Implications of Biological Agents in Prunus Replant Disease

8/9/2019 Implications of Biological Agents in Prunus Replant Disease

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Dying Trees do Tell Tales:

Implications of Biological Agentsin Prunus Replant Disease.

February12th, 2009

Southern San Joaquin Valley Almond Day

David DollUniversity of California Cooperative Extension

Merced County

G. Browne1, B. Holtz2, B. Lampinen3

CPGRU USDA-ARS, Department of Plant Pathology, UC Davis1,UCCE Madera2, UC Davis Plant Sciences3

David Doll

UC Agricultural and Natural Resources

UCCE Merced County

6-23-10


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Replant Disease of Almond

CP-fumigated plot Non-fumigated plot

Healthy (L) and

PRD-affected almond trees

(R) in Butte County, 2003

Symptoms onalmond:

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UCCE Merced County

6-23-10


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Responses to spot, strip, and

broadcast fumigation treatments(Location: Firebaugh, pre-plant fumigated Oct 2006, planted Jan 2007)

Tr

t.

Fumigant, rate per treated

areaa

Treated area in tree

row

(and % of total area)

Fum.

per

orch.

acre

(lbs)

Disease

severity

rating

6/20/07

Trunk

diameter

February

2008 (mm)

1 Control None 0 1.8 202 Methyl bromide, 400 lb/a 8-ft strip (38%) 152 0.8 24

3 Telone II, 350 lb/a 8-ft strip (38%) 133 1.0 27

4 Chloropicrin (CP), 400 lb/a 8-ft strip (38%) 152 0.1 38

5 CP, 300 lb/a 8-ft strip (38%) 114 0.4 37

6 CP, 200 lb/a 8-ft strip (38%) 76 0.1 39

7 CP, 400 lb/a 8x8-ft tree sites (17%) 68 0.5 348

Midas (IM:CP. 50:50), 300

lb/a8-ft row strip (38%) 152 0.3 36

9 Telone C35, 550 lb/ac 8-ft row strip (38%) 209 0.1 36

10 Pic-clor 60, 550 lb/ac 8-ft row strip (38%) 209 0.0 39

11 Pic-clor 60, 400 lb/ac 8-ft row strip (38%) 152 0.3 35

12 Telone C35, 550 lb/ac 8x8-ft tree sites (17%) 93 0.3 3313 Telone C35, 550 lb/ac Broadcast (100%) 550 0.1 37

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UCCE Merced County

6-23-10


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Replant Disease of Almond

Healthy RD-affected

Healthy (L) and replant disease-affected (R) almond trees,Madera County 2007

David Doll


UCCE Merced County

6-23-10


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Effects of replant disease on root system

0

1000

2000

3000

4000

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Root diameter (mm)

Control

Pre-plant chloropcirin

0

1000

2000

3000

4000

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Root diameter (mm)

Control

Pre-plant chloropcirin

Marianna 2624 rootstocLovell peach rootstock

Totalrootlengthpersample

(cm)

Root length densities at 0 to 2 ft depth; determined by root

excavation and digital imaging

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UCCE Merced County

6-23-10


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What causes replant disease?Probesting, E.L., and Gilmore, A.E. 1941. The relation ofpeach root toxicity to

re-establishing of peach orchards. Proc. Am. Soc. Hort. Sci. 38:21-26.Probesting, E.L. 1949. The peach replant problem. Hort. News 30:2213-2214.

Probesting, E.L. 1950. A case history of a "peach replant" situation. Proc. Amer. Soc.Hort. Sci. 56:46-48.

Patrick, Z. A. (1955). "The peach replant problem in Ontario. II. Toxic substancesfrom the microbial decomposition products of peach root residues."Canadian Journal of Botany 33: 461-486.

Wensley, R. N. (1956). "The peach replant problem in Ontario. IV. Fungiassociated with replant failure and their importance in fumigated andnonfumigated soils." Canadian Journal of Botany 34: 967-982.

Mountain, W. B. and H. R. Boyce (1958). "The peach replant problem in Ontario.V. The relationship ofparasitic nematodes to regional differences inseverity of peach replant failure." Canadian Journal of Botany 36: 125-134.

Gilmore, A.E. 1959. Growth of replanted peach trees. Proc. Am. Soc. Hort. Sci.73:99-111.

Hine, R.B. 1961. The role ofamygdalin breakdown in the peach replant problem.Phytopathology51:10-13.

Hine, R.B. 1961. The role offungi in the peach replant problem. Plant DiseaseReporter45:462-466.

Gur, A., Cohen, Y. 1989. The peach replant problem- some causal agents. Soil Biol.Biochem. 21:829-834.

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UCCE Merced County

6-23-10


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What causes replant disease?

Peach Root Toxicity:

-Allelopathy

Nematodes:-Ring, Rootknot, etc.

