpeanutsincanerotation.PeanutFactSheet.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/factsheets/peanutsandsugarcane.pdf

12 PCA.Cottongrowers:haveyouconsideredpeanuts?PeanutFactSheet.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/factsheets/peanutsandcotton.pdf


http://youtu.be/dHXvHgXk8vI?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7


http://www.pca.com.au/pdfs/factsheets/peanutsandsugarcane.pdf


http://www.pca.com.au/pdfs/factsheets/peanutsandcotton.pdf


http://youtu.be/dHXvHgXk8vI?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7



December 2014



1.5 Disadvantages of peanuts as a rotation crop

Peanutsrequiresignificantsoildisturbancetoreduceharvestlosses(deepripping,inter

row-cultivation),makingthemunsuitableasarotationcropinafullno-tillsituation.

Peanuts have limited herbicide options both pre- and post-emergent, so where herbicide-

resistant weeds are present, peanuts may not be suitable.

Asalegume,peanutsareunsuitableasarotationwithotherlegumecropsbecauseofthe

likelihoodofsharedpestanddiseasebuild-up.

1.6 Pre-plant weed control

Depending on the weed spectrum, weed control pre-planting can be achieved by using

trifluralinorpendimethalinincorporated.13

1.7 Potential crop contaminants

PCArequiresthatallnewpaddocksbetestedforpesticideandheavymetalresiduesprior

to planting. These tests can be carried out at PCA’s Innovation and Technical Centre. 14

Pleasechecktherequirementsofyourchosenprocessor.

1.8 Seedbed requirements

Carefullypreparingthesoilisanimportantpartofsuccessfullygrowingpeanuts.Peanuts

preferaweed-free,moderatelyfineseedbed.Becausetheydevelopanextensiveroot

system, deep ripping to break up soil compaction may be necessary. Peanuts also require

loose soil in which to peg (i.e. re-enter the soil to develop underground nuts). 15

Peanutsproduceadeeptaprootcapableofexploitingmoistureandnutrientreservesdeep


14 PCA.Soilpreparation.PeanutCompanyofAustralia,http://www.pca.com.au/soil-preparation.php


i More information

PeanutCompanyof

Australia.

Australian Pesticides

and Veterinary Medicines

Authority.




http://www.pca.com.au/soil-preparation.php



http://www.pca.com.au/


http://www.apvma.gov.au





December 2014



intheprofile.Consequently,soilspreparedforpeanutsshouldbefreeofanyhardpansor

compaction layers. Deep ripping is recommended to at least 30 cm depth in heavier soils.

Peanutshavelargeseedanddonotrequireaparticularlyfineseedbed,butgoodsoil–seed

contact is essential to encourage rapid and even germination. Press-wheels on the planter

are essential.

Toencouragegoodcropestablishment,theseedbedshouldberelativelyevenandfree

fromweedsandexcessstubble.Somegrowersareadoptingminimumtillagepracticesto

protectthesoilsurfacefromerosionandtoimprovesoilstructure.Discusstheimplications

ofminimumtillagewithyouragronomist.

Peanuts have been traditionally planted in rows 90 cm apart, as the standard row

configurationandpreferredspacingtominimiselossesduringharvesting.Mostharvesting

equipmentisdesignedtohandlerows90cmapart;despitethis,somegrowershave

plantedrowspacingsrangingfrom65to100cm.Somegrowershaveusedatwin-row

plantingconfigurationforplantings.Fourrowsareplantedwiththetwooutsiderows90cm

apart,andthetwoinsiderows70cmapart.Thisconfigurationleadstofastercanopycover,

reducing weed pressure, and generally improving yields. Twin row is particularly appropriate

forultra-earlyvarieties.

Peanutsarenormallyplantedonflatground,butplantingsinglerowsonahillortworows

on a bed can assist the digging process and improve drainage in wet areas. 16

1.9 Soil moisture

Peanuts are considered a relatively drought-tolerant crop. They have various physiological

mechanismsforavoidingtheeffectsofdroughtandanextensiverootsystemabletoexploit

moisture reserves at depth. Even in drought seasons, peanuts will nearly always produce

someyield.However,fewgrowerscanaffordmediocreyieldsbecauseofthehighinput

costs.Peanutsarebestgrownwheretherainfallisreliableorwhereaccesstoirrigationis

available.








December 2014



1.9.1 DrylandPeanutsproduceayieldevenduringdryseasons;however,inadrylandsituationthey

needtobegrowninasummer-dominantrainfallareaof~500mm/seasontoreduceriskof

negative gross margins.

Evenduringdrought,peanutswillnearlyalwaysproducesomeyield,butfewgrowerscan

affordmediocreyieldsbecauseoftheinputcosts.

Toreduceriskindrylandsituations,seasonalforecastsmustbetakenintoaccount,andthe

optionofsupplementaryirrigationispreferableasabackup.17 Peanuts need 600–700 mm

ofwaterovertheseasonforahigh-yieldingcrop.

1.9.2 Irrigation

What will Irrigation do?

Irrigation may be used to manipulate the soil conditions, especially at pegging and at

harvest.Thecropuses2–6ML/ha,dependingonrainfallandsoiltype.Consultan

agronomisttodetermineanappropriateirrigationschedule.Ifwaterislimited,strategicor

supplementary irrigation is recommended.

17 PCA.Irrigationversusdrylandcropping.PeanutCompanyofAustralia,http://www.pca.com.au/irrigated-vs-dryland-peanuts.php

i More information

Gross margin

assessmentfor dryland

peanut production in

northern Queensland.

Agbiz tools, Queensland

Government.

Researchers monitor

drylandpeanutsfor

Aflatoxinrisk.Media

release, Universityof

Queensland.



http://www.pca.com.au/irrigated-vs-dryland-peanuts.php



https://publications.qld.gov.au/dataset/agbiz-tools-plants-field-crops-and-pastures/resource/1b19cf0a-ef5b-472e-a0c6-4526f5922c5f






http://www.qaafi.uq.edu.au/risky-nuts







December 2014



Peanutscanbewateredwithsprinklerssuchascentrepivotsortravelersorbyflood

irrigation (depending upon soil type). Trickle (tape) irrigation can be used in some

circumstances. 18

Irrigatorsshouldavoidholdingoffwateringinfavourofpossibleraintominimisecropstress.

Priortoplanting,budgetfortotalcropwateruseat5–7ML/ha.Peanutsareverysensitive

to water stress, despite their hardiness as a crop. Minimise water stress during the critical

flowering–podfillstages.Stresscanincreasetheincidenceofdiseaseandultimatelyaffect

kernelquality.Lackofuniformityofwaterapplicationisamajorissueoftenarisingfrom

inadequate equipment or poor system design. Soils most suited to peanuts generally

haveverylowwater-holdingcapacity,sowaterusemustbecarefullymonitored.Knowthe

required irrigation intervals to maintain adequate soil water. 19

The600–700mmofwaterrequiredovertheseasonforahigh-yieldingcropcancomefrom

rain,irrigationorstoredsoilmoisture.However,thetotalamountofmoisturethatthecrop

receivesisnotasimportantasthetimingofrainfallorirrigation,whichcanhaveadramatic

effectonbothcropyieldandquality(Table3).

Table 3: Growth stages and irrigation needs of peanuts

Growth stage Irrigation requirementsGermination and emergence Goodmoistureconditionsrequired;irrigationcanensurecropis

planted on time

Vegetative Peanutscantoleratemildwaterstressatthisstage;stressmaybebeneficial.

Peg initiation Nowaterstressatthisstage,verysensitive;useirrigation

Podformationandfilling Nowaterstress;useirrigation

Maturity Decreasing water use as the crop matures


19 GMills,RRachaputi,GWright,YChauhan,JBarnes(2004)YieldpotentialofpeanutsatMackay—Whatarethe key barriers to obtaining it? GRDC Update Papers, February 2004, http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it




http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it






December 2014



Irrigationschedulingusingasystemofpanevaporationmeasurementsandcropfactors

hasbeenfoundveryeffective.Devicesincludingtensiometers,gypsumblocksand

EnviroSCANprobes,whichprovideindirectmeasurementsofsoilwater,canalsobevery

useful.

Irrigation systems

Ifwaterisavailable,itmaybeusedtoimprovepeanutyieldsandreturns.Themainsystems

usedforirrigatingpeanutsinclude:furrowirrigation,orvariousformsofsprinklerirrigation

including centre pivot, lateral moves, travelling irrigators or solid-set sprinklers. 20

Irrigationsystemsincludesurfaceflow,sprinklersorvariousformsofmicro-ordrip

irrigation. Each has its own uses and relative suitability.

Surface(e.g.floodorfurrow)irrigationissuitedtoheavysoilswithlimiteddeepdrainage,

andtotheapplicationoflargevolumesofwatertolargeareas.Energycostsarelow,

usuallyrelyingongravitytomovewater.Surfaceirrigationisunsuitableforporoussoilsor

‘fussy’cropswhosewaterrequirementsarequitenarrow.

Sprinklersystemsrangefromunder-treetofixedoverheads,rainguns,linearmoveand

centre pivots. These systems can water large areas and are reasonably precise in water

delivery. They require water under pressure to operate, and thus have high energy costs.

Theyhavehighinfrastructurecostsandcanbeanobstacletoflexiblecrophusbandry.In

someregions,remnantnativetreesmayposeproblemsforuseofcentre-pivots.

Micro-irrigationsystemsincludemini-sprinklers,driportrickle,andsubsurfaceirrigation.

Theyallowprecisewaterdeliverytoplantsandtheirroots.Theycanbeusedinavarietyof

conditions and can maintain high-value crops in various soils. They require a pressurised

watersupplyandcanberelativelyexpensivetoinstallbutalsoprovidehighlevelsofwater-

useefficiency.

Systems with increased technology and pressurised water delivery have underpinned

improvementsinwater-useefficiencyinmanyregions.Theygiveirrigatorsmuchmore

controloverwherewatergoes,howmuchisapplied,andhowmuchislosttorunoff,

drainage or evaporation. 21


21 http://npsi.gov.au/files/products/national-program-sustainable-irrigation/npsi06121/npsi06121-irrigation-essentials-updated.pdf

i More information

Irrigation essentials

updated. National

ProgramforSustainable

Irrigation.

Irrigation system

selection and design

guidelines. Victorian

Resources Online.

ME Qureshi et al. (2002)

Profitabilityofgrowing

sugarcane under

alternative irrigation

systems in the Burdekin

delta.



http://npsi.gov.au/files/products/national-program-sustainable-irrigation/npsi06121/npsi06121-irrigation-essentials-updated.pdf






http://vro.depi.vic.gov.au/dpi/vro/vrosite.nsf/pages/lwm_farmwater_efficient_irrigation_wheel




http://www.assct.com.au/media/pdfs/2002_pa_ag5.pdf








December 2014



1.10 Yield and targets

Yield expectations vary between regions (Table 4).

Table 4: Yield expectations for Queensland crops 22

Region Expected yieldSouthern Queensland dryland 1.5–4.0 t/ha (average 2.5 t/ha)

NorthQueensland(highrainfall)dryland 2.5 – 6.0 t/ha (average 4.0 t/ha)

Irrigated 4.0 to 8.0 t/ha (average 5.0 t/ha)

At the Douglas Daly Research Farm in the Northern Territory, results suggest that 3–4.75 t/

haofpeanutscanbeachievedwithcorrectmanagementtechniques.23

Australianpeanutproducersarecommonlyachievingonly50–70%ofthegeneticyield

potentialofcommercialpeanutvarieties.24

Figure 4:

8000

KingaroyBundabergKununurraP’cheru

6000

4000

2000

00 2000 4000 6000 8000

Sim

ulated

Observed

y = 0.98x = 20.181R2 = 0.825

Peanut pod yield (kg/ha).

Generally growers using better practices are achieving yields in the range 4.5–7.0 t/ha, with

somefarmershavingreportedupto8.0t/ha(Figure4).Frequentlyyieldsdonotexceed6.0

t/ha.Failuretoalignwiththeessentialelementsofbestmanagementpractices(BMP)in

peanutproductiongenerallyresultsineitherfailuretoachievetargetyieldsoraconsistent

declineinyieldsoverensuingyears(Table5).BMPrelatesbothtothemanagementfactors

employedintheoverallfarmingsystemandtothespecificmanagementtechniquesapplied

to peanut crop agronomy and management operations. New peanut growers have an

excellentopportunitytoimplementBMPfromstart-upbecauseofthecollectiveexperience

ofresearchersandagronomistsandthevaluablepracticalknowledgeoffellowpeanut

producers.

TheGrainsResearchandDevelopmentCorporation(GRDC)-fundedproject‘Best

ManagementPracticesintheProductionofHighInputPeanuts’conductedbythe


23 CHam(2004)GrowingpeanutsintheTopEndoftheNT(Arachis hypogaeaL.).NTDepartmentofPrimaryIndustry, Fisheries and Mines, http://www.nt.gov.au/d/Content/File/p/Crop/177.pdf

24 GMills,RRachaputi,GWright,YChauhan,JBarnes(2004)YieldpotentialofpeanutsatMackay—Whatarethe key barriers to obtaining it? GRDC Update Papers, February 2004, http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it



http://www.nt.gov.au/d/Content/File/p/Crop/177.pdf






December 2014




DepartmentofAgricultureFisheriesandForestryQueensland(DAFF)hasallowed

successfulandsustainablepeanutproductionmethodstobedocumentedandmade

readily available.

Table 5: Factors causing production loss in peanuts

Factor causing production loss Approx. loss (%)Inadequate/poor irrigation management 20%

Poor rotations yield decline 20%

Poor harvest management (losses wet harvests) 15%

Diseases(Cylindrocladiumblackrot,soil-borneandfoliardiseases) 10%

Inadequate plant stands or plant populations 15%

Poor weed management 10%

Poornutrition(micro-+macro-nutrientdeficiency) 10%

Total 100%

Importantly, new production environments such as Mackay and the Burdekin will present

newchallengesfordefiningBMPgiventhespecificconditionsthatapplyineachregion,

particularly in relation to optimum planting and harvesting windows. However, the essential

rulesforsuccessfulproductionremainthesameacrossregions.BMPfocuseson

sustainableyieldinaprofitableframeworkinvolvingthewholefarmingsystem.25

1.10.1 Seasonal outlookFormoreinformation,visittheBureauofMeteorology, Climate outlooks.

1.10.2 Fallow moisture and double-croppingThe Agricultural Production Systems Simulator model (APSIM) was used to simulate the

relativebenefitsofdouble-cropping(wheatandpeanuts)overpeanutswithawinterfallow

intheBurnettdistrictofQueensland.Simulationresultsdemonstratedthat,ingeneral,

double-croppingcouldbepracticedsuccessfullyintheSouthBurnett.26

Background

Double-croppingisfrequentlypracticedonRedFerrosolsintheBurnettdistrict.Wheatis

commonlyplantedafterpeanutswithverylittlestoredwateratplanting.Insomeinstances,

wheatisplantedalmostimmediatelyafterapeanutcropifplantingrainfall(25mm)has

occurred. In many cases, the resulting wheat crop is not viable. Questions have been

raisedaboutthevalidityofthisdouble-croppingpractice:howoftendoesthewheatcrop

jeopardisethefollowingpeanutcrop,andwhatarethelong-termyieldsforwheatand

peanuts planted in this way?

One way to address this issue is with simulation models. APSIM is a cropping system

25 GMills,RRachaputi,GWright,YChauhan,JBarnes(2004),YieldpotentialofpeanutsatMackay—Whatare the key barriers to obtaining it? GRDC Update Papers, February 2004, http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it

26 RD Connolly, M Bell, G Wright (1998) Simulating peanut/wheat cropping in the Burnett with APSIM. 9thAustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/1998/9/177connolly.htm


http://www.bom.gov.au/climate/ahead/




http://www.regional.org.au/au/asa/1998/9/177connolly.htm




December 2014




modelcapableofintegratingtheeffectsofweather,soilandcroppingmanagement.We

usedAPSIMtoinvestigatetheviabilityofdouble-croppingintheBurnett.

APSIMwasparameterisedforatypicalRedFerrosolsoilnearKingaroy.Twocropping

systemsweresimulated:peanutfollowingwheat,andpeanutwithawinterfallow.Plant-

availablewater(PAW)capacityforthesoilsimulatedwas110mmtoadepthof1.8m.The

lowerlimitofwaterextractionforthetwocropswasderivedfromexperimentaldata.Inthe

model,wheatwasplantedbetween1Mayand31Julywhenavailablewaterinthetop0.50

mwas>25mm.Peanutswereplantedbetween15Octoberand31Decemberon≥55mm

ormorePAWinthetop0.50m.A90-yearweatherrecordforKingaroywasused.

Outcomes

Simulated median peanut yields were 2.8 t/ha in the peanut–wheat rotation and 2.9 t/ha

inthepeanut-onlysystem.Thedistributionsofpeanutyieldsfromthepeanut–wheatand

peanut-only systems were similar. This indicated that, on average, wheat did not reduce

plantingsoilmoistureoryieldofthefollowingpeanutcrop.Thiswasbecausethepeanut

cropcommonlyreceivedadequatesoilwaterafterplantingtomaintainyields.Evenifsoil

water at planting was high, low in-crop rain could result in low peanut yields. In general, a

winterfallowdidnotresultinimprovedutilisationofrainfallforpeanutgrowth,orincreased

yields. 27

1.10.3 Water-use efficiencyPeanutsandothertropicallegumesoftenfacewaterstress,butplantingcultivarswithhigh

water-useefficiencycanminimisetheyieldlossesintimesofstress.

Go‘on-farm’tohearQueenslandpeanutgrowersdiscusswateruseefficiency.

27 RD Connolly, M Bell, G Wright (1998) Simulating peanut/wheat cropping in the Burnett with APSIM. 9thAustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/1998/9/177connolly.htm

i More information

RD Connolly et al. (1998)

Simulating peanut/wheat

cropping in the Burnett

with APSIM. Australian

Agronomy Conference.

PCA/DPIF. Managing

weeds.










http://www.pca.com.au/bmp/pdfs/4c_weed.pdf





December 2014




Researchshowsthatremote-sensingimageryofirrigatedpeanutcropswithsimpleairborne

digitalvideocamerasystemsoffersgrowersandconsultantsacost-effectivetechniqueforthe

assessmentofspatialvariabilityincropperformance.Imagesofnear-infraredreflectance(NIR)

takenfromirrigatedpeanutcrops(pivots)insouthernQueenslandshowedmajorvariability

arisingfromcropstress,mostlikelyaresultofpoorirrigationdistributionand/orpoorwater

infiltration(Figure5).

TheNIRfrompeanutcropstaken~4–6weeksbeforeharvestwashighlycorrelatedwithfinal

podyield,andthisoffersapotentialyield-forecastingtechniqueforgrowersandindustry.The

closeassociationalsoallowsanassessmentofthemagnitudeoftheyielddeficitresultingfrom

spatialvariability(or‘yieldgap’).Thisprovidesgrowersandconsultantswithausefulmethodto

calculatetheeconomicimpactofreducingtheyieldgapintheirownfieldsandhaspotentialfor

useasastrategictooltoidentifyproblemsandimprovevariousaspectsofcropmanagement.

The research has shown that NIR images can provide growers with indicative yield maps and

the likely yield gap and resulting reduction in gross income prior to harvest. The imagery can

directcropinspectionandhencethedetectionandearlywarningofwater,disease,nutrientand

otherstressesforpotentialin-seasonmanagement.ThestrongrelationshipbetweenNIRand

podyieldinpeanutcropsalsosuggestspotentialforusingthetechnologyasayield-forecasting

toolforregionalirrigatedandrainfedproduction,withasignificantpotentialroleinotherfield

crops. 28

Figure 5: Peanut pivot in the Texas region, Queensland, showing extreme crop variability associated with poor soil infiltration and distribution in the outer pivot.

28 GWright,ARobson,GMills(2004)Applicationofremotesensingtechnologiestoimproveyieldandwater-useefficiencyinirrigatedpeanuts.12thAustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/2004/poster/1/5/698_wrightg.htm

i More information

D Rowland et al. (2004)

Variation in water-use

efficiencyofpeanut

varieties across peanut

production regions.

Australian Agronomy

Conference.

PCA/DPIF. Irrigation

system design.

PCA/DPIF. Crop

modelling and

AQUAMAN.

G Wright et al. (1994)

Water-useefficiency

and carbon isotope

discrimination in peanut

underwaterdeficit

conditions. Crop Science

34.

i More information

D Rowland et al. (2012) Variation in carbon isotope ratio and its relation to other traits in peanut

breedinglinesandcultivarsfromU.S.trials.Journal of Plant Breeding and Crop Science 4.

G Wright et al.(2004)Applicationofremotesensingtechnologiesto improve yield and water-

useefficiencyinirrigatedpeanuts.AustralianAgronomyConference.

KT Hubick et al. (1986) Correlation betweenwater-useefficiencyandcarbonisotope

discrimination in diverse peanut (Arachis) germplasm. Australian Journal of Plant Physiology 13.

P Songsri et al.(2013)Associationofstomatalconductanceand root distribution with water-use

efficiencyofpeanutunderdifferent soil water regimes. Australian Journal of Crop Science 7.


http://www.regional.org.au/au/asa/2004/poster/1/5/698_wrightg.htm


http://www.regional.org.au/au/asa/2004/poster/1/3/2/288_rowlanddl.htm







http://www.pca.com.au/bmp/pdfs/5b_irrig_WUE.pdf



https://www.crops.org/publications/cs/abstracts/34/1/CS0340010092







http://www.academicjournals.org/article/article1380036089_Rowland et al.pdf

http://www.academicjournals.org/article/article1380036089_Rowland et al.pdf



http://www.publish.csiro.au/paper/PP9860803.htm

http://www.publish.csiro.au/paper/PP9860803.htm

http://www.cropj.com/songsari_7_7_2013_948_955.pdf

http://www.cropj.com/songsari_7_7_2013_948_955.pdf



December 2014



1.10.4 Nitrogen-use efficiencyLike other legumes, peanuts are able to produce their own N via a symbiotic relationship

withastrainofthesoilbacteriarhizobia.Thesebeneficialbacteriainfectthepeanutroot

systemandformscharacteristicnodules,fromwhichN2gasis‘fixed’fromtheatmosphere.

TheNisthenavailabletotheplantforgrowthanddevelopment.Forpeanuts,useGroupP

rhizobial inoculum.

NotalllegumesgrownbyAustralianfarmershavethesamecapacityforN2fixation(Table

6).Ofthecroplegumes,navybeansareweak,fixingonly~20%oftheirneedswith

theremaindersuppliedfromsoilandfertilisersources.Ontheotherhand,fababeans,

lupinsandsoybeansthathavegoodcapacityforN2fixation.Peanuts,fieldpeas,lentils,

mungbeans and chickpeas are in between. 29

Table 6: Estimates of the amounts of N2 fixed annually by crop legumes in Australia (source: primarily Unkovich et al. 2010)

%Ndfa,PercentageoflegumeNderivedfromN2fixation;DM,drymatter;rootN=shootN×0.5(soybeans),1.0(chickpeas)or0.4(remainder);totalNfixed=%Ndfa×totalcropN

Legume %NdfaShoot DM

(t/ha)

Shoot N Root N Total crop N Total N

(kg/ha)

Soybeans 48 10.8 250 123 373 180

Lupins 75 5.0 125 51 176 130

Faba beans 65 4.3 122 50 172 110

Field peas 66 4.8 115 47 162 105

Peanuts 36 6.8 190 78 268 95

Chickpeas 41 5.0 85 85 170 70

Lentils 60 2.6 68 28 96 58

Mungbeans 31 3.5 77 32 109 34

Navy beans 20 4.2 105 43 148 30

1.11 Disease status of paddock

Peanuts are susceptible to several soil-borne diseases, especially Sclerotinia blight, white

mould and Cylindrocladium black rot. Good rotational practices, crop management and

hygienearethebestdefencesagainstthesediseases.Limitedfungicideoptionsare

available to combat peanut soil diseases.

Soil-borne diseases can lead to substantial yield and quality loss. Although some

productsareavailabletolessentheeffectsofthesediseases,thebestpolicyistofollow

a recommended rotational program (involving grass or cereal crops) and practice good

cultural management. In particular, excessively aggressive cultivation should be avoided,

especially where soil is pushed against the plant.

Sclerotinia blight can be particularly devastating in some areas. It is recommended that a

registeredfungicidespraybeusedandappliedasaprotectantbeforesymptomsappear.

29 DHerridge(2013)ManaginglegumeandfertiliserNfornortherngrainscropping.GRDC,http://grdc.com.au/GRDC-Booklet-Managing-Fertiliser-N

i More information

DEEDI Qld. Rhizobium

inoculation. Get the best

fromyourlegumecrop.

i More information

D Herridge (2013)

Managing legume and

fertiliserNfornorthern

grains cropping. GRDC.

GC Wright, GL Hammer

(1994) Distributionof

nitrogen and radiation

useefficiencyinpeanut.

Australian Journal of

agricultural Research 45.


http://grdc.com.au/GRDC-Booklet-Managing-Fertiliser-N


https://www.daff.qld.gov.au/__data/assets/pdf_file/0005/58946/Rhizobium-brochure.pdf







http://www.publish.csiro.au/paper/AR9940565.htm








December 2014



Thismaybeasearlyaswhenthecropis6–8weeksold,orwhenthefirstflowerpetals

drop.Oneortwofollow-upfungicideapplicationsmayberequiredifsymptomsdevelop. 30

1.12 Insect status of paddock

Peanuts can tolerate higher insect thresholds than other, more determinate crops, because

theycompensategrowthfollowingdamage.

Peanuts are indeterminate in vegetative and reproductive development. This means the

plantsdonotstopgrowinginordertoflowerandproduceacrop.Theycontinuetogrow

leavesandstemswhilealsofloweringandsettingpods.Thepodsmustthereforecompete

withtheshootsforcarbohydrateandnutrients.

In traditional peanut-growing areas (e.g. the South Burnett), soil pests can cause major

economic damage. Foliar pests rarely cause economic damage. The worst soil-insect

damageusuallyoccurswherethereisalonghistoryofpeanutgrowingwithfewnon-

legume crops in the rotation.

In drought years, Etiella is a major problem in dryland crops. Etiella larvae are able to

reachthepodsindrysoil,anddamagedpodsareatgreatlyincreasedriskofaflatoxin

contamination. Most other pest problems occur only occasionally.

As peanuts expand into newer areas, some pests, such as Helicoverpa, mites and mirids,

will be a more constant problem. Soil pests are likely to become important in newer areas

asmorepeanutsaregrown,andnewspeciesmaybeencounteredthatarespecificto

the soil type in question. Pest damage to peanuts can start as soon as the crop is planted

anditcontinuesuntilmaturity.Underintensiveproduction,anumberofpestswillwarrant

control. 31


31 DAFF(2010)Insectpestmanagementinpeanuts.DepartmentofAgriculture,FisheriesandForestryQueensland, https://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/integrated-pest-management/ipm-information-by-crop/peanuts

i More information

P Harden et al. (2103)

Peanut production guide.

PCA.

i More information

DAFF (2010) Soil insects

in Queensland.

H Brier et al. (2012)

Good bug? Bad bug?

Anidentificationguide

forpestsandbeneficial

insects in summer

pulses, soybeans,

peanuts and chickpeas.


https://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/integrated-pest-management/a-z-insect-pest-list/soil-insects


https://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/integrated-pest-management/ipm-information-by-crop/peanuts

https://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/integrated-pest-management/ipm-information-by-crop/peanuts






http://thebeatsheet.com.au/wp-content/uploads/2012/04/GoodBadBug-FINALscreen22Feb3.pdf







Section 2 PEANUTS - Pre-planting


December 2014



SECTION 2

Pre-planting

2.1 Varietal performance and ratings yield

In 2014, a 5-year license agreement was implemented between the processors Peanut

CompanyofAustralia(PCA)andG.CrumptonandSon,andPCAandCliftonFarming.

TheagreementallowsaccesstoallcurrentandfuturePCAvarieties(Table1).Theonly

exclusionwillbefora2-yearperiodforany‘introduced’varietycommerciallyreleasedthat

waspartofthePCAprogrampriorto1July2007.

All growers need a Sub-License Agreement to grow any PBR variety.

Seedisnotapartofthelicenseagreement.Whenavarietyiscommerciallyreleased,PCA

willprovidepureseedtotheotherprocessorsbasedontheirshareofthecrop.Eachparty

willthenberesponsiblefortheprovisionofseedtotheircontractedgrowers.






December 2014



Table 1: Peanut variety summary 2014–15

Thistableisaguidetovarietalselection.Consultyourlocalpeanutagronomistforspecificrecommendationonvarietiesforyourfarm.PBR,PlantBreeder’sRights:thesevarietiesareprotectedundertheAustralianPlantBreedersRights Act 1994 and the regulation therein

Generally recommended for: Susceptible to:

Variety Type

Weeks (Days) To Maturity South Qld (Approx)

Growth Habit

Peg Strength

Seed Size

Dryland – South Qld

North Qld Irrigated & High Rainfall Dryland

Irrigated Central & South Qld

Leaf Diseases

Soilborne Diseases

Wheeler p Virginia 20 (140) Erect Medium Large Yes No Yes Yes (Highly susceptible to net blotch)

Yes, maybe some tolerance to CBR

Middleton p Virginia 19 (135) Semi-erect

Medium Large Yes No Yes Yes (Highly susceptible to net blotch)

Some tolerance toAflatoxinIncidence

Fisher p Virginia 20 (140) Semi-erect

Medium Large Yes No South Qld only CQ - No

Yes (Some tolerance to net blotch andleafspot)

Some resistance to CBR Tolerance to Sclerotinia

Menzies p Runner 20 (140) Semi-prostrate

High Medium No Yes No Yes Some tolerance to CBR and White Mould

Holt p Runner 20 (140) Semi-prostrate

High Medium - Large

Yes (Consult Agronomist)

Yes Yes Yes Some resistance to CBR. Some tolerance to Sclerotinia and White Mould

Page p Runner 19 (135) Semi-prostrate

High Medium Yes (Consult Agronomist)


Yes Yes Some resistance to CBR Tolerance to Sclerotinia, White Mould & Fusarium

Redvale p Ultra Early

15 (105) Erect High Medium Yes (Consult Agronomist)



Yes Limited tolerance to rust (Susceptible to net blotch)

Susceptible to CBR

Redvaleisavaluablevarietyoptionforgrowersinallregions.Indrylandareasinsouthern

Queensland,Redvalecanavoidend-of-seasondroughtandhenceaflatoxinrisk,yetcan

still produce a high-yielding crop with good grades in above-average seasons.

Incoastalregions,Redvaleoffersanearly-maturingoptionforearlyorlateplantingtoallow

alegumebreak-croptobetterfitintoacanesystem.Itwilluseupto30%lesswaterand

fungicidesthanothervarieties,yetstillyield>5t/haifmanagedproperly.

In North Queensland, Redvale hasperformedverywellunderwetconditions.Itisworth




December 2014



consideringwhereagrowerwantstominimisecropinputs(irrigation,fungicides)yetstill

havethepotentialforyieldsof>4.5t/ha.1

2.1.1 Hi Oleic varieties‘HiOleic’isareferencetotherelativelevelsofoleicandlinoleicacid(orO/Lratio)inthe

peanutkernels.Thebalanceofthesetwooilsdeterminestheincreaseinrancidityovertime,

i.e.keeping-qualityorshelflife.OlderpeanutvarietieshaveanO/Lratiointherange1–2.

