1

COURSE SEMINARCOURSE SEMINARONON

2

WEED MANAGEMENT WEED MANAGEMENT

IN IN

DIRECT SEEDED RICEDIRECT SEEDED RICE

SpeakerGAURAVI.D. No. A-

12014

SupervisorProf. M.K.SINGH

Co- SupervisorDR. S.K.VERMA

INTRODUCTIONINTRODUCTION

3

INDIA (Rice)

Area 43.8 mhaProduction 96.4 mtProductivity 2.2 t/ha

4

Why shift from transplanting Why shift from transplanting to direct seed rice?to direct seed rice?

Lowering of water table

Costly

Destruction of soil structure

5

Practice of sowing sprouted/unsprouted seeds into puddled/ Practice of sowing sprouted/unsprouted seeds into puddled/ unpuddled soil by broadcasting/dibbling /drum seeding unpuddled soil by broadcasting/dibbling /drum seeding

Direct Seeding Direct Seeding

6

Different methods of rice Different methods of rice establishmentestablishment

Dry Seeding TransplantingWet Seeding

Broadcasting

Drilling

Broadcasting

Drum Seeding

Manual

Mechanical

7

Advantages of DSRAdvantages of DSR

ReduceReduce Labour requirement-costLabour requirement-cost Water requirementWater requirement

Helps maintain proper plant standHelps maintain proper plant stand

Direct-seeded plants mature 7 to 10 Direct-seeded plants mature 7 to 10 days earlier than transplanted rice. days earlier than transplanted rice.

8

Problems of Direct Seeded RiceProblems of Direct Seeded Rice

EstablishmentEstablishment

Weeds – Weeds – More diverse weed floraMore diverse weed flora

9

Weed - Weed - A weed is a plant A weed is a plant growing where it is not desired growing where it is not desired

.(Jethro Tull 1713).(Jethro Tull 1713)

E. colona E. crus-galli

10

WEED MANAGEMENTWEED MANAGEMENT its is the its is the combination of the techniqe of combination of the techniqe of prevention, eradication and control to prevention, eradication and control to manage weeds in a crop or in a crop or enviorment.enviorment.

11

Weed flora of direct seeded Weed flora of direct seeded ricerice

Grasses - Grasses - Echinochloa crusgalli , E. colonum Echinochloa crusgalli , E. colonum Ischaemum rugosum, Digera arvensis Ischaemum rugosum, Digera arvensis Leptochloa apniceaLeptochloa apnicea

Sedges - Sedges - Cyperus iria, Cyperus difformis, Cyperus Cyperus iria, Cyperus difformis, Cyperus rotundusrotundus

Broad Leaf - Broad Leaf - Ammania baccifera, Caesulia axillaris Ammania baccifera, Caesulia axillaris

Different weed management practices for direct-seeded rice systemsDifferent weed management practices for direct-seeded rice systems

12

PREVENTIVE METHODPREVENTIVE METHOD

USE CLEAN CROP SEEDUSE CLEAN CROP SEED

MACHINERY USED FOR TILLAGE MACHINERY USED FOR TILLAGE SOWING HARVESTING OPRETION SOWING HARVESTING OPRETION SHOULD ALSO BE CLEANDSHOULD ALSO BE CLEAND

BUND AND IRRIGATION CANAL BUND AND IRRIGATION CANAL FREE FROM WEED FREE FROM WEED

13

CULTURAL PRACTICESCULTURAL PRACTICESAPPROCHES IN DSRAPPROCHES IN DSR

Stale seedbed techniqueStale seedbed technique

Tillage practicesTillage practices Competitive varietiesCompetitive varieties Row spacing and seed rateRow spacing and seed rate Crop residue as mulchesCrop residue as mulches FloodingFlooding

14

15

Stale seedbed practiceStale seedbed practice In this practice, weed seedlings are In this practice, weed seedlings are

allowed to emerge after light irrigation and allowed to emerge after light irrigation and then killedthen killedby nonselective herbicide application or by nonselective herbicide application or tillagetillage