Microbial involvement:

-Bacteria

-Fungi

No such thing:

Just a growth response to

fumigation

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UCCE Merced County

6-23-10


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Soil from old peach

orchard

Pre-plant fumigation

treatments applied to

microplots before

planting with Nemaguard

Control MBr 400 lb/A MBr 2700 lb/A

Chloropicrin 400 lb/A Chloropicrin 2700 lb/A

At end of first growing season, Nemaguard peach seedlings

David Doll


UCCE Merced County

6-23-10

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Peach Root Toxicity:

-Allelopathy



-Bacteria

-Fungi

No such thing:


fumigation

David Doll


UCCE Merced County

6-23-10

D id D ll


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Nemaguard Seedlings planted in soils that have been previously cropped inpeaches or grapes for 15 years. Microplot trials.

0

10

2030

40

50

60

70

80

90

Peach Soil Grape Soil

Control

Methyl Bromide

Chloropicrin

Telone II

Telone C35

Maximu

mS

hootLength(cm)

Min. sig. dif. = 24 Min. sig. dif. = 15

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UCCE Merced County

6-23-10

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-Bacteria

-Fungi

No such thing:


fumigation

David Doll


UCCE Merced County

6-23-10

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Butte County orchard RD trials (2001-2004):No significant counts of plant parasitic nematodes (3 orchards)

Sugar floatation and mist chamber extractions

Parlier microplot trials (2002-2005):Only pin nematode (Paratylenchus sp.) present in significant number

(3 repeated trials); not correlated with RD incidence

Madera County orchard trials (2003- ):

To date, minor or no nematode involvement; sampling continuing

Conclusion:RD and nematode parasitism not the same, they are distinct replant

problemswith biological agent(s) other than plant parasitic nematodes


Nematode Involvement in PRD:

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UCCE Merced County

6-23-10

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-Bacteria

-Fungi

David Doll


UCCE Merced County

6-23-10

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Hypotheses, Prunus replant disease (PRD):

PRD is induced by unfavorable shifts in soilborne microbialcommunities associated with previous cultivation of thehost

The shifts can be detected by complementary culture-basedand culture-independent sampling of fine roots and therhizosphere

Community members contributing to (or suppressing)

incidence of PRD can be cultured and tested forpathogenicity (or disease suppression)

Effects of semi-selective soil treatments on incidence andseverity of PRD will provide additional evidence formicrobial roles in the disease


David Doll


UCCE Merced County

6-23-10

David Doll


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Roots from healthy tree Roots from RD-affected tree

Roots and soil from healthy and RD-affected trees

Whole-organism assays

Direct quantification (nematodes)

Isolation and quantification in culture

(fungi, bacteria)

Molecular assays

DNA fingerprinting (PCR of

rDNA; fungi, bacteria,

cloning of fragments, DNA-

sequence-based id)

Soil treatments

Semi-selective

chemicals or

treatments in

Microplot, GH

tests


David Doll


UCCE Merced County

6-23-10

David Doll


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0

10

20

30

40

50

Discoloredroots

(%)

Control

Divide

nd

Maxim

Rido

mil

Stre

pt.+Ch

loram

.

Nem

acur

No heat Autoclaved

Effects of semi-selective soil treatmentsGreenhouse trial:

David Doll


UCCE Merced County

6-23-10

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Effects of semi-selective soil treatments

Microplot trial:

What causes replant disease?UC Agricultural and Natural Resources

UCCE Merced County

6-23-10

David Doll


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d

a

bc

d

cd

d

bc

ab

Top fresh wt. of plants per plot (g)

Effects of semi-selective treatments on severity of PRD,microplots



UCCE Merced County

6-23-10

David Doll


19/33

Hypotheses, Prunus replant disease (PRD):

PRD is induced by unfavorable shifts in soilborne microbialcommunities associated with previous cultivation of thehost

The shifts can be detected by complementary culture-basedand culture-independent sampling of fine roots and therhizosphere

Community members contributing to (or suppressing)

incidence of PRD can be cultured and tested forpathogenicity (or disease suppression)

Effects of semi-selective soil treatments on incidence andseverity of PRD will provide additional evidence formicrobial roles in the disease



UCCE Merced County

6-23-10

David Doll


20/33

Roots from healthy tree Roots from RD-affected tree

Roots and soil from healthy and RD-affected trees

Whole-organism assays

Direct quantification (nematodes)

Isolation and quantification in culture

(fungi, bacteria)

Molecular assays

DNA fingerprinting (PCR of

rDNA; fungi, bacteria,

cloning of fragments, DNA-

sequence-based id)

Soil treatments

Semi-selective

chemicals or

treatments in

Microplot, GH

tests



UCCE Merced County

6-23-10

David Doll


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2003 Trial Year


-1.0 1.0

Arthro-2Bacill-4

Bacill-6

Entero

Flav-4Microb-1

Microb-3

Pseud-1RhizA-2

Pseud-2

Pseud-3

Rhiz-1RhizA-1

Vario-1

Control

Chloropicrin

Methyl Bromide

Control*Bleach

Control*Rinse

Chloropicrin*Rinse

Chloropicrin*Bleach

Methyl Bromide*Bleach

Methyl Bromide*Rinse N=266

Ordination significant

at P=0.008 for axis 1

and P=0.002 for axis 2.