NewervarietieshaveanO/Lratiointherange20–40.Thisgreatlyimprovestheirshelflife

andflavour.AllvarietiesavailablefromPCAareHiOleic.2

2.1.2 Yielding abilityA peanut grower’s income is determined largely by the yield and quality achieved. Like

many crops, substantial variations in yield may exist. Climatically, some areas may have

differentyieldpotential,anddifferencesdoexistamongvarieties.However,management

factorsareoftenamajordeterminantoffinalyield,socaremustbetakenwithallaspectsof

growing the crop.

Similarly,kernelqualitycanbeinfluencedbymanagementfactors.Growersaredirectlypaid

onkernelquality;therefore,itisimportantthattheyunderstandwhichmanagementfactors

candirectlyaffectkernelquality.

These include:

• goodcroprotationandfreedomfromdisease

• good nutrition, especially calcium (Ca) and boron

• good irrigation/moisture management

• optimum maturity determination

• good harvesting conditions

• controlled drying



i More information

New peanut showcases

‘speed breeding’. GRDC

Ground Cover Issue 92.

i More information

PCA. Hi Oleic peanut

summary.


http://youtu.be/LOJJpt7r-1M?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7



http://youtu.be/LOJJpt7r-1M?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7

http://grdc.com.au/Media-Centre/Ground-Cover/Ground-Cover-Issue-92-May-June-2011/New-peanut-showcases-speed-breeding



http://www.pca.com.au/pdfs/hi-oleic/hioleicsummary.pdf

http://www.pca.com.au/pdfs/hi-oleic/hioleicsummary.pdf



December 2014



On-farmyieldisnormallymeasuredintonnesperhectare(t/ha)offarmers’stockpeanuts,

whichmeansunshelledpods(in-shell)cleanedofextraneousmatterandatthemoisture

contentusedforgrowerpaymentcalculation.

Underexcellentconditions,theRunnerandVirginiavarietiesarecapableofyields>7t/ha.

Theultra-earlyvarietiestendtoyieldless,butarestillcapableofyieldsof5t/ha.

Thedifferentvarietiesproducedifferentlevelsofshell;growersshouldbeawareof

thisbecausetheyarenotpaidfortheirshell.Runnertypesproduce19–22%shelland

Virginiatypes,22–25%shell.Well-grown,irrigatedcropswillbeatthelowerendofshell

percentage,whereasimmatureanddrought-affectedcropsgenerallyexhibithighershell

percentages. 3

Ultra-early varieties, such as Tingoora ,canescapeend-of-seasondroughtsandgive

reliableyield.Ultra-earlymaturityalsoprovidesashort-rotationoptionforhigh-inputgrowers

(i.e.irrigatedregionsinsouthernandNorthQueensland)wherecommercialpodyieldsof>5

t/ha have been achieved.



http://youtu.be/7s9g40o9u2M?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7


http://youtu.be/7s9g40o9u2M?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7



December 2014



However,ultra-earlyvarietieswillhaveloweryieldpotentialthanfull-seasonvarietiesin

seasonswithgoodrainfall.

ThepeanutvarietySutherlandhasdemonstratedsignificantlyhigherlevelsofresistanceto

rust (caused by Puccinia arachidis)andlateleafspot(causedbyCercosporidium

personatum) than currently grown varieties such as Menzies and Holt. It gives growers

anothermethodofmanagingleafdiseaseinpeanutcrops.4

2.2 Quality of planting seed

Peanut seed is easily damaged and must be treated as gently as possible. Once a seed is

split, the two halves will not germinate.

Seedistreatedwithfungicidebeforeplantingtoreduceseedlingdiseases.Itisnot

worthwhileforfarmerstoplantuntreatedseed,becausegerminationrateswilldropto

<40%.

Plantingcanstartanytimeafterthesoiltemperaturereaches18°Catplantingdepth(50–70

mm).Thisismeasuredat09:00(9am)for3daysinarow.Plantingisdelayedifrainis

expectedwithin3–4days.Plantingisalsotimedtoensurethatthecropisreadyforharvest

beforefrostsbeginandwhenthereisalowriskofrain.

Inhigh-rainfallareas,formationofraisedbedspriortoplantingmaybenecessary.5

2.2.1 Growing peanuts for seedPeanutseedismoredelicatethanmostotherseedandneedscareandattentionfrom

plantingoftheseedcropthroughharvesting,drying,shellingandseedpreparation.

Growingpeanutsforseedisaspecialistactivitybecausehigh-qualityseedisessentialto

4 GRDC(2010)Newvarietiesaddanothertoolinleafdiseasemanagement.ManagingLeafDiseasesinPeanutsFact Sheet, Summer 2010, GRDC, http://www.grdc.com.au/uploads/documents/GRDC_FS_Peanutleafdisease.FINAL.pdf



http://youtu.be/0jdqJTTdO1A?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7

http://www.grdc.com.au/uploads/documents/GRDC_FS_Peanutleafdisease.FINAL.pdf



http://youtu.be/0jdqJTTdO1A?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7



December 2014



ensure optimum plant populations. The industry requires quality seed with high germination

rates, vigour and purity.

Peanutgerminationandvigourcanbeaffectedanytimethroughthegrowingseason.

Particularattentionmustbepaidtocropnutrition,managementofweedsanddiseases,

minimising moisture stress, and correct harvesting and drying techniques.

Clean land

Landmustbefreeofweedsandvolunteerpeanuts.Preferredpaddockshavenotgrown

peanutsforatleast3yearsanddonothaveahistoryofsoil-bornediseases.Contamination

ofseedcropsfrompeanutvolunteersofadifferentvarietyisamajorconcern.

Goodrotationsareneededtoachievecleanlandstatus.Preferredrotationsinclude

pastures, sugarcane, and grain crops such as maize, sorghum, wheat and barley.

Clean machinery

Peanutseedmustbekeptseparatefromallotherpeanuts.Allhandlingequipmentshould

be cleaned to avoid contamination.

Allmachinerymustbefreeofkernelsandpods.Thisincludesplanters,diggers,threshers,

elevators, drying bins, silos and trucks.

Irrigation

Ifwaterisavailable,irrigationcanensuregoodyieldsanddramaticallyimproveseedquality

butneedstobeconsideredintermsofbudgetandrisk.

Supplementary calcium

Peanuts,especiallyseedcrops,haveahighrequirementforCa.LowseedCaresultsin

poor germination.

Supplementary Ca can be applied as lime or gypsum, and in combination with irrigation, it

canmakeabigdifferencetogermination.

Limeispreferredifthesoilsareacidic.Ideally,thelimeshouldbeappliedandlightly

incorporatedbeforeplanting.Ratesareusually2.5–3.5t/ha.

GypsumisthepreferredoptionforapplyingCabecauseitismoresolubleandmore

availablethanlime.Gypsumisbestappliedclosetofloweringat1t/haoverthewholecrop

or banded over the row at 400–600 kg/ha. Lime can also be applied over the row where

soilsareacidic,butitmustbeappliedsoonafteremergence.

Maturity

Check crops regularly as harvest nears. The hull scrape method will help to determine the

best time to dig. Slightly immature kernels give better physical quality than over-mature

ones.

i More information

QDPI/CSIRO. Managing

cadmium in summer

grain legumesfor

premium quality produce.

Cadmium. Nuts2u.

Incitec Pivot Fertilisers.

Gypsum.


http://www.clw.csiro.au/publications/general2002/grain_legumes_brochure.pdf




http://www.pca.com.au/bmp/pdfs/Nuts2U_02.pdf

http://farmercommunity.incitecpivotfertilisers.com.au/Articles and Publications/Fertiliser Facts/Gypsum




December 2014



Digging and threshing

Diggersthatinvertpeanutsarepreferredforseedcropsbecauseinvertedpeanutsdry

uniformlyandquickly.

Threshingisoneofthemostcriticalaspectsofseedproduction.Theimpactreceived

duringimproperthreshingmaydamagepeanuts,makingthemunsuitableforseed.

Mechanical injury causes broken or bruised seed tissue. Such damage leads to seed

deteriorationinstorage,increasingthechanceoffungalinvasionoftheseed.

Physicaldamagetotheseedisoneofthecausesofthe‘J-shaped’rootsystemthatcan

developwhenpeanutsaretryingtoestablish.Plantswithdeformedrootsystemsdonot

yield as well as those with a normal root system.

Slow cylinder speeds are essential. As conditions change throughout the day, the harvested

cropshouldbecheckedforlooseshellkernelandhulldamage.

Allowthepeanutbushtodrysufficientlyinthewindrowbeforethreshing.Greenbushesare

toughandrequireaggressivethreshingactiontoseparatethepodsfromthebush.Moisture

contentof18–22%isideal(Table2).

Table 2: Effect of seed moisture at threshing on germination

Source: Six steps to high quality peanut seed. North Carolina Agricultural Extension Service

Threshing moisture Average germination<20% 89%

20–25% 84%

>26% 75%

Drying

Peanutsforseedshouldgenerallybepre-cleanedbeforedrying.

Seed can be easily damaged by over-drying, rapid drying and/or drying at overly high

temperatures. Drying damage can result in poor germination and poor shelling quality, with

an increase in splits and skin slippage.

Peanutsforseedshouldbedriedatamaximumof35°C,andnomorethan7°Cabove

ambientairtemperature.Theminimumrelativehumidityforseedis65%,comparedwith

50%forcommercialcrops.Moistureshouldnotberemovedfasterthan0.5%perhour.

Peanut seed contracts

PCA has a program to produce seed peanuts. This aims to provide the industry with quality

seed with high germination rate and varietal purity. Growers are contracted to produce this

seedandmustmeetspecificconditionsincludingpaddockandmachineryclean-down

inspections,calciumapplicationandpreferablyirrigation. 6

6 PCA/DPIF(2007)Peanutseedproduction.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/7a_other_seed.pdf


http://www.pca.com.au/bmp/pdfs/7a_other_seed.pdf

Section 3 PEANUTS - Planting


December 2014



SECTION 3

Planting

Peanuts in northern New South Wales (NSW) and Queensland are usually grown through

summer,plantedanywherefromSeptembertoearlyJanuary.IntheNorthernTerritory,

irrigated peanuts can also be planted in March and harvested in September. The crop

usuallytakes18–24weeksfromplantingtodigging.Growingthroughthesummermonths

meansthatthecropcantakeadvantageofavailablerainfall.

Planningfortheharvestisessentialwhendeterminingwhentoplant.Plantingshouldbe

timedtoavoidrainatharvestandthelikelihoodoffrosts.

Soiltemperaturesshouldbemonitoredregularlyasplantingapproaches.Keeptrackofthe

soil temperature at the desired planting depth (e.g. 50 mm). Measure the soil temperature

at 09:00 (9am).

Aminimumsoiltemperatureof18°Cisrequiredforgermination(measuredat50mm

depth at 9am). Soil temperatures can be measured using a probe thermometer, or likely

soiltemperaturescanbefoundattheBureauofMeteorology (Agricultural observations

bulletins: NSW, Northern Territory, Queensland).

Temperaturehasamajorinfluenceonpeanutgrowthanddevelopment.Peanutgrowthis

favouredbywarmtemperatures>25°C.Drymatterproductiondropsby~25%whennight

temperaturesreach15°Candby50%whennighttemperaturesdropto9°C.

Careshouldalwaysbetakenwhenhandlingpeanutseed.Theseedislargeandfragileand

easilydamaged.Neverdroporwalkonbagsofpeanutseedanddonotleavetheseedin

direct sunlight. 1 Once a seed is split, the two halves will not germinate. 2

3.1 Seed dressings

Seedmustbetreatedwitharecommendedfungicideseeddressing(checkregistrations

at APVMA)toreducetheincidenceofseedlingdiseases.Itisnotworthplantinguntreated

peanutseedbecausegerminationisoften<20%. 3

1 L Wieck, P Harden, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) Peanut CompanyofAustralia,http://www.pca.com.au/pdfs/ growing-peanuts/ppg2014.pdf


3 PCA/DPIF(2007)Cropestablishment.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/3d_establish.pdf


http://www.bom.gov.au

http://www.bom.gov.au/products/IDN65176.shtml

http://www.bom.gov.au/nt/observations/agricultural.shtml

http://www.bom.gov.au/products/IDQ60604.shtml

http://apvma.gov.au/



http://www.pca.com.au/bmp/pdfs/3d_establish.pdf



December 2014



3.2 Inoculation

Peanutsarealegume.Theyareabletofixnitrogen(N2)fromtheatmospherevianodules

ontheirrootsystem.Thesenodulesarecausedbyatypeofbacteriacalledrhizobia,which

infecttheplant’srootsystem.FailureoftheplantstonodulatewillreduceN-fixingabilityand

lower yields.

Native rhizobia exist in many soils, but it is recommended that growers inoculate their

peanutstoensuregoodnodulationandanadequatesupplyofN.Therhizobialstrainused

intheinoculantisanimprovedstrain,designedspecificallyforpeanuts(GroupP),andis

regardedasmoreeffectivethanthenativestrainsinthesoil.

Growersstrivingformaximumyieldsshouldinoculatetheirpeanutseveryseason.

Waterinjectionisthebestmethodforapplyingthepeatinoculant.Donotmixtheinoculant

intoaslurryandapplytotheseed;thiswilldamagetheseed.

Granular inoculant (when available) can be applied via granular application boxes,

commonlyusedforapplyinggranularsoilpesticides,etc.However,theapplicationof

granular inoculant and granular pesticides together is not recommended. 4

3.3 Germination

InQueensland,certifiedpeanutseedmusthaveaminimumgerminationrateof80%. 5

3.4 Reduced tillage

Peanutsaremoredifficulttogrowusingreducedtillageorno-tillagemethodsthanmost

othercrops.Peanutsneedloosesoilforthecroptopegintoandtomakediggingeasier.

This is generally achieved through deep ripping prior to planting.

Fieldtrialsofno-tillpeanutsplantedintowheatstubbleintheBurnettareaofQueensland

haveyieldedmixedresults.Onsandiersoils,outcomesarelikelytobebetter,particularlyif

thesoilishard-settingwithpoorwaterinfiltration.Commercialevaluationofno-tillplanting

intosugarcaneresidueshowslittleornodifferenceinyieldcomparedwithconventional

planting.No-tillinthesugarcanerotationwillbecomemorebeneficialascontrolledtraffic

practices increase.

Weedcontrolisoftenmorecostlyintermsofchemicaluseunderaminimum-tillagesystem

becauseinter-rowcultivationisnotused.However,thiscanbeoffsetbyreducedmachinery

andfuelcosts.

OnthelighterredscrubandforestsoilsoftheBurnettregion,podlossesfromcuttingand

pullingthecropfromreduced-tillandno-tillblocksweremuchlessthanexpected.

4 L Wieck, P Harden, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) Peanut CompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf







December 2014



Somegrowersusestriptillage,wheretheplantbediscultivatedandtheinter-rowisleft

uncultivated. GPS-controlled machinery enables the operator to maintain the beds in the

samepositionfromoneseasontothenext.6

Consideringthatwateristhemostlimitingresourceintherainfedenvironmentofthe

Burnett,minimumtillreducestheamountofrainfallrequiredtoprepareaseedbed.7

3.5 Time of planting

Plantingcanstartanytimeafterthesoiltemperaturesatplantingdepthreach18–20°Cat

9amfor3daysinarow.Delayplantingifthesoiliscoolorifrainisexpectedwithin3–4

days.

Plantingshouldbetimedtoensurethatthecropisreadyforharvestattheendofthewet

seasonandbeforethefirstfrost(Table1).Spanishandultra-earlytypesmatureearlierthan

Virginiaandrunnertypes,sotheycanbeplanted2–3weekslater.Insomepartsofcoastal

and northern Queensland (near Cairns), and the Northern Territory, peanuts can grow over

the winter months but growth is limited. 8

Table 3: Preferred and possible planting times for Virginia and runner peanuts

Region Preferred PossibleNorthern NSW and southern Qld Mid Oct.–late Nov. Start Oct.–mid Dec.

Central Qld Mid Nov.–mid Dec. MidSept.–earlyJan.

Atherton Tableland and Lakeland Mid Nov.–mid Dec. MidNov.–lateJan.

Bundaberg Early Sept.–mid Dec. Mid Sept.–end Dec.

Mackay Sept. (ultra-early varieties) mid Nov.–mid Dec.

Sept.–Jan.

3.6 Seeding rate

Althoughpeanutscancompensateforsuboptimalplantpopulations,thecropcannotmake

upforpoorplantstandsorlargegaps.

To achieve the correct plant density, calculate the required seeding rate to ensure that

adequatenumbersofseedsareplantedregardlessofseedsize(Table2).ForVirginia

andrunnertypes,anacceptableplantpopulationunderfullirrigationis130,000–150,000

plants/ha.Aimforpopulationsofupto180,000plants/haforSpanishorultra-earlyvarieties

underfullirrigation.Table3providestheseednumberspermetreofrowneededtoachieve

the desired plant population.

Underdrylandconditions,Virginiaandrunnertypesrequireratesof50,000–60,000

plants/ha in southern Queensland and 80,000–90,000 plants/ha in North Queensland.


7 RMason,JPage,MCloete.UsingminimumtillageandcontrolledtraffictoreducetheriskofcroppingintheBurnett, http://actfa.net/wp-content/uploads/2014/07/Using-minimum-tillage-and-controlled-traffic-to-reduce-the-risk-of-cropping-in-the-Burnett-R-Mason-et.-al..pdf


i More information

R Mason et al. Using

minimum tillage and

controlledtrafficto

reduce theriskof

cropping in the Burnett.

Y Dang et al. (2013)

Tillage impact in long

term no-till GRDC

Update Paper.

GRDC (2007) Why

Australia has the world’s

greatest herbicide

resistance problem.

GRDC Ground Cover

Issue 68.

EA Roesner (1998)

Minimumtillageeffects

on soil structure

measured using image

analysis. Australian

AgronomyConference.



http://actfa.net/wp-content/uploads/2014/07/Using-minimum-tillage-and-controlled-traffic-to-reduce-the-risk-of-cropping-in-the-Burnett-R-Mason-et.-al..pdf








http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2013/02/Tillage-impact-in-long-term-no-till




http://grdc.com.au/Media-Centre/Ground-Cover-Supplements/Ground-Cover-Issue-68-Integrated-Weed-Management-Supplement/Why-Australia-has-the-worlds-greatest-herbicide-resistance-problem






http://regional.org.au/au/asa/1998/8/119roesner.htm








December 2014



Plant Spanish or ultra-early types at a rate to give 120,000–150,000 plants/ha in North

Queensland and 80,000 plants/ha in southern Queensland.

Afieldestablishmentof<80%istypical.Thereareseveralreasonsforthislow

establishment rate, including peanut susceptibility to seedling diseases despite seed

dressings,soilinsectdamagetoseedduringproductionandplanting,andthedifficultyof

producing good-quality seed. 9

Table 4: Planting rates (kg/ha) required for different-sized peanut seed to achieve desired plant populations, assuming 80% field establishment

Plant population (no. of plants/ha)

No. of seeds per kg:

750 1060 1300 1400 1600 1800

60,000 100 71 58 54 47 42

80,000 133 94 77 71 63 56

100,000 167 118 96 89 78 69

120,000 200 142 116 108 94 84

140,000 233 165 135 125 109 97

160,000 266 188 154 142 126 112

Table 5: Seed numbers per metre of row required to achieve desired plant populations

Plant population (no. of plants/ha)

Row spacing (cm)

86 cm 91 cm 96 cm 102 cm

60,000 5 5.5 6 6

80,000 7 7 8 8

100,000 9 9 10 10

120,000 10 11 12 12

140, 000 12 13 14 14

160,000 14 15 15 16

3.7 Sowing depth

Depthofplantingisnotascriticalforpeanutsasitisformostothercrops.Theidealis

50–70mmdeep,butplantingdepthsmayrangefrom35to100mm.Wherepeanutsare

tobeplantedintodrysoilandthenfurrow-irrigated,plantat25–35mmdepthtoavoid

waterlogging the seed.

Thepeanutseedislarge,andinordertogerminate,itmustabsorb35%ofitsweightin

water. Large-seeded varieties such as Wheeler and Middleton need better soil moisture

at planting than small-seeded varieties such as the Spanish and ultra-early types. All seed

mustbeplacedintomoistsoil,withnodrybandsofsoilintheprofile.

Ifmoistureandtemperatureareacceptable,theemergingseedlingisverystrongandcan

breakthroughsoilsurfacecrusts. 10








December 2014



3.8 Row configuration

Fieldtrialshaveshownthatgrowingultra-earlyvarietiesintwin-rowconfigurationsandat

increasedplantpopulationscanleadtoyieldscomparabletothoseoffull-seasonvarieties.

Trialshaveshownthatwithirrigation,oringoodrainfallyears,twin-rowplantingcanresultin

significantimprovementinpodyieldandkernelgradescomparedwithsingle-rowplanting,

duetobettersynchronisationoffloweringandpodding,andmoreevencropdevelopment

(Figures 1–4). 11

Figure 1: Single rows (conventional practice) of peanuts are planted with 90-cm spacing between the rows. (Photo: PCA)

Figure 2: Twin rows of peanuts are planted 20–30 cm apart under a 90-cm arrangement. (Photo: PCA)

11 RCNRachaputi,SKrosch,GWright.Optimisingrowspacingfortheultra-earlyTingoora,GRDC,PeanutCompanyofAustralia,theQueenslandGovernment,http://www.pca.com.au/pdfs/growing-peanuts/2010rowspacing.pdf


http://www.pca.com.au/pdfs/growing-peanuts/2010rowspacing.pdf




December 2014



Figure 3: A field trial with peanuts, comparing a single-row (foreground) and twin-row (background) configurations. (Photo: PCA)

Figure 4:

Tonn

es p

er h

ecta

re

Pod yield6

5

4

3

Do

llars

per

to

nne

Single row Twin row

Kernel gradout900

850

800

750

700

100 000

200 000

100 000

200 000

Pod yield and kernel grade of peanuts at Tingoora grown under single- and twin-row configurations under irrigated conditions (Bundaberg, 2009–10 season).

In2002,researchersfromtheUniversityofGeorgiaintheUnitedStatesreleasedtheresults

of6yearsofstudyontwin-rowplantingpatterns.Workinthe1970sinAlabamabyE

HauserandGBuchananhadalreadyshownthattwinrowsallowedforbetterweedcontrol.




December 2014



TheGeorgiaresearchwascarriedoutfrom1996to2001onnumeroussmallplotsand

on-farmdemonstrationsitesthroughoutthestate,comparing17.5–35.5-cmtwinrowswith

1-m single-row patterns. Seeding rates were kept constant: 3 seeds/30 cm on each twin

row or 6 seeds/30 cm on single-row planting patterns.

Several positive conclusions were drawn:

• Twin rows result in quicker canopy coverage than single rows.

• Yields increased by 549 kg/ha, averaged over early to late plantings.

• Gradesincreasedanaverageof1–2%.

Theresearchersestimatedthatif50%oftheGeorgiapeanutacreagewasplantedtotwin-

rowpatterns,therewasapotentialeconomicreturnofUS$28millioninincreasedyieldand

another $4 million in increased grade value to producers.

In1999,~35%oftheGeorgiapeanutacreagewasintwin-rowpatterns;by2002,50%was

in twin-row patterns.

Trialsonplantingtwinrowsunderstrip-tillagemethodsshowedthatamajorfactorfor

successwastocentrethesubsoilerbetweeneachsetoftwinrows.Theyieldresponse

was not as great as with conventionally tilled twin rows it but was still positive compared

with single rows.

Withstriptillage,itwasdifficulttoachieveanadequateplantstandandavoidexcessive

digginglossesduetoplantingonlevelsoilandlackofgoodrowdefinitionfordigging

efficiency.

Fortwinrows,itwasimportanttousea76-cmcut-frogonthediggertoavoidpulling

peanutsofftheinsidetwinrows.

Since2000,theUniversityofGeorgiahasrecommendedplanting6seeds/30cmon

single rows and 3 seeds/30-cm row on twin rows. Their research indicated no advantage

to exceeding 6 seeds/30 cm on single rows or 3 seeds/30 cm on twin rows, and that 2

seeds/30cmwasinsufficient.12

3.9 Sowing equipment

Peanuts must be planted with a row-crop planter (Figure 5). Combine planters are not

suitable.Thepeanutseedislargeandfragile.PlateplanterssuchastheCovingtonand

Jankearecommonlyused,aswellasrotaryconeandfingerpick-upplanters(e.g.Mason

DeereandKMC).VacuumprecisionplanterssuchasJohnDeereandMonosemaregentle

andwellsuitedforpeanuts.NodetandGaspardovacuumplantersmustbemodifiedto

plant peanuts. Kinze planters with ‘edible bean’ cups are not suitable.

12 PCA.Twinrowsboostyieldsandgrades.PeanutCompanyofAustralia,http://www.pca.com.au/twin-rows-boost-yields.php


http://www.pca.com.au/twin-rows-boost-yields.php




December 2014



Recommended planting equipment includes:

• JohnDeereMaxEmergevacuumprecisionplanter;MasonDeere-typeplanterwith

rotary cones

• NodetandGaspardopneumaticplanters,withmodifications

• Covingtonboxorsomeinclinedplateplanters,orflatplateplanterssuchasthe

International 186 and 184 series

• Monosem vacuum precision planter 13

Figure 5: A 4-row planter modified to plant two twin rows.

3.9.1 Press-wheelsTheuseofpress-wheelsisessential(Figure6).Theygivebetterseed–soilcontact,which

promotesfasterandmoreuniformemergence.Soft-centredortwin-inclinedpress-wheels

arepreferred,particularlyonsoilsthatformsurfacecrusts.Hard-centredpress-wheelscan

be used on some soils that do not crust, although the pressure may have to be reduced. 14

13 P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated 2014) Peanut Company ofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf







December 2014



Figure 6: Press-wheels on the planter are essential for good seed–soil contact.

3.9.2 PlantersThesoft-skinnedpeanutseediseasilydamaged.Therefore,theseed-meteringmechanism

oftheplantermustaccuratelydistributetheseedwithoutexcessiveagitationorshearing

action.Manydifferentseed-meteringmechanismsareavailable.Noneofthecombine

planters has acceptable seed meters but row-crop planters have more suitable metering

methods (Table 4).

Correct-sized plates will minimise damage to seed, and nylon (or similar) plates generally

accumulate less seed dressing than do metal plates.

Onallpeanutplanters,maintainanaccurateplantingrateevenifplacementdepthvaries,

becausethepeanutplantcanonlycompensateforsmallgaps.

Thehorizontalorflatplateplanterisrenownedforitstendencytoshearoffkernels.This

destroysseedandcausesmissedplantspaceswhereanon-viableportionofseedfilledthe

plate cell. Precision is not high.

Theinclinedplateplanter(e.g.Covington)isveryreliableforplantingpeanuts,eventhe

largerseedsizes.Althoughseedplacementisoftennotprecise,plantingratesareusually

reasonablyaccurate.Theseplantersarenotsuitableforroughseedbedsoroperatingat

high speed (maximum speed 6 km/h).

Rotary cone planters are reasonably reliable and provide accurate seed placement.

However, very large kernels can cause bridging—a blockage in the chute opening.

Vacuumplanters(e.g.JohnDeereMaxEmerge)arewidelyusedforplantingpeanuts.

These planters can make skin slippage worse on over-dried kernels, leaving a ‘bald’

kernelexposedwithnofungicidetreatment.Looseskinscanalsoblocktheair-holes.

This mechanism gives accurate seed placement, and adaptation to peanut planting is

reasonablystraightforward.




December 2014



BrushmetershavebeendevelopedbyKinzebutarenotsuitableforpeanutsbecauseof

thesizeofpeanutseed.Combineplantersshouldnotbeused. 15

Table 6: Seed-metering mechanisms for row-crop planters

Metering Precision Agitation Suitability CommentsHorizontal plate Low High Low High potential to shear peanut

kernels (IHC 184 and IHC 186)

Inclined plate Low Med High Commonlyused(Covington,Janke)

Rotary cone Medium Medium Medium–high

Suitableforpeanuts(MasonDeere,KMC)

Finger pickup High Low Low Not easily adapted to large peanuts (MasonDeerefingerpickup)

Vacuum pneumatic plate

High Low High Very accurate. High potential to removekernelskins(Nodet,JohnDeere, Gaspardo, Monosem)

Brush meter High Low Low Available models not readily adaptable

Combine planters – – None Unacceptable, will not work




Section 4 PEANUTS - Plant growth and physiology


December 2014



SECTION 4

Plant growth and physiology

The peanut (Arachis hypogaea) is a summer-growing legume that originated in South

AmericaandiswelladaptedtowarmerregionsofAustralia.Ifconditionsallow,itcanshow

perennialcharacteristicsandsurviveforseveralyears.

Like other legumes, peanuts do not rely on soluble nitrogen (N) in the soil to supply the

plant’sNrequirements.Rather,rhizobialbacteria‘infect’therootsandtakeN2from

theatmosphere,makingitavailabletotheplant.Unlikeotherlegumes,thematurefruit

developsintoalegumepodunderground(Figure1)andtheplanthasfourleafletsperleaf,

not three.

Figure 1: Inverted peanut bush.

Peanutpodsaremadeupofanoutershellthatusuallycontainstwokernels.About70%

ofthepod’sweightiskernel.Thekernelsarehighinoil(44–56%)andprotein(22–30%).

Dependingonvarietyandconditions,thepeanutplantcangrowtoaheightof~60cmand

canspreadupto100cm.Theplantisuniqueinthatitflowersabovegroundandthen,once

pollinated,producesitsfruitbelowthesoilsurface.

Theflowers,whicharesmall,yellowandpea-shaped,areproducedintheaxilsofthe

leaves.Theflowersareself-pollinated,usuallyatnight.Aftertheovaryisfertiliseditbegins

to elongate and grow towards the soil.

This‘peg’(asitiscalled)reachesthesoilabout7–10daysafterpollination.Theovaryis

carriedinthetipofthepegandstartstogrowintoapodafteritpushesintothesoil.Pods

will not develop unless there is darkness, mechanical resistance and moisture. 1

1 PCA/DPIF(2007)Thepeanutplant.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/2a_peanut_plant.pdf


http://en.wikipedia.org/wiki/Fruit

http://en.wikipedia.org/wiki/Legume

http://www.pca.com.au/bmp/pdfs/2a_peanut_plant.pdf



December 2014



4.1 Botanical types

Peanutsaredividedintotwobroadbotanicaltypesbasedonthefollowingdifferences:

• thebranchingpatternoftheplant

• thedormancyoftheseed

• thematurityoftheplant

TheVirginiagroupdoesnotproduceflowersonthecentralbranch,onlyonthelateral

branches. The seeds show some dormancy and the crop is relatively late maturing

(130–170 days). Within the Virginia group, there are both erect and runner (prostrate) types

(Figure 2).

Figure 2: Some varieties have runner, or prostrate, growth habit.

TheSpanishgroupproduceserectplantswithflowersonboththecentralandlateral

branches.TheseedsoftheSpanishgroupshowlittledormancyandthecropisearly

maturing (100–130 days).