EFFECT OF TILLAGE SYSTEM ON SEEDLING EMERGENGE EFFECT OF TILLAGE SYSTEM ON SEEDLING EMERGENGE OF DIFFERENT WEED SPECIES UNDER AEROBIC RICE OF DIFFERENT WEED SPECIES UNDER AEROBIC RICE

SYSTEMSYSTEM

16

EFFECT OF HIGH SEED RATESEFFECT OF HIGH SEED RATES

In many countries, high seeding rates are used in In many countries, high seeding rates are used in direct-seeded rice systems.direct-seeded rice systems.

High seeding rates result in rapid canopy closure.and High seeding rates result in rapid canopy closure.and reduce weed competition.reduce weed competition.

High seeding rates may help to suppress weed growth High seeding rates may help to suppress weed growth and reduce grain yield losses due to weeds.and reduce grain yield losses due to weeds.

In such conditions, farmers cannot use high seeding In such conditions, farmers cannot use high seeding rates because of the high cost incurred for seeds. rates because of the high cost incurred for seeds. Because of the availability of suitable sowing drills or Because of the availability of suitable sowing drills or planters with preciseplanters with precise

seed-metering devices , seeding rates of only 15 to 25 seed-metering devices , seeding rates of only 15 to 25 kg ha−1 are used for sowing dry-seeded rice crops.kg ha−1 are used for sowing dry-seeded rice crops.

17

IN ROW-SEEDED CROPS,WEED EMERGING BETWEEN THE ROWS CAN BE IN ROW-SEEDED CROPS,WEED EMERGING BETWEEN THE ROWS CAN BE DISTINGUISHED AND PULLED OUT.DISTINGUISHED AND PULLED OUT.

DIRECT-SEEDED CROP SHOULD BE GROWN USING NARROW ROW SPACING TO OBTAIN FASTER CANOPY CLOSURE AND LESS PENETRATIONOF LIGHT AND ULTIMATELY LESS WEED GROWTH.

IN WEED-FREE ENVIRONMENTS, THE GRAIN YIELDIN WEED-FREE ENVIRONMENTS, THE GRAIN YIELDMAY BE SIMILAR BETWEEN A CROP PLANTED WITHMAY BE SIMILAR BETWEEN A CROP PLANTED WITH20-CM OR 30-CM ROW SPACING.20-CM OR 30-CM ROW SPACING.

SEED-SOWING DRILLS ARE CAPABLE OF SEEDING AT 18- TO 20-CM SEED-SOWING DRILLS ARE CAPABLE OF SEEDING AT 18- TO 20-CM ROW SPACING.ROW SPACING.

EFFECT OF ROW SEEDLING IN NARROW SPACINGEFFECT OF ROW SEEDLING IN NARROW SPACING

18

CROP RESIDUES OF PREVIOUS CROPS IF CROP RESIDUES OF PREVIOUS CROPS IF LEFT ON SOIL SURFACE AS MULCH CAN LEFT ON SOIL SURFACE AS MULCH CAN SUPPRESS WEEDS IN DSR THROUGH SUPPRESS WEEDS IN DSR THROUGH MULTIPLE MECHANISMS, INCLUDING, MULTIPLE MECHANISMS, INCLUDING, CREATING A PHYSICAL HINDRANCE TO CREATING A PHYSICAL HINDRANCE TO EMERGING WEEDS OR BY RELEASING EMERGING WEEDS OR BY RELEASING ALLELOCHEMICALS IN THE SOIL.ALLELOCHEMICALS IN THE SOIL.