Ordination of bacterial incidence, Parlier trial, 2004


UCCE Merced County

6-23-10

David Doll


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What causes replant disease?Ordination of cultured fungal incidence, Firebaugh replant trial, 2007

N=150

Ordination

significant at

P=0.002 for eachaxis -1.0 1.0

.

Cylind

Fusoxy1

Fus1

Fus3 Fus4Unk-C

Tricho-2

Acremon

Asper

Control CP

Control*Rinse

Control*Bleach

CP*Rinse

CP*Bleach


UCCE Merced County

6-23-10

David Doll

UC A i l l d N l R


23/33

What causes replant disease?Testing pathogenicity of bacteria and fungi on

Nemaguard peach


UCCE Merced County

6-23-10

David Doll

UC A i l l d N l R


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What causes replant disease?Pathogenicity of bacteria associated with replant disease on NG peach


UCCE Merced County

6-23-10

David Doll

UC A i lt l d N t l R


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Pathogenicity of fungi associated with replant disease on NG peach

Disea

seserveritysco

re

(0=healthy,5=dead

)


UCCE Merced County

6-23-10

David DollUC Agricultural and Natural Resources


26/33



-Bacteria

-Fungi


UCCE Merced County

6-23-10



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Non-Fumigant Management of

Replant DiseaseApplication of pre-plant cropping and fallow treatments.Microplot experiments.


UCCE Merced County

6-23-10



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0

200

400

600

800

Responses of Nemaguard peach seedlings to short-termfallow, rotation treatments. Microplot Experiments.

Topfreshwt.endoffirst

year(grams)


Replant Disease


UCCE Merced County

6-23-10



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Replant DiseaseThe affects of Piper-Sudan on replant disease of peach. FieldTrials. Planting: OHenry Peach on Nemaguard following 20

yr old Santa Rosa Plums on Marianna 2624


UCCE Merced County

6-23-10



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Non-Fumigant Management ofReplant Disease

Responses to spot, strip, and broadcast fumigation treatments, Firebaugh(pre-plant fumigated Oct 2006, planted Jan 2007)

Fumigation treatment

(Oct 2007)

Fumigant

per

treated

acre

(lbs)

Fumigant

per

orchard

acre

(lbs)

Sudan grass rotation

(Jul-Sep 2007)

Disease severity

rating

(0 to 5 scale)

(7 Jul 2008)

Increase

in trunk

diameter

by 30 Aug

2008

(mm)

Control 0 --

no 1.5 7.9

yes 0.9 14.1

MB, by conventional

shanks to 8-wide row

strips

400 168no 0.9 22.6

yes 0.5 20.4

Telone C35, by

conventional shanks to 8-

wide row strips

540 227no 0.3 28.3

yes 0.3 31.9

Telone C35, by GPS-

controlled shanks to 5x 6

tree spots

540 81no 0.7 21.4

yes 0.5 24.2

Inline, by single drip

emitters

to 4-dia. tree spots

540 43no 0.8 20.8

yes 0.6 21.3

Chloropicrin, by GPS-

controlled shanks to 5x6

tree spots

400 60no 0.6 24.2

yes 0.2 26.5

None, yeast extract root

spray and drench at

planting

0 --no 1.2 10.4

yes 1.0 14.0

Minimum significant difference (according to 95% confidence intervals): 8.9


UCCE Merced County

6-23-10



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18

18.5

19

19.5

20

20.5

21

21.5

22

Control Sudan

TreeDiamter

(mm)

a

b

P=0.048


Replant Disease

g

UCCE Merced County

6-23-10



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Conclusions:

Replant disease (RD) of almond is a biologically induceddisease showing poor growth or survival in almondplanted after Prunus. Prevented by pre-plant fumigation with fumigants containing

Chloropicrin.

Some fungi and bacteria are being implicated, multipleapproaches are being used to determine causal agentsand developing greenhouse assays.

An unfavorable microbial community may beresponsible for the disease: Shifting the microbial community in favor of the newly planted

Prunus sp. tree may provide some level of disease control.

Pre-plant application of treatments or cover cropping mayprovide alternative control reducing the use of fumigants

g

UCCE Merced County

6-23-10



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Thank you!

Almond Board of California

USDA-ARS Pest Mgt. Program for Integrated

Alternatives to Methyl Bromide

TriCal, Inc.

Commercial almond and peach growers of CA

Multiple scientific personnel involved

g

UCCE Merced County

6-23-10

Documents

Implications of Biological Agents in Prunus Replant Disease