The crop matures in about 18–24 weeks depending on variety and season temperatures

(Figure 3). 2

Foragepeanutsareusedforgrazingandforgroundcoverinorchards.Thesearedifferent

speciesfromthevarietiesgrownfortheirediblekernels.Onespecies,Pinto’speanut

(Arachis pintoi),isgrowninareasofQueenslandandNewSouthWaleswithaverageannual

2 GWright,PHarden,LWieck,(2014)Peanutproductionguide,August2014.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf

i More information

GC Wright et al. (1991)

Physiologicalanalysisof

peanut cultivar response

totiminganddurationof

drought stress. Australian

Journal of Agricultural

Research 42.

RCN Rachaputi. More

efficientbreedingof

drought-resistant

peanuts in India and

Australia. Adoptionof

ACIAR Project outputs

2003–2004.

Y Chauhan et al. (2010)

Physiologyofmungbean

anddevelopmentofthe

mungbean crop mode.

Australian Summer

GrainsConference.










http://aciar.gov.au/files/node/9074/AS 03-04 CS1-1997-114.pdf







https://www.grdc.com.au/uploads/documents/2010ASGCPowerPointPresentationsPDF/Chauhan_MunbeanModelling_slides.pdf








December 2014



rainfall>1000mm.Thekernelsaremuchsmallerthanthecultivatedtypesandarenot

suitablefortheedibletrade. 3

Figure 3: Trials such as this help plant breeders to assess the qualities of new varieties under field conditions.

4.2 Growth and development

Thelengthofeachgrowthstagedependsmainlyontemperature.Peanutsarenotas

sensitivetodaylengthassoybeans;however,longdaysandhighnighttemperaturescan

alterthebalancebetweengrowthofthebushandthepods.Atypicalgrowthcyclefora

Virginia variety in both south and north Queensland is shown in Table 1. 4

Table 7: Growth stages of a Virginia peanut variety in southern and northern Queensland

Growth stage

Days after planting

Southern Qld Northern Qld

Planting to emergence 6–14 6–12

Emergencetofirstflower 20–40 28–38

Flowering 35–65 28–65

Pegging 45–75 36–75

Pod-filling 60–130 55–130

Harvest maturity 140–150 125–150

4.2.1 Germination and emergenceApeanutseedhastwocotyledons,orseedleaves,andanembryo.Afteremergence,the

cotyledonsunfoldabovetheground.Theembryoisnottotallyprotectedbythecotyledons

and can easily be physically damaged during the harvesting, storage, shelling and planting

operations.



i More information

KJBoote (1982) Growth

stagesofpeanut(Arachis

hypogaea L.). Peanut

Science 9.

BE Warrick. Plant growth

anddevelopmentof

peanuts. Soil, Crop and

MoreInformation.




http://www.peanutscience.com/doi/abs/10.3146/i0095-3679-9-1-11




http://www.soilcropandmore.info/crops/Peanut/PGD.htm






December 2014



A damaged embryo will not develop properly, and although it may germinate and establish,

yieldwillbemuchlowerthanfromundamagedseed.Plantsgrowingfromdamagedseed

oftenhaveacurledorJ-shapedrootsystem.Thisdefectcanalsobeasymptomofpre-

emergence herbicide damage.

Itisrecommendedthatpeanutseedisplantedatsoiltemperaturesofatleast18–20°C,but

seedwillgerminatebestatsoiltemperaturesof20–35°C.Theradicle,orroot,takes1–2

daystoemergefromtheseed.

After5days,thetaprootis10–15cmlong.Lateralrootsthenstarttodevelopand

secondaryrootsgrowfromthelaterals.After5–10days,therootissupplyingmineralsfrom

the soil to the plant.

Figure 4: Peanuts take 7–14 days to emerge.

Effectiverootingdepthofthepeanutplantis~100–120cm.Wheretherearenosoil

restrictions, the peanut plant has a long, spike-shaped root up to 150 cm long, with the

primaryrootsystembranchingtoadepthof60–80cm.

Emergencethroughthesoil,knownas‘cracking’,begins6–14daysafterplanting(Figure

4).Dryorcoolsoilscandelayemergenceforupto3weeks,oftenresultinginpoor

establishment due to soil-borne disease.

Emerging peanut seedlings can push through quite hard and crusted soil, hence the term

‘cracking’, but very crusted soil will restrict emergence. 5

4.2.2 Vegetative growthAfter20days,theremaybe8–10fullyexpandedleaves.Unlikemostlegumes,peanuts

have4leafletsperleaf,whichpartiallyfoldupatnight.

Peanutfoliagecangrowatadailyrateof150–200kg/haoncefullcanopycoverisreached.

Peanuts are indeterminate in vegetative and reproductive development. This means the






December 2014



plantdoesnotstopgrowinginordertoflowerandproduceacrop.Plantscontinuetogrow

leavesandstemswhilefloweringandsettingpods.Thepodsmust,therefore,compete

withtheshootsforcarbohydrateandnutrients.Indeterminatecropsaremorelikelytobe

abletocompensateforlowlevelsofinsectdamage.

Therearedifferencesindeterminacybetweenvarieties.TheVirginiatypesaremore

determinate than Spanish types. Newer varieties achieve higher pod yields than older

varieties,becausealargerportionofthenewervarieties’growthgoesintopodsthanto

vegetation.

4.2.3 FloweringVirginiatypes,includingtherunnertypestypicallygrowntoday,startfloweringabout28–40

daysafteremergenceandcontinuefor25–30days.Flowerscanappearthroughoutthe

season.

Theyellowflowersopenatnight,self-pollinateintheearlymorningandwitherbyevening

ofthesameday(Figure5).Flowersgrowalongthebranchesandeachnodecanproduce

severalflowers.Generally,only~15–20%offlowerssuccessfullyproduceapod.Aplant

may have 200 pods.

Droughtandtemperatures>35°Cwillreducethenumberofflowersproduced.Ifwater

stressreducesflowernumber,theplantcanrecoverbyproducingaflushofflowerswhen

adequate water is received.

Lowhumidityandhightemperaturesatfloweringcancauseshort-termplantwaterstress.

Thisresultsinflowerswithpistilsthataretooshortandadverselyaffectsthevitalityofthe

pollengrains,reducingthechancesoffertilisation.

Peanutsareself-pollinated;therefore,beesarenotneededanddifferentvarietiescanbe

grown side by side with little contamination. 6

Figure 5: The small yellow flowers open at night, self-pollinate in the early morning and wither by evening.






December 2014



4.2.4 PeggingAftertheovaryisfertilised,itbeginstoelongateandbendtowardsthesoil.Thepeg,or

strings,canbeseenabout1weekafterfertilisation.Thepegshangdownfromthestems

and continue to grow until they have penetrated the soil (Figure 6). Because one node can

produceseveralflowers,severalpegscandevelopfromasinglenode.

Pegsmaybe2–15cmlong.However,thoselongerthan~7cmoftendonotreachthe

groundorpenetratethesoiladequately.Iftheselongpegsdevelopapod,itismorelikelyto

be immature and lost at harvest.

Pegsenterthesoil8–12daysafterpollination.Thetipofthepegissharp,allowingitto

penetratethesoiltoadepthof1–7cmundercool,moistconditions.Mostofthepegsthat

onlypenetrate1–1.5cmdevelopapod,buttherateofdevelopmentisslower.

Assoilsbecomeharder,itismoredifficultforthepegstopenetrate.Thepegsaremore

sensitivetosoilcompactionthanaretheroots,sosoilmoisture,which‘softens’hardsoils,

can be critical at this stage.

Thefertilisedembryoisinthetipofthepegandbeginstodevelopandenlargesoonafter

enteringthesoil.Afterthetipofthepegenlargesunderground,itiscalledapod. 7

Figure 6: The peg forms at the base of the flower and grows down into the soil before the pods begin to develop.






December 2014



4.2.5 Pod developmentTheperiodbetweenthepegenteringthesoilandtheshellreachingfullsizeiscalledpod

development.Poddevelopmentlasts~30daysandreliesonthesoilsurfacebeingkept

moist.Thisisacriticaltimeforirrigators. 8

4.2.6 PodfillFromabout60daysonwards,podsareformedandfilled.Podsarefullsizeabout3–4

weeksafterpegburial,eventhoughseedgrowthinsidethepodhasbarelybegun.Theshell

reachesmaximumdryweightwellbeforethekernels.

Peanutpodnumberscanincreaseatadailyrateof100,000–500,000pods/haovera

15–25-dayperiod,andpodweightcanincreaseatadailyrateofupto100kg/haforthe

75–150daysafteremergence.

Some nutrients, particularly calcium (Ca) and boron, are absorbed through minute hairs

onthepegandshell.Thismethodofnutrientuptakeisrelativelyinefficient,whichmeans

thatpeanutshaveamuchhighersoilCarequirementinthetop5–10cmofsoilthanother

plants.

When soil Ca levels are very low, the developing kernels abort and the empty shell is called

a ‘pop’ (Figure 7). 9

Figure 7: Pops (shells without a kernel or with a shrivelled kernel) of Virginia or runner types are typical of low soil calcium levels. A mild deficiency may cause the embryo to turn dark.

4.2.7 MaturityCrops may take 110–170 days (16–24 weeks) to reach harvest maturity, depending on

variety, planting time, seasonal conditions and location. Temperature largely controls the

time to harvest.

Aspeanutsmature,theinsidelayeroftheshellchangescolourfromwhite,throughyellow,

orange,browntoblack.Thisgivesanindicationofharvestmaturity.








December 2014



Oncethepodsmature,thepegsbegintodeteriorate,particularlyiffoliardiseaseshave

affectedthecrop.Yieldlossbeginstooccurifpeanutsarenotharvestedwithin7–10days

ofpeakmaturity,becausethepegsweakenandthepodsfallofftheplant.

Peanutsoftenproduceaveryunevencrop,witharangeofmatureandimmaturekernels

presentatharvest.Therelativeproportionofmatureandimmaturekernelsisassessedand

willaffectthequalitygradingofthecrop(Figure8).Thepaymentsystemsarebasedon

gradingthecropintodifferent-sizedkernels,eachwithadifferentvalue.Immatureorsmall

kernels receive a lower price. 10

Figure 8: Inspect the kernels to determine the best time to harvest.

4.3 Seed dormancy

Mature peanut kernels are dormant to some degree. Interestingly, seeds that develop at the

pegendofthepodhavealongerdormantperiodthanthoseattheoppositeend.

Theperiodofdormancydependsonvarietyandstorageconditions.

Spanish types have virtually no dormancy (5–50 days), whereas Virginia types can be

dormantfor100–120days.

Ifsufficientmoistureisavailable,seedswithlittleornodormancyperiodcansproutinthe

fieldbeforeharvest.CurrentlygrownSpanishvarietiescanhavethisproblem,butpre-

harvest sprouting is generally not problem with Virginia or runner types. 11






Section 5 PEANUTS - Nutrition and fertiliser


December 2014



SECTION 5

Nutrition and fertiliser

Peanutsdifferfromothercropinsomeoftheirnutritionalneeds.Mostofthepod’scalcium

(Ca)andboron(B)istakendirectlyfromthesoilratherthanviatheroots.Calciumisoften

appliedtothecropbeforeflowering.Peanutrootsdependonarbuscularmycorrhizal(AM)

fungi(previouslyknownasvesiculararbuscularmycorrhizal,orVAM)andareveryeffective

atutilisingresidualphosphorus(P)frompreviouscropsintherotation.1

5.1 Nutritional requirements

Peanutshavespecialnutritionalneedsbecausethefruitgrowsundertheground.The

fertilityofthesoilwherepegsandpodsdevelopisimportantbecausethepodabsorbs

mostofitsrequiredCaandBthroughtheshell,ratherthanthroughtheroots,andthen

throughthepeg.Thisinfluencesthemethodandtimingofsomefertiliserapplications,

whichmaydifferconsiderablyfromthoseofothercrops.

Soilsnaturallycontainbeneficialfungithathelpthecroptoaccessnutrientssuchas

Pandzinc(Zn).Thecombinationofthefungusandcroprootisknownasarbuscular

mycorrhiza(e)(AM).Manydifferentspeciesoffungicanhavethisassociationwiththeroots

ofcrops.Manythatareassociatedwithcropsalsoformstructurescalledvesiclesinthe

roots.

TheseverereductionorlackofAMshowsupaslong-fallowdisorder—thefailureofcrops

to thrive despite adequate moisture. Ongoing drought in the 1990s and beyond has

1 PCA/DPIF(2007)Cropnutrition.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheriesQueensland, http://www.pca.com.au/bmp/pdfs/3b_nutrition.pdf



http://www.pca.com.au/bmp/pdfs/3b_nutrition.pdf




December 2014



highlightedlong-fallowdisorderwhereAMfungihavediedoutthroughlackofhostplant

rootsduringperiodsoflongfallow.Ascroppingprogramsrestartafterdryyears,ayield

dropislikelyfromreducedAMlevels,makingitdifficultforthecroptoaccessnutrients.

Long-fallowdisorderisusuallytypifiedbypoorcropgrowth.Plantsseemtoremainintheir

seedlingstagesforweeksanddevelopmentisveryslow.

BenefitsofgoodAMlevelsare:

• improveduptakeofPandZn

• improved crop growth

• greater drought tolerance

• improved soil structure

• greater disease tolerance

Ingeneral,thebenefitsofAMaregreateratlowerlevelsofsoilPbecauseAMincreasea

plant’s ability to access this nutrient. 2

Peanutshaveanexceptionalabilitytoextractsomenutrientsfromthesoil,particularlyP

andZn.Thisiswhypeanutshaveareputationforbeingabletorespondbettertofertiliser

leftafterpreviouscropsthantofertiliserdirectlyappliedtothepeanutcrop.AMfungiare

onereasonforthisphenomenon.Thesefungioccurnaturallyinmostsoilsandreadilyinfect

peanut root systems.

TheAMfungiassisttheplant’srootstoextractPandZnfromthesoil.Sodependentare

peanutsonAMfungiforuptakeofPthatifthefungiarenotpresent,thecropneedssoilP

levels up to 10 times higher than normally required.

IntheSouthBurnett,Queensland,peanutsarecommonlyfertilisedwithPbyover-fertilising

thepreviousmaizecrop.SomegrowersalsoapplyPbeforeoratplanting.Similarly,on

theAthertonTableland,peanutsareoftengrownontheresidualfertiliserfollowingapotato

crop.

Differentfertiliserprogramsareneededonothersoiltypes.Iron(Fe)deficiencyisaparticular

problemonheavierclaysoilswithpH>8.0,becausepeanutrootsarenotveryefficientat

accumulating Fe.

Copper (Cu), magnesium (Mg) and Zn responses have also been recorded on lighter sands

incoastalandinlandareas,andZndeficiencycanalsobeaproblemonsoilswithpH>7.5.

Otherfactorscancausesymptomssimilartothoseofnutrientdeficiencies.Forexample,

nighttemperatures<9°Ccauseleafyellowingandaslightinterveinalchlorosis(Figure1),

andVerticilliumwiltshowsasapale-greencolouraroundtheleafmargins.

2 DAFF(2010)Nutrition—VAMandlongfallowdisorder.DepartmentofAgriculture,FisheriesandForestryQueensland, 14 Sept. 2010, http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/nutrition-management/nutrition-vam


http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/nutrition-management/nutrition-vam

http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/nutrition-management/nutrition-vam



December 2014



Figure 1: Yellowing between veins is typical of cool temperatures, <9°C.

Table1presentstheessentialnutrientsforpeanutsandtheconcentrationsfoundinthe

youngestfullyexpandedleaves.Usethesevaluesasaguideonly.Nutrientlevelsvary

dependingonthepartofplantthatissampled.Levelsalsochangeastheplantmatures

andnutrientsarerelocatedintothepodsasthekernelsdevelop.AsoiltestforCaprovides

theonlyreliableguideforpoddevelopment.3

Table 1: Classification of nutrient status of peanut crops by analysis of the youngest fully expanded leaves

Note:thesevaluesapplyonlybeforethecropstartstofillpods.Sources:Belletal.1990;ReuterandRobinson1986;Reuter and Robinson 1997

Nutrient Severely deficient

Deficient Marginally adequate

Adequate High

N(%DM) <3.2 3.2–3.7 3.8–4.1 4.2–4.5 >4.5

P(%DM) <0.19 0.19–0.23 0.24–0.26 0.27–0.40 >0.40

K(%DM) <0.7 0.7–1.3 1.4–1.7 1.8–2.5 >2.6

S(%DM) <0.15 0.16–0.20 0.21–0.25 0.26–0.30 >0.3

B (mg/kg DM) <13 13–23 24–30 30–50 >50

Mo (mg/kg DM) <0.02 0.02–0.05 0.05–0.13 0.13–1.0 >1.0

Cu (mg/kg DM) <1.3 1.3–1.7 1.8–2.1 2.2–5.0 >5.0

Mg(%DM) <0.2 0.2–0.25 0.25–0.3 0.30–0.80 –

Ca(%DM) – <1.0 1.0–1.2 1.4–2.0 –

Mn (mg/kg DM) – <10 – 50–350 600–800

Zn (mg/kg DM) <12 15–18 18–20 20–50 >200

Fe (mg/kg DM) <25 25–35 35–50 50–300 –






December 2014



5.2 Soil fertility

Soilfertilityisveryimportantforpeanuts.Duringthegrowingofthepeanutpod,CaandB

are absorbed through the shell rather than through the plant’s roots. This has implications

forthemethodandtimingoffertiliserapplications.

Peanutstolerateawiderangeofsoilaciditylevels;however,theidealpHis6.0–7.0.Soils

that are more acidic (pH <6.0) should be limed. Ensure your soil test is properly interpreted

byaqualifiedagronomist.4

Potassium(K),P,Caandsulfur(S)arethenutrientsmostcommonlyappliedtopeanuts,

but growers should also check magnesium levels, which are becoming depleted in some

Australian soils.

Micronutrientsmustnotbeignored—deficiencycansometimesleadtomajoryieldlosses.

Zinc,Bandmolybdenum(Mo)arecommonlyapplied.Copperisoftendeficientonvery

sandysoils.Somesoilsalsohavemanganese(Mn)deficiency.

Foliarapplicationsofmicronutrientsarecommon;however,soilapplicationsarealso

suitableforsomenutrients.5 Your agronomist can provide advice.

5.3 Crop removal rates

Nutrientmanagementneedstotakeintoaccounttheremovalfromthefarmofnutrients

contained in crop products such as grain and hay (Table 2). Peanuts have a high K content

comparedwithmostgraincrops(althoughonlyhalftheKconcentrationofsoybeanseed),

andwhenhayistakenfromthepaddock,evenmoreKisremoved.

Table 2: Mineral content of peanut kernel, shell and hay

Source:Thistablehasbeencompiledfromarangeofsources;thereisagreatdealofvariationbetweensamplesandsourcesandthesevaluesprovideageneralguideonly;n.a.,notavailable

Mineral element content (%) Nutrients removed (kg/t)

Kernel Shell Hay Hay Nut-in-shell

N 4.6 1.3 1.5 15 40

P 0.4 0.03 0.15 1.5 3

K 1.0 0.9 2 20 8

S 0.2 n.a. 0.2 2 2+

Ca 0.07 0.2 0.8 8 1.3

Mg 0.2 0.1 0.3 3 2

Fe 0. 001 0.15 n.a. n.a. 0.5

Cu 0.001 0.001 0.0005 0.005 0.01

Zn 0.006 0.002 0.001 0.01 0.05

Mn 0.002 0.004 n.a. n.a. 0.02

B 0.03 0.001 0.003 0.03 0.2


5 PCA.Peanutsandfertilisers.PeanutCompanyofAustralia,http://www.pca.com.au/peanuts-and-fertilisers.php

i More information

PeanutCompanyof

Australia. Peanuts and

fertilisers.



http://www.pca.com.au/peanuts-and-fertilisers.php






December 2014



Table2providesvaluesindicatingthequantityofeachelementremovedatharvest.Thisisa

guidetowhatmustbereplacedtomaintainsoilfertility.Forexample,eachtonneofhaywill

containabout20kgK,requiring40kgofmuriateofpotash(orequivalent)toreplaceit.6

5.4 Soil testing

Soiltestingisessential.Aswellasteststothetraditionaldepthof0–1cm,deepertests

shouldbeconsideredtochecknutrientlevelsatdepth.Manysoilshavereasonablelevelsof

nutrientsinthetopsoilbutnutrientsareverylowdeeperintheprofile.Consider10–20and

20–30 cm tests.

It is recommended that growers obtain a complete nutrient analysis or soil test prior to

plantingpeanuts.Peanutsareregardedasgoodscavengersfornutrients,butifany

nutrients are lacking in the soil, including micronutrients, then yield potential may be limited.

Your soil test should be analysed through an ASPAC-accredited laboratory and properly

interpretedbyaqualifiedagronomist.

Onceyouhaveanalysedsoiltestresultsyoucanplanafertiliserprogrambasedon

availablenutrientsand,mostimportantly,yourbudgetorexpectedyield.Ifthehayistobe

baledafterharvest,youwillneedadifferentfertiliserprogram.

Replacementsrateswillneedtobeadjustedbasedonremovalofbothpeanutsandhay.

5.5 Nutrient availability and soil pH

AllpHlevelspresentedhererefertothesoilaciditytestingmethodusing1partsoil:5parts

water (pHH2O).Soilacidity,orpH,affectstheplant’sabilitytotakeupnutrientsfromthesoil.

IfthepHisnotwithintherangerequiredforoptimalplantgrowth,theplantisnotableto

makethebestuseofthenutrientsinthesoil,evenifthecorrectamountsarepresentinthe

soil. It is important to correct soil pH so that the investment in nutrient applications is not

wasted.

Peanutstolerateawiderangeofsoilaciditylevels.TheidealsoilpHrangeis5.5(slightly

acidic)to7.0(neutral).Ifthesoilismoreacidic(i.e.pH<5.5),nodulationandN2fixationcan

be reduced and trace element imbalances can occur, potentially causing aluminium (Al) and

Mntoxicity.Ifthesoilismorealkaline(i.e.pH>7.0),deficienciesinZn,andpossiblyFe,can

develop.

A soil test will show whether the pH needs adjusting with products such as agricultural lime.

TheamountoflimeneededtocorrectlowpHdependsonthebufferingcapacityofthesoil

andtheextenttowhichitisnecessarytoraisepH.Thebufferingcapacityofasoilisits

ability to ‘absorb’ Ca without causing a change in soil pH.

Clay soils and soils with higher organic matter, such as the red volcanic soils around

Kingaroy,Queensland,generallyhaveahigherbufferingcapacitythansandysoils.Although


i More information

PCA/QDPIF. Crop

nutrition.

i More information

C Guppy et al.

Interpreting soil tests in

thelightofP, K and S

research.

M Bell, C Guppy.

Interpreting soil test

resultsforthenorthern

region.





http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2012/04/Interpreting-soil-tests-in-the-light-of-P-K-and-S-research




http://grdc.com.au/Media-Centre/Ground-Cover-Supplements/GCS108/Interpreting-soil-test-results-for-the-northern-region






December 2014



morelimemaybeneededtocorrectthepHinhighlybufferedsoils,thesesoilsareableto

‘hold’thepHatthenewlevelforlongerthanpoorlybufferedsoils.

Whenyouhaveyoursoilsanalysed,askfora‘limerequirement’figure,whichrepresents

the lime required to reach, say, pH 6.5. This is based on well-researched data that take

intoaccountthebufferingofthesoilandtheamountthepHistoberaised.Thecalculation

usedgivestheamountoflimerequiredtotreata10-cmlayerofsoilonly,soifthelimeis

mixedintothetop20cmofsoil,therecommendedratemustbedoubledtotreattheextra

soil.

ThereisanimportantdistinctionbetweencorrectingpHandcorrectingCadeficiency.Once

thepHiscorrect,Caapplicationsmaystillbeneededtofeedthecrop(Figure2).Calcium

nutritionisparticularlyimportantforgrowersonsandysoils.7

Figure 2: Lime or gypsum banded over the row will provide calcium to the plant.

5.6 Calcium

Becauseoftheirundergroundfruitinghabit,peanutshavearelativelyhighrequirementfor

Ca. Calcium is not very mobile within the plant, and the peanut pod takes up its own Ca

directlyfromthesoil.Consequently,availableCamustbepresentinthepoddingzone(the

top2–10cmofsoil).GrowersshouldcheckthatapplicationsofCapost-plantareavailable

to the crop.


i More information

Incitec Pivot Fertiliser.

Nutrient advantage.



http://www.nutrientadvantage.com.au/

http://www.nutrientadvantage.com.au/



December 2014



AdequateCaisessentialforensuringhigh-qualitykernels.InsufficientCamayleadto

smallerkernelsandkernelswithhollowhearts(notcompletelyfilled).LowCawillalso

reducethegerminationofseedpeanuts.Inlargerseededpeanuts(Virginiatypes),low

Ca can lead to kernel abortion, causing empty pods or ‘pops’ 8 as well as splits and poor

germination. 9

ToprovideanadequatesupplyofCainthepoddingzone,naturalgypsum(calciumsulfate)

isusuallyappliedatearlyfloweringoverthepeanutrow.Gypsumisarelativelysoluble

sourceofCathatiseasilyabsorbedbythepods.Gypsumcontains23%Caandisapplied

atratesof600–1000kg/ha.10

GypsummaybeusedasaCafertiliser,butitmaynotbetheproductofchoice.Lime

should be used on acid soils that are low in Ca. Not only does lime supply Ca, it also

correctsacidity(raisesthesoilpH).However,itisineffectiveinneutralandalkalinesoils.

Typically,gypsumisappliedduringthefallowperiod.Therateatwhichgypsumisapplied

asaCafertiliserwherethepHdoesnotneedamendingis1–2.5t/ha.Thiscanremain

effectiveforseveralyears.11

Dolomite contains Ca and Mg. It can correct soil acidity and supply some Ca. However, you

shouldfindouttheratioofCatoMginthesoilbeforeusingdolomite.TheCalevelshould

beatleastdoublethatofMg.Otherwise,theMgcaninterferewiththepod’suptakeofCa.

Alternatively,finelimecanbeapplied4–6weekspriortoplanting(ifsoilpHis<6.0)and

lightlyincorporated.Limeislesssolublethangypsum.Itisusuallyappliedatratesof2.5–5

t/haandcontains35–40%Ca.12

NotethatpeanutsneedmuchhigherCalevelsinthesurfacesoil(top5–10cm)thanother

crops.Itisamajorfactorinkerneldevelopmentandquality.

DeficiencysymptomsarelikelywheresoilsurfaceCalevelsarelow,largekernelvarieties

arebeinggrown,andthesoilsurfaceisdry.SandysoilsgenerallyhavelowCalevels.

AseverelackofCainthepoddingzonewillcausepops(fullsizepodswithnokernels

inside)orpodswithonlyonekernel(Figure3).Amilddeficiencymaycausetheembryoto

turn dark, reducing germination and vigour.

LowsoilmoisturecanlimittheuptakeofCabecausesoilCacanonlymovethroughthe

soilwhenitisdissolvedinwater;therefore,popsarealwaysworseinadryseason.Itis

commontohavepaddockswherenopopsarerecordedinwetseasonsandquiteafewin

drier seasons.




11 IncitecPivot.Gypsum.Fertfacts.IncitecPivotLtd,http://www.incitecpivotfertilisers.com.au/en/Soil%20,-a-,%20Plant%20Tests/~/media/Gypsum%20Fact%20Sheet.ashx






http://www.incitecpivotfertilisers.com.au/en/Soil ,-a-, Plant Tests/~/media/Gypsum Fact Sheet.ashx





December 2014



FoliarsymptomsofCadeficiencyincludeyellowing,multiplebranching(rosetting),deathof

thegrowingpointandpetiolecollapse.Suchsymptomsarerareinfieldconditions.

Figure 3: Pops (shells without a kernel or a shrivelled kernel) of Virginia or runner types are typical of low soil calcium. A mild deficiency may cause the embryo to turn dark.

Calciumdeficiencyinthepoddingzonecanbeovercomewithapplicationsofgypsumor

lime.LimingwillgenerallycorrectCadeficiencyforseveralyears.However,insomevery

sandysoils,theabilitytoholdalargeamountofCaintheshallowpod-zoneislimited

andsomeCamaybeleachedfromthezonewithinaseason.AnnualapplicationsofaCa

sourcemaythenberequired.ChoosepH-neutralandmoresolublesourcesofCa,suchas

gypsum, rather than lime in this situation.

Where soil pH is acceptable but Ca is low, gypsum applied in bands over the row (i.e. into

thepeggingzone)ismoreeconomicalandmoreeffectiveovertherelativelyshortperiodof

pod-filling.

Arateof400–600kg/haappliedinbands30–40cmwideisusuallyadequate,although

soils with very low Ca or high Mg may need a higher rate.

ChooseSpanishandrunnertypesforsoilswithalowabilitytoholdpositivelycharged

nutrientssuchasCa(i.e.soilswithacationexchangecapacity,orCEC,of<4cmol/kgor

meq/100 g). In these situations (e.g. on sandy soils), the soil cannot hold enough Ca to

adequatelyfillpodsinthelargerVirginiatypes,whicharelessefficientataccumulatingCa.

Inthesesoils,the‘exchangeable’Caneedstobe~70%ofthetotalCEC,i.e.thedesired

cationbalanceisCa70%,Mg15%,K5%,andothers,includingsodium(Na)10%.

InredandbrownforestsoilsoftheinlandBurnett,theCECandCalevelsareusually

adequate, but extra Ca is sometimes applied because the topsoil is dry, reducing the

efficiencyofCauptake.Normallimingpractices(tomaintainpH)usuallymeetthis

requirement.

Only10–14%oftheCatakenupbythecropendsupinthepods;mostisinthefoliage

(66%)androots.TheshellsandkernelsextracttheirCadirectlyfromthesoilinthepodding

zone, whereas Ca absorbed by the roots is carried to the stems and leaves but not down

the peg to the pod.

LargerkernelvarietiesofpeanutsneedhighersoillevelsofCa.Small-seededSpanish




December 2014



types are much less susceptible to low soil Ca than runner types, which in turn are less

susceptible than Virginia types.

Forlarge-seededvarieties,theneedforCaalsodependsonthelevelofsoilK.Popscan

resultfromlowCainthepoddingzoneand/orinhibitedCauptakebecauseofhighlevelsof

other nutrients, particularly K.

ApplyCaifasoiltestshowsanyofthefollowing:

• Ca<70%oftheCECandCEC<6cmol/kg

• Ca>70%oftheCECandCEC6–10cmol/kg,butsoilslikelytobequitedryduring

pod-filling

• CEC<4cmol/kg,regardlessoftheproportionofCECasCa

LowCacanaffectthegerminationofseed,aswellasthepeanut’sabilitytoresist

pathogens such as Aspergillus flavus(thecauseofaflatoxin),Rhizoctoniaandsomefungi

causing pod rots.

AnalysisofpeanutfoliagewillnotshowwhethersufficientCaisavailableforkernel

development. A soil test in the pod-zone will give a better indication.

SeedpeanutsfromcropsgrownundermarginaltolowCahavepoorgermination.Thelevel

ofCainthekernelneedstobe≥420mg/kgforsatisfactorygermination.Asaprecaution,

apply extra Ca to all seed crops.

Gypsumismoresolublethanlimeandispreferableforover-the-rowapplications,

particularlyiftimingisclosetoflowering.GypsumalsocorrectsdeficiencyofSandshould

beusedonalkalinesoils(pH>7)insteadoflime.