Crop residue as mulchesCrop residue as mulches

19

The use of residue as mulches can help in suppressing weed The use of residue as mulches can help in suppressing weed emergence and weed growth in dry-seeded rice systemsemergence and weed growth in dry-seeded rice systems

20

EFFECT OF ESTABLISHMENT METHOD ON WEED EFFECT OF ESTABLISHMENT METHOD ON WEED MANAGEMENTMANAGEMENT

21

22

Effect of sowing methods in DSREffect of sowing methods in DSR

TreatmentTreatmentWeed dry matter Weed dry matter

(q/ha)(q/ha)Effective tillers Effective tillers

/m/m22

Grain yield Grain yield (q/ha)(q/ha)

Pudding- direct broadcastPudding- direct broadcast 2.71 (9.8)2.71 (9.8) 258258 41.441.4

ZT- direct line ZT- direct line 3.23 (14.8)3.23 (14.8) 173173 35.935.9

ZT- direct broadcastingZT- direct broadcasting 3.42 (16.8)3.42 (16.8) 190190 38.238.2

Transplanting 1.0 (0) 240240 54.9

Late transplantingLate transplanting 1.09 (1.2)1.09 (1.2) 260260 49.349.3

CD (p=0.05)CD (p=0.05) 0.280.28 3737 8.98.9

Walia et al (2006) Lomy sand, PR 115

23

Effect of crop establishment methods in DSREffect of crop establishment methods in DSR

TreatmentTreatmentPlant Plant

height (cm)height (cm)LAI at 60 LAI at 60

DASDASWeed dry Weed dry

mattermatterGrain yield Grain yield

(q/ha)(q/ha)B:C ratioB:C ratio

Dry seedingDry seeding 80.880.8 2.892.89 32.332.3 38.4138.41 0.480.48

Drum seedingDrum seeding 82.182.1 3.273.27 19.419.4 50.6250.62 1.19

Zero tillageZero tillage 83.083.0 2.982.98 38.938.9 42.2742.27 0.800.80

TransplantedTransplanted 83.383.3 3.463.46 15.315.3 55.29 0.960.96

CD (p=0.05)CD (p=0.05) 0.90.9 0.170.17 7.17.1 4.124.12 --

Yadav and Singh (2006)Sity loam

24

EFFECT OF FLOODINGEFFECT OF FLOODING

Flooding is considered the best weed Flooding is considered the best weed management option in rice.management option in rice.

Flooding can suppress the emergence Flooding can suppress the emergence and growth of several weed speciesand growth of several weed species

Early and continuous flooding at a Early and continuous flooding at a shallow depth (shallow depth (e.g., 2 e.g., 2 cm) can also cm) can also help to suppress the emergence and help to suppress the emergence and growth of problematic weedsgrowth of problematic weeds

25

Effect of GenotypesEffect of Genotypes

Competitive cultivar can suppress weed seed production, limit future weed infestation, and become a safe, environmentally benign and low cost tool for weed management

early fast growth, maximum number of leaf, tall stature of plant and more tillering capacity have better competitive ability against weed than slow growing cultivars

The choice of a cultivar plays an important role in crop-weed competition due to the cultivar’s morphological characters and the competitive ability of rice is usually associated with lightinterception-related traits

26

27

Roy and Mishra (1999) Sandy loam

GenotypesGenotypesDry weight of Dry weight of weeds (g/mweeds (g/m22))

Plant height Plant height (cm)(cm)

Panicle/mPanicle/m22 Panicle Panicle length (cm)length (cm)

Grain yield Grain yield (q/ha)(q/ha)

SBR 34-69-141.241.2 68.068.0 281.4281.4 19.519.5 21.521.5

ES 18-11-2 62.862.8 63.063.0 264.7264.7 18.518.5 19.219.2

CD (p=0.05)CD (p=0.05) 4.04.0 3.23.2 6.86.8 0.50.5 1.21.2

Performance of rice genotypes under DSRPerformance of rice genotypes under DSR

MECHANICAL MECHANICAL PRACTICES PRACTICES

IN DSRIN DSR Using hand pused weeeder (e.g., cono Using hand pused weeeder (e.g., cono

weeder)weeder)

Note;- the use of mechanical weeder is Note;- the use of mechanical weeder is feasiable only where rice planted in feasiable only where rice planted in rowrow

28

DRY-SEEDED RICE ROW SEEDING WITH INTERROW DRY-SEEDED RICE ROW SEEDING WITH INTERROW WEEDING USING HOES AND WITHOUT ANY HERBICIDE WEEDING USING HOES AND WITHOUT ANY HERBICIDE ACHIEVED HIGHER GRAIN YIELD (SATOSHI ET AL., ACHIEVED HIGHER GRAIN YIELD (SATOSHI ET AL., 2009). 2009).

