Weed Management and Conservation Agriculture - R.K. Malik

WEED MANAGEMENT AND CONSERVATION

AGRICULTURE

R.K.MALIK

CSISA PROJECT

CIMMYT INDIA

Thinking about tomorrow

Shift in Strategy from CA to CA-

PLUS• Match CA with stimulus designed to boost growth and

development of cereal systems.• Late sowings make the crops ( and CA) uncompetitive

and less inputs further exhaust them and make them more uncompetitive.

• Impact assessment need to concentrate on DOS, Hybrids, other component technologies and intercropping.

• Weed shift under CA is different in South Asia with RWCS or MWCS.

• It is important to understand the Good Agronomic Practices that allow competition in favour of crop

Ecological consideration in

Weed Management.

– Understand how weeds invade .

– How weeds continue to exist inspite of

good control measures..

– How the ecosystem functions.

– Introduce system approach in IWM

PHALARIS and BARNYARD GRASS

• INEVITABLE CONSEQUENCE RICE- WHEAT CROPPING SYSTEM.

• ADAPTED AND OCCUPIED DOMINANT POSITION BY SUMMED ACTIVITIES UNDER MODIFIED MANAGEMENT

• DIVERSITY BETWEEN WEEDS IN LATE 1970s

• DIVERSITY WITH IN PHALARIS IN EARLY 1990s

• BROAD LEAF WEEDS TO PHALARIS, THEN PHALARIS TO PHALARIS

• COLONUM TO CRUSGALLI AND CRUSGALLI TO GLABRASCENCE AND EVEN COLONA TO COLONA

-492-616

-995

-79

270

1534

1147

1049 1200

3163

-1200

-900

-600

-300

0

300

600

900

1200

1500

1800

2100

2400

2700

3000

3300

1993-94 1994-95 1997-98 1998-99 1999-2000

Years

N

et

retu

rns (

Rs/a

cre

)

Karnal Sonipat

Crisis lead to opportunities - Wheat

INTENSIVE AGRICULTURE AND WEED

SPECIALIZATION• HOHENHEIM UNVERSITY FARM WITH

INTENSIVE FARMING WEED SPECIES FROM

1860 TO 1980 REDUCED 50%.

• GREATEST LOSS OCCURRED UPTO 1940 -

BEBORE HERBICIDE USE ( ALDRICH AND

KREMER BOOK )

• HAAS AND STREIBIG FROM DENMARK --

ROLE OF CROPPING SYSTEM AND

AGRONOMIC PRACTICES.

Tillage vs weed seed distribution

• Over 60 % seeds in 19cm soil found in 1cm soil depth in Zero tillage.

• Concentration of seeds decreases with soil depth.

• With chisel plowing 30% seeds found in 1cm depth.

• Mould board plough has equal distribution in all 19cm depth.

» Yenish et al WS 1992 429

NUMBER OF WEEDS SPP IN ORGANIC AND CONVEENTIOALFARMS (Schmidt&Steiner1987,Plakholm1990,Hermann et al 1986,

Hald&Reddersen1990 )

0

20

40

60

80

100

120

140

160

180

Organic farms Conventional farms

SWITZERLAND

AUSTRIA

GERMANY

DENMARK

CROP ROTATION

• EFFECTIVE BECAUSE

• SELECTION PRESSURE IS DIVERSIFIED

• DIVERSIFICATION PREVENTS THE PROLIFICATION OF MOST SUITED WEED

• CHANGES THE COMPOSITION AND ABUNDANCE OF WEED SPP

• ROTATION EMPLOYS VARYING PATTERNS OF RESOURCE COMPETITION

Franke, 2003

Dry weight of red rice in two varieties of rice (Kwon et al 1991)

0

100

200

300

400

500

600

700

800

Dry

weig

ht

of

red

ric

e

( g

/ m

2 )

0 2 5 10 20 40

Red rice ( plants / m2 )

LemontNewbonnet

Weed competitiveness in DSR

• BASMATI

• HYBRIDS

• COARSE RICE

• First two fit well with DSR

Growth of Weedy rice and rice (Diarra

et al 1985 )

0

20

40

60

80

100

120

140

160

180

200

Dry weight LAI Flag leaf area.