Adrawbackoftherelativelyhighsolubilityofgypsumisthatveryheavyrainmayleachit

fromthepeggingzoneinsandysoils.Whenusinggypsumonthesesoils,timeapplication

ascloseaspracticaltoflowering.

Becauselimeislesssoluble,itisbestappliedatleast1monthbeforeplantingtoensure

that the Ca has become available. Calcium is needed in the pod-zone, so do not

incorporate the lime deep into the soil. Lime applied to soils with a pH >6.5 may cause Zn

orMgdeficiency.13

5.7 Nitrogen

HighlevelsofNareneededforhigh-yieldingpeanutcrops.However,likeotherlegumes,

peanutsfixN2fromtheairviasymbioticbacteria(rhizobia)livinginnodulesformedonthe

peanut plant roots (Figure 4).

Nitrogenisrequiredforgrowthandistakenupthroughouttheseason.Itissourcedfrom

thesoilorfromNfixation.Growersmustinoculatepeanutseedwithefficientstrainsof






December 2014



rhizobiapriortoplantingtoensureoptimumNfixation.Whenthesuitablerhizobiabecome

establishedinfields,farmersmaynotneedtoaddNfertiliserstopeanutcrops.14

Figure 4: Many nodules, like those on these roots, are needed to fix sufficient nitrogen. Inoculating the soil with rhizobia at planting is essential.

Poornodulation,waterloggingoralackofothernutrientsessentialforNfixation,such

asPandMo,cancauseNdeficiency.Generally,plantsrecoverquicklyfromtemporary

waterlogging.Ashallowcultivationwillallowthesoiltoaerateandwillhastenrecoveryfrom

waterlogging.

SymptomsofNdeficiencyincludestuntingoftheplantandyellowingoftheleaves,

frequentlywithareddishdiscolorationofstems(Figure5).

RatesofNupto50kg/hamaybeusefulwherewaterlogginghaskilledrhizobiaorwhere

nodulationissloworhasfailed.GreatestbenefitwillcomefromapplyingNwhenthecrop

ispodding;however,20–30kg/haofearly(starter)Nmaybewarrantedinsituationswhere

soilNisverylowpriortonodulesbecomingestablishedandfunctional(afterabout1

month).Thiscanhappenwhenasugarcanetrashblanketisincorporatedbeforeplanting

the peanut crop.

Toavoidtheseproblems,inoculateseedcarefully,donotplantinareasproneto

waterlogging,andprovidethenutrientsessentialforsuccessfulnodulation.

ExcessivesoilN,fromeithernaturalfertilityorfertiliser,candelaynodulation,cancause

excessivevegetativegrowth,andleadtofewerflowersproducingmaturefruit.

Nitrogenfixationcanprovideupto70%ofthetotalNuptakeoftheplant,often≥200kg

N/ha.Theremainderisobtainedfromthesoil.High-yieldingcropswillfixmoreNthanlow-

yielding ones.

Checktheplantrootsforsignsofnodulation.Slicethroughthenoduleandnotethecolour

inside.ReddishcolourindicatesthatNisbeingfixed;green,thenoduleismaturebutnot

fixingN;white,thenoduleisimmature;andbrown,oldnodules.






December 2014



Nitrogenfixationof100kg/haunderdrylandconditionshasbeenrecordedatKingaroy,and

200 kg/ha under irrigation at Bundaberg.

TotalNuptakefromsoilreservesandsymbioticfixationunderhigh-density,irrigated

conditions may reach 300–350 kg/ha (excluding N in the roots) and under dryland

conditions100–200kg/ha.Commonly,anadditional30–40%oftheNisstoredintheroots

and pods (i.e. 100–120 kg N/ha under irrigation and 40–80 kg N/ha in dryland situations).

About25%ofthetotalcropNremainsintherootsafterharvestand30–50%isremovedin

theharvestedpods,withtheremaining25-45%leftasstubbleorremovedashay.

Peanut crops generally do not add N to the total soil N store, although they will contribute

solubleNtothenextcrop.Peanutresiduestypicallycontain2%Nbyweightand,ifleftin

thepaddock,releaseNquitequicklytoafollowingcrop.

Itispossibletogainupto100kgN/hainthesoilstorefromthepeanutcrop,butonlyifa

cropoflarge,healthyplantsdoesnotyieldaswellasexpected.Withthenew,high-yielding

varieties,thenetNbalanceafterthepeanutcropismorelikelytobenegative,becausethe

peanut crop has put more N into the pods than what remains in the plant residues. 15

Figure 5: Pale plants and leaves are typical of low nitrogen levels, often associated with poor nodulation or wet soils.

5.8 Phosphorus

PeanutsalsorequirerelativelylargeamountsofPbutthepresenceofarbuscular

mycorrhizal(AM)fungiontheirrootsmakesthemveryefficientatabsorbinganyreservesin

the soil.

ExperimentsatKingaroybytheDepartmentofAgriculture,FisheriesandForestry,






December 2014



Queensland(DAFF)showedthatveryhighlevelsofPwereneededwhennoAMfungi

werepresent.Soilsthathadbeensterilisedrequired~240kgP/hatoachievefullgrowth

potential,butwhentheAMfungiwerenotdestroyed,theratewasjust30kgP/ha.

PeanutgrowershavetraditionallyusedhighratesofPonalternatecrops(e.g.maize)during

croprotation.Peanutsrespondbettertofertiliserleftoverfromthepreviouscropthanto

fertiliserdirectlyappliedtothelatestcrop.16

PeanutplantsrequiremoderateamountsofP.WhenAMfungiarepresentinthesoil,

peanutplantsbecomeveryefficientatextractingsoilP.Phosphorusisrequiredforgeneral

plant growth and plays an important role in root development and crop maturation.

DeficiencysymptomsshowwhensoilPlevelsare<20mg/kgofsoil(Colwellorbicarbonate

Ptests)orwhereAMfungiarenotpresent.ManyAustraliansoilsarenaturallylowinP,but

manycroppedsoilshaveaconsiderablePbankbecauseofresidualphosphatefertilisers

applied over the years.

ThefirstsignofPdeficiencyisalightflecking,graduallybecomingmoreyellowuntilparts

oftheleafdie(Figure6).SeverelyP-deficientplantsarestunted,withsmallleaflets,often

bluishgreenincolourandlaterdevelopingpalespotsbetweentheveinsbeforeturning

yellowandfallingoff.Thestemsmaybepurplish.Severedeficiencysymptomsmayonly

appearwhengrowthhasalreadybeendepressedby70–80%.

Figure 6: Top: light flecking gradually becoming more yellow until parts of the leaf die indicates phosphorus deficiency. Bottom: leaves folded together can also indicate a lack of phosphorus.






December 2014



PeanutgrowerstraditionallyappliedhighratesofPonothercropsintherotation,rather

than directly applying P to the peanut crops.

DirectapplicationsofParenecessarywhensoillevelsare<20mg/kgofsoil(bicarbonate

P).ForirrigatedcropsandcropsontheredsoilsoftheAthertonTableland,Pratesof30

kg/ha,andoccasionallyhigher,maybeneeded.Thiscontrastswithratesof~10kgP/ha

fordrylandcropsonmanyredsoilsinsouthernQueensland.IntheSouthBurnett,where

soiltestlevelsare<10mg/kg,apply10kgP/habroadcastbeforeplantingandafurther10

kg P/ha at planting.

ThetotalPtakenupbyapeanutcropmayrangefrom5kg/hato>30kg/ha.AMfungihelp

peanutplantstoexploitresidualPfromearlierfertiliserapplicationsandsoilPreservesthat

areunavailabletomanyothercrops.PeanutsextractsomePfromrelativelydeepinthesoil,

butmostisextractedfromthetop40cm.

ActivityofAMfungalisreducedathighsoilPconcentrations;therefore,banded

applicationsoffertiliserdonotachievethebestuptakeofP(unlikeformostothercrops).

ThemaximumrateofuptakeofPstartsatflowering.About65%ofthePtakenupbythe

plantistranslocatedtothepodsandremovedfromthepeanutfieldatharvest.17

5.9 Sulfur

PeanutsrequireS,alongwithN,toformproteins.SoilreservesofSdeclinewheresoilsare

croppedformanyyearswithoutapplicationsofS-containingfertilisers.

Sulfurdeficiencyinpeanutsisdifficulttodiagnosefromfoliarsymptoms.Thesymptoms

canincludepaleyellowingofyoungleaves,whileolderleavesremaindarkergreen(Figure

7).Thisissimilartotheappearanceofothernutrientdisorders,suchastheearlystagesof

NandFedeficiency,andtosomenon-nutrientdisorders.

Figure 7: Pale yellow leaves on the top of the plant are typical of sulfur deficiency. Sulfur deficiency is unlikely where gypsum is used to supply calcium.






December 2014



Applicationsof10–20kgS/haaregenerallyadequateunlessaveryhighyieldpotential

exists. Total S taken up by peanut crops can be up to 60 kg/ha, with very high-yielding

crops expected to require more.

SourcesofSincludesomeN(sulfateofammonia)andK(sulfateofpotash)fertilisers,as

well as superphosphates.

High-analysisPfertiliserssuchastriplesuperphosphate(20%P)containlessSthansingle

superphosphate(1%Sv.11%S),whichmeansthatSinputsmaybecomenecessaryas

theuseofsinglesuperphosphatedeclines.Ifgypsumisused(seeCalcium above) no other

sourceofSshouldbeneeded.

Useofsuperphosphate(with~11%Scontent)onlight-texturedsoilshasoftenmaskedS

deficiency.TheformofsoilStakenupbyplants(sulfate-S)issolubleandcanbeleached

downthesoilprofile.Therefore,soilteststhattakeaccountoftheSindeepersoillayerswill

betterguidefertiliserrequirements.18

5.10 Potassium

PeanutsrequirelargeamountsofKtogrowthecropcanopy,althoughonly20–30%ofthe

total crop K is removed in the harvested product.

Deficienciesaremostlikelyinsandysoilsandarealsocommoninlong-termcroppingareas

ontheredandbrownforestsoilsintheSouthBurnett.Deficienciesaremorelikelyonsoils

withahistoryofhay-making.

SoilKcontentisoftenhighestinthetopsoillayers,becausemostoftheplant’sKisstored

inthecropresiduesandKdoesnotleacheasilythroughtheprofile(exceptinlightsands).

Underdirectdrill,theKaccumulatesinjustthetop5–10cm.Thislayerisoftendrywhen

thepeanutcropneedstotakeupKforlatergrowth,anddespiteahighsoil-testvalue,the

cropcanstillbecomeK-deficient.

Potassiumdeficiencyinpeanutscausestipandmargin(andsometimesinterveinal)

yellowing,followedbyearlyleafdropanddeathoftissue(Figure8).Symptomsfirstappear

on older leaves. Stems may also show some dead spotting and are shorter and thinner

than in adequately supplied plants.






December 2014



Figure 8: Potassium deficiency typically showing yellowing then browning of the tips and leaf edges.

Indeficientsituations,anapplicationof50–100kgK/hamaybeneededandshouldbe

placed below the pod-zone.

Wheresoillevelsare<0.15cmol/kg,apply50–100kgK/haforafewcropsuntilsoillevels

increase.Annualapplicationsof~15kg/hawillmaintainsatisfactorysoilKlevels.Peanuts

remove~10kgKforeachtonneofpodsharvested.

Occasionalsamplingofthesubsoil(30–40cmdeep)willhelpyoutodevelopthebest

strategyforKfertiliserapplication.

PeanutscanextractKfromthesoilfasterthantheyneedit,especiallyintheseedlingstage.

As a result, the K concentration in the plant can be high in the early growth stages until

flowering,whenitstartstoberedistributedfromleavestopods.

HighlevelsofKinthepod-zonewillinhibittheCauptakeofdevelopingpodsifthesupply

ofCaislimited.Althoughtheshellwilldevelop,onlyonekernelorevennokernelswillform.

HighlevelsofKinthepod-zonecanalsoleadtoreducedshelflifeofpeanutkernelsby

causinganincreasedincidenceofbreakdown.TrytoavoidlargeapplicationsofKtothe

soilsurfacejustbeforeplanting.Ifpossible,applyKdeeperthan5cm.




December 2014



Removing peanut hay will rapidly deplete soil K levels, because there is ~20 kg K in each

tonneofpeanuthay. 19

5.11 Boron

Borondeficiencycanhavesevereeffectsonpeanutyieldsandquality.Boron,likeCa,must

betakenupdirectlyfromthesoilbythedevelopingpod.Eventhoughnofoliarsymptomsof

deficiencyoccur,thedevelopingpodsmaybedeficient.

Boronishighlysolubleandreadilyleachedfromsandyandsandy-loamsoils.Theselight-

texturedsoilsandcalcareoussoilsofhighpHaremostlikelytobedeficientinB.Somered

soilsoftheAthertonTablelandarealsodeficient.

Thekerneldevelopsa‘hollowheart’andtheembryoofthekernelmaygodark(Figure9).

Theseeffectsreducekernelweightandlowerthelikelihoodofgermination.Hollowheartis

theclassicsymptomofBdeficiencyanditwillshowuplongbeforeleafsymptoms.

PeanutplantsseemtotoleratelowlevelsofBbetterthanmanyotherplants.Foliar

symptomsofBdeficiencyincludestubby,rosettedbranches(similartothesymptoms

ofCadeficiency),crackingofbranches,discolorationofnodalareas,andleaveswitha

yellow–greenmosaicappearance.Deficienciesalsocauseshelldeformityandrandomshell

cracking (other conditions also cause cracking).

Figure 9: Kernels with ‘hollow heart’ are classic symptoms of low soil boron. Hollow hearts will form well before deficiency symptoms on the foliage.

BorondeficiencycanbecorrectedwithsoilapplicationsofBfertilisers,suchaboraxor

regular liquid applications to the soil under a growing crop. Boron applied to the leaves can

be taken into the plant but cannot be moved to the pod to supply the developing kernels.

Limitapplicationsto0.5kgB/ha,whichis~5kg/haofboraxappliedtothesoilorSolubor®

sprayed at 2.5 kg/ha. Do not apply more B unless there has been leaching rain.






December 2014



Soiltestsusinghot-water-extractableBcanhelpdeterminetheneedforB,butarenotvery

reliable.

ExercisecautionwhenapplyingBbecauseitiseasytochangedeficiencyintotoxicity,even

usinglowratesofBfertiliser.Ratesofonly4kgB/hahaveproducedsymptomsofboron

toxicityinpeanuts.BorontoxicitylookslikeKdeficiency,withyellowingatthemarginsand

betweentheveinsand,eventually,browningofthemargins.20

5.12 Copper

LowsoilCuisnotcommon;itwouldmainlybeexpectedonlightsandysoils.

CopperdeficiencyhasbeenseenonsomeofthecoarsesandysoilsoftheMareeba–

DimbulahIrrigationArea,andinsomeofthecoastalsandsnearBundaberg.

Plantsareseverelystuntedandtheycandieifthedeficiencyisnotcorrected.Leavesshow

aninterveinalchlorosis,withthetipsandleafmarginsdying.Theleaveseventuallywither

anddropoff.Thepinchedand‘burnt’leaftipscanbeverydistinctive(Figure10).

Threeorfourapplicationsofcoppersulfateorcopperoxychloridewillusuallycorrectthe

deficiency.Besurethatthereissufficientleafareaforfoliarapplicationstobeeffective.

Coppersulfatecanbecorrosivetobrassboom-sprayfittings.

Figure 10: Top: leaf symptoms of low copper levels—distorted leaf tips. Bottom: copper deficiency in the field showing yellowing and browning leaf tips.

Withmicronutrientapplications,somephytotoxicitycanoccur;however,thisdamagedoes






December 2014



notaffectthecrop.21Duringfloweringinweeks4and5,applyfoliarfertilisers(1%solution),

especially Cu (on very sandy soils) and Zn. 22

5.13 Iron

LackofFeisanimportantfactortoconsiderwhengrowingpeanutsonalkalinesoils.

PeanutplantsrequireFeearlyinthecropgrowthtohelpestablishfunctioningnodulesto

startNfixation.

IrondeficiencyismostlikelyoncalcareoussoilsorothersoilsofpH≥8.0.Waterloggingor

toomuchlimeinsomesoilscaninduceFedeficiency.Eventemporarywaterloggingfrom

floodirrigationcanbeenoughtoinducedeficiencyifsuppliesofplant-availableFeare

already marginal.

IrondeficiencyhasbeenseenonsomeoftheheavysoilsoftheBurdekinandMareeba

irrigationareas,andonpartsoftheDarlingDowns.Ithasalsobeenconfirmedonsome

heavysoilsaroundBiloela,wheretheupperleavesturnaverylightyellowafterrainor

irrigation.IrondeficiencyiscommononthealkalinesoilsintheNorthernTerritory.

Plants are usually stunted and pale, with leaves showing interveinal chlorosis (yellowing),

eventually becoming very pale yellow and almost white (Figure 11).

Figure 11: Top: iron deficiency, showing the pale leaves with the veins staying green and eventually losing most of their colour. Bottom: iron deficiency at Jandowae on a high pH soil.


22 PCA.Peanutproductionseasonplan.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/checklist.pdf







December 2014



ThereissomedebateoverthebestwaytotreatFedeficiency.Foliarsprayswith3%Fe

solutionasferrousammoniumsulfateareusedintheUSA.Thisgenerallycorrectsthe

deficiencyforafewweeks;threespraysmaybeneeded.UreahelpstheuptakeofFe.

ChelatedFe(Fe-EDDHA)canbeusedinbothsoilandfoliarapplications,butferrous(Fe2+)

sourcesarenotusefulassoilapplications.InIsrael,Feisplacedinabandatplantingto

supply both the plant and rhizobia.

Irondeficiencycanpreventtheformationofhealthyrhizobialnodules.Asaresult,lowFe

levelscancauseNdeficiencybecausetherhizobiaareunabletosupplyNtotheplant.

SomevarietiesaremoretoleranttolowlevelsofFe. 23

5.14 Magnesium

PeanutsarelesssusceptibletoMgdeficiencythanothercrops.AtlevelsofsoilMgwhere

aresponsewouldbeseeninmaizeandsoybeans,peanutsdonotshowsymptomsof

deficiencyorrespondtoMgfertiliser.Itappearsthatpeanutsaremoreefficientatextracting

Mgfromsoil,justastheyhaveagreaterabilitytoextractP,althoughthemechanismsare

probablydifferent.

SandysoilsareoftenMg-deficient,forexample,InnotHotSpringsinNorthQueensland,

thetobaccosoilsoftheMareeba–DimbulahIrrigationAreaandsomeofthesoilsaround

Bundaberg.HighlevelsofKcaninduceMgdeficiency.

Magnesiumdeficiencyshowsasyellowing(beginningatthemarginsandmovingtowards

themidrib)followedbyorangediscolorationandfinallynecrosis(death)ofolderleaves.

Veinsoftenshowabrowndiscolorationontheundersideoftheleaf(Figure12).Younger

leavesremainrelativelynormalinappearance.Magnesiumdeficiencysymptomsare

generallyseenonleavesinthemiddleoftheplant;boththeoldestandyoungestleavescan

look normal.

Dolomite will supply both Mg and Ca but can raise the pH, so should be used with care on

high-pHsoils.FoliarfertilisersareavailabletotreatMgdeficiency.






December 2014



Figure 12: Top: typical symptoms of magnesium deficiency with browning patches on the leaf. Bottom: in the early stages, the veins on the top of the leaf are slightly lighter yellow than the rest of the leaf and the veins underneath the leaf are a darker colour.

UptakeofMgiscloselyrelatedtodrymatteraccumulation.Thus,theconcentrationofMg

intheplanttissueremainsrelativelyconstantthroughoutthelifeofthecrop.

HighlevelsofsoilMgcanreducekernelquality.Magnesiumcanmovefromthefoliageto

thepodandcanpartiallyreplaceCaunderCa-deficientconditions,reducingkernelquality.

AddingMgtothepod-zonecanalsoreducetheuptakeofCaandthereforeincreasethe

incidenceofpopsandpodrots.

ThesoiltestlevelforMgisnotwelldefinedforpeanuts.Cropresponseshavebeen

obtainedinothercropsifexchangeableMgis<0.2cmol/kg.Ifasoiltestisatorbelowthis

value, apply a test strip to determine whether there is a crop response to Mg. 24

5.15 Manganese

Manganesedeficiencyortoxicityisunlikely,exceptinveryhighorverylowpHsoils,

respectively.However,shortperiodsofMntoxicitycanoccurduringperiodsoflowoxygen

availability(waterlogging,orwetsoilwithalotofincorporatedorganicmatter)insoils

otherwiseadequateforpeanutproduction.

Deficienciesaremostlikelyonalkalinesoils,duetotheinsolubilityofMnathighpH,andon

some very sandy soils.

Manganesetoxicitymayoccurunderwetconditionsonveryacidsoils;however,inthese






December 2014



soils,otherlimitingfactorssuchasCadeficiencyorAltoxicityarealsolikely.Rhizobiaare

oftenmoresensitivethantheplantitselftoMntoxicity.Asaresult,short-termwaterlogging

orwetperiods,combinedwithburied‘lumps’oforganicmattersuchascanetrash,can

resultindeathofrhizobiaandshort-termNdeficiency.Ifthishappensearlyintheseason,

theplantsmayre-nodulate,butifitoccursduringpodfill,re-nodulationmaynotoccurand

fertiliserNtopdressingsmaybeneededforthecroptomature.

WithMndeficiency,theolderleavesturnyellowandtheveinsstaygreen(Figure13).

Younger leaves are green and distorted.

Figure 13: Laboratory symptoms of manganese deficiency (field symptoms may be slightly different). Older leaves turn yellow with green veins, and young leaves are green and distorted.

Lime will correct Mn toxicity by raising soil pH. Inter-row cultivation may help to restore soil

oxygenlevelsquicklyandreducetoxiclevelsofMnafteraverywetperiod.25

5.16 Molybdenum

MolybdenumisessentialforproteinsynthesisandNfixation.Molybdenumdeficiencyis

most likely where peanuts are grown on acidic soils (pH <5.5). Soil tests over time will show

whether the soil is becoming more acidic and is more likely to respond to Mo.

IfthelevelofMoistoolowforNfixation,symptomsofNdeficiencywillappear.The

samesymptomswillshowifnodulationhasfailedortherhizobiahavediedfollowing

waterlogging.

Molybdenumcanbesuppliedbymixingwithotherfertiliserorasafoliarspray.Mo-

superphosphatewith0.04%Moorafoliarsprayofsodiummolybdateat300g/hawill

supply100g/haofMo.

In most situations where Mo is low, it will need to be applied to each crop. In some cases,

ModeficiencycanbecorrectedindirectlywithlimeordolomiteraisingsoilpHto~6.Often

theproblemisoneofunavailabilityatlowpH,ratherthanactuallowMo. 26








December 2014



5.17 Zinc

PeanutsappeartotoleratelowerlevelsofZnthanmanyotherlegumesbecauseAMfungi

help to extract this nutrient. However, growers in Israel suggest that peanuts can be more

sensitivethanmaizeorcottontolowlevelsofZn.

ZincdeficiencycanoccurinsoilswithapH>7butisunlikelyinacidsoils,exceptforthe

very light sands and wallum areas in the coastal Burnett.

Zincdeficiencyappearsasinterveinalyellowingwithabrowningaroundthemidribofthe

leaf(Figure14).

Figure 14: Top: leaf symptoms of zinc deficiency in the laboratory (note the browning around the midrib of the leaf). Bottom: field symptoms may be slightly different.

ZincdeficiencycanbecorrectedwithfoliarorsoilZnfertiliserapplications.

PeanutsareverysensitivetoZntoxicity,whichmaybuildupaftercontinualapplications

onothercrops,suchasirrigatedmaize.SymptomsofZntoxicityincludestunting4weeks

aftergermination,leafchlorosis,andflattenedstemsthatdevelopacharacteristicvertical

split at soil level. See Cadmium managementbelowformoreinformationonZntoxicity. 27






December 2014



5.18 Cadmium management

Soilswithalonghistoryofsuperphosphateapplicationscanhaveproblemswithcadmium

(Cd) accumulation in the peanut kernel.

Cadmium is a heavy metal that accumulates in the human body and can cause health

problems.ItisthereforeimperativethatCdinpeanutkernelsisminimised.

CadmiuminAustraliansoilshasprimarilybeenintroducedasacontaminantofphosphatic

fertilisersfrommarinedepositsofphosphaterockfromnearbysources(e.g.Nauruand

ChristmasIslands).Thehighuseofphosphate(andother)fertilisershasaddedCdtosoils

that now grow peanuts.

NotallCdinasoilisavailableforuptakebyplants.Cadmiumuptakeisgreatestwhenthe

soil has low pH (i.e. acidic soils), low clay content (i.e. sands) and low organic matter levels.

MarketingcompaniessuchasthePeanutCompanyofAustralia(PCA)requiresoiltests

beforeplantingifCdcontaminationislikelyinasoil.

GrowerscanmanageCduptakebythepeanutplant,andsubsequentmovementoftheCd

into the developing kernel.

LimeapplicationstokeepsoilpH≥6willreducetheamountofplant-availableCd,as

willincorporationoforganicmatter(e.g.acanetrashblanket).However,bothofthese

strategiesrequireafewmonthsoftimeandsoilmoisturetohaveasignificantimpact.

PlacementmustoccurwhereverthereisCdinthesoilprofile(mostlythetop40cm,orto

thedepthofpreviouscultivationorploughings)tobeeffective.Rememberthattolimethe

top30cmofthesoilprofiletoatargetpH(e.g.6.5),limemustbeappliedattherequired

rate to treat each 10 cm layer.

PeanutvarietiesdiffersubstantiallyintheirabilitytomoveCdfromtheleavesdownintothe

developing kernel. Low Cd-accumulating varieties should be grown on high-risk soils. Seek

advice on the varieties best suited to your situation as new varieties become available.

ThepeanutplantalsoseemstomoveZnpreferentially,insteadofCd,tothekernel,so

strategicapplicationsoffoliarZnwillhelptoreduceCdinthekernelstoacceptablelevels.

Todothis,regularapplicationsofupto1kg/haofelementalZn(4kg/hazinchepta-

hydrate)arerequiredthroughoutthepod-fillingphase.Becarefulnottoover-fertilisewith

Zn—toxicity can occur. Conduct soil tests and consult your local agronomist.

Zinc applications to the soil can reduce kernel Cd, but increased Cd uptake by the plant

andZntoxicitycanoccur;therefore,soilapplicationsinvolvemorerisksthandofoliar

applications. The best solution is to build soil Zn levels slowly over time and conduct regular

soil tests to avoid over-application. 28


i More information

QDPI/CSIRO. Managing

cadmium in summer

grainlegumesfor

premium quality produce.

Cadmium. Nuts2u.

Incitec Pivot Fertilisers.

Gypsum.







http://www.pca.com.au/bmp/pdfs/Nuts2U_02.pdf



Section 6 PEANUTS - Weed control


December 2014



SECTION 6

Weed control

Weedscompetewiththepeanutcropformoisture,nutrientsandlight.Theycausemajor

problemsatharvesttime,andreducethequalityofthecrop.

Peanuts do not grow very tall and consequently do not compete very well with weeds. Early

controlofweedsduringthecrop’sfirst6weeksiscritical.Yieldswillbeslashedifweedsare

allowed to compete unchecked at this stage.

Thepresenceofweedsalsocauseslossesduringdigging,threshinganddrying—

entanglingmachinery,knockingpeanutsoffthebush,andleadingtomoulddamageby

causing uneven drying in the windrow.

Weedscanalsorestrictairflowduringthedryingprocess,creatingpocketsofmoisture,

whichhavethepotentialtocauseaflatoxin.

Acombinationofcultivation,herbicidesandhand-chippingisusuallyrequiredtocontrol

weeds. 1

Manyherbicidesareregisteredforuseinpeanuts.Correctuseofherbicideshasproved

relativelysafeandveryeffectiveagainstadiversityofbothgrassandbroadleafweeds.

However,growersshouldavoidsprayingbroadleafherbicidesduringthemainflowering

periodifpossible.


i More information



Authority.










December 2014



Mechanicalcultivationisstillusedinmanyareas;however,growersneedtobecarefulof

rootpruningandespeciallyofthrowingdirtupagainsttheplantstemduringcultivation.

These activities have been shown to exacerbate several soil-borne diseases, such as white

mould. 2

Controlofweedsisoneofthemajorfactorsinvolvedinsuccessfullygrowingpeanuts.

Because the peanut crop grows underground, weeds make digging and threshing

operationsverydifficult,resultinginhighlosses.Peanutplantsthemselvescanalsobea

problemweedwhengrowinginfallowsandothercrops.

Aweedmanagementprograminpeanutsrequiresthetimelyuseofcultural,mechanical

and chemical practices (Figure 1).

Weedmanagementisawhole-of-farm,whole-of-yearconcern.Weedsshouldneverbe

allowedtoseedinfallows,peanutcropsorrotationcrops.Preventingweedsfromseeding

willreduceweedpopulationsinthelong-termandreducetheriskofweedsdeveloping

resistance to herbicides.

Weedsreducetheeffectivenessoffungicideapplicationsbecausesomeofthefungicide

fallsontheweedinsteadofonthepeanutfoliage.

Figure 1: The weed on the left is at the 2-leaf stage and requires less herbicide to control than the more mature weed on the right.

Weed control in the crop starts with the seedbed preparation. Do not plant peanuts unless

weedsareundercontrolatthetimeofplanting.

Studiesofweedsinmanycropsshowthatweedsstarttocompetewiththecropassoon

as they have germinated. For peanut crops, it is especially important to have weeds under

control early, because the peanut plants do not compete well with weeds, particularly in the

first6weeksofthecropcycle.

Peanutsusuallymaintainyieldpotentialifthegrowereradicatesweedswithinthefirst3–4

weeksafterplantingandthepeanutcropremainsweed-freefortherestoftheseason.

Yieldswillgenerallysufferifweedsremaininthecropduringthe4–8weeksafterplanting.

Someweedscanonlybecontrolledwithherbicidesthatalsohaveanadverseeffecton

peanuts.Theseweedsmustbecontrolledbeforeplantingpeanuts.

Weeds in peanuts are a major problem at harvest time. Losses occur during digging,






December 2014



threshinganddrying.Somepeanutfarmershavelostfingerstryingtofreeapeanutpuller

choked with weeds. 3

6.1 Digging

Duringdigging,thepeanutplantisremovedfromthegroundwithmachinessuchasa

digger-inverter,toplacethepeanutsupside-downfordrying.

Weedsbecomeentangledwiththepeanutcrop,causingpeanutstobelostfromthebush

andmakinginversiondifficult.Theyalsocauseunevendryingandmoredirttoberetained

in the windrow. Grasses with extensive root systems or creeping growth habits, such as

couchgrassandcrowsfootgrass,cancausemajorproblems.

Diggingisaffectedbythedragorbaulking,whichoccursoverthebladeswhentryingtocut

through these grasses.

Diggers require coulter blades to break up bellvine and convolvulus vine, allowing them

toflowthroughthebladesection.Despitethecoulters,thevinewilldragoverthecutter

sectionandcausepoorinversion.Thewindrowwillalsobefarlessopenandconsiderable

moulddamagecanoccurtopeanutsinapoorlyinverted,tightwindrowifitrains.

