use of herbicides in sequence for control of weeds in maize
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my seminar on Use of Herbicides in Sequence for Control of Weeds in Maize byTRANSCRIPT
Seminar
On Use of Herbicides in Sequence for
Control of Weeds in Maize
UMESHA, CPAL(S)2013Sr. M.Sc.(Agri.)
Sequence of presentation Introduction
Meaning and Principle for sequential application
Importance of sequential application of herbicides
Effect of Sequential application of herbicides
Conclusion
Future line of work
INTRODUCTION
Maize (Zea mays L.) or Indian corn is one of the most important cereals of the world. Apart from direct human consumption, maize grains form an important ingredient of poultry and cattle feed.
In India, maize is grown over an area of 8.33 million ha with an annual production of 16.68 million tonnes and an average productivity of 2002 kg ha-1.
In Karnataka, maize occupies an area of 1.07 million ha with an annual production of about 3.03 million tonnes and an average productivity of 2833 kg ha-1
Maize has 3 major unique characteristics
Its most obviously, maize looks different to the small grain cereals like wheat, barley and rice.
Commercial varieties of maize in more technologically advanced farming systems are actually ‘hybrids’.
Maize is physiologically different to many other crops having system of photosynthesis which is called C4, this means that it uses less water for a given level of yield
Among all weed control methods cultural and mechanical are tedious and time consuming besides labour intensive and costly. These operations are difficult to carryout in the field.
Use of pre and post-emergent herbicides would make the herbicidal weed control more acceptable to farmers, which will not change the existing agronomic practices but will allow for complete control of weeds.
Due to continous use of preemergent herbicides in crops and cropping system, the emergence pattern of weeds has changed.
This has resulted in development of post emergent herbicides. But the efforts made to evaluate the efficacy pre and postemergent herbicides applied in sequence lacking in maize.
Among all the pests(insects, animals, diseases and weeds) in India, weeds alone are responsible for about 25% loss of crop production.
weeds have been recognized as potential pests, its removed by culturally, mechanically and chemically.
Weeds reduce crop yield by 31.5%
22.7 % in winter
36.5% in summer, kharif seasons
Impact of weeds on different crop ecosystems It is estimated that loss of agriculture production
most developed countries- 5%
less developed countries- 10%
least developed countries- 25%
It is estimated that yield loss by
weeds - 45%
Insects - 30%
Diseases - 20%
other pests - 5%
The world food loss due to weeds was 287 mt of 11.5% of total food production.
Weeds Common name Local name Family
A. Grassy weeds
Cynodon dactylon Pers. Bermuda grass Garike, doob grass Poaceae
Digitaria marginata Crabgrass - Poaceae
Dinebra retroflexa - Poaceae
Echinochloa colonum Watergrass Jangli dan Poaceae
Eleusine indica L Goosegrass - Poaceae
Panicum spp. Panicum Barnyard grass Poaceae
Setaria italica Banara, bani Poaceae
B. Sedges
Cyperus rotundus L. Nut sedge Jeku, Motha purple Cyperaceae
Weed flora in maize
Contd…..C. Broad leaved weedsAgeratum conyzoides L Bill goat weed Mahkua Asteraceae
Amaranthus viriids L Pigweed Jungli chauli AmaranthaceaeAlternanthera sessilis L. - - AmaranthaceaeArgemona mexicana L. Mexican poppy Barghar, satyanasi Papavaraceae Commelina benghalensis L. Dayflower, spider wort
TropicalInsansia. Egali Commelinaceae
Cynotis cuculata Baghmula ,jigali Commelinaceae
Corchorus trilocularis Tiliaceae
Digera arvensis L. Lahasua AmaranthaceaeEuphorbia hirta L. Garden spurge Bari dudhi Euphorbiaceae Euphorbia prostrate - Euphorbiaceae
Euphorbia geniculata Chotti dudhi Euphorbiaceae
Phyllanthus niruri L. Niruri Hezar dena Euphorbiaceae
Portulaca oleracea L. Purslane Kulfa PortulacaceaeParthenium hysterophorus L. Carrot weed Congress Asteraceae
Physalis minima L. Ground cherry Ban makaya SolanaceaeTridax procumbens L. Tridax phulani Asteracea
Sl. Sl. NoNo
HerbicideHerbicidess
RecommenRecommended doseded dose
(kg a.i/ha)(kg a.i/ha)
Time of Time of applicatioapplicatio
nn
Method of Method of applicatioapplicatio
nn
Type of weed Type of weed controlcontrol
1 Atrazine 1-1.5 PRE (0-3DAS)
Soil applied
Control annual weeds
2 Simazine 1-1.5 PRE (0-3DAS)
Soil applied
Controls annual weeds
3 Pendimethalin
0.75-1 PRE Soil applied
Late emerging annual weeds commelina sp
44 2,4-D 1.0 POST(3-4WAS)
Foliage applied
Control Broad leaved weeds
Different herbicides used in maize
5 Alachlor 1.2-2.0 PRE (0-3DAS)
Soil applied
Control most of the annual grasses and broad leaved weeds
6 Paraquat (Directed spray)
1.00 POST Foliage applied
Control all weeds
7 Glyphosate (Directed spray)
0.1 POST Foliage All type of weed control
8 Butachlor 1.00 PRE Soil applied
Control annual weeds and BLW
Contd…..
Preplant Soil incorporation of EPTC at 3-4 Kg/ha, mixed with about 0.5kg/ha of either Atrazine or simazine is a very effective treatment will also control sedges.
Atrazine and simazine were first highly successful pre emergence Herbicides in maize which replaced the earlier used herbicides 2,4-D and MCPA in1960.
Maize shows high tolerance to triazine group upto 5-6kg/ha in commonly 1-2 kg/ha can be used to avoid phytotoxic residue hazards of these herbicides.
In dry areas atraziine and simazine should be slightly in corporated into soil to improve herbicide efficacy.
Alachlor and butachlor are most effective pre emergence herbicides against the annual grasses than simazine and atrazine but they weak against the broadleafs therefore judicious combination of two groups of herbicides should control both types of weeds effectively.
Linuron is reported effective also against c.dactylon, Pendimethalin(1kg/ha) has been newly added to the list of pre emergence herbicides in maize.
For early post emergence control of young weeds in maize a
very good herbicde combination is 0.5 kg alachlor +0.25 kg atrazine +5% phytobland oil emulsion spray.
Combination of propalachlor and linuron is preferred over
alachlor and metalachlor. Later at 3-6 leaf of weeds cyanazine (0.75kg/ha)can be used on even still older weeds .
Merits and demerits of PRE emergence herbicides
Merits: Can be applied while planting /sowing
With adequate rain, provides control through first 4 weeks
Reduces late emerging weeds impact in maize
Low annual grass populations
Low to moderate population of annual BLW, Amaranths viridis.
Demerits:
Dependence on adequate rain within narrow period of time
Not effective on difficult BLW, perennial and high grass populations
Moderate to high grass populations
Biennial and perennial weeds.
Merits and demerits of POST emergence herbicides
Merits Controls late emerging weeds.
Consistent control of low to moderate annual weed populations
Demerits
Narrow window application, care should be taken applied at
particular stage.
Moderate to high populations of grasses
It is application of herbicide one after the other i.e. pre-plant followed by pre emergence/