OPINED THAT RICE FARMERS CAN USE ROTARY WEEDING OPINED THAT RICE FARMERS CAN USE ROTARY WEEDING INSTEAD OF HERBICIDE IN CONTROLLING WEEDS AND INSTEAD OF HERBICIDE IN CONTROLLING WEEDS AND ACHIEVE THE SAME GRAIN YIELD OF WET-SEEDED RICE. ACHIEVE THE SAME GRAIN YIELD OF WET-SEEDED RICE. (MNGUU 2010) (MNGUU 2010)

Conti…..Conti…..

29

30

HERBICIDESHERBICIDES

Pre -plant herbicidesPre -plant herbicides Preplant herbicides: These are used to knock down existing Preplant herbicides: These are used to knock down existing

weeds of a perennialweeds of a perennial

nature before planting.nature before planting. Use glyphosate @ 1.0 kg a.i./ ha in 400–500 L of water. It is Use glyphosate @ 1.0 kg a.i./ ha in 400–500 L of water. It is

preferable that the control of perennial weeds and seeding of preferable that the control of perennial weeds and seeding of rice should be done 7–10 days after glyphosate spray. rice should be done 7–10 days after glyphosate spray.

Use flat fan nozzles for spraying. Use flat fan nozzles for spraying. Best results are obtained when weeds are in active growth Best results are obtained when weeds are in active growth

stages. If weeds are vegetating (not growing).stages. If weeds are vegetating (not growing). Apply light irrigation several days before glyphosate spray. This Apply light irrigation several days before glyphosate spray. This

knocks down all weeds, including knocks down all weeds, including Cynadon dactylon and Cyperus Cynadon dactylon and Cyperus rotundus.rotundus.

Use paraquat @ 0.5 kg a.i. /ha in 600 L of water (preferably Use paraquat @ 0.5 kg a.i. /ha in 600 L of water (preferably should be used when perennial weeds are not present, and should be used when perennial weeds are not present, and sowing can be done immediately after spray). sowing can be done immediately after spray).

CONTI……CONTI……

31

HERBICIDESHERBICIDES

Pre-emergence herbicidesPre-emergence herbicides Pre-emergence herbicides are generally Pre-emergence herbicides are generally used before the emergence of used before the emergence of

weeds. Thus,these chemical molecules are applied immediately after the weeds. Thus,these chemical molecules are applied immediately after the sowing of the crops.sowing of the crops.

Use Use pendimethalin @ 1.0 kg a.i./ ha in 600–750 L of water/ha in moist pendimethalin @ 1.0 kg a.i./ ha in 600–750 L of water/ha in moist conditions and in evening hours.conditions and in evening hours.

Pretilachlor with safener at 0.50 kg a.i./ ha in standing-water Pretilachlor with safener at 0.50 kg a.i./ ha in standing-water conditions.conditions.

Post-emergence herbicidesPost-emergence herbicides Postemergence herbicides are used to Postemergence herbicides are used to knock down weeds after they are knock down weeds after they are

up orup or

growing vigorously.growing vigorously. Use Use Almix at 0.004 kg a.i. ha for the control of broadleaf weeds and Almix at 0.004 kg a.i. ha for the control of broadleaf weeds and

annual sedges. It also suppresses annual sedges. It also suppresses Cyperus rotundus for a fewCyperus rotundus for a fewdays.days. Use Use 2,4-D at 0.5–0.75 kg a.i./ ha for knocking down 2,4-D at 0.5–0.75 kg a.i./ ha for knocking down Sesbania, annual Sesbania, annual

sedges and broad leaf weeds.sedges and broad leaf weeds. Use Use Azimsulfuron @ 0.030 kg a.i./ ha to control most weeds, Azimsulfuron @ 0.030 kg a.i./ ha to control most weeds,

including including Cyperus species, except grasses.Cyperus species, except grasses.