Otherweedswithstrongtaproots,suchasSida,dragandcausethebunchingofpeanuts

andsoilintheinvertersectionofthedigger.

Largebroadleafweedswiththickstems,suchasthornapple,causepoorinversionand

result in dragging and choking in the cutter section.

Growersoftenusearotaryhoeordiscstoloosenthesoilontheheadlands,toallowthe

cutterbladestopenetratebeforereachingthepeanutplants.Thispracticealsohelpsto

control weeds that may otherwise invade the crop area. 4

6.2 Threshing

Weedsalsoaffectthethreshingoperation.Bindingweedssuchasconvolvulusandbellvine

producelargevolumesofleafmatter,whichtheharvestermustseparatefromthepodsin

the sieving process.

Taprootedandthick-stemmedweedsbecomecaughtinsieves,furtherreducingthe

capacityandefficiencyoftheharvester.

Soilleftonweedrootsreducestheseparationefficiency,resultinginhigherlevelsofleafand

trash remaining in the harvested product. This contamination reduces the crop value. 5

3 PCA/DPIF(2007)Managingweeds.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/4c_weed.pdf









December 2014



6.3 Drying

Efficientcuringreliesonacleanpeanutsample.Weedsmaycausehighlevelsof

extraneousmatter(leafmaterial,sticksanddirt),whichreducesair-flowthroughthe

peanuts.Thiscausespocketsofmoisturetoremainandcanresultinmouldandaflatoxin

development.

Thefruitofwildgooseberries,wildcucumberandwildgherkinscanalsocausecuring

problems.Thepodorfruitisastorehouseofmoistureanditwillnotdryasquicklyasthe

peanuts.Thiscanleadtothedevelopmentofmouldand,potentially,aflatoxin,despite

correctcuringpractices.Pre-cleaningbeforecuringwillhelp,butitisnotalwayspossibleto

removethefruitcompletely.6

6.4 Management options

Acombinationofcultivationandherbicidesisusuallyneededtocontrolweedsinpeanuts,

although in irrigated crops, weeds are usually controlled using only herbicides.

6.4.1 CultivationIn dryland crops, growers may use two inter-row cultivations to control weeds, to loosen

thesoilforthepegstopenetrate,andtomakecuttingeasier.Inveryloose,friablesoils,

inter-rowcultivationmaynotbenecessary.Afterheavyrainorprolongedwetperiodsoron

soilsthatcrust,aninter-rowcultivationtoaeratethesoilmaybenefitthecropevenifvery

fewweedsarepresent.

Cultivatorsshouldbesetsotoavoidthrowingsoilontothepeanutplant;thiscancause

damageanddisease.Movesoilupto,butnotontotheplant.Ifalatecultivationis

unavoidable, do not disturb pegs that have entered the soil. Avoid late inter-row cultivations

in situations where Sclerotinia blight is a known problem.

Hand-chippingcanstillbeverycost-effectivetocontrol‘escaped’weedsbeforeharvesting

the crop.

6.4.2 HerbicidesThefollowinginformationregardingherbicidesandtheiruserelatestoQueensland

registrations.Checkthelabelforuseinotherstates.

Grass weeds

Grassesareusuallycontrolledbeforeplantingbyusinganincorporatedherbicidesuchas

trifluralinorpendimethalin.Imazethapyr(e.g.Spinnaker®) or imazapic (e.g. Flame®) applied

post-emergencecangivegoodsuppressionofnutgrass.

S-Metolachlor (Dual®) applied post-plant pre-emergence controls some grasses.

Fluazifop-p(e.g.Fusilade®), sethoxydim (Sertin®),quizalofop-p-ethyl(e.g.Targa®) and






December 2014



haloxyfop(e.g.Verdict™)willcontrolgrass‘escapes’aftercropemergenceandarealso

effectiveonJohnsongrass(Sorghum halepense) and volunteer sugarcane.

Paraquat will control only very small grasses.

Glyphosateprovidesusefulfallowweedcontrol.

Broadleaf weeds

Bentazon (Basagran®),acifluorfen(Blazer®), 2,4-DB (Buttress®), paraquat, imazapic (e.g.

Flame®) and imazethapyr (e.g. Spinnaker®)arethemaincontrolsavailableforbroadleaf

weeds.

Basagran®willcontrolmanybroadleafweeds;however,itwillnotcontrolwildgooseberry

or Sesbania. Use Blazer®iftheseweedsarepresent.UsingBasagran® or Blazer® under

conditionsofhightemperatureandlowhumiditymayresultinpoorweedcontrol.Spraying

may need to cease by 9am to 10am. Even irrigated crops can have stressed weeds in the

middleofthedaydependingontheevaporativedemandonthatday.

Paraquatgivescheap,effectivecontrolofseveralcommonweeds.Itcanscorchpeanut

leaves;however,theydorecoverrapidly.Thepeanutcropshouldbesprayedbeforethe

7–8-leafstage.Goodcoverageisessential.UnlikeBasagran® and Blazer®, paraquat will

controlstressedweeds,butusually,theymustbeyoungerthanthe4-leafstage.Many

growers mix Basagran® with paraquat to reduce the burn on the peanuts that can result

fromusingparaquatonitsown.Thismixwillalsoreducecontroloflegumeweeds.

Dual® is sometimes banded over the row at planting to control Commelina benghalensis.

Unliketrifluralin,Dual® does not require mechanical incorporation, but it does need rain or

irrigationwithin10daysofapplication.

Prometrynprovidesgoodcontrolofmanyweedsinirrigatedpeanuts.Itscostandtheneed

formoisturemakeitunsuitablefordrylandpeanuts,exceptinhigh-rainfallareas.Some

damagetopeanutshasoccurredwhereatankmixofDual® and prometryn was used on

heavysoils.Growersshouldconsulttheirpeanutagronomistbeforeapplyingprometryn.

Ropewickweederswithglyphosateareusedtocontrollargebroadleafweeds,Johnson

grass and volunteer maize and sorghum.

Weed peanuts

Volunteerpeanutplantsgrowinginothercropsandinthefallowbetweencropsarevery

difficulttocontrol.

Manyherbicidesandcombinationsofherbicideswillseverelydistortpeanuts,butmay

notreliablykillthem.ResearchatKingaroyhasidentifiedseveralproductsthatwillcontrol

volunteer peanuts, but they are not yet registered.

Fallowspraysofglyphosateatupto2L/haandSpray.Seed® (paraquat + diquat) have not

killed all volunteer peanuts even when used in combination with other herbicides such as

2,4-D amine, dicamba and atrazine.




December 2014



Herbicidesusedinrotationcropsofsorghumandmaizedonotalwaysgivereliablecontrol

ofvolunteerpeanuts.CombinationsofatrazineandStarane™(fluroxypyr)haveproventhe

mosteffective.Contactyourlocalagronomisttofindoutthelatestinformationoncontrolling

volunteer peanuts.

Forconservationcroppingfallowmanagement,infallowpaddocksuseglyphosate,2,4-D

amine,dicamba,atrazineandStarane™tocontrolgrasses,broadleafandwoodyweeds.


Section 7 PEANUTS - Insect control


December 2014



SECTION 7

Insect control

Variousinsectpestsattackpeanuts;however,comparedwithhorticulturalcropsand

cotton,insectsarenotconsideredamajorproblemforpeanuts.Regularscoutingforinsect

pestsisstillwarranted.GrowersshouldbudgetonatleastonesprayforHelicoverpa.

Peanut crops in cotton- and lucerne-growing areas may have more aboveground pests

thancropsthataremoreisolated.Soilpestssuchaswhitegrubsandwhitefringedweevil

(Graphognathus leucoloma)aresignificantpestsinestablishedpeanut-growingareas.

Intraditionalpeanut-growingareas,foliarinsectpestshavenotbeenamajorproblem.

However, this has changed recently as peanuts have moved into new production areas,

especially areas that have predominantly grown cotton or horticultural. 1

7.1 Types of insect pests

Foliage feeders

ThemainfoliagefeederstendtobeHelicoverpa sp. and cluster caterpillar (Spodoptera sp.).

Largenumbersoftheselarvae(>6larvae/m)canbedamagingwhentheplantsarevery

small;controlmeasuresmaybewarranted.

Growersalsoneedtocheckcropscarefullyduringthemainfloweringandpeggingperiod.

Theseinsectswillattackbothflowersandpegsandcanreduceyieldpotential.Controlmay

bewarrantedwherethereare>2larvae/mofrow.

1 PCA/DPIF(2007)Managingpests.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheriesQueensland, http://www.pca.com.au/bmp/pdfs/4b_insect.pdf



http://www.pca.com.au/bmp/pdfs/4b_insect.pdf




December 2014



InNorthQueensland,redshoulderedleafbeetle(Monolepta australis) can be a regional pest

ofsignificance.Theyhaveashortlifecycle,andtwopopulationsgenerallyoccurthroughout

the season. Expect heaviest pressure in paddocks adjacent to avocadoes and other tree

crops.Apreventativeapproachtomanagementisrecommended;managethepestin

thetreecrop(wheremanyregisteredcontroloptionsexist).Effectiveinsecticideoptionsin

peanutsarefew;however,forlatestinformationpleaseconsultyouragronomist.

Sucking insects

Severalsuckinginsectswillattackpeanutsandareoftenresponsibleforthespreadof

viruses.Themostcommonlyobservedarethevegetablejassidandthelucerneleafhopper.

Thesecanattackthecropatanystageandoftenbuilduptohugenumbers.Growers

oftenoverlookthesepestsbecausetheyarenoteasilyseen,butinlargenumbers,they

cancausesignificantcropdamage.If≥25%ofthecrop’sleaveshavesmallyellowspotsor

stippling, and or the leaves are turning yellow at the tips and margins, then chemical control

measures may be warranted.

Thrips,miridsandmitescanalsobeaprobleminsomeareas.Regularscoutingofthecrop

is essential to determine whether control measures are warranted. 2

7.2 Growth stages

7.2.1 Pre-emergencePest damage to peanuts can start as soon as the seed is planted, but this is not common.

Wherepre-emergencedamageoccurs,itisusuallyfromlarvaeofthewhitefringedweevil.

Falsewirewormlarvae,whitefringedweevil,largewhitegrubs(‘canegrubs’)andmole

crickets all can occasionally damage germinating seeds.

7.2.2 Emergence to first flowering Duringvegetativegrowth,damageismainlytofoliagebyeitherleaf-chewingorsap-feeding

pests.Sap-feedingpestsincludelucerneandvegetableleafhoppers(jassids),peanutmites

andcowpeaaphids,andmayoccuranytimeaftercropemergence.

Peanut mites can damage peanuts during prolonged dry periods (Figure 1). The mite

disappears with rain and the plant outgrows the damage.

Thetwo-spottedmiteisnotusuallyapestofpeanuts.However,ifpeanutsaresprayed

heavily with non-selective (hard) pesticides, or are grown in areas where adjacent crops

areheavilysprayed,thentwo-spottedmiteinfestationsmayoccur.Inthevegetativestage,

controlmayberequiredifthemiteisstillpresentand>10plantsoutof30have>30%

reductioninleafarea.

Leaf-chewingpeststhataffectpeanutsincludeHelicoverpa and the cluster caterpillar.

Redshoulderedleafbeetleoccasionallydamageisolatedpatchesofacrop.

Almost every peanut crop will contain some Helicoverpa larvae. Control is rarely needed,






December 2014



aspeanutsareverytolerantofdefoliation.Naturallyoccurringoutbreaksofnuclear

polyhedrosisvirus(NPV)willoftenkilllarvaebeforetheydamagethecrop.

Cluster caterpillars are less common than Helicoverpa and rarely need control.

InNorthQueensland,whitefringedweevilscancauseseveredamage.Larvaechewthe

taproots,whichcancauseplantstodie,andadultscandefoliateyoungplantswhen

present in large numbers.

Thelarvaeofthepeanutwhitegrub,Heteronyx piceus,andrelatedspeciescaninflict

damagesimilartothatcausedbywhitefringedweevillarvae,butthisseldomresultsinplant

death.Adultpeanutwhitegrubscancauseseveredefoliationinyoungplants. 3

Figure 1: Peanut mites cause damage like this only in dry years.

7.2.3 Flowering, pegging and podfillSap-suckingpestspresentduringthevegetativestagecancontinueintoflowering,pegging

andpodfill.Miridsmayalsoaffectthecrop,feedingonbudsandflowersandcausingthem

to abort.

Helicoverpa, usually H. armigera,sometimesfeedonflowersandpegs.Ifsignificant

numbersofflowersandpegsarebeingchewedoff,somecontrolmaybeneeded.Cluster

caterpillars also attack peanut pegs. This pest is more common in coastal regions and the

tropics.

Root-chewinglarvaeofwhitefringedweevilandwhitegrubscancausesignificantplant

losses and pod damage.

Heavyinfestationssilverleafwhitefly(SLW,Bemisia tabaci)atfloweringandpoddingcan

greatlyreduceplantvigourandyield.However,peanutsarenotfavouredhostsforthis

exotic pest, and populations in most years are usually low.

Westernflowerthrips(Frankliniella occidentalis) are another exotic pest and a potential

threat to peanuts, mainly because they transmit Tomato spotted wilt virus (TSWV). Although

TSWVinfectionsareofteninitiatedbywesternflowerthripsfeedingduringthevegetative






December 2014



stage,severeTSWVsymptomsareusuallynotmanifesteduntilflowering.However,the

incidenceofTSWVinAustralianpeanutshasnotyetreachedthedamaginglevelsreported

in other crops or in peanut crops overseas. 4

7.2.4 Mature cropsThe lucerne seed web moth (Etiella) may leave holes in pods and appear close to harvest,

particularly during dry seasons. Damage is less common in irrigated crops and runner types

seemmostaffected. 5

7.3 Damage caused by pests

Soil insects and pod damage

InsomepartsofQueensland,whitefringedweevilscancauseseveredamage.Larvaeofthe

weevilattackthetaprootoftheplant.Thismaycausedirectdeathoftheplantorindirectly

leadtoitsdemisebyprovidinganentrysitefordiseasessuchasCylindrocladium black rot

(CBR).Thelarvaewillalsochewpegsanddevelopingpods.Thebeststrategyformanaging

thispestappearstobetocontroltheadultsbeforetheylayeggs.

Variouswhitegrubsandcanegrubswillalsofeedonroots,pegsanddevelopingpods.

Mechanicalcultivationcanbeusefulincontrollingsomeofthesepestsandsomesoil-

applied insecticides may also be warranted.

Etiellamothsandlarvaemaybecommononsomeofthesandiersoiltypesandareoften

especiallyactiveagainsttherunnertypespfpeanuts.Theadultmothlaysitseggsonthe

peanutplant.Thelarvaehatchandmovedowntheplantintothesoiltofeedonthepods.

Growers should check crops at least 1 month prior to harvest. In extreme cases, the crop

mayhavetobedugearly.Irrigationisthebestformofdefenceagainstthispest.6

7.4 Management of insect pests

Inweeks2and3duringcropestablishment,checkforsoilandfoliarinsects,especially

Helicoverpa and cutworms (Agrotis sp.).

Inweeks4–7duringflowering,checkforfoliarinsects,especiallyjassids,leafhoppers,mites

and Helicoverpa.Continuetoscoutforfoliarinsectsduringweeks8and9,whenpegging

occurs, and through to canopy closure and pod-setting in weeks 12 and 13.

Inweeks14and15whenpod-fillingisunderway,checkforinsects,especiallyarmyworms

(Spodoptera sp.),whichstayatorjustbelowgroundlevelduringthedaybutfeedonpegs

during the night. 7




7 PCA.Peanutproductionseasonplan.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/checklist.pdf

i More information



Authority.












December 2014



7.5 Major insect pests of peanuts

7.5.1 Aphids (Aphididae)Importance: Cowpea aphids (Aphis craccivora) are common (Figure 2). They are not

consideredapest;however,theyarevectorsofthePeanut mottle virus. Peanut mottle virus

is usually not a problem in peanuts, but can be a major concern in navy beans growing

nearby.

Registered chemical: Check current registrations on the APVMA website. 8

Figure 2: Cowpea aphids.







December 2014



7.5.2 Cluster caterpillar (Spodoptera litura)Importance:Clustercaterpillars(Figure3)aresignificantbutinfrequentintraditional

growing regions such as the South Burnett. They are more abundant in coastal regions and

the tropics, where serious damage has been reported.

Damage:Clustercaterpillarsarefoliageandpegfeeders.Younglarvaefeedingroups,

leavingthebiggerveins.Largerlarvaearesolitary,chewinglargepiecesofleafand

attacking and severing pegs, causing pod death.

Action level:Sampleweeklyduringthevegetativestageandfromfloweringtotheendof

podfill.Examinefiveplantsatsixwidelyspacedlocations(i.e.30plants).

Control:RarelyaproblemifinsecticidesareusedtocontrolHelicoverpa. 9

Registered chemical: Check current registrations on the APVMA website.

Figure 3: Cluster caterpillar (top left), eggs (top right), and moth (bottom).







December 2014



7.5.3 Cutworms (Agrotis spp.)Importance: Minor and sporadic.

Damage:Seedlingsarechewedoffaroundgroundlevel(Figure4).Damageisusually

patchyandtendstoprogressoutwardsfromtheinitialdamagesite.

Action level: Not determined. Check presence with germinating seed baits.


Figure 4: Cutworms.

7.5.4 Lucerne seed web moth (Etiella behrii)Importance:Majorbutsporadic.Canbesevereindroughtyears.Infestationsareworse

onlighter,sandiersoilsandindryseasons.CropsofvarietyFlorunnertendtobemore

affectedbyEtiella than other varieties. Can also be a problem in irrigated crops when soils

aredryingdownbeforeharvest.Etielladamageisamajorriskfactorforaflatoxin.

Damage: In dry seasons when soils are dry and cracked, newly hatched larvae are able

toreachtheundergroundpods(Figure5).Larvaeborestraightintopodsandfeedwithin

themuntilreadytopupate.Larvaethenemergefromthepodsandsometimesproduce

webbing around the pods. Note that other, less damaging caterpillars (e.g. Endotricha sp.)

commonlymakewebbingatthebaseofplants.

Etiellaexitholesare2–3mmindiameterandtheseallowtheaflatoxin-producingfungus

Aspergillus flavustoenterpods.AflatoxinlevelsinEtiella-damaged pods can be >4 times

greaterthaninundamagedpodscontainingaflatoxin.Etiella damage is not obvious until

harvest. Etiellalarvaearefrequentlystillinsidepodsatharvestandcanbedrivenoutintheir

thousands when pods are dried postharvest.

Action level:Ifithasbeenadryseason,checkthecropregularly,startingatleast1month

priortoharvest.Samplefiveplantsatsixpositionsalloverthepaddock(i.e.30plants).







December 2014



Ifpodshavemuchwebbingandfrass,pullearlyanddry.Lighttrapsarebeingtrialledto

monitor Etiella moth activity and predict pod damage.

Figure 5: Left: lucerne seed web moth—a problem in dry seasons, particularly on light sandy soils. Right: the blue green larvae tunnel into pods and destroy the kernel. It is difficult to separate damaged and sound pods at harvest.

Registered chemical: None registered.

Cultural control: Pull crop early and dry. Eliminate alternative hosts such as Sesbania and

rattlepod (Crotolaria spp.). 11






December 2014



7.5.5 False wireworms (Gonocephalum spp. and Pterohelaeus spp.)

Importance: Minor and sporadic.

Damage:Larvaefeedondecayingvegetablematter,cropresiduesinthesoilandnewly

germinatedseed(Figure6).Boththeseedandthegrowingpointoftheplantaredamaged,

resultinginpatchystands.Duringsummer,adultsring-barkorcutoffyoungplantsatorjust

below ground level.

Action level: Not determined. Check presence with germinating seed baits.

Control: Seed treatment will reduce but not eliminate the problem.

Registered chemical: None registered. 12

Figure 6: False wireworm.






December 2014



7.5.6 Helicoverpa punctigera and H. armigeraImportance:Minorandfrequent.Cancausedamagefromemergencetopegging.

Damage: Most crops will contain some Helicoverpa larvae (Figure 7). Heliothis punctigera

mainly attacks the leaves and growing points whereas H. armigerausuallydamagesflowers

andpegs.Peanutsaretolerantofdefoliation,andevenquitehighpopulations(e.g.5larvae/

m2)havelittleimpactonyieldinwell-growncrops.However,severedefoliationorflower

and peg damage during podding can reduce crop potential. Usually, naturally occurring

outbreaksofNPVkilllarvaebeforetheydamagethecrop.

Action level:Sampleweeklyduringvegetative,floweringandpeggingstages.Sample

five1-mlengthsofrowatsixpositionsacrossthepaddock.Duringthevegetativestage,

sprayifthereare>12larvae/mofrow.Duringfloweringandpeggingstages,sprayif>3–5

larvae/marepresentandlarvaearefeedingonflowersandpegs.


Biological control: NPV products, e.g. ViVUS. 13

Figure 7: Helicoverpa larvae mainly eat leaves, but can chew flowers and pegs.







December 2014



7.5.7 Lucerne leafhopper (Austroasca alfalfae)Importance:Minortosignificantandfrequent.Lucerneleafhopperisyellow-greenand

moredamagingthantheemeraldgreenorblue-greenvegetableleafhopper.Thispestis

more common in tropical regions.

Damage:Nymphsandadultsfeedonthesap-conductingsystemandinjectatoxin.

Leavesturnyellowanddiefromthetip(hopperburn)andplantgrowthisstunted(Figure8).

Damage is worse when plants are stressed.

Action level:Sampleweeklyduringthevegetative,floweringandpeggingstages(30

leaves/week).Samplefiveleaveshalfwayuptheplantatsixpositionsacrossthepaddock.

Sprayif>7of30leaveshaveyellowingorburninthevegetativecropstage.


Figure 8: Top: lucerne leafhopper. Bottom: ‘hopper burn’, typical yellow leaf tips caused by lucerne leafhoppers.







December 2014



7.5.8 Vegetable leafhopper (Austroasca viridigrisea)Importance:Minorandfrequent.Vegetableleafhopperisemerald(blue-green)incolour

andlessdamagingthantheyellow-greenlucerneleafhopper(Figure9).Itisverycommonin

most peanut crops.

Damage:Nymphsandadultssuckthecontentsofleafcells.Theleafcelldies,leaving

awhitespot.Adjacentspotsformthestipplepatterncharacteristicofvegetablejassid

damage. Damage is worse when plants are stressed.

Action level: Usually does not need control, except where there are extremely high

populationsduringhot,dryweather.Sampleweeklyduringvegetative,floweringand

pegging stages.


Figure 9: Vegetable leafhopper.







December 2014



7.5.9 Pineapple mealybug

Importance: Minor and sporadic. Its importance may increase in irrigated crops.

Damage:Infestedplantsarestunted.Nutsoftencollapseandassumeablackishcolour

whenthewaxy,fluffy,whitemealybugsarepresentinlargenumbers(Figure10).Damageis

usually in poorly drained sites.

Action level: None determined.

Registered chemical:Noregistrations.Pesticidecontrolisnotfeasibleforthispest.

Cultural control: Avoid planting in poorly drained areas. 16

Figure 10: Mealybug.






December 2014



7.5.10 Mirids (Miridae), green and brown (Creontiades sp.)Importance: Widespread but probably not as damaging as in mungbeans. Peanuts in

lucerne-growing areas are at most risk.

Damage:Miridsinfestingcagedpeanutplantshavebeenshowntoreducethenumberof

pods produced (Figure 11). Mirid attack may result in uneven crop maturity.

Action level:Aprovisionalthresholdof3–4mirids/m2hasbeensetforpeanuts.


Figure 11: Mirids are widespread and suspected of damaging peanuts in the field.






December 2014



7.5.11 Peanut mite (Paraplonobia spp.)Importance:Minorandinfrequent;shouldnotbeaprobleminoverheadorspray-irrigated

crops.

Damage:Ageneralyellowingandsilveringoftheleaveswillshowupinpatchesofthecrop

during prolonged dry periods. As damage becomes more severe, lower leaves are shed

andplantsdie.Mitesjumpofftheplantattheleastdisturbance(evenashadowacrossa

leaf),socareisneededtofindtherelativelylarge,darkgreen–blackmites(0.5mmlong)on

theunder-surfaceofthelowerleaves(Figure12).

Themitesdisappearafterrainandplantsusuallyoutgrowthedamage.

Action level:Sampleweeklyiftheweatherhasbeendryforaprolongedperiod.Only

spraythepatcheswithobvioussilveringifrainisnotexpected.


Figure 12: Peanut mite damage to a leaf.







December 2014



7.5.12 Two-spotted mite (Tetranychus urticae)Importance: Minor and sporadic. A problem where peanuts grow next to cotton.

Damage:Suckingofthetissuecausesleafmottlingandyellowing.Inseverecases,leaves

will die (Figure 13).

Action level: Not determined.


Figure 13: Two-spotted mites are usually a problem only in cotton districts.







December 2014



7.5.13 Redshouldered leaf beetle (Monolepta australis) Importance:Minorandsporadic.Mostcommonincoastalregionswherethelarvaefeed

on sugarcane roots.

Damage:Adultswarmsfeedonfoliageandflowers.Overalldamageininlandregionsis

generallyminor;adultsusuallyoccurinisolatedpatchesinacrop(Figure14).However,

very high populations across whole crops have caused major damage in coastal regions,

shreddingleavesandflowers.Larvaldamagetorootsisnotsignificant,aspeanutsarenot

apreferredlarvalhost.



Figure 14: Redshouldered leaf beetle.






December 2014



7.5.14 Silverleaf whitefly (Bemisia tabaci, type B)Importance: Potentially a serious pest in coastal and tropical regions (Figure 15). Heavy

SLW populations severely damaged many peanut crops in central Queensland in 2002.

However, this was an exceptionally bad season, and in most seasons, SLW is not a

problembecausepeanutsarenotapreferredhost.

Damage:SevereSLWdamagecanreduceplantvigourandyield.SevereSLWinfestations

in young plants can stunt plant growth and greatly reduce a crop’s yield potential. Later

infestationsatfloweringandpoddingcanreducepodsetandpodyield.Generally,the

impactofSLWismoresevereindrought-stressedcrops.


Registered chemical:NopesticidesregisteredforSLWmanagementinpeanuts.Inthe

longterm,solerelianceonpesticidesforSLWisnotsustainableandtheintegratepest

management(IPM)-friendlyoptionsavailableincottonaretooexpensiveforpeanuts.Avoid

theuseofnon-selectivepesticidesagainstotherpests,tohelpconserveSLWparasites.

Cultural control: Avoid planting peanuts close to earlier maturing susceptible hosts such

as cotton, cucurbits and sweet potatoes.

Biological control:SLWareparasitisedbyanumberofsmallnativeandintroduced

wasps.LadybirdsandhoverflylarvaehavealsopredatedonSLW.Therefore,useofnon-

selective pesticides should be avoided. 21

Figure 15: Silverleaf whitefly.






December 2014



7.5.15 Storage insectsImportance:Widespreadandsignificant.Indianmealmoth(Plodia interpunctella) and the

tropical warehouse moth (Ephestia cautella)arethemostcommon.Larvaeofthelucerne

seed web moth (Etiella behrii) can be delivered to storage depots inside the pod but do not

re-infestinstorage.

Damage: Storage moth larvae damage kernels, particularly at high moisture levels (Figure

16).

Action level:Controlmeasuresshouldbeundertakenatthefirstsignofdamage.

Cultural control: Adopt good hygiene by cleaning threshers, bins, elevators and around

sheds.Keepharvestedcrop<12%moisturecontentonnut-in-shellbasisandkeepcool.

Checkwithpeanutshellersbeforeusinganystoredgraininsecticidesonpeanuts.22

Check current registrations on the APVMA website.

Figure 16: Insect damage to stored kernels.







December 2014



7.5.16 Thrips (Thysanoptera)Importance:Mostdamagebythripsisminorandinfrequentandshouldnotbeaproblem

inirrigatedcrops(Figure17).However,therecentlyintroducedwesternflowerthrips

(Frankliniella occidentalis)isasignificantthreattopeanuts.Sincethearrivalofwestern

flowerthripsinAustralia,therehasbeenadramaticincreaseintheincidenceofTSWVand

Capsicum chlorosis virus in many other susceptible crops. TSWV has severely damaged

peanut crops in many overseas countries, including the USA.

Damage:Thripsdamageischaracterisedbyageneralyellowing,silveringanddistortionof

theleavesthatshowupinpatchesofthecropduringprolongeddryperiods.Thripsmay

alsoattackflowers,leadingtoflowerabortion.TSWVsymptomsaremanyandvaried,but

includestunting,yellowinganddistortionofplants,followedbywilting,plantcollapseand

death.Earlyleafsymptomsincludepaleringspots.

Action level:Sampleweeklyifithasbeendryforalongtime.Onlysprayaffectedpatches,

orifthereare>4–6thripsperflower.However,beawarethatwesternflowerthripsare

resistanttomanypesticides,andthatpesticidesareineffectiveinstoppingthespreadof

TSWV. 23

Figure 17: Thrips.






December 2014



7.5.17 Whitefringed weevil (Graphognathus leucoloma)Importance: Major and sporadic.

Damage: Larvae chewing into the taproot cause the most damage (Figure 18). This results

inseverelyreducedvigourorthedeathoftheplant.Pegscanalsobedamagedandmature

larvaewillchewthedevelopingnut.Infestationsinacropareusuallypatchy.Adultswill

chew leaves and may cause patchy seedling stands in North Queensland. Root damage

fromlarvaemayallowCBRinfection.

Action level:MonitorcropsafterrainfromNovembertoJanuaryforemergingadults.


Cultural control:Reducelarvaecarryoverfromthepreviousseason’scrop.Remove

volunteerpeanutsfrommaizetoreducethecarryoveroflarvaeinthesoil.Avoidplanting

on land planted to, or adjacent to, peanuts or lucerne in the previous season. Reduce

thefrequencyoflegumeandtubercropsintherotationtohelpreducepopulations;for

example,avoidplantingpotatoesafterpeanuts. 24

Figure 18: Whitefringed weevil. Left: the larvae chew into pods and roots; they do not have an obvious head like a white grub. Right: adults feed on leaves and do little damage







December 2014



7.5.18 Cane whitegrubs (Lepidiota spp.)Importance:SignificantandsporadicinNorthQueensland,usuallyfollowingagrass

pasture(Figure19).MinorandinfrequentinsouthernQueensland.

Damage:Younglarvaefeedonsoilhumusandsmallplantroots.Olderlarvaeattackmajor

roots,killingsomeplantsandreducingthevigourofothers.Thiscanprovideanentrypoint

forCBR.Thedevelopingnutscanalsobeattacked.


Cultural control: Cultivation may physically damage many canegrubs, but is not a reliable

controlmethod.Ifgrubnumbersarehigh,thefirstcropfollowingpasturemayneedtobe

pulledearly.Alternatively,plantanon-legumecropinthefirstyearafterapasturerotation.


Figure 19: Canegrubs are a greater problem in North Queensland than in southern districts







December 2014



7.5.19 Peanut whitegrubs (Heteronyx piceus)Importance:IntheSouthBurnett,majorandfrequent.Inotherareas,infrequent.

Damage:Younglarvaefeedonsoilhumusandpossiblysmallplantroots.Olderlarvae

chew into both immature and mature pods, reducing yield and quality (Figure 20). Unlike

canegrubs, peanut whitegrub larvae do not cause plant death.