Red Rice

Riceg

cm2

Uneven water distribution

MORE WEEDS

MORE INSECTS AND DISEASES

STAGE OF DEVELOPMENT IN AGRICULTURE

�Rice wheat cropping system - high

productivity zone

�Simple weed flora

�Transplanted rice

� Herbicides X Water Management

� Herbicides X Puddling

� Rice nurseries weed management

� Crop rotation

�Direct seeded rice

Sesbenia crop for green manuring

Long term studies of green manuring and

without green manuring and herbicide on the growth and yield of wheat crop

189C. D. at 5%

5260-Weed free

4006-Weedy

5126120Clodinafop (R*)

511060Clodinafop

Without green manure

5284-Weed free

5048-Weedy

5176120Clodinafop (R*)

523460Clodinafop

With green manure

Yield (kg ha-1)Dose (g a.i. ha-1)Treatment

*R – Rotational herbicide

Studies on long term effect of commonly used herbicides with or without green manuring on yield of

both the crops in rice-wheat sequence

1328C. D. at 5%

62791500Butachlor (Rotational)

7069-Weed free

3408-Weedy

61801500Butachlor

Without green manuring

70041500Butachlor (Rotational)

7205-Weed free

4873-Weedy

68481500Butachlor

With green manuring

Yield (kg ha-1)Dose (g a.i. ha-1)Treatment

Zero tillage against

Phalaris

Soil

See

d

Ban

k

}

Phalaris minor intensity

85

112

29

77

110

220

54

128

0

30

60

90

120

150

180

210

240

NEPZ EPZ VZ Mean

Agro-climatic zones

Nu

mb

er

ZT CT

Contamination of wheat seed (collected just before sowing) with P. minor (2001-02)

Contamination of wheat seed (collected from grain market) with P. minor (1999-2000)

Alarming contamination level in own saved wheat seeds

(Yadav and Malik 2005)

Treatments:1. Date of sowing (3)- main plot

a) October 25

b) November 10

c) November 25

2. Residue level (5)-sub-plot� 0, 4, 6, 8 and 10 t/ha

Effects of early sowing and residue mulch on weed suppression under ZT conditions

October 25 November 10November 25

10 t/ha

8 t/ha

4 t/ha

0 t/ha

6 t/ha

0

10

20

30

40

50

60

70

0 t/ha 4 t/ha 6 t/ha 8 t/ha 10 t/ha

P. minor (no./m2) a

abbc

cc

0

10

20

30

40

50

60

25-Oct 10-Nov 25-Nov

P. minor (no./m

2)

c

b

a

Effect of residue on weed seed predation

0

10

20

30

40

50

60

P. minor C. album Rumex M. indica

% seed predation

CT ZT+residue

b

a

NSNS

NS

Weed seed predation during fallow period after wheat harvest 2011

Emergence rate of the first (A), second (B), and third (C) flush of Phalaris minor under conventional (●, solid line)

and zero-tillage (□, dashed line) in wheat (Source: Franke et al. 2007).

Polynomial relationship between sowing time and grain yield of wheat under ZT and

CT

ZT CT

2010-11 2009-10

Changes in weed management practices in

wheat

Source : Field survey Source : Data base of CSISA

2008-09

Wheat Productivity & Date of

Sowing

17 Oct 27 Oct 7 Nov 16 Nov 26 Nov 6 Dec 16 Dec 26 Dec

Polynomial relationship between sowing date and wheat yield (2005-06)

Daily reduction of wheat yield was 0.74 kg/ha in Oct (17-31), 8.85 kg/ha during 1-15 Nov, 17.25 kg/ha during 16-30 Nov and 30.11 kg/ha in Dec

Y = -0.2797x2 + 165.41x - 19908

R2 = 0.0427

2500

3000

3500

4000

4500

5000

5500

6000

6500

290 300 310 320 330 340 350 360 370

Gra

in y

ield

(kg

/ha)

Maximum yield was 4545 kg/ha on 23 Oct

COMPETITION FOR RESOURCES

• IF DRY WEIGHT OF CROP AND WEED IS

SAME- BOTH ARE MAKING SAME DEMAND FOR SPACE.