Effect of stale bed method, on weed Effect of stale bed method, on weed managementmanagement

Singh, 2013

TREATMENT Weed density (no./m2)30DAS 60DAS

Rice establishmentDry seeded after stale bedusing shallow tillage

8.15 11.30

Dry seeded after stale bedusing glyphosate1kg/ ha

7.25 10.49

LSD(P=0.05 0.82 NS

33

Effect of seed rate and weed control in Effect of seed rate and weed control in WSR WSR

TreatmentTreatmentWeed dry Weed dry

matter (q/ha)matter (q/ha)WCE (%)WCE (%)

Effective Effective tillers/mtillers/m22

Grain yield Grain yield (q/ha)(q/ha)

Seed rate (kg/ha)Seed rate (kg/ha)

4040 9.239.23 52.6352.63 389.9389.9 44.744.7

5050 9.229.22 52.7452.74 394.8394.8 45.845.8

6060 9.219.21 52.8552.85 401.3401.3 46.246.2

CD (p=0.05)CD (p=0.05) NSNS -- NSNS NSNS

Weed control treatmentsWeed control treatments

Pretila 0.75 Pretila 0.75 7.677.67 61.5961.59 410.4410.4 50.650.6

Pendi 0.75 Pendi 0.75 7.637.63 61.9361.93 417.6417.6 53.653.6

2 HW2 HW 7.567.56 65.5265.52 420.3420.3 54.254.2

Unweeded Unweeded 15.4715.47 -- 306.1306.1 15.415.4

CD (p=0.05)CD (p=0.05) 0.170.17 -- 29.229.2 4.544.54

Payman and Singh (2008)Loamy sand, Wet seeding, SPD

34

Effect of weed control treatments on weed and Effect of weed control treatments on weed and yield of DSRyield of DSR

TreatmentTreatmentWeed dry Weed dry

mattermatter

(g/m(g/m22))WCE (%)WCE (%)

Panicles /Panicles /mm22

Grain yield Grain yield (q/ha)(q/ha)

Butachlor 1.5Butachlor 1.5 35.2335.23 77.5977.59 444444 26.926.9

Butachlor 1.0 fb 2,4-D 0.6Butachlor 1.0 fb 2,4-D 0.6 34.8434.84 77.8477.84 460460 27.827.8

Pendimethalin 1.5Pendimethalin 1.5 25.7125.71 83.6783.67 460460 28.028.0

Pendimethalin 1.0 fb 2,4-D 0.6Pendimethalin 1.0 fb 2,4-D 0.6 17.8117.81 88.6788.67 465465 30.030.0

Weed free Weed free 6.046.04 96.1696.16 518518 31.331.3

Unweeded Unweeded 157.24157.24 -- 283283 14.314.3

CD (p=0.05)CD (p=0.05) 21.6221.62 -- 5858 3.43.4

Kalia and Bindra (1996) Sility clay loam, Dhan 221

35

Effect of different weed control treatments on Effect of different weed control treatments on weeds and DSRweeds and DSR

TreatmentTreatmentWeed density Weed density

(No/m(No/m22))Weed dry wt. Weed dry wt.