Cultural control:Intensivepeanutrotationsinaregion,oronasinglefarm,leadtopeanut

whitegrubproblems.AvoidplantingbeforeNovemberiftheareahasawhitegrubhistory.

Conventionaltillagehasverylittleeffectonwhitegrubs. 26

Figure 20: Damage by whitegrubs is often underestimated, as damaged pods are left behind at harvest.







December 2014



7.5.20 Wireworms (click beetles, Elateridae )Importance:Notfullydocumented.UsuallynotaproblemintheSouthBurnettbut

significantdamagehasbeenreportedinCentralandNorthQueensland.Onaverage,

infrequentratherthanregular.

Damage: Larvae can attack germinating seed and damage seedling roots. Larvae also

attack pods, sometimes boring numerous small holes per pod (Figure 21).

Action level: Not determined. Check adult presence with germinating seed baits.

Control: Seed treatment will reduce, but not eliminate damage to seedlings.


Figure 21: Wireworm damage to a peanut kernel (top) and to a peanut pod (bottom).




Section 8 PEANUTS - Nematode control


December 2014



SECTION 8

Nematode control

Nematodes are microscopic, thread-like organisms that live in soil and plant roots. There

aremanyspeciesofagriculturallysignificantnematodes,andresistanceandsusceptibility

ofcropscandifferforeachroot-lesionnematode(RLN)species.Peanutstendtobe

affectedmostbyPratylenchus brachyurus,whichcancausesignificantreductionsinyield

andquality.Podsarediscoloured;therefore,thecropwillnotachievenut-in-shellquality.

Concerns also exist regarding the root-knot nematode Meloidogyne hapla.

Incereals,significantRLNspeciesareP. thornei and P. neglectus. Peanutsarenothostsof

these two species. 1

SymptomsofP. brachyurus include stunted bushes and small lesions on roots, pegs

and shells that may not be obvious. Nothing can be done to treat these nematodes in

thecurrentcropandnochemicalsareregisteredforuseagainstnematodesinpeanuts;

however, croprotationcanreducenematodepopulationssignificantly(Table1).Maizeisthe

mosteffectiverotationcrop.2

Table 1: Research showing effects of rotations on the incidence of known peanut pathogens 3

Foreachpathogenandyear,meansfollowedbythesameletterarenotsignificantlydifferent

Pathogen Continuous peanut, winter fallow

Continuous peanut, winter oats

Peanut rotated with soybean, oats and maize

Year 7 Year 9 Year 7 Year 9 Year 7 Year 9Root-knot nematodes (/g DW root)

465a 1580a 690a 1775a 32b 29b

Root-lesion nematode (/g DW root)

480 215 668 63 376 201

Verticillium wilt at harvest (%plants)

16.5a 47.8a 4.4b 37.8ab 3.7b 23.1b

Sclerotinia at harvest (%plants)

0 5.8a 0 3.6a 0 15.9b

Plant mortality due to crown rot (%plants)

23.7a 20.7a 24.6a 17.8a 1.6b 6.3b

1 GMMurray,JPBrennan(2009)ThecurrentandpotentialcostsfromdiseasesofwheatinAustralia.ReportforGrainsResearchandDevelopmentCorporation,https://www.grdc.com.au/~/media/B4063ED6F63C4A968B3D7601E9E3FA38.pdf

2 DAFF(2012)Root-lesionnematodes.DepartmentofAgriculture,FisheriesandForestryQueensland,http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/peanuts/managing-peanut-diseases/root-lesion-nematodes

3 MBell,GHarch,JTatnell,KMiddleton(2003)Theimpactofcroprotationonpeanutproductivityinrainfedcroppingsystems.AustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/2003/c/5/bell.htm


https://www.grdc.com.au/~/media/B4063ED6F63C4A968B3D7601E9E3FA38.pdf


http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/peanuts/managing-peanut-diseases/root-lesion-nematodes







December 2014



AsurveyofpeanutplantingsinNorthQueenslandshowedthattheRLNM. hapla was

confinedtoredbasalticsoilsaroundTolgaandAthertonwithalongcroppinghistory.The

RLN P. brachyuruswaswidespreadthroughouttheAthertonTablelandsbutnotfound

insoilsthathadrecentlybeenbroughtintocultivation.Infestationsofbothspecieswere

heavierwherepeanutshadbeengrownonthesamelandfortwoormoresuccessive

seasons.YieldresponseswereobtainedonlyintrialswhereinfestationsofM. hapla were

severe, and not where P. brachyurusoccurredbyitself.4

8.1 Types of nematodes

8.1.1 Root-lesion nematodes (Pratylenchus brachyurus)Importance:MostwidespreadnematodeaffectingpeanutsinAustralia.

Damage:Cancausesignificantreductionsinyieldandquality.Podsarediscoloured,

meaning that the crop will not achieve nut-in-shell quality.

Symptoms: Stunted bushes. Small lesions on roots, pegs and shells may not be obvious

(Figure 1).

Management strategies:

• .Chemical:Nothingcanbedoneinthecurrentcrop,excepttoidentifynematodesas

thecause.Nochemicalsareregisteredforuseagainstnematodesinpeanuts.

• Cultural:Croprotationcanreducenematodepopulationsignificantly.Maizeisthemost

effectiverotationcrop.5

Figure 1: Root-lesion nematodes: the dark markings on these pods are caused by nematodes burrowing into the shell. The small white lumps are lenticels (or pores) which swell up in wet soil.

4 RABroadley(1981)Distributionandcontrolofroot-knotandrootlesionnematodesonpeanutsinnorthQueensland. Australian Journal of Experimental Agriculture 21, 223–226, http://www.publish.csiro.au/paper/EA9810223.htm

5 PCA/DPIF(2007)Managingdisease.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/4a_disease.pdf

i More information

M Bell et al. (2003) The

impactof crop rotation

on peanut productivity

inrainfedcropping

systems. Australian

AgronomyConference.

RA Broadley (1981)

Distribution and control

ofroot-knot and root

lesion nematodes

on peanuts in north

Queensland. Australian

Journal of Experimental

Agriculture 21.

GM Murray, JPBrennan

(2009) The current and

potentialcostsfrom

diseases ofwheatin

Australia. GRDC Report.

K Owen et al. Root lesion

nematode—Queensland.

Fact Sheet. Soil Quality

Pty Ltd.

DAFF (2012) Root-lesion

nematodes. DAFF Qld.

Pratylenchus brachyurus.

Wikipedia.

i More information

EL Davis, AE

MacGuidwin (2000)

Lesion nematode

diseases. The Plant

Health Instructor.

Root lesion nematode

dominates in the north.

GRDC Plant Parasitic

Nematodes Fact Sheet.


http://www.publish.csiro.au/paper/EA9810223.htm


http://www.pca.com.au/bmp/pdfs/4a_disease.pdf




















http://www.soilquality.org.au/factsheets/root-lesion-nematode-in-queensland






http://en.wikipedia.org/wiki/Pratylenchus_brachyurus

http://en.wikipedia.org/wiki/Pratylenchus_brachyurus

http://www.apsnet.org/edcenter/intropp/lessons/Nematodes/Pages/LesionNematode.aspx





http://www.grdc.com.au/uploads/documents/GRDC_NematodesFS_North_4pp.pdf






December 2014



8.1.2 Root-knot nematodes (Meloidogyne hapla)Importance: Not a major problem in traditional peanut areas, but may become important in

new production areas.

Symptoms:Typicalrootgallsareformedandinseverecases,plantsarestunted(Figure2).


• .Chemical:Noactionispossibleinanaffectedcrop,exceptconfirmingnematodes

asthecauseofthedamage.Nochemicalsregisteredforuseagainstnematodesin

peanuts.

• Cultural: Rotation with cotton, sorghum or maize will reduce the population. 6

Figure 2: Root-knot nematodes: the typical root galls should not be confused with nitrogen-fixing nodules.

8.2 Effects of cropping history on nematode status

Nematode (Pratylenchus) numbers build up steadily under susceptible crops and cause

decreasingyieldsoverseveralyears.Theamountofdamagecausedwilldependon:

• thenumbersofnematodesinthesoilatsowing

• thetoleranceofthevarietyofthecropbeinggrown

• the environmental conditions

GrowerscroppingpeanutsinrotationwithcottonshouldconsidertheeffectofRLNspecies

oncropsfollowingcotton.Someresearchersreportthatthenematodeisquiteoftenfound

in cotton. 7


7 AMachado,LFerraz,MInomoto(2012)PathogenicityofPratylenchus brachyurus on cotton plants. The Journal of Cotton Science 16, 268-271, http://www.cotton.org/journal/2012-16/4/upload/JCS16-268.pdf

i More information

Pratylenchus brachyurus.

AtlasofLivingAustralia.



http://www.cotton.org/journal/2012-16/4/upload/JCS16-268.pdf

http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:9cc0863f-1136-0b3b-e044-00144f3b4a43

http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:9cc0863f-1136-0b3b-e044-00144f3b4a43

Section 9 PEANUTS - Diseases


December 2014



SECTION 9

Diseases

Peanutsaresusceptibletoseveralfoliardiseases,especiallyleafspot,rustandnetblotch.

Protectivefungicidesareavailabletokeepmostfoliardiseasesatbay.1

Itiscommontoseesomepeanutplantsdyingthroughouttheseasonfromarangeof

causes.Onlywhentheplantpopulationissignificantlyreducedshouldconcernberaised.2

Peanuts are also susceptible to several soil-borne diseases, especially Sclerotinia blight,

white mould and Cylindrocladium black rot (CBR). Good rotational practices, crop

managementandhygienearethebestdefenceagainstthesediseases.Effectivefungicides

areavailabletocontrolthefoliardiseases;however,fungicideoptionsarelimitedforcontrol

ofthesoil-bornediseases.3

Conditionsfavouringrapidcropgrowthalsofavourthedevelopmentofdisease.4

Theyoungseedlingisnormallyprotectedbytheseeddressing(afungicide).Acommon

seedling disease in peanuts is crown rot, caused by Aspergillus niger, which is endemic in

mostsoils.Crownrotoftenkillsveryweakseedlingsandisveryprevalentwhensoil















December 2014



temperatures are high. 5Notethatthisisadifferentdiseasefromthataffectingcerealcrops

(caused by the Fusarium pathogen).

9.1 Damage caused by disease

InherentproblemsofkernelqualityandaflatoxincontaminationcausedbyAspergillus flavus

can be aggravated by poor disease control. Peanut producers have access to an excellent

rangeofprovenoptionsthatworkwellifrecommendationsarefollowed.Theseinclude

combiningimportantelementsofIntegratedDiseaseManagement(IDM)thatwillassist

overalldiseasecontrol.Sticktotherulesof:

• controlofpeanutvolunteers,whichharbourdiseasebetweencropcycles

• preventionnotcure—fungicidesaremuchmoreeffectiveifusedpreventatively

• thorough and regular disease scouting

• timelyroutineandstrategicfungicideapplicationinlinewithlabelrecommendations

• rotationofchemistrytoavoidresistance

• good spray-application technology

• effectivecroprotation—rotationsminimiseincidenceofleafandsoil-bornediseases

(lessofanissueincane-farmingsystems)6

9.2 Management of disease

Total prevention is not possible. Peanut volunteers on headlands and in rotation crops can

carrydiseases,andinfectedresiduesfromlastyear’scropscanbeasourceoftheleaf

pathogens.Athree-prongedapproachmustbetakentomanageleafdiseasesinallpeanut

varieties:controlofvolunteerpeanutplantsthatmayharbourtheleafspotandrust

pathogens,carefulpaddockselection,andanappropriatefungicidesprayregime.Avoid

planting peanuts in the same paddock as the previous year and beside paddocks where




http://youtu.be/a53hM-cGJYE?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7




http://youtu.be/a53hM-cGJYE?list=PL2PndQdkNRHE5T6IEtlEsbJWM92KvGmv7



December 2014



peanutsweregrownthepreviousyear,particularlyiflateleafspotwaspresentinthe

previous crop.

9.2.1 Crop rotationCroprotationcanhaveasignificantimpactonmanydiseases.Forexample,whereone

peanutcropfollowsanother,seedlingdiseasesaregenerallymorecommonandleafspot

will appear earlier and be more severe.

Peanutdiseasesspreadintonewpeanut-growingareasindifferentways.Rustspores

canbeblownwiththewindforlongdistances,whereasleafspotsporestravelforshorter

distances. Equipment, particularly diggers and threshers, can spread soil-borne diseases.

Some diseases are already present in almost all soils, e.g. Aspergillus flavus(theaflatoxin-

producingfungus).

Inmanyenvironments,afungicideprogramisneededtocontrolfoliardiseasessuchasleaf

spot, rust and net blotch. This may involve 2–10 sprays, depending on district and season.

Foliar diseases are a greater problem in more humid areas such as North Queensland and

coastal areas than in the inland Burnett and Central Queensland.

Diseases can be divided into categories depending on when and how they attack the

peanut plant. Some alternative causes, such as seed damage, are also included. 7

9.2.2 Fungicide program for high risk areas

Toachievehighyields,growersmustcontrolleafdiseases.Thetimingoffungicidesprays

will depend on the disease incidence in the region.

In areas where diseases are always present and disease pressure is almost always severe,

itiscriticalthatearlyprotectantfungicidesareappliedassoonas21daysafteremergence

(DAE)ofthecrop.Thefungicideprogramshouldcontinueuntiljustbeforedigging.


i More information



Authority.










December 2014



IntheBundabergarea,applicationofchlorothalonilproductsfrom21DAEat10-day

intervalshasbeenshowntoeffectivelycontrolleafspotandrustinsusceptiblevarieties.

AdditionofoneortwospraysusingotherproductssuchasAlto® (cyproconazole) or

Folicur® (tebuconazole) can also assist. In an average year, 14-day schedules are not

frequentenoughbecausethecropgrowstooquicklyintheseregions,withnewleaves

beingproduced(andthereforeunprotected)onthetopofthecanopyeveryweek.If

growingamoretolerantline(i.e.thenewlyreleasedD281-p40-236A),protectivefungicide

spraysshouldstillcommencefromweek4,butthesprayintervalmaybeextendedupto

21 days later in the crop.

InNorthQueensland,theseschedulesarejustasimportant,butmorefrequentrainfall

eventsrequiregrowerstomanagefungicideapplicationintervalswithamorevaried

approach. Always seek advice on the latest registrations and recommendations. 8

9.3 Disease symptoms

Symptomsofdiseasewillbeconsideredasfollows:

1. Seedlings dying

2. Leaves with brown spots

3. Leaves with colour variations

4. Branch wilting or plant death

5. Ill-thrift

6. Pods damaged at harvest

9.3.1 Causes of seedlings dying (or poor emergence)

Soil-borne fungi including Aspergillus niger (Aspergillus crown rot) and Rhizopus arrhizus

Importance: Widespread.

Damage: Can be serious, causing low plant population or creating large gaps in the stand.

Remaining plants may not compensate.

Symptoms: Seed does not emerge. Seedlings die. Fungal growth on the seed may or may

not be present (Figures 1 and 2).

Spread: Already present in all soils.


• Chemical:Treatseedwitharecommendedfungicide.

• Cultural:Plantintowarmsoil(~18°C).Donotplantifweatherconditionsarelikelyto

causesoiltemperaturetofallbelow18°Corriseabove50°C.Plantingtoodeepwill

increasetheriskofseedlingdisease.


i More information



Authority.








December 2014



Figure 1: Aspergillus crown rot infection (left). Seedling showing crown rot symptoms (right).

Figure 2: Close-up view of crown rot fungus.

Damaged seed

Importance: Minor.

Damage:Similareffecttosoil-bornefungi,exceptthatthelossesareunlikelytocontinue

afteremergence.Remainingplantsmaystillshowpoorvigour.

Management strategy:

• Cultural: Check planting equipment to minimise damage to seed. Handle seed

carefully.Selectseedfromcropsthathavenotbeenaffectedbydroughtandhave

been cured slowly. 9






December 2014



9.3.2 Causes of leaves with brown spots

Early and late leaf spot (caused by Cercospora arachidicola and Cercosporidium personatum)

Importance:Majorinmostpeanutareas.Favouredbyhighrainfallandsprinklerirrigation.

TheSutherlandvarietyisresistanttoleafspot.

Damage:Leavesfalloffandstemsandpegsareweakenediftheepidemicstartsearly

andisuncontrolledandweatherconditionsfavourdiseasespread.Conditionsfavouring

rapidpeanutgrowthalsofavourthespreadofleafspot.Leavesmustbewetfromrain,dew

orirrigationforlongperiods(~10h)totriggerinfections.Croppotentialisreducedwhen

infectedleavesfalloff(Figure3).Harvestinglossesincreaseasinfectedpegslosestrength

and break during pulling and threshing.

Figure 3: Leaf drop caused by leaf spot (left) compared with a non-diseased area (right).

Symptoms:Small,darkspotsbecomebrowntoblackonbothsidesoftheleafasthey

enlargeupto10mm;theremaybeayellowhaloaroundthespots(Figure4).Spotsappear

onthelowerleavesfirst,butarenotvisiblefor7–10daysafterinfection.Symptomsoflate

leafspotaresimilar,butspotsdonothaveaprominentyellowhalo,andmassesofspores

areoftenseenontheundersideoftheleaf(Figure5).Lowerleavesareinfectedfirst,and

infectionisonlynoticedifthedensepeanutcanopyisparted.Later,stemsandpegsmay

alsobecomeinfected.Sporesarespreadmainlywhendewdriesoffinthemorningor

whenrainstarts.Theydonotspreadoverlongdistances,soinfectionswilloftenstartfrom

infectedcropresidues.




December 2014



Figure 4: Early leaf spot: brown spots on upper (left) and lower (right) leaf surfaces, some showing a yellow halo around the spot.

Figure 5: Late leaf spot: black spot on the underside of the leaf (left) and coalesced black spots near the base of the leaf (right).

Spread:Thefungalsporesarespreadbywindandrain.However,theresidueofprevious

peanutcropsisthemainsourceofinoculum,sopeanutsfollowingpeanutsareoftenthe

mostheavilyaffected.




December 2014




• Chemical:Bothdiseasescanbecontrolledbythesamefungicides.Inhigh-rainfall

areasandforirrigatedcrops,asprayscheduleof10–14daysisneeded.Leafspot

increases rapidly during warm, wet weather and irrigation. Fungicides also break

down more quickly under these conditions and a shorter interval between sprays

mustbeusedtoprotectnewfoliage.Somefungicidescanonlyprovideprotection,

whereasotherscancontrolinfectionsthatoccurred3–6daysbeforeapplication.These

eradicantfungicideswillnotcontrolwell-establishedinfections.Sprayupto4weeks

beforeharvest.Whenchoosingfungicides,considerotherdiseasesinthecropand

whetherthecropwillbebaledforhay.

• Cultural: Total prevention is not possible. Peanut volunteers on headlands and in

rotation crops can carry the diseases between crops and they should be destroyed.

Avoid peanut–peanut rotations. Sow the Sutherland variety, because it is resistant to

leafspot.

Rust (caused by Puccinia arachidis)

Importance:WidespreadinmostpeanutareasnorthofKingaroy.TheSutherlandvarietyis

resistant to rust.

Damage:Cancausemajorcroplossesifitstartsearlyandisuncontrolled.Onceruststarts

inacrop,dewsandfogsaresufficienttocreateaseriousepidemic.

Symptoms: Small, yellow spots quickly produce typical ‘rusty’ spores (Figure 6). Spores

arenotvisiblefor7–10daysafterinfection.Theyareusuallyfoundunderthelowerleaves

andspreadveryrapidly.Infectionsareoftenfirstfoundasa‘hotspot’withafewplants

covered in rust (Figure 7).

Spread: The spores can blow long distances between crops.


• Chemical:Spraywithafungicideuntilthecropiswithin2weeksofharvest.Aspray

programsimilartothatforleafspotmaybeneeded.Considerotherdiseasesthatmay

be in the crop.

• Cultural:Rustsporescannotsurviveforverylongintheabsenceoflivingplants,so

destroy volunteer peanut plants between crops, especially on headlands, contour

banksandaroundbuildings.Therearenoknownalternativehostsforpeanutrust.




December 2014



Figure 6: Typical rust spores on upper and lower surfaces.

Figure 7: Rust-affected crop.

Thefirstsignsofinfection,thesmallyellowflecksontheleaves,soondevelopintosmall

orange pustules. The pustules contain numerous red-brown powdery spores that are

spreadduringdry,windyweather.However,liketheleafspots,prolongedleafwetnessfrom

rain,irrigationordewisnecessaryforinfection.10

Puccinia arachidisisadifferentspeciesofrustfromthosethattypicallyaffectcerealcrops.







December 2014



Net (or web) blotch (caused by Didymosphaeria arachidicola)

Importance:ItisnowthemajorfoliardiseaseintheSouthBurnettinwetyears.

Damage:Causesrapiddefoliation(andsubsequentyieldloss)duringcool,showery

weather.

Symptoms:Anetworkofveryfinebrownlinesdevelopsonthetopsurfaceoftheleaf.

Thesejointogethertoformbrownishblotches,whichmaygothroughtheleaf(Figure8).

Spread:Thefungussurvivesonpeanutresiduesfromthepreviousseason.


• Chemical: Spray as soon as symptoms are seen during cool, showery weather. Not

allfungicidescontrolnetblotch.Sprayprogramsforleafspotandrustprotectagainst

netblotchprovidedappropriatefungicidesareused.InthedrylandcropsoftheSouth

Burnett,anincreaseinthenumberoffungicideapplicationswillbeneededtomanage

net blotch in wet years.

• Cultural:Netblotchepidemicsaredifficulttopredict,butirrigationmaycreateideal

conditionsforinfection.Itmaybenecessarytoadjustirrigationpractices.Spanish

varieties are more susceptible than Virginia types, which are more susceptible than

runner types. For variety characteristics, see GrowNotes Peanuts Section 2. Pre-

planting.

Growersshouldnotconfusethisdiseasewiththenetblotchthataffectscerealcrops.

Figure 8: Net blotch may occur with slightly differing appearance on affected leaves.




December 2014



Pepper spot and scorch (caused by Leptosphaerulina arachidicola)

Importance: Minor but widespread.

Damage:Leavesdropoff.Isoftenoneoftheearliestfoliardiseasestoinfectcrops.

Symptoms:Thesamefunguscausestwodifferentsymptomsunderdifferentweather

conditions.Pepperspotoccurswhenverysmallspots,<1mm,developonthetopofthe

leaf(Figure9).ScorchoccurswhenaV-shapedpartoftheleafdies(usuallyonthemargin)

andayellowzoneformsnexttoit.

Spread:Thefungussurvivesonpeanutresiduesandisspreadbywind.


• Chemical:Thefungicidesusedforcontrollingtheotherfoliagediseasesusuallycontrol

thisfungus.Useaprotectantfungicideifnootherdiseaseinfluencesthechoice.

• Cultural: These diseases are not usually serious in traditional production areas using

the current varieties.

Figure 9: Pepper spot looks sooty.

Physiological spotting

Importance: Minor.

Damage:Leafsymptomsonly.

Symptoms:Darkbrownmarkingsonleaves,similartoleafspot.Someoftheseappearlike

‘eyebrows’ (Figure 10).

Cause: Unknown.

Management strategies: None needed. 11






December 2014



Figure 10: Physiological spotting; note ‘eyebrow’ markings.

9.3.3 Leaves with colour variations

Capsicum chlorosis virus (CaCV)

Importance:Usuallyminor;sometimesoccursateconomicallydamaginglevelsincoastal

Queensland.

Damage:Affectedplantssetfewkernelsandthosethatdosetaresmallandofpoor

quality.Severelyaffectedplantsarestuntedandmaydie,leavinggapsinrows.

Symptoms: CaCV causes mottling and dark (necrotic) spots on leaves (Figure 11).

Internodesarereducedinlengthandtheterminalgrowingpointswiltanddie.Affected

plantsarestunted,particularlywheninfectedearlyinlife,andmayeventuallydie.

Spread: Several thrips species spread the virus, e.g. tomato thrips and melon thrips. CaCV

belongs to the same virus group as Tomato spotted wilt virus and the transmission process

forbothvirusesisalmostidentical.Thripsacquirethevirusfrominfectedplantsasimmature

larvaeandtransmittootherplantsasactiveadultinsectsafterthevirushascirculatedand

multiplied in the insect. The virus is not spread by other insects such as aphids and jassids.

CaCV is not spread by contact, in soil or in seed.

CaCVinfectscapsicum,tomatoandpeanut.Billygoatweed(Ageratum conyzoides) is a

majorweedhostofthevirusthroughoutcoastalQueensland.Thisweedcommonlyoccurs

aroundcane-fieldsandalongroadsides.




December 2014



Figure 11: Capsicum chlorosis virus: mottling and dark (necrotic) spots develop on leaves, internodes are reduced in length, and terminal growing points wilt and die.


• Treatment:Infectedplantscannotbecured.Managementaimstoreducedisease

levelsincrops,particularlyearlyinfection.

• Cultural: Control weeds around and within crops, particularly billygoat weed. Avoid

planting new peanut crops adjacent to old crops or near capsicum crops.

Peanut mottle virus (PMV)

Importance: Minor.

Damage:Slightleafmottlinginpeanutvarietiescurrentlygrown.

Symptoms:Leavesshowalightmottlethroughtopatchesofdarkgreen(Figure12).

Spread: By aphids.


• Cultural:UsePMV-freeseed,ifavailable,innewandisolatedareas.Onlyseedshown

tobePMV-freecanbegrownintheBurdekinBeanSeedQuarantineArea.




December 2014



Figure 12: Peanut mottle virus: leaves showing a light mottle through to dark green.

Tomato spotted wilt virus (TSWV)

Importance: Minor, but potentially serious under certain conditions.

Damage:Theincidenceofinfectedplantsisusuallylow.Plantsinfectedearlymaybe

stuntedandproducefewnuts.Plantsinfectedafter40daysareusuallynotstunted,but

somebranchesmaybeaffected.

Symptoms: This virus produces distinctive patterns on leaves, usually including concentric

yellow rings or lines (Figure 13).

Spread:Thripsspreadthediseasefromhostplants—capsicum,tomato,lettuceand

broadleafweedssuchasstinkingrogerandcobbler’spegs.Onlyadultthripsthatdevelop

frominfectedlarvaecantransmitthevirus.Thesethripscanbeblownlongdistances.


• Cultural: Control weeds in and near the crop. Avoid planting young crops next to old

cropswherediseaseispresent,becausesignificantmovementofthripsoccursover

relatively short distances.

• Chemical:Controlthripsifpossible.Often,however,insecticidesarenoteffective

againstTSWVbecausethripsfeedingtimesthatleadtotransmissionareshort,about5

minutes,andspreadisoftenfromincomingthripsthatfeedbutdonotsettleandbreed

in the crop.




December 2014



Figure 13: Tomato spotted wilt virus: affected plants are stunted with small, distorted leaves (top) showing green and yellow mosaic patterns, often circular (bottom).

Verticillium wilt (caused by Verticillium dahliae)

Importance:Minoroverall,butcanbeseriousonsomefarmsinsomeseasons.Often

occurs on crops grown on the best soils in the South Burnett and in irrigated crops in low-

rainfallareas.

Damage:Infectionbeforeearlypodfillmayreduceyield,buttheimpactissmallifleaf

symptomsappearafterthistime.

Symptoms:Pale-greenblotchesappearbetweentheveinsandaroundtheleafmargins

(Figure 14). The margins then become brown and die. Under dry conditions, these areas

dry out, giving the plant a scorched appearance. The vascular tissues in stems and roots

are discoloured reddish brown. Wilting and plant death sometimes occur.

Spread: Hosts include the weeds cobbler’s pegs, Noogoora burr and Anoda weed, and

many crop plants such as cotton.




December 2014




• Treatment:Onceinfectionoccurs,nothingcanbedonetocontrolVerticilliumwilt.

• Cultural:Removeweedhostsandinfectedcropresidues.Makinghaymaybe

warrantedifalargeamountoffungalinoculumispresentintheleavesandstems

throughout the paddock. Dig the crop as early as possible. 12

Figure 14: Verticillium wilt: close-up view of yellow leaves with green veins and water-soaked margins (top); plant stunted by Verticillium wilt (bottom).






December 2014



9.3.4 Branch wilting or plant death

Sclerotinia blight (caused by Sclerotinia sclerotiorum and S. minor)

Importance: Major and expanding. Sclerotinia minor is the main problem in the South

Burnett, and S. sclerotiorum is the main problem on the Atherton Tableland and at

Coominya, south-eastern Queensland.

Damage:Thesediseasescandevastateacropinafewdaysifitiscontinuouslywet.

Sclerotinia sclerotiorum,particularly,showsupfirstinwetterpartsofthepaddockwherethe

bushesarelargerorwheretheremaybeshadeforlonger.

Symptoms:Usually,thefirstsignofSclerotiniablightisawiltingbranchorbush(Figure

15).Theplantwillbegintoshowvisiblewiltingonlyafterithasbeeninfectedformany

days.Earlydetectionisessential.BothspeciesofSclerotiniaproducefluffy,whitemould

likecottonwool.However,thesizeoftheblackrestingbodies(sclerotia)formedonandin

stemsisdifferent;thoseofS. sclerotiorum are larger than a wheat grain, whereas those

ofS. minor are smaller and similar in size to raw sugar crystals (Figure 16). Stems wilt and

becomedryandbleachedwherethefungusispresent.

Thelifecyclesofthetwospeciesdiffer.Sclerotinia minor does not usually produce small

mushrooms that release spores into the wind, whereas S. sclerotiorumdoes.Infectionsof

lowerstemsandpegsdevelopfromgerminatingsclerotia.

Spread: Sclerotinia minorspreadsbyphysicalmovementofthesclerotia;S. sclerotiorum

spreads by sclerotia and by wind-blown spores.

Figure 15: The first sign of Sclerotinia blight is a wilting branch or bush.




December 2014




• Cultural:Preventioninfuturecropsisdifficult.Avoiddamagetoplantsfrominter-row

cultivations.

• Chemical:Monitorthecropforinfection,especiallyincool,dampconditions.Spray

withafungicideassoonasthediseaseisseen.Correcttimingisessentialtoachieve

themosteffectivecontrol.Applyregisteredfungicide(Rovral®, a.i. iprodione).IfthefieldhasahistoryofSclerotiniablight,considersprayingasaprecautionwhenthe

rowhashalf-closed.Morethanonespraymaybeneeded.Avoidthecontinueduse

ofchlorothaloniltocontrolleafdiseasesinfieldswhereSclerotiniablightisaproblem.

Continuetousechlorothalonilifthedamagefromleafspot,rustandnetblotchislikely

to be worse than the Sclerotinia blight.

Figure 16: The white fluffy mycelium of Sclerotinia sclerotiorum is similar to S. minor. Note the relatively large black sclerote of S. sclerotiorum, which is the main type on the Atherton Tableland and at Coominya (left). Small black sclerotes are produced by S. minor, which is the most common in peanuts in the South Burnett (right).

Cylindrocladium black rot (CBR) (caused by Cylindrocladium crotalaria)

Importance: Major in the Burnett and Atherton Tableland.

Damage:Thediseaseiscausedbyasoil-inhabitingfungus.Althoughwetconditionsallow

infection,particularlywhenplantsareyoung,CBRismoreevidentwhenconditionsturndry

and bushes start to wilt and die.