• BROAD LEAF WEEDS MAKE DIFFERENT

DEMAND ON SAME RESOURCES, OCCUPY DIFFERENT NICHES IN TIME AND SPACE.

Chemical Control

Modern varieties

More

fertilizer

High Moisture

Rice-wheat

Weed seed bank

Continuos useLess dose Faulty method

Zero tillage and Glyphosate- Perennial weeds

Double zero tillage- RWC ZTW followed by PTR

Less Nitrogen and More Perennial

Tillage systems and weed infestation in pearlmillet-wheat rotation after 5 years, Research Farm, CCS HAU Hisar, 2001-02

A

B

CA= ZT –ZT

B= MB-ZT

C= CT-ZT

Pearlmillet-wheat

Population of weeds (before spray) and grain and straw (yield of wheat during 2005-06 (9th year) in Pearlmillet

wheat crop rotation (CCS HAU, Hisar)

36.241.6Average

33.643.2CT-CT

42.455.2CT-ZT

32.826.4ZT-ZT

Pearlmillet-wheat

BLWGrassy

Population of weeds

(No./m2) before spray

Tillage treatments

SOIL MOITURE EFFECTS ON GLYPHOSATE

�STRESSED PLANTS ( 13 % w/w soil moisture)

PRODUCED SHOOT REGROWTH OFAsclepias syriaca EQUAL TO UNTREARTED.

�AT OPTIMUM MOISTURE ABSORPTION AND

TRANSLOCATION WERE 44 AND 20%

COMPARED TO 29 AND 7 % IN STRESSED

PLANTS.

Glyphosate efficiency

• Sodium carbonate or bicarbonate

reduce glyphosate activity.

• Ca,Fe,Zn,Al,and Mg cations reduce

its activity.

• Diammoniumsulphate and urea

increase its activity.

Kumar et al ( 2012)

Sulfonylurea herbicides.

� Inhibit Acetolactate synthase enzyme.

� ALS is the first common enzyme of branched chain

amino acids pathway.

� ALS is present in plants and Mos not in animals,

hence no animal toxicity.

� Differential root ALS activity exist in S-R corn.

» Forlani etal.1991 ws 553.

Fops and dims

� Aryloxyphenoxypropanoicacid-fops.

� Cyclohexanedione - dims.

� Both inhibit fatty acid synthesis.

� Acetyl-CoA carboxylase present in

stroma of chloroplasts , other plastid

� This enzyme is affected in grasses.

Fops antagonism vs BL

Herbicides

� Decreased uptake e.g. haloxyfop Vs bentazon.

� Decreased amount reaching the site of action.

� Decreased translocation - DCF-2,4-D.

GREEN REVOLUTION TO GENE REVOLUTION?

� Green Revolution – growth was faster between 1960 to 1990

� Such progress has now slowed down

� The green revolution small farmers productivity, and decrease in food prices

� To resume and to spread such growth now need a paradigm shift – Gene Revolution

HERBICIDE RESISTANT WHEAT

� IMIDAZOLINONE RESISTANT WHEAT DEVELOPED

� POTENTIAL OF GENE TRANSFER

BETWEEN WHEAT AND WEED ( AEGILOPS

CYLINDRICA ) ESTABLISHED.

