WEED MANAGEMENT AND CONSERVATION AGRICULTURE R.K.MALIK CSISA PROJECT CIMMYT INDIA
Oct 24, 2014
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
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