Symptoms:Thetaprootandsiderootsstarttodecayfromthetiptowardsthemain

crownoftheplant(Figure17).Thereisinternal,darkbrowndiscolorationoftheroots,

andsometimesthestems,buttheonlysymptomseenonfoliageisageneralyellowing.

Eventually,theplantdiesfromlossoftherootsystem.Redfungalstructures(aboutpinhead

size)mayformondeadordiseasedtissue.Thesestructuresdonotusuallyoccuron

infectedtissueintheSouthBurnett.




December 2014



Spread:Byinfectedplantpartsandsoil.


• Treatment:Nothingcanbedoneforthecurrentcrop.Thefutureofgrowingpeanuts

onthatlandlikelydependsonsurvivingoneortwobadcrops,afterwhichlossesmay

be acceptable.

• Cultural:SomegrowersontheAthertonTablelanduseirrigationandfertiliserto

reducetheeffectsofCBR.Thelateralrootsfeedonthemoistureandnutrientsafterthe

taproothasdied.Arotationof2yearsofmaizefollowedbypeanutsseemseffectivein

keeping the inoculum to a low level on the Atherton Tableland.

IntheSouthBurnett,CBRcanbequitesevereinaffectedpartsofafieldforafew

successive crops, but generally, the severity decreases in subsequent crops. This does not

appeartobethecaseontheAthertonTableland,wheretheseverityofthediseasevaries

fromseasontoseasondependingonweatherconditions.

DamagetotherootsystembysoilinsectsandnematodescanincreaseCBRinfections.

Soybeans,lupinsandlucernearehostsforCBR.




December 2014



Figure 17: Cylindrocladium black rot: roots usually become blackened and die back from the tips (top left). The red resting bodies are typical of CBR, but are not always present (top right). Kernels infected with CBR (bottom).




December 2014



White mould (caused by Sclerotium rolfsii)

Importance: Major. Widespread across all peanut-growing areas. Worse in some years

andinsomefields.

Damage:Wiltinganddeadplants.Preferstoliveondeadplantmatter.Attackspeanut

plants mainly when soil organic matter levels are low. Diseased leaves drop and are

responsibleforthemovementofinoculumbetweenplants.

Underdryconditions,thefunguscanliveunderthesoilinthemoisturearoundrootsand

pods.

Symptoms:Producesfluffywhitemycelium,thickerthanthatofSclerotinia spp. In the

mycelium are very small, spherical, white and then brown resting bodies, about pinhead

size (Figure 18). Plant stems may be destroyed near soil level, and pegs and pods can be

attacked.Podscanbeaffectedwithoutanysignofinfectiononthesoilsurface.

Spread: Already present in virtually all soils.


• Treatment:Nothingcanbedoneforthecurrentcrop.

• Cultural: Avoid damaging the plants or throwing too much soil around the crown when

inter-row cultivating. Build up soil organic matter status. Decomposed soil organic

mattermayreducetheincidenceofwhitemouldbystimulatingantagonisticorganisms.

Fresh (or under-composed) organic matter can stimulate white mould and make the

problem worse. This is particularly the case where decomposed soil organic matter

levels are low. The best control is usually to have a good rotation with grass or cereal

crops.

ThewhitemouldsituationinNorthQueenslandmaybedifferentfromthatintheBurnett.

White mould is appearing where crops have been well rotated, soil organic matter levels

appearhigh,and,inparticular,wherestubbleisretainedonthesoilsurface.

InNorthQueensland,avoidplantingpeanutsintofreshstubbleorcropresiduesmaintained

onthesoilsurface.Giveorganicmattertimetobreakdownordecompose.Deepploughing

maybeanoption,assclerotiadonotsurvivedeepburyingformorethanayear.




December 2014



Figure 18: White mould: the white mycelium is slightly thicker than that of Sclerotinia and tends to form more on the soil surface (top). Note the sclerotia, which are spherical and white, then turn brown (bottom) (those of Sclerotinia are black and an irregular shape).

Collar rot (caused by Lasiodiplodia theobromae)

Importance: Major problem in the Central and South Burnett, but is known in all peanut

growing areas.

Damage: Losses can be severe, up to total crop loss across an entire paddock. The

disease seems to be worse where the soil is degraded through erosion or scalping during

land levelling.

Symptoms:Arapidcollapseofplantsfromcompleterottingoftherootsandstemsat

ground level (Figure 19). Plants die throughout the season.

Infectionoccursatsoillevelwherestemsandcrownssufferfromheatstress,soilabrasion

or drought.




December 2014




• Treatment:Nothingcanbedoneforanaffectedcrop.

• Cultural:Maintainlightirrigationswherepossible,sotheplantcansurviveonsurface

roots.Donotdelayharvest.Rotationofatleast2yearsinothercropsshouldreduce

thelevelofsporesinthesoil.Tominimiserisk,plantearlyandconsiderplantingon

bedstoobtaingroundcoverbeforethemiddleofsummer.

Figure 19: Collar rot: bushes rapidly wilt and rot at ground level (top). Affected pods go grey inside in the early stages, then the whole pod rots (bottom left). Note the characteristic small black resting bodies on the stem (bottom right).

Aspergillus crown rot (caused by Aspergillus niger)

Importance: Widespread in all peanut-growing areas.

Damage:Causesseriousplantlossesinsomefieldsinsomeyears.Plantsmaybekilledat

anystageuptoharvest,althoughdeathofyoungplantsismorecommon.

Symptoms:Inseedlings,thesoft,below-groundstemisattackedandcanbekilledrapidly.




December 2014



Theaffectedtissuebecomesyellowanddepressedandusuallydevelopsasooty,black

massofspores(Figure20).Therotfrequentlydevelopsnearoldpiecesofseedattachedto

the stem.

Inplants,atypicalcrownrotdevelopsandthesootygrowthofthefungusisoftenpresent

onaffectedtissues.Ifthedamageisnearthebaseoftheundergroundpartofthestem,

theplantwillsurviveforawhileonrootsthatgrowabovetheaffectedarea.Suchplants

generally die during dry weather.

Spread:Thefungusispresentinallpeanut-growingareas.Itismostseriouswhere

peanutshavebeengrowninthesameareaforanumberofyears.

Thefungusisoftenpresentinseedthatbecomesinfectedinthefieldorduringharvesting

and handling.


• Chemical:Usegoodseedtreatedwithrecommendedfungicides.

• Cultural:Avoiddamagetotheseedbeforeplanting.Donotplantdeeperthan

necessary. Take care when cultivating to avoid damaging plants. Rotate with other crops.

Figure 20: Aspergillus crown rot can kill plants from seedlings to maturity. The infection usually starts at ground level (top). Note the characteristic black spores (bottom).




December 2014



Charcoal rot (caused by Macrophomina phaseolina)

Importance: Not normally a major problem. May become serious in crops where soil

temperature becomes very high during the growing season. It also appears to be drought-

induced.

Damage: Plants die progressively during the season.

Symptoms: Root tissues are discoloured beneath the bark layer. Developing pods can rot

(Figure 21).

Spread: Already present in most soils.


• Cultural:Ifpossible,keepthesoilsurfacemoisttominimisestressduetohighsoil

temperatures or drought. To minimise risk, plant early and consider planting on beds to

obtaingroundcoverbeforethemiddleofsummer.

Figure 21: Charcoal rot.




December 2014



Rhizoctonia stem rot (caused by Rhizoctonia solani)

Importance: Rarely causes problems under traditional dryland peanut production

conditionsinAustralia.Maybeaproblemundersprinklerirrigationwherethesoilsurface

stays cool and moist.

Damage:Plantscanbekilledfromseedlingtomaturity.

Symptoms: Distinctly zonate brown sunken lesions, which can completely girdle stems,

causingpartoralloftheplanttodie(Figure22).Pegsandpodsmayalsobeaffected.

Spread:Thefungusisalreadypresentinmanysoilsandcansurviveinsoilformanyyears.


• Cultural:Littlecanbedone,excepttoirrigatesothattheplantiswetfortheleast

possible time. Gypsum application may reduce pod rots. Avoid covering the crown and

branchesoftheplantwithsoilduringcultivation.Rotatecropstoincreaseormaintain

levelsofsoilorganicmatter.13

Figure 22: Rhizoctonia stem rot. (Photo used with kind permission of Chip Lee, Texas A & M University, College Station, TX, USA)

9.3.5 Ill-thrift

Root-lesion nematodes (Pratylenchus brachyurus)

Importance:MostwidespreadnematodeaffectingpeanutsinAustralia.

Damage:Cancausesignificantreductionsinyieldandquality.Podsarediscoloured(Figure

23);therefore,thecropwillnotachievenut-in-shellquality.

Symptoms: Stunted bushes. Small lesions on roots, pegs and shells may not be obvious.






December 2014




• Chemical:Nothingcanbedoneinthecurrentcrop,excepttoidentifynematodesas

thecause.Nochemicalsareregisteredforuseagainstnematodesinpeanuts.

• Cultural:Croprotationcanreducenematodepopulationsignificantly.Maizeisthe

mosteffectiverotationcrop.

Figure 23: Root-lesion nematodes: the dark markings on these pods are caused by nematodes burrowing into the shell. The small white lumps are lenticels (or pores), which swell up in wet soil.

Root-knot nematodes (Meloidogyne hapla)

Importance: Not a major problem in traditional peanut areas, but may become important

in new production areas.

Symptoms:Typicalrootgallsareformed(Figure24),andinseverecases,plantsare

stunted.


• Chemical:Noactionispossibleinanaffectedcrop,exceptconfirmingnematodesas

thecauseofthedamage.Nochemicalsareregisteredforuseagainstnematodesin

peanuts.

• Cultural: Rotation with cotton, sorghum or maize will reduce the population. 14






December 2014



Figure 24: Root-knot nematodes: the typical root galls should not be confused with nitrogen-fixing nodules.

9.3.6 Pods damaged at harvest

Soil insects

Lucerne seed web moth (Etiella),whitegrublarvaeandwhite-fringedweevillarvaeall

damage pods (see GrowNotes Peanuts Section 7. Insect control).

Pod-rotting fungi, including Lasiodiplodia theobromae, Pythium spp. and Rhizoctonia solani

Importance: Major and widespread.

Damage: Many pods (and pegs) are mouldy and/or decayed, causing serious yield and

quality losses.


• Cultural: Harvest quickly to reduce losses.

Aflatoxin-producing fungi (Aspergillus flavus and A. parasiticus)

Importance: Major and widespread, particularly in dryland crops.

Damage:Kernelscontaminatedwithaflatoxinbringareducedpriceand,incasesofvery

high levels, may be downgraded to oil quality (Figure 25).

Highsoiltemperaturesanddroughtduringfloweringandpodfillarethemajorcausesof

aflatoxincontamination.Podsdamagedbyinsects,diseaseorrainafteradryperiodor

afterharvestallowthefungusaccesstothekernels.

Aspergillus flavusdevelopsmostrapidlyat25°–35°Candwhenpodmoistureis14–35%.

Symptoms:Thegreenishyellowfungiarenotalwaysvisibleinharvestedkernels.The

toxins can only be detected in a laboratory using chemical extraction and analytical

instruments.

i More information

DEEDIQld.AfloMan.


http://www.apsim.info/afloman/



December 2014



Cultural management strategies:Irrigationwillminimisetheriskofpre-harvestaflatoxin.

However,iftheplantisallowedtostressjustpriortomaturity,A. flavus can still invade the

pod.

Dig as soon as the crop is mature.

Leavingpeanutsinthewindrowtodryto13%moistureincreasestheriskofaflatoxin

becauseofthechanceofrainre-wettingthecrop.Theriskismuchhigheriftheplants

weremoisture-stressedbeforeharvest.Peanutsinwell-invertedwindrowshavealowerrisk

because they dry quicker.

Harvestirrigatedareasseparatelyfromdrylandareas.Thismaymeanturninginthemiddle

ofarowiftheirrigatordoesnotcoverthepaddock.Mixingpeanutsfromthesedryendsof

rowscommonlyresultsinaflatoxin-positiveloadsfromirrigatedcrops.

Clean out threshers, bins and elevators between seasons, as one contaminated nut can

downgrade a whole load.

Startcuringthecropwithin3hofharvesttostopfurtherdevelopmentoftheaflatoxin.

Harvestednutsshouldnotbeleftovernightbeforecuring,evenifonlypartofabinis

threshed.

Lowsoilcalciummayincreasetheriskofaflatoxinwheresoilconditionsarefavourablefor

A. flavus mould development.

Gypsummayreducetheriskofaflatoxincontamination.15






December 2014



Figure 25: Aflatoxin: peanuts contaminated with aflatoxin will be downgraded and may be rejected.

9.4 Soil-borne diseases

Severalsoilbornediseasescanleadtosubstantialyieldandqualityloss.Threediseasesof

particular consequence are white mould, Sclerotinia blight and CBR.

Althoughsomeproductsareavailablethatcanlessentheeffectsofthesediseases,the

bestpolicyistofollowarecommendedrotationalprogram(involvinggrassorcerealcrops)

and practice good cultural management. In particular, excessively aggressive inter-row

cultivation should be avoided, especially where soil is pushed against the plant.

Sclerotinia blight can be particularly devastating in some areas. It is recommended that

aregisteredfungicidespray(e.g.Rovral®at1L/ha)beappliedasaprotectantbefore

symptoms appear. This may be as early as when the crop is 6–8 weeks old, or when the




December 2014



firstflowerpetalsdrop.Oneortwofollowupfungicideapplicationsmayberequiredif

symptoms develop. 16 Roval®ismoreeffectiveatcontrollingS. sclerotiorum than S. minor.

9.4.1 Neocosmospora vasinfectaNeocosmospora vasinfectaisamajorsoil-bornefungalroot-rotpathogenfoundinall

peanut-growingareasofAustralia.Ithascausedyieldlossesofupto90%.

ThereisalackofinformationavailablegloballyregardingNeocosmosporainfectionin

peanuts, but this is being addressed through new research work being undertaken by

GrainsResearchandDevelopmentCorporation-fundedPhDstudent,KylieWenham.

Theprojectisassessingthepathogen’sformandstructuralcharacteristics,thegrowthand

developmentofthefungusbothin vitro and in situ,theoptimalgrowthconditionsfavoured

bythefungus,aswellastheoptimalenvironmentforthefungustoproliferateandinfect

crops.


i More information

New research tackles

devastating peanut root

rot. GRDC Media Centre.



http://grdc.com.au/Media-Centre/Media-News/North/2014/11/New-research-tackles-devastating-peanut-root-rot



Section 10 PEANUTS - Plant growth regulators and canopy management


December 2014



SECTION 10

Plant growth regulators and canopy management

Notapplicableforthiscrop.


Section 11 PEANUTS - Crop desiccation/spray out


December 2014



SECTION 11

Crop desiccation/spray out

Notapplicableforthiscrop.


Section 12 PEANUTS - Harvest


December 2014



SECTION 12

Harvest

Peanutsareanindeterminatecrop,whichmeansthatfromabout4weeksonwards,

thecropwillcontinuewithbothfloweringandvegetativegrowth.Commonly,thecropis

stillfloweringatharvest.Becausethecropdoesnotmatureevenly,itcanbedifficultto

determine the best time to dig.

Ifthecropisdugtooearly,significantweightandqualitylossmayoccurbecausethepods

havenotproperlyfilledout.Ifitisdugtoolate,thepeanutsmaybeover-ripeandoftenthe

largestandbestpodsareleftinthesoilduringdigging.1

12.1 Hull scrape test

Themostcommonmethodfordeterminingcropmaturityiscalledthehullscrapetest.This

involvestakingnoteofcolourchangesundertheouterskinoftheshelltoindicatekernel

maturity.

Theouterskinofthepod(exocarp)isremoved,whichexposesthecolouringunderneath.

Theexocarpcanberemovedbyscrapingthepodwithapocketknifeor‘blasting’thepods

withthestreamofwaterfromahigh-pressurewatercleaner.Thepodsareusuallyplacedin

a mesh basket while the exocarp is removed.

Itisimportanttonotethecolourinthesaddleareaofthepod(Figure1).Thisiswherethe

colourchangesfirstoccuronthepod.








December 2014



Figure 1: The saddle area of the pod is where colour changes first appear.

The colours that occur are:

• black: mature to over-mature

• dark brown: mature

• orange/light brown: close to mature

• yellow: immature

• white: immature to underdeveloped

Approximately200podsshouldbescraped.Thismeansdiggingcarefullybyhandatleast

sixorsevenrepresentativebushesfromdifferentpartsofthepaddock.Excesssoilshould

beremoved(usuallybywashing).Allpodswithadiametergreaterthanthatofaballpoint

pen(i.e.5–8mm)shouldberemoved.Growersshouldtakenoteofthepegstrengthas

each pod is removed.

Podsshouldbeplacedinmaturitycategoriesastheyarescraped.Thecolourswillfadeas

thepodsdryout,andkeepingthemmoistwillavoidthis.Sometimesitisdifficulttotellthe

differencebetweenorangeandbrown.Colourchartsareavailableforcolourcomparisons.

Alternatively,growerscanshell-outanypeanutstheyareunsureofandlookattheinsideof

the shell and the kernel.

Peanuts that are mature will be dark brown inside the pod and the seed coat will be thin

and tight on the kernel. With experience, growers become more adept at observing the

maturitydifferences.

Growersmustconsidertheotherfactorslistedbelowindeterminingwhentodig,butasa

generalguide,thecropisreadyfordiggingwhenthefollowingmaturitylevelsarereached:

• Virginiavarieties:digwhen60–65%brownandblack

• runnerandultra-earlyvarieties:digwhen65–80%brownandblack2






December 2014



12.2 When to dig

The crop’s maturity is assessed to determine harvesting time. Harvesting is a two-part

operation. First, the taproot is cut and the plant shoots and peanut pods inverted to dry

partiallyinthefieldforseveraldaysbeforeaseparatethreshingoperationisdone.

Thehullscrapetestshouldbeusedasaguideonlyfordeterminingwhentodig.Other

factorswillalsoinfluencethedecision,including:

• peg strength

• disease (bush health)

• weather conditions

• soil conditions

• area to be harvested

Allofthesefactorsshouldbeconsidered.3

12.2.1 Peg strengthThepegextendsfromthebranchesofthepeanutplantanditisthe‘lifeline’connectingthe

pod,belowthesoil,totherestofthebush.Ifthepegbecomesweakanddetachesfrom

the pod, then the pod cannot be recovered during harvesting and is lost.

Themainfactorsreducingpegstrengthinclude:

• over-maturity

• foliardisease

• soil-borne disease

Totestpegstrength,carefullydigseveralbushesfromdifferentpartsofthepaddock

(usually when collecting the maturity sample). Shake the bushes to simulate the mechanical

diggingaction.Ifasignificantnumber(10–20%)ofthepodsfalloff,thenpegstrengthis








December 2014



declining and urgent digging needs to be considered. The hull scrape test should be done

though;thismaystilldeterminethefinaldiggingdate.

12.2.2 DiseaseSometimes it is evident that disease is spreading rapidly through the crop, and there is not

sufficienttimetowaitforthecroptomatureproperly.Insuchsituations,adecisionmay

have to be made to dig the crop early to salvage the peanuts.

12.2.3 Weather conditionsGrowers must take into account the expected weather conditions when determining the

timetodig.Forexample,ifprolongedwetweatherisforecast,itmaybebettertodigalittle

early and have the peanuts properly inverted in a windrow, rather than still in the ground.

Thismaybeespeciallysoifthecropisdiseased.

Soiltrafficabilityfollowingheavyrainmustalsobeconsidered.

12.2.4 Soil conditionsGrowerssometimesdigbasedontheirexperienceofwhentheirsoilismostfriable.Asoil

that sets very hard when dry may make it almost impossible to avoid large losses when

digging.Itmaybenecessarytoirrigateanddigsuchpaddocksbeforetheybecometoo

dry.

Heavy soils usually have only a ‘narrow window’ available in which to harvest in relation to

soil moisture.

12.2.5 Area to be harvestedIfagrowerhasaverylargeareatobeharvestedandthecropsappeartobematuringallat

once, it may be necessary to dig some paddocks earlier than the optimum in order to avoid

lossesresultingfromthelastdugpeanutsbeingover-mature. 4

12.3 Digging and inverting

Aspeciallydesigneddiggerorpullerisusedtoremovethepeanutsfromthesoil.These

machinesarelinkage-mountedandmaycomein2-,4-or6-rowconfigurations.Cutter

blades are usually either attached to the digger or mid-mounted on the tractor. It is essential

to keep these blades sharp and to check that they are not cutting either too deep or too

shallow.

Duringdigging,thetaprootoftheplantiscutjustbelowthelevelofthepeanutsandthesoil

around the pods is loosened. The bush, with pods attached, is usually carried to the back

ofthediggerwhereitistheninverted.Thisleavesthepeanutslyinginawindrow.Tworows

ofpeanutsarenormallycombinedintoonewindrow.

Itisimportantthatthepeanutsareproperlyinvertedtoallowgoodaircirculationtofacilitate

4 PeanutCompanyofAustralia,http://www.pca.com.au/





December 2014



drying(Figure2).Ifthepeanutsarewellinverted,theyarelesslikelytobedamagedif

rainfalls.Italsokeepsthepodsupawayfromthesoilsurfaceforeasierharvestinganda

cleaner sample.

Amoisturecontentof16–18%isoptimalforthreshing.Controlleddryingbringsthepeanuts

slowlytosafestoragemoisturecontentandensuresoptimumquality.Extendedperiodsof

paddockdryingcancausehigherlosses,moresplits,poorerqualityandincreasedriskof

rain damage. 5

Acombineorthresherisusedtoseparatethepeanutsfromthebush.6

Factorsinfluencingharvestlosses:

• Soil type and soil management. Hard-setting and heavy soils are unsuitable.

• Poor late-season disease control can reduce pod quality and harvestability.

• Harvest management and timely access to harvesting equipment is critical.

• Cropmaturityshouldbecarefullyassessedtooptimiseyieldandquality.

• Kernelqualitylossesandaflatoxincanresultfromdelayedthreshinganddrying.7

Several practices, outlined below, have been shown to reduce actinomycete growth post-

harvest,andthusreducethechanceof‘off-flavour’contamination.

• Whenwindrowsremainwetfromrainaftercutting,fluffingisessentialtoimprove

aerationandensurerapiddry-downofpodsinordertominimiseactinomycetegrowth

on and around the pods.

• Short digging-to-thrashing intervals (3–5 days) can minimise the time that pod or kernel

moistureisinarangesuitableforactinomycetegrowth(i.e.>15%podmoisture).

Windrowsshouldnotbeleftinthepaddockfor>5days,becauseactinomycete

growthonpods(andthusoff-flavourcontamination)islikelytooccur.Thisisespecially

importantinareassuchasNorthQueensland,wherepost-harvestrainfallislikely.

• Thoroughpre-cleaningofharvestedpodsremovesextraneousmatterincludingdirt,

sticks,corncobs,gherkins,immaturepodsandpotatoes.Iftheproductisnotcleaned,

build-upofextraneousmaterialscancausewet,hotspotsandsubsequentoff-flavour

contamination in storage bins. 8

5 PeanutCompanyofAustralia,http://www.pca.com.au/


7 GMills,RRachaputi,GWright,YChauhan,JBarnes(2004)YieldpotentialofpeanutsatMackay.Whatarethe key barriers to obtaining it? GRDC Update Papers February 2004, http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it

8 GRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March2013,GRDC,http://www.grdc.com.au/GRDC-FS-PeanutOffFlavour







http://www.grdc.com.au/GRDC-FS-PeanutOffFlavour




December 2014



Figure 2: A peanut crop with well-inverted and aerated windrows allows rapid drying after wet weather at harvest. (Photo: PCA)

12.4 Windrowing

Peanutsusuallycontain40–50%moisturewhendug.Thepeanutsareleftinvertedinthe

windrowforseveraldaystobringthemoisturecontentdowntotheoptimumforthreshing,

whichis~12–16%.Thismaytake3–10days,dependingonprevailingweatherconditions.

Growerswithoutaccesstodryersoftenhavetoletthepeanutsdrydownto10%moisture

inthewindrow.Thismaytake5–14days.Theriskofdamagetothecropfrominclement

weather increases the longer the crop remains in the paddock. Also, as the crop dries

downto<12%,thepegsmaybecomeweakerandmorebrittleandcroplossesarelikelyto

increase.

Inaddition,theriskofaflatoxincontaminationismuchhigherifthepeanutsareleftformore

thanafewdaysinthewindrow.Thebestoptionisalwaystothreshearlyandartificiallydry.

12.5 Threshing

Threshersorpeanutcombinesaredesignedtopickupthewindrowfromthepaddock

andseparatethepodsfromthebush.Thepodsaredeliveredtoabinontopofthe

thresherwhilethebushiscarriedoutofthemachineandeitherspreadoverthepaddock

ordroppedinawindrowforhay-baling.Thresherscomeinconfigurationsof2–8rows.

MostofthemodernmachinesareimportedfromtheUSAandareattachedtothedraw

barandhydraulicsofthetractor.AMADASIndustriesandJohnDeere,however,havealso

developedself-propelledthreshersineither6-or8-rowconfigurations.




December 2014



Theidealmoisturecontentforthreshingis~12–16%.Below12%,threshinglossescan

increasefromthepick-up,podsandkernelsmaybedamaged,andtheincidenceofloose

shell kernels (LSKs) increases.

The thresher should be checked and maintained regularly. Excessive drum speed can also

resultindamagedpods.Inaddition,fansandblowersmayneedappropriateadjustments.9

12.6 Wet harvest issues and management

Wetconditionsatthetimeofharvestcanencouragethegrowthofactinomycetes,and

increasethechanceofcropcontamination.Alongintervalfromcuttingtothrashing(>5

days)incombinationwithpoorlyaeratedwindrows,whichpreventtheplantandpodsfrom

dryingrapidlydowntosafemoisture(i.e.<10%podmoisturewithin2–4days)canleadto

conditionsidealformicrobialgrowth.10

9 P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) Peanut CompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf,






Section 13 PEANUTS - Post harvest handling and storage


December 2014



SECTION 13

Post harvest handling and storage

PeanutdiggingstartsinlateautumnandextendsthroughtheperiodMarch–June,when

theyarelefttoair-dryinthefieldfor3–5daystoreducekernelmoisturecontentsto12–16

%.Thisisfollowedbythreshingoperationstoseparatethepodsfromthebush.

Podsarethenplacedinaerationdryersiloseitheron-farmorattheshellingplanttofurther

reducethekernelmoisturecontentdownto8.5%,thedeliverystandardenablingsafe

storage(Figure1).Typically,peanutsareonlyheldon-farmforabriefperiod(1–2days)

beforedeliverytoashellingplant,wherequalityisassessedandkernelsareremovedfrom

thepodsandundergofurtherprocessingpriortosaletocustomers.

13.1 How to dry and store peanuts on-farm

Toproducepeanutsofoptimumquality,mostgrowersartificiallydrytheirloads.Regular

checks are required because over-drying can lead to kernel damage (especially higher

levelofsplits),whichresultsinreducedgrade-outandlowerpricespertonne.Peanuts

thatarenotdriedtotheproperintakemoisturereadyforstoragewillhavetobedriedafter

delivery.PeanutCompanyofAustralia(PCA)hasfacilitiesinKingaroy,GayndahandTolga

forcontractdrying.Growersshouldensurethattheybooktheirloadsinfordryingwiththe

depot’sIntakeOfficer.

Tomaintainquality,loadsmustbedriedslowlyandcarefullyundercontrolledconditions.

Thefollowingguidelinesshouldbefollowed:

1. Pre-clean loads to remove dirt.

2. Startdryingwithin3–6hofthreshingtopreventmouldandrelatedaflatoxin

development.

3. Keepanevendepthofpeanutsoverthedryerfloor,generally≤2mispreferred.

4. Airtemperatureintheplenumshouldnotexceed11°Caboveambienttemperatures

(uptoamaximumof35°C).

5. Themoistureremovalrateshouldnotexceed0.5%perh,averagedoverthetimeof

drying.

6. Therelativehumidityofthedryingairshouldbe50–65%.

7. Useaminimumcontinuousairflowof200L/sperm3ofpeanuts.

8. Regularly check the temperature and humidity in the air tunnel.

9. Thepeanutsmusthavetimetoequilibratefollowingdryingandbeforedelivery(at

least 24 h).




December 2014



10. Regularlycheckthemoisturecontentofthepeanuts.1

Peanutsshouldonlybestoredaftertheyhavebeendrieddowntoapodmoisturecontent

of<~10%.

13.1.1 AflatoxinInorderminimisetheriskofaflatoxincontamination,peanutsshouldbedriedevenlyand

gently,andthreshers,bins,trucks,etc.,shouldbefreeofanyoldpeanutsororganicmatter.2

13.1.2 Off-flavour contamination Ifpeanutsaregoingtobestoredon-farm,theyneedtobeinsecureandaeratedstorage

binsthatpreventleakageandingressofmoisture.Moisturecanleadtodevelopmentof

microbialhotspotsandoff-flavourcontamination.

Contaminationofpeanutsbymicroorganismscalledactinomycetescanoccurinthe

fieldduringthegrowingseasonandduringpost-harveststorageandhandling.These

actinomycetes produce volatile compounds that contaminate the peanuts, causing must

yandearthyoff-flavours.Actinomycetesporesareprevalentintheenvironmentandoccur

onsoiladheringtopeanutpods,inforeignmaterialaccompanyingpods(soil,sticks

and other plant debris, including immature potatoes) and in storage bins. Post-harvest

off-flavourcontaminationofpeanutsisariskiftemperature,humidityandpodmoisture

conditionsareconducivetothegerminationandgrowthofactinomycetespores.

Temperatures>25°Candrelativehumidity>70%arehighlyconducivetoactinomycete

growth. Storage above these limits is discouraged. 3

Generally,on-farmstorageafterJulywillresultinahighriskofactinomycetegrowthand

potentialoff-flavourcontaminationduetoincreasingambienttemperatureandrelative

humidity. 4

1 P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) Peanut CompanyofAustraliahttp://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf




i More information

DAFF(2012)Aflatoxinin

peanuts.








https://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/peanuts/growing-peanuts/aflatoxin-in-peanuts

https://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/peanuts/growing-peanuts/aflatoxin-in-peanuts



December 2014



Figure 1: Peanut-drying silos allow pods to dry down to safe moisture content for storage. (Photo: PCA)

13.2 Pre-cleaning

Pre-cleanersarespecificallydesignedtoremovesoil,sticks,stonesandotherextraneous

matterfromaloadofpeanuts.Theyusuallyconsistofasetofrollersandscreensand

sometimes use blowers. Pre-cleaning a load prior to drying makes curing much more

efficientanduniformandovercomesproblemswithwetspotsintheload.

Pre-cleaningwilloftenremovemanyofthelooseshellkernelsandimmaturepodsthat

tendtoharbouraflatoxininfection.Manygrowershavefoundthatbypre-cleaningtheycan

dramaticallydecreasetheincidenceofaflatoxinintheirloads.

ForgrowerswhoarealongdistancefromPCA’sreceivaldepots,pre-cleaningensuresthat

theyarenotpayingfreightonextraneousmatter.Manygrowershavecommentedthatthey

havepaidfortheirpre-cleanerthroughsavingsmadeonfreightoverseveralyears.