(g/m(g/m22))Grain yield Grain yield

(q/ha)(q/ha)

Pretilachlor 0.37 + SafenerPretilachlor 0.37 + Safener 3.8 (14.0)*3.8 (14.0)* 15.2 (13.3)15.2 (13.3) 57.357.3

Pretilachlor 0.56 + SafenerPretilachlor 0.56 + Safener 3.6 (12.0)3.6 (12.0) 14.8 (1.2)14.8 (1.2) 57.757.7

Pretila 0.37 + Safe + 1 HW Pretila 0.37 + Safe + 1 HW 2.4 (5.0)2.4 (5.0) 12.4 (5.3)12.4 (5.3) 59.759.7

Pretilachlor 0.62Pretilachlor 0.62 4.5 (20.0)4.5 (20.0) 17.5 (20.7)17.5 (20.7) 55.455.4

Pretilachlor 0.94Pretilachlor 0.94 3.9 (14.0)3.9 (14.0) 16.1 (15.8)16.1 (15.8) 57.257.2

Pretila 0.62 + 1 HW Pretila 0.62 + 1 HW 3.0 (8.0)3.0 (8.0) 13.5 (8.2)13.5 (8.2) 59.059.0

2 HW (20 and 45 DAS)2 HW (20 and 45 DAS) 8.7(74.3)8.7(74.3) 24.5 (50.0)24.5 (50.0) 58.358.3

WeedyWeedy 9.6 (92.3)9.6 (92.3) 33.0 (99.7)33.0 (99.7) 40.840.8

CD (p=0.05)CD (p=0.05) 0.8 (6.8)0.8 (6.8) 1.8 (10.3)1.8 (10.3) 0.50.5

Mahajan et al (2003)*Figures in parenthesis are original valuesSq. root transformation is used

36

Effect of seeding methods, intercropping and Effect of seeding methods, intercropping and weed management in DSRweed management in DSR

TreatmentTreatmentWeed density Weed density

(no/ha)(no/ha)Panicles/mPanicles/m22 Grain yield Grain yield

(q/ha)(q/ha)B:C ratioB:C ratio

Seeding methodsSeeding methods

SurfaceSurface 1.85 (90.4)1.85 (90.4) 365365 4646 1.771.77

AnaerobicAnaerobic 1.83 (87.1)1.83 (87.1) 373373 4747 1.841.84

CD (p=0.05)CD (p=0.05) NSNS NSNS NSNS

IntercroppingIntercropping

Sole riceSole rice 2.07 (129.7)2.07 (129.7) 356356 4141 1.651.65

Rice + Dhaincha 1.61 (47.8) 381 52 1.97

CD (p=0.05)CD (p=0.05) 0.020.02 99 33

Weed managementWeed management

Pretila 0.3 fb HW 1.63 (49.6) 413 57 2.21

2 HW 2 HW 1.73 (58.9)1.73 (58.9) 381381 5353 1.971.97

UnweededUnweeded 2.22 (178.1)2.22 (178.1) 291291 2222 0.980.98

CD (p=0.05)CD (p=0.05) 0.060.06 1313 33

Ravisankar et al (2008) Coimbatore, T.N Indian J Agron 53(1): 57-61

Clay loam

37

CONCLUSIONCONCLUSION Weeds are one of major problem in DSR, reduces 5-95% yieldWeeds are one of major problem in DSR, reduces 5-95% yield DSR is a labor-, fuel-, time-, and water-saving technology.DSR is a labor-, fuel-, time-, and water-saving technology. DSR is cost-effective and gives a higher net return than DSR is cost-effective and gives a higher net return than

puddled transplanted rice.puddled transplanted rice. Weed management is critical in DSR, but with an different Weed management is critical in DSR, but with an different

weed management approach weeds can be managed.weed management approach weeds can be managed.There is a need to integrate different weed management strategiesThere is a need to integrate different weed management strategies.. Use of a stale seedbed practiceUse of a stale seedbed practice Higher seed rate and quick growing varietiesHigher seed rate and quick growing varieties Use of crop residue as mulchesUse of crop residue as mulches Use of weed-competitive cultivarsUse of weed-competitive cultivars Appropriate herbicide mixtures, timing,Appropriate herbicide mixtures, timing,