� HERBICIDE RESISTANT WHEAT MUST BE

ACCOMPANIED BY PLAN THAT WOULD

MINIMIZE POTENTIAL FOR JUMPING GENE

� ( ZEMETRA ET AL WS 1998 313 )

Wheat weed, pest and disease management practices in high productivity zones

% reporting herbicide only 96.4

Number of applications per season 1.0 (± 0.27)

% reporting insecticide/fungicide 1.0

Crop budget for weed, pest and disease (Rs./ha) 1700

Gross revenue, 000 Rs. 29.7

Net revenue, 000 Rs. 1.6

Net revenue with zero-tillage, 000 Rs. 4.3

N = 499

Rice weed, pest and disease management practices in high productivity zones

% reporting herbicide application 97.6

% reporting hand weeding 60.3

Frequency of hand weeding 0.68 (± 0.62)

Frequency of herbicide used 0.98 (± 0.15)

Frequency of hand or herbicide 1.66 (± 0.64)

Manual weeding labour days/ha 5.51 (± 5.3)

% reporting pesticide/fungicide use 88.5

Crop budget for weed, pest and disease (Rs./ha) 2800

Production cost (Rs./kg) 6.8

Gross revenue, 000 Rs. 38.6

Net revenue, 000 Rs. 4.2

Net revenue with zero-tillage in wheat, 000 Rs. 4.3

N = 468

Dry Direct Seeded Rice

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00

Tillage & Planting

Ferttilizer Appln

Seed

Pesticides

Herbicides

Harvesting

Drying

Wages (employees)

Rental (Land & water)

Administrative fees

Financial Cost

Risk

Ite

ms

%age

India Uruguay

Cost analysis of DSR

Cyperus rotundus control

Post-emergence:1. Pyrazosulfuron (25-30 g ai/ha)

1. Halosulfuron (60 g ai/ha)

2. Azimsulfuron (35 g ai/ha)

3. Bispyribac (suppress) (30 g ai/ha)

Echinochloa spp./ Phalaris ( resistance)/ regeneration

Pre-emergence: 1. Pendimethalin (1.0 kg ai/ha)2. Oxadiargyl (90 g ai/ha)

Post-emergence:1. Bispyribac (25 g ai/ha)2. Bispyribac + oxadiargyl (20 g + 90 g ai/ha)3. Bispyribac + azimsulfuron(20 + 20 g ai/ha)

E. colona E. crus-galli

Leptochloa & Eragrostis sppcontrol

Pre-emergence: 1. Pendimethalin (1.0 kg ai/ha)

2. Oxadiargyl (90 g ai/ha)

Post-emergence:

1. Cyahalofop (120-150 g ai/ha)

2. Azimsulfuron (35 g ai/ha)Leptochloachinensis

Ergrostis japonica

Leptochloachinensis

Ergrostis japonica

Cyperus rotundus and Physalis

• Halosulfuron (60 g ai/ha)

• Azimsulfuron ????

PhysalisC.rotundus

Complex flora dominated by Cyperus

• Tank mixtures– Pyrazosulfuron + bispyribac

– Halosulfuron + bispyribac

– Bispyribac + azimsulfuron

– WEEDY RICE

– Herbicide resistant maize/ wheat / rice

– Weed management in upland Kharif crops

–

–

Complex annual flora

• Oxadiargyl+ bispyribac

• Pendimethalin + bispyribac

• Azimsulfuron + bispyribac

• Shifting weed flora

• Intercrop weed management

Weedy rice: Emerging problem in DSR

• Stale seedbed

• Certified seed (free

from weedy rice seeds)

• Removing panicles

before seed production

• Hybrid rice

Cultivated rice weedy riceCultivated rice weedy rice

Weedy rice in rice fieldWeedy rice in rice field

New emerging problematic weeds

• Weedy rice

• Leptochloa

• Eragrostis

Leptochloa chinensis

Ergrostis japonica

Leptochloa chinensis

Ergrostis japonica

Physalis minima

•Carfantrazone@20g/ha-

30 to35days after sowing.

•Dose may be increased if

the weed crosses 4-5 leaf

stage.

•Fop and dims have to be

applied in sequence

Ageratum conyzoides

•Use pre-seeding herbicides specially Glyphosate@ 1% sol.+ 0.5% surfactant.

•Surfactant can be applied even 2-3 days before seeding crops.

• There is no need to wait for 3 weeks even if it is applied on weeds carried over from rice to wheat.

Other Crops

Maize- Atrazine @0.5kg/ha-Pre

emergence

Atrazine @ 0.25kg/ha(Post

emergence

Soyabean-

Pendimethalin@1kg/ha(Pre

emergence)- and other dinitroaniline

Imazethapyr @ 100 g

Fenoxaprop@100g AI/ha

Sugarcane-Atrazine, 2,4-D,

Metribuzin

Cotton-Pendimethalin@1.5kg/ha

GM CROPS- NEW

TECHNOLOGY

�High Yielding Varieties helped increasing production.

� In turn, increase input use (fertilizer, irrigation etc)

�Together, increased pest problems.

�Pesticide use increased resistance

�In the absence of alternate pesticides, GM crops became necessary- foundation of GM

Technology

…however, poor application techniques result in poor control.

Uncontrolled phalarisresulting from poor

herbicide distribution

TILLER SURVIVAL

• SENESCENCE OF FOLIAGE--DEATH OF

TILLERS

• HIGH WEED POPULATION--800 PLANTS

• AVERAGE TILLER SURVIVAL--1.4 OUT OF 14

NUMBER OF SPIKELETS

• FIXED VERY EARLY

• NUMBER OF FLORETS

• DIFFERENTIATED ( EACH SPIKELET )

• LAST ONE ------- AND SUCCESSIVE ---NOT

DEVELOPED.

• WEED COMPETITION AND RESOURCE

AVAILABILITY.

NUMBER OF SPIKELETS

• SET AT :

• FIRST STAGE OF RAPID

ELONGATION OF GROWING

POINTS

• FIRST EAR PRIMORDIA---- 4-5

LEAF STAGE

• IWM AND INM IMPORTANT

POST INITIATION REPRODUCTIVE DEVELOPMENT

• DRY WEIGHT OF CROP/WEED

• CANOPY COVER AND PLANT HIEGHT

• ALLOCATION OF FOOD MATERIAL FROM

SOURCE TO SINK

PHLOEM TRANSPORT

• SYSTEM---DISTRIBUTES FOOD

• TRANSPORT DIRECTION---SOURCE TO SINK

• MAIN ENERGY---- WITHIN PLANT

• LOADING AND OFFLOADING--- METABOLISM

XYLEM TRANSPORT

• ROOT PRESSURE----NOT SUFFICIENT

• SUCTION EFFECT-- TRANSPIRATION

• MAIN ENERGY -- SUN

• RH INSIDE PLANT-- 100%

• RH OUT SIDE -- 50--90 %

Fops and dims

• Aryloxyphenoxypropanoicacid-fops.

• Cyclohexanedione - dims.

• Both inhibit fatty acid synthesis.

• Acetyl-CoA carboxylase present in

stroma of chloroplasts , other plastid

• This enzyme is affected in grasses.

Fops antagonism vs. BL Herbicides

• Decreased uptake e.g. haloxyfop Vs bentazon.

• Decreased amount reaching the site of action.

• Decreased translocation - DCF-2,4-D.

MOISTURE STRESS AND

EFFICIENCY OF FOPS

• RETENTION OF FENOXAPROP ON DIGITARIA REDUCED

• RETENTION OF DICLOFOP ON WILD OAT REDUCED

• LESS SURFACE AREA CONTACT DECREASED

RETENTION

• DE-ESTERIFICATION REACTION NECESSARY FOR

FENOXAPROP ACTION IS INHIBITED BY MOITURE

STRESS.

• MOITURE STRESS INDUCED DETOXIFICATION OF

FENOXAPROP.

• ROSSI ET AL WS 1993 335

Sulfonylurea herbicides.

• Inhibit Acetolactate synthase enzyme.

• ALS is the first common enzyme of branched chain amino acids pathway.

• ALS is present in plants and Mos not in animals ,hence no animal toxicity.

• Differential root ALS activity exist in S-R corn.

» Forlani etal.1991 ws 553.

Spray Volume and herbicide

efficiency

• Small droplets with less volume are more effective.

• Spray volume effects herbicide retention.

• It affects the degree of spray distribution.

• It results into high concentration at the foliage.

• High concentration gradient between concentrated droplets results into greater rate of diffusion into leaf cells.

� High fertilizer use will increase

the weed flora in favour of

grasses.

� Simplification of weed flora will

lead to increase in herbicide use.

Ten important weeds in rice-wheat

Spergula arvensisPolypogon monopeliensis

Rumex meritimusConvolvulus arvensis

Fumaria parvifloraCircium arvense

Ageratum conzoidesAnagalis arvensis

Commelina benghlensisRumex maritimus

Anagalis arvensisMedicago denticulata

Avena ludovicianaMelilotus indica

Phalaris minorChenopodium album

Physalis minimaAvena ludoviciana

Chenopodium albumPhalaris minor

Eastern IGPNorthwest IGP

Rainfed transplanted rice

� Upper, medium and low toposequence

� Fimbristylis miliacea

� Cyperus iria

� Cynodon dactylon

� Paspalum distichum

� Cyperus difformis

Weeds of Rice in Eastern U.P. and Bihar

1. Cyperus rotundus

2. Echinocloa colona

3. Physalis minima

4. Eragrostis japonica

5. Commelina spp. (Commelina diffusa and C. benghalensis)

Grain yield of wheat after 11 years of zero-tillage at farmers field in Haryana (Average of 6 sites)

0

1000

2000

3000

4000

5000

6000

1997-

98

1998-

99

1999-

2K

2000-

01

2001-

02

2002-

03

2003-

04

2004-

05

2005-

06

2006-

07

2007-

08

Year

Gra

in Y

ield

(kg h

a-1)

Zero-Tillage Conventional Tillage

Wheat weed, pest and disease management practices in high productivity zones

1700Crop budget for weed, pest and disease (Rs./ha)

1.6Net revenue, 000 Rs.

4.3Net revenue with zero-tillage, 000 Rs.

29.7Gross revenue, 000 Rs.

1.0% reporting insecticide/fungicide

1.0 (± 0.27)Number of applications per season

96.4% reporting herbicide only

N = 499

Rice weed, pest and disease management practices in high productivity zones

4.3Net revenue with zero-tillage in wheat, 000 Rs.

4.2Net revenue, 000 Rs.

38.6Gross revenue, 000 Rs.

6.8Production cost (Rs./kg)

88.5% reporting pesticide/fungicide use

2800Crop budget for weed, pest and disease (Rs./ha)

5.51 (± 5.3)Manual weeding labour days/ha

1.66 (± 0.64)Frequency of hand or herbicide

0.98 (± 0.15)Frequency of herbicide used

60.3% reporting hand weeding

0.68 (± 0.62)Frequency of hand weeding

97.6% reporting herbicide application

N = 468

The next green revolution

The Economist 2008

CROP-LIVESTOCK

INTERACTIONS-Crop residues - Traction

-Fodder crops

-Feed crops - Manure

Indirect system interactions

(risk; resource use)

LIVESTOCK SYSTEMCROP SYSTEM

Rice-wheat

Residue management

Crop types

Use of resource conservation

technologies/conservation

agriculture

Markets for crop inputs

(e.g. combine) & produce

(e.g. crop resides)

Livestock feed

management

Livestock types

Markets for livestock inputs &

produce (milk & meat; dung

as fuel)

A schematic representation of crop-livestock interactions

Similar interactions with other enterprises

100%

0%Metaxuron 80 WP (KABU)

1%Metribuzin 70 WP

12%Metsulfuron 20WP(Algrip)

1%2, 4-D ester

7%Total (Sulfo+Metaxuron)

1%Atlantis (Iodo+ Meso sulfuron)

47%Clodinofop Propargyl 15 WP

25%Sulfosulfuron 75 WP

2%Fenoxaprop p ethyl 10 EC

5%Isoproturon 75 WP

% Total markerMolecules

Wheat Herbicide