Section 14 PEANUTS - Environmental responses


December 2014



SECTION 14

Environmental responses

14.1 Climate

Basedonclimatealone,peanutscanbegrownfromVictoria,throughNewSouthWales

(NSW) to North Queensland, the Northern Territory and Western Australia. However,

commercialpeanutproductioninareassouthofNarrabriinNewSouthWalesandinthe

north-westofAustraliahasbeenlimited.

In the USA, peanuts are mostly grown at much higher latitudes.

Growersindifferentlocationsneedtochoosedifferentvarietiesandmanagementstrategies

iftheyaretomaximisecropyields.

In some areas, planting times are critical. For instance, in southern regions, crops must

beplantedtomaturebeforecoldweatherinautumn.Early-maturingvarietieswillperform

betterintheseareas.Innorthernregions,cropsshouldbeplantedsotheywillbereadyfor

harvestafterthemainwetseason.

Irrigation is necessary in most areas to produce reliable economic peanut yields. 1

14.2 Temperature

Warmtemperaturesof~25–30°Cwillpromptvegetativegrowth,whereastheoptimum

temperatureforreproductivegrowthis~22–24°C.Plantingshouldbescheduledsothat

cropsexperiencewarmtemperaturesearlyintheseasonfollowedbycoolerweatherfor

floweringandthenmaturebeforethereisanyriskoffrost(Figure1).Hotsoilscanalso

damage peanut plants (Figure 2).

1 PCA/DPIF(2007)Climateandsoils.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/3a_climate.pdf


http://www.pca.com.au/bmp/pdfs/3a_climate.pdf



December 2014



Figure 1: Upper panel: yellowing between the veins of leaves is typical of cool night temperatures <9°C. Lower panel: frost kills the leaf tips but plant growth and pod-filling cease long before it is cold enough to frost.

Figure 2: Hot soil can cause leaf distortion and thickening as well as pollen sterility in peanuts during flowering.




December 2014



To determine when to sow, measure the soil temperature at planting depth at 09:00 (9am)

eachday.Whentemperaturesof18–20°Carerecorded3daysinarow,itistimetoplant

providedadequatesoilmoistureispresent.Ifseedsaresownintocoolsoil,emergence

will be slow because the seeds and seedlings are more susceptible to disease attack. Rain

within2–3daysofplantingwilllowersoiltemperatureandmayaffectemergenceifthesoil

temperaturefallsbelow18°C.

Lengthofthegrowingseasonrangesfrom110to170days(16–24weeks),dependingon

location and variety. For example, Early Bunch, an early-maturing variety, matures in ~170

days in Victoria, 140 days in Kingaroy and 120 days in Bundaberg. This delay in maturity is

due to cooler temperatures in elevated and southern regions. Very dry conditions can also

delay maturity.

Youcanpredictthecroplifecyclequiteaccuratelyusingtheheat-sumapproach.Thermal

timeiscalculatedastheaccumulationofheatunitsaboveabasetemperatureof9°Cup

toanoptimumof29°C.Thus,atypicaldayof35°Cmaximumand23°Cminimumwill

yieldameandailytemperatureof(35+23)/2=29°C,andathermaltimeof29–9=20°C

degree-days.Thethermaltimesforeachofthedaysthroughouttheseasonarethenadded

togethertogivethetotalheatunitsforaparticularenvironment.

Virginiaandrunnertypesrequirethermaltimeof~550degree-daystoprogressfrom

plantingtothebeginningofflowering,950degree-daystothebeginningofpodfilland2150

degree-daystomaturityformostlocationsinQueensland.

Cropscanflowerin~35daysinBundabergbuttakeupto45daysinKingaroy,as

thecritical550degree-daysareaccumulatedmuchfasterunderBundaberg’shigher

temperatures.

Temperaturecanalsoinfluencegrowthratesthroughitseffectsonphotosynthesis.Low

nighttemperatureshavealargeeffectongrowthrates.Kingaroy’snighttemperaturesare

~5°ClowerthanBundaberg’s,andcropstakeabout30dayslongertomatureinKingaroy.

However, Virginia Bunch produces similar dry matter amount and pod yield in both

locations. Although growth rates are lower in Kingaroy, the crop has longer to compensate,

and so yields are similar.

Asminimumtemperaturesdropto<17°C,peanutgrowthbeginstoslowdown.Drymatter

productiondropsbyabout25%whennighttemperaturesreach15°Candby50%at9°C.

Theplantsvirtuallyceasegrowingandfillingpodslongbeforeitiscoldenoughforfrost,so

cropsmustbeharvestedbeforefrostislikely.IninlandsouthernQueensland,thismeans

thatcropsshouldbereadyforharvestbeforetheendofApril. 2

14.3 Rainfall

Peanuts are moderately drought-tolerant but, like all crops, need readily available moisture

throughouttheseasontoproducehighyields.Whererainfallisreasonablydistributed

throughthegrowingseason,cropsproduceabout5–10kg/haofpodspermmofrainfall.






December 2014



FordrylandpeanutsinQueenslandandnorthernNSW,averagerainfallof≥400mmfrom

September to March is needed to produce a reasonable crop.

Foroptimalyields,~600mmofwaterisrequired.Thismeansirrigationrequirementsmay

be2.5–6ML/hadependingonvariety,location,rainfallandirrigationmethod.

Areaswithhighrainfall(>900mmannually)orconsistentlyhighhumiditygenerallyhave

moreproblemswithleafdiseases.Awell-managedfungicideprogramisneededinthese

areastocontrolleafspot,rustandnetblotch.

Dryconditionsatharvestareessential.Harvestlossescanresultfromextendedraineither

justbeforeorjustafterdiggingthepeanuts.High-rainfallareashaveagreaterriskofharvest

losses due to delayed harvest. 3

14.4 Daylength

Peanutsarenotaffectedbychangesindaylengthtothesameextentassomeothercrops

(e.g.soybeans).Thegrowthstagesofpeanutsaremainlycontrolledbytemperature.

However,reproductivegrowthmaybereducedwhendaylengthis>14hifnight

temperaturesarealso>20°C.AreasinsouthernAustraliamaythereforebeaffected,but

therearenoresearchdatatoconfirmthis.

Theamountofsunlightcanstronglyinfluencepeanutgrowth.Inwettropicalareas,such

asnorthQueensland,peanutsoftenshowrankgrowthwherethevegetativegrowthfar

outweighspodgrowth.Thisappearstobeaneffectofmoistureandtemperature.Short

daysandcloudyconditionscombinetoreducetheamountoflighteachday. 4

14.5 Soils

Soiltypeisamostimportantaspectofgrowingpeanuts.

Peanutsyieldbestinwell-drained,friable(loose)soils(Figure3).Eventhoughpeanutshave

traditionally been grown in red soils, texture rather than colour that determines whether a

soilissuitableforpeanutproduction.Peanutswillgrowandproduceacropinmostsoils,

buttheabilitytoharvestthecropwithminimallossesdeterminesthesoil’ssuitabilityfor

peanuts.

Soiltypeisprobablyoneofthetwomostlimitingfactorsforpeanutgrowth,alongwiththe

typeofirrigation.

Peanutstolerateawiderangeofsoilaciditylevels,howeverideallythepHshouldbe

between 6.0 and 7.0. Soils that are more acidic than this (below pH 6.0) should be limed.

Makesureyoursoiltestisproperlyinterpretedbyaqualifiedagronomist.5



5 http://www.pca.com.au/soil-preparation.php






December 2014



Heavy clay and poorly drained soils may not be suitable, because waterlogging at harvest

makesitdifficulttoextractthepodsgentlyandcleanly.

Blackcrackingclaysoilsusedforirrigatedcottonandothercropsaregenerallynotsuited

topeanuts.Asaruleofthumb,asoilissuitableforpeanutsifharvestingequipmentcan

operateeffectively4–5daysafterheavyrainorirrigation.

Figure 3: Some black soils are suitable for peanut production, but they must be friable and well drained.

Thetypeofsoilcaninfluencethevarietygrown,becausesomevarietiescanbeharvested

fromheaviersoilswithfewerproblems.Spanishvarieties,whichhavestrongpegsandpods

tightlyclusteredaroundthetaproot,canbesuccessfulinheaviersoils.However,wetsoilat

maturity will cause Spanish types to germinate and split. By contrast, some Virginia types

haveweakerpegsandtheirpodsarespreadover≥30cm.Thesetypescanhavehighyield

losses in soils that set hard at harvest.

Irrigationmanagementcanbeusedtosoftenthesoilandhelpharvestingonsomeheavier

or hardsetting soils, provided the soil does not become waterlogged.

Soilsmustbefreeofsticks,stumpsandlargestonesthatcaninterferewithharvestingand

damageequipmentworkingbelowandonthesoilsurface.

Peanutsarerelativelytolerantoflow-fertilitysoilscomparedwithothercrops.However,for

irrigatedcrops,amoderatefertiliserprogramisusuallyneeded.Asoiltestwillprovidea

guidetothenutrientstatusofthesoil.

IrondeficiencyisaproblemonsoilsofpH>7.5,usuallymoresoonheavysoils,especially

in wet conditions.




December 2014



Soil calcium is a critical nutrient in peanuts. Lighter sandy soils usually have low calcium

levelsinthepod-zoneandgrowersmustcorrectanydeficiency(Figure4).

Pesticide residues and heavy metals can contaminate peanuts. Organochlorines (e.g.

dieldrin, endrin, BHC, heptachlor and DDT) are the most common problems. A soil test,

along with the pesticide history, will indicate likely problems. 6

Figure 4: Light-textured soils are often deficient in calcium.




Section 15 PEANUTS - Marketing


December 2014



SECTION 15

Marketing

15.1 Consumption

Domesticpeanutconsumptionis~50,000tonnes(t)ofnut-in-shell,increasingat2–3%

per year. The Australian industry has worked hard to increase production and processing

efficienciestomeetthisdemand.

Australian peanut production usually meets the domestic demand, unless there is a severe

drought. The industry is now actively developing and supplying export markets.

Australiaisoneofthefewpeanut-producingcountries,ifnottheonlycountry,where

importsarepermittedwithminimaltariffs.

Recently,Australiahasimported5,000–8,000tofpeanutseachyear,mainlyfromArgentina

and Nicaragua.

Thereareabout120manufacturersinAustraliausingpeanutsforsnack-food,confectionery

orpeanutbutter(Figure1).Sevenprocessorsaccountfor~80%ofthemarket.

Figure 1: Peanuts are widely used in snack foods.




December 2014



Peanuts are sold as:

• nut-in-shell raw, boiled or roasted

• kernels raw, roasted, blanched or salted

• kernelsmanufacturedintopeanutbutterorusedinconfectionery

• peanutoilforcooking,foodprocessingandmargarine(Figure2)

• peanutmeal,theresidueafteroilextraction—ahigh-proteinstockfeed

• shellsforstockfeed,pottingmixandsoilconditioners1

Figure 2: Worldwide, most peanuts are crushed for oil.

15.1.1 Food valuePeanutscontain26%protein,higherthaneggs,dairyproductsandmanycutsofmeatand

fish.Thishighproteinlevelmakespeanutsanutritionalsnack-food,evenimprovingthe

nutritionalvalueofconfectionery.

Peanutshavehighfibrecontentandalowglycemicindex,oneofthelowestofallfoods.

Peanuts are:

• cholesterol-free

• verylowinsaturatedfat

• richinvitaminE,thiamine,niacin,folicacid,vitaminK

• agoodsourceofvitaminB6,biotinandpantothenicacid

• alow-sodiumfood(unsaltedpeanuts)2

1 PCA/DPIF(2007)Peanutindustry.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheriesQueensland, http://www.pca.com.au/bmp/pdfs/2c_indust_hist.pdf



http://www.pca.com.au/bmp/pdfs/2c_indust_hist.pdf




December 2014



15.2 World production

Worldconsumptionofpeanutsisincreasingatarateof~3%perannum.Peanutsare

calledgroundnutsinmanypartsoftheworld,particularlyAsiaandAfrica.Theyhavealso

beencalledgooberpeasinsouthernstatesoftheUSA.

In2004–05,worldpeanutproductionwas31,582milliont,ofwhichAustraliacontributed

<0.2%.China,IndiaandtheUSAarethemainproducers,growing15,7.0and2.2milliont,

respectively (see Table 1).

About95%oftheworld’sproductionisconsumedwithinthecountryoforigin,with>50%

crushedforoilandusedforcooking.Only~5%istradedontheworldmarket,themajority

ofwhicharerunnerpeanuts.

Thepriceofpeanutsontheworldmarkethasshownlittlemovementoverthepast10

years, except in those years when the USA has had a crop shortage. The USA tends to set

worldpricesasadominantexporter.PeanutsfromChinaandArgentinausuallytradeata

price5–20%lessthantheUSprice.

Worldpeanutpriceshaverisenrecentlybecauseofincreaseddemandforoilseeds

worldwide. 3

Table 1: 2004–05 peanut production, imports and exports (’000 t, nut-in-shell)

Source:PeanutCompanyofAustralia

Production Imports ExportsChina 15,000 UK 250 China 600

India 7,000 Netherlands 260 Argentina 500

USA 2,200 Germany 230 USA 400

Indonesia 920 Japan 150 SouthAfrica 25

Argentina 800 Indonesia 120 Brazil 2

Senegal 695 Canada 100 India 0

Burma 500 Hong Kong 85 Sudan 0

Sudan 400 France 66

Other 4067 Other 544 Other 278

Total 31,582 Total 1,805 Total 1,805

15.3 Contract options

Contractoptionsformarketingarebasedonapriceforeachgradeofpeanutsintheload.

For example:

Snackfood (Jumbo) ](Grade 1) ](Grade 2) ] } Edible Kernel Portion

Manufactuing (Grade 5 Splits) ](Grade 7 MFG)

Oil Through Sieve Oil crushingHand picked






December 2014



Thisgradingsystemappliestoallvarietiesofpeanuts,i.e.Virginia,runnerandultra-early

types.Paymentismadeonthebasisofkernelweightandqualityasdeterminedfromthe

sample taken at intake (see sample receival advice, Figure 3).

Jumbo,Grade1andGrade2refertothesizecategoriesineachpeanuttype.Althoughthis

gradingsystemappliestoallpeanuts,aJumboinaVirginiavariety(750kernels/kg)isadifferent

sizetoaJumboinarunnervariety(1300kernels/kg)anddoesnothaveanequalpayment.

Contractsareonaper-hectarebasisandofferflexiblepaymenttermsdependingon

growers’ individual requirements. Growers’ payments are processed through the PCA

KingaroyOffice,andqueriesregardingthepaymentsystemshouldbedirectedtothe

growers’localPCArepresentativeorGrowerPaymentsOfficer,Kingaroy.4

Growershaveachoiceofthreeprocessors:

PCA:

133 Haly Street, Kingaroy, Qld

PO Box 26, Kingaroy, Qld 4610

Ph: (07) 4162 6311

Email: [email protected]

G Crumpton & Sons Co. Pty Ltd

PO Box 672, Kingaroy, Qld 4610

Ph: (07) 4162 3547

Fax: (07) 4162 4582

Email: [email protected]

CliftonFarmingPtyLtd

118WillowSpringsRd,Clifton,Qld4361

(07) 4697 3311



mailto:[email protected]?subject=Email from PCA website

mailto:[email protected]


Section 16 PEANUTS - Current research


December 2014



SECTION 16

Current research

Soon to be populated.


Section 17 PEANUTS - Key contacts


December 2014



SECTION 17

Key contacts

James Clark - Chair

HunterValleygrowerJamesbringsextensiveknowledgeand

experienceindrylandandirrigatedfarmingsystemstothe

NorthernPanel.Hehasbeenamemberofthepanelsince2005

andchairmansince2008.Jamessaysthepanel’sroleisto

capture and invest in growers’ priorities and empower them to

adopt new production gain opportunities. He strongly believes

the grains industry needs to continue building RD&E capacity to

ensure growers remain competitive.

M 0427 545 212

E [email protected]

Loretta Serafin - Deputy Chair

Loretta has more than 12 years’ experience as an agronomist

in north-west NSW and currently works with the NSW DPI in

Tamworth.Sheisatechnicalspecialistfornorthernfarming

systems and provides expertise and support to growers, industry

andagronomistsintheproductionofsummercrops.Shehasa

passionforhelpinggrowersimprovefarmefficiencyandseesher

role as a conduit between advisers, growers and the GRDC to

ensure that growers’ needs are being met.

M 0427 311 819

E [email protected]

John Sheppard

John,apanelmembersince2006,hasawealthofpractical

farmingexperienceandbringsawheatbreeder’sperspective

tothepanel.Heviewsthepanelasanopportunityforgrowers

andprofessionalstoworktogethertoshapethefutureofthe

industry, and develop best management practices, as well as new

varieties and products. He is particularly interested in genotype-by-

environmentinteractionandthepreservationofgeneticresources.

M 0418 746 628

E [email protected]


mailto:colane%40bigpond.com?subject=

mailto:loretta.serafin%40dpi.nsw.gov.au?subject=

mailto:moorkulla%40gmail.com?subject=



December 2014



Jack Williamson

Jack,aprivateagriculturalconsultant,runsabroadacrecommodity

productionfarminGoondiwindi.Previousrolesasaterritorysales

managerforNufarmandasacommercialagronomistforMcGregor

GourlayAgriculturalServiceshavegivenJackextensivefarming

systemsknowledge,anddiversecropmanagementandfieldwork

experience.JackisamemberoftheNorthernGrowerAlliance

(NGA) local consultative committe and Crop Consultants Australia,

andwaspreviouslypresidentoftheMacIntyreValleyCottonField

Day Committee.

M 0438 907 820

E [email protected]

Julianne Dixon

JulesismanagerofAMPSResearchandapassionateagronomy

consultant, communicator and industry advocate. Her role

involvesthedevelopmentandexpansionofself-funded,privatised

research, development and extension. Her experience in project

managementandstrategicdevelopmentextendsacrossallfacets

ofanintegratedgrainsbusiness.Shehasanestablishednetwork

in eastern Australia and Western Australia, including researchers,

leading growers, agronomy consultants and commercial industry.

M 0429 494 067

E [email protected]

Keith Harris

Keith has served on the Northern Panel since 2011 and brings

more than 30 years’ experience in property management. Keith,

based on the Liverpool Plains, NSW, consults to Romani Pastoral

Companyonthemanagementofitshistoricholdings‘Windy

Station’and‘Warrah’,nearQuirindi.Heseesthemainaimof

the panel as representing growers and conducting research that

provides growers with the tools they need to maximise property

performanceandminimiserisk.

M 0428 157 754

E [email protected]


mailto:jack.williamson1%40bigpond.com?subject=

mailto:juliannedixon%40bigpond.com?subject=

mailto:kharris%40romanipastco.com.au?subject=



December 2014



Kelly Becker

BasedatTheodore,Queensland,Kellyisacertifiedmungbeanand

chickpea agronomist and also advises growers on wheat, corn

and sorghum crop production. She has been involved with variety

trialsonacommercialbasisandindustryfarmpracticetrialsas

an agronomist. She strives to be proactive within the industry and

aimstoassistgrowerstoimprovefarmingoperationsbyensuring

that they are up to date with new practices and technology.

M 0409 974 007

E [email protected]

Penny Heuston

Penny brings extensive experience to her second term on the

NorthernPanel.Sheiscommittedtomaximisingtheprofitabilityof

grainproductioninalow-rainfallenvironmentthroughincreased

productivity and good risk management practices. She was

principalinafarmadvisorybusinessincentralwestNSWand

workedwithgrowersacrossnorth-westNSWbeforejoining

DeltaAgribusiness,wherehermainfocusistheWarren,Nyngan,

Tottenham and Gilgandra areas.

M 0428 474 845

E [email protected]

Rob Taylor

Rob is a grain grower at Macalister on Queensland’s Darling

Downsandfarms2300hectaresofmaize,sorghum,wheat,barley

andchickpeasontheJimbourPlain.Robiscurrentlychairofthe

AgrifoodSkillsInitiativefortheWesternDownsRegionalCouncil

area.Robviewshisroleonthepanelastakinginformationand

feedbackfromgrowers,advisersandresearcherstotheGRDCto

ensure research is targeted.

M 0427 622 203

E [email protected]

Will Martel

Central NSW grower Will has served on the Northern Panel since

2011. Previously he worked in a Quirindi grain trading company

and with Brisbane-based Resource Consulting Services (RCS)

where he benchmarked more than 400 growers across Australia

ontheirperformance,focusingonwhole-farmprofitabilityrather

than individual enterprise gross margins. His main role on the panel

isidentifyinginvestmentareasthatwillenablegrowerstoremain

economic and environmentally sustainable.

M 0427 466 245

E [email protected]


mailto:kbecker19%40bluemaxx.com.au?subject=

mailto:pennyheuston%40deltaag.com.au?subject=

mailto:currfarm%40ozxpress.com.au?subject=

mailto:wandgmartel%40bigpond.com.au?subject=



December 2014



Dr Stephen Thomas - GRDC Executive Manager Commercial

BeforejoiningtheGRDCSteveheldaseniorpositionwiththeNSW

DepartmentofPrimaryIndustriesatOrange.Inearly2009hewas

appointed executive manager practices at the GRDC and in 2011

was appointed executive manager research programs. Currently

Steveholdsthepositionofexecutivemanagercommercial.He

sees the GRDC’s role is to interact with growers regularly to

determinetheirneedsandfocusonthebigpictureacrossentire

farmingsystems.

T 02 6166 4500

E [email protected]

Sharon O’Keeffe - GRDC Northern Regional Manager

SharonistheNorthernRegionalManagerfortheGrains

Research Development Corporation (GRDC), based in Boggabri

NSW.Sharon’sroleistoidentifyandoverseeregionalresearch,

development and extension (RD&E) needs, manage the regional

deliveryofinformationandpromotetheGRDC’sproductsand

services. Her role strengthens links between GRDC panels,

researchers, industry, advisors and growers. Sharon holds a

MastersinAgricultureandaBachelorofRuralScience(hons).

M 0409 279 328

E: [email protected]

David Lord - Panel Support Officer

David operates agricultural consultancy Lord Ag Consulting. For the

pastfouryearshehasworkedasaprojectofficerforIndependent

Consultants Australia Network (ICAN), which has given him a good

understandingoftheissuesgrowersarefacinginthenorthern

grains region. David’s new role is Northern Panel and Regional

GrowerServicessupportofficer.

M 0422 082 105

E [email protected]


mailto:steve.thomas%40grdc.com.au?subject=

mailto:sharon.okeeffe%40grdc.com.au?subject=

mailto:northernpanel%40gmail.com?subject=

Section 18 PEANUTS - References


December 2014



SECTION 18

References

A: IntroductionCCollis(2012)Peanutsbackinflavourbutmysterylingers.GroundCover,Issue97,March–April2012,

GRDC, http://www.grdc.com.au/Media-Centre/Ground-Cover/Ground-Cover-Issue-97-March-April-2012/Peanuts-back-in-flavour-but-mystery-lingers

GRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March 2013, GRDC, http://www.grdc.com.au/Downloads.ashx?q=/~/media/07956E2C47544ED9BA2F677D6576C567.pdf

P Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf

PCA.Areyouinterestedingrowingpeanuts?PeanutCompanyofAustralia,http://www.pca.com.au/growing-peanuts.php

1: Planning and paddock preparationMBell,GHarch,JTatnell,KMiddleton(2003)Theimpactofcroprotationonpeanutproductivity

inrainfedcroppingsystems.AustralianAgronomyConference,http://www.regional.org.au/au/asa/2003/c/5/bell.htm

RD Connolly, M Bell, G Wright (1998) Simulating peanut/wheat cropping in the Burnett with APSIM. 9th AustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/1998/9/177connolly.htm

GRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March 2013, GRDC, http://www.grdc.com.au/Downloads.ashx?q=/~/media/07956E2C47544ED9BA2F677D6576C567.pdf

CHam(2004)GrowingpeanutsintheTopEndoftheNT(Arachis hypogaeaL.).NTDepartmentofPrimary Industry, Fisheries and Mines, http://www.nt.gov.au/d/Content/File/p/Crop/177.pdf

PHarden,LWieck,GWright(2013)Peanutproductionguide,August2013.PeanutCompanyofAustralia, http://www.pca.com.au/pdfs/growing-peanuts/ppg2013.pdf


DHerridge(2013)ManaginglegumeandfertiliserNfornortherngrainscropping.GRDC,http://grdc.com.au/GRDC-Booklet-Managing-Fertiliser-N

GMills,RRachaputi,GWright,YChauhan,JBarnes(2004)YieldpotentialofpeanutsatMackay—What are the key barriers to obtaining it? GRDC Update Papers, February 2004, http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it















http://www.nt.gov.au/d/Content/File/p/Crop/177.pdf






December 2014



PCA.Benefitsofpeanutsincanerotation.PeanutFactSheet.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/factsheets/peanutsandsugarcane.pdf

PCA.Cottongrowers:haveyouconsideredpeanuts?PeanutFactSheet.PeanutCompanyofAustralia, http://www.pca.com.au/pdfs/factsheets/peanutsandcotton.pdf

PCA.Irrigationversusdrylandcropping.PeanutCompanyofAustralia,http://www.pca.com.au/irrigated-vs-dryland-peanuts.php

PCA.Soilpreparation.PeanutCompanyofAustralia,http://www.pca.com.au/soil-preparation.php

PeanutCompanyofAustralia,http://www.pca.com.au

GWright,ARobson,GMills(2004)Applicationofremotesensingtechnologiestoimproveyieldandwater-useefficiencyinirrigatedpeanuts.12thAustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/2004/poster/1/5/698_wrightg.htm

2: Pre-plantingGRDC(2010)Newvarietiesaddanothertoolinleafdiseasemanagement.ManagingLeafDiseasesin

Peanuts Fact Sheet, Summer 2010, GRDC, http://www.grdc.com.au/uploads/documents/GRDC_FS_Peanutleafdisease.FINAL.pdf



PCA/DPIF(2007)Peanutseedproduction.PeanutCompanyofAustralia/DepartmentofPrimaryIndustries and Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/7a_other_seed.pdf

3: PlantingPCA.Soilpreparation.PeanutCompanyofAustralia,http://www.pca.com.au/soil-preparation.php

PCA.Twinrowsboostyieldsandgrades.PeanutCompanyofAustralia,http://www.pca.com.au/twin-rows-boost-yields.php

PCA/DPIF(2007)Cropestablishment.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesand Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/3d_establish.pdf

RCNRachaputi,SKrosch,GWright.Optimisingrowspacingfortheultra-earlyTingoora,GRDC,PeanutCompanyofAustralia,theQueenslandGovernment,http://www.pca.com.au/pdfs/growing-peanuts/2010rowspacing.pdf

L Wieck, P Harden, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014) PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/ growing-peanuts/ppg2014.pdf

4: Plant growth and physiologyP Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014)

PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/ppg2014.pdf

PCA/DPIF(2007)Thepeanutplant.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesand Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/2a_peanut_plant.pdf








http://www.pca.com.au






http://www.pca.com.au/bmp/pdfs/7a_other_seed.pdf












December 2014



5: Nutrition and fertiliserDAFF(2010)Nutrition—VAMandlongfallowdisorder.DepartmentofAgriculture,Fisheriesand

Forestry Queensland, 14 Sept. 2010, http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/nutrition-management/nutrition-vam

IncitecPivot.Gypsum.Fertfacts.IncitecPivotLtd,http://www.incitecpivotfertilisers.com.au/en/Soil%20,-a-,%20Plant%20Tests/~/media/Gypsum%20Fact%20Sheet.ashx

PCA.Peanutsandfertilisers.PeanutCompanyofAustralia,http://www.pca.com.au/peanuts-and-fertilisers.php

PCA.Peanutproductionseasonplan.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/checklist.pdf


PCA/DPIF(2007)Cropnutrition.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/3b_nutrition.pdf

6: Weed controlP Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014)



PCA/DPIF(2007)Managingweeds.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesand Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/4c_weed.pdf

7: Insect controlP Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014)


PCA.Peanutproductionseasonplan.PeanutCompanyofAustralia,http://www.pca.com.au/pdfs/growing-peanuts/checklist.pdf

PCA/DPIF(2007)Managingpests.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/4b_insect.pdf

8: NematodesMBell,GHarch,JTatnell,KMiddleton(2003)Theimpactofcroprotationonpeanutproductivityin

rainfedcroppingsystems.AustralianAgronomyConference,AustralianSocietyofAgronomy,http://www.regional.org.au/au/asa/2003/c/5/bell.htm

RABroadley(1981)Distributionandcontrolofroot-knotandrootlesionnematodesonpeanutsinnorthQueensland. Australian Journal of Experimental Agriculture 21, 223–226, http://www.publish.csiro.au/paper/EA9810223.htm

DAFF(2012)Root-lesionnematodes.DepartmentofAgriculture,FisheriesandForestryQueensland,http://www.daff.qld.gov.au/plants/field-crops-and-pastures/broadacre-field-crops/peanuts/managing-peanut-diseases/root-lesion-nematodes
























December 2014



AMachado,LFerraz,MInomoto(2012)PathogenicityofPratylenchus brachyurus on cotton plants. The Journal of Cotton Science 16, 268-271, http://www.cotton.org/journal/2012-16/4/upload/JCS16-268.pdf

GMMurray,JPBrennan(2009)ThecurrentandpotentialcostsfromdiseasesofwheatinAustralia.ReportforGrainsResearchandDevelopmentCorporation,https://www.grdc.com.au/~/media/B4063ED6F63C4A968B3D7601E9E3FA38.pdf

PCA/DPIF(2007)Managingdisease.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesand Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/4a_disease.pdf

9: DiseasesGRDC(2010)Newvarietiesaddanothertoolinleafdiseasemanagement.ManagingLeafDiseasesin

Peanuts Fact Sheet, Summer 2010, GRDC, http://www.grdc.com.au/uploads/documents/GRDC_FS_Peanutleafdisease.FINAL.pdf

PHarden,LWieck,GWright(2013)Peanutproductionguide,August2013.PeanutCompanyofAustralia, http://www.pca.com.au/pdfs/growing-peanuts/ppg2013.pdf


PCA/DPIF(2007)Managingdisease.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesand Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/4a_disease.pdf

12: HarvestGRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March2013,GRDC,



GMills,RRachaputi,GWright,YChauhan,JBarnes(2014)YieldpotentialofpeanutsatMackay.What are the key barriers to obtaining it? GRDC Update Papers February 2004, http://grdc.com.au/Research-and-Development/GRDC-Update-Papers/2004/02/Yield-potential-of-peanuts-at-Mackay-What-are-the-key-barriers-to-obtaining-it

PeanutCompanyofAustralia,http://www.pca.com.au/

13: StorageGRDC(2013)Peanutoff-flavours.Northernregion.PeanutOff-flavourFactSheet,March2013,GRDC,



14: Environmental issues

PCA/DPIF(2007)Climateandsoils.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesand Fisheries Queensland, http://www.pca.com.au/bmp/pdfs/3a_climate.pdf






















December 2014



15: MarketingP Harden, L Wieck, G Wright (2013) Peanut production guide, August 2013. (Updated August 2014)


PCA/DPIF(2007)Peanutindustry.PeanutCompanyofAustralia/DepartmentofPrimaryIndustriesandFisheries Queensland, http://www.pca.com.au/bmp/pdfs/2c_indust_hist.pdf



Documents

GRDC GrowNotes Northern Peanuts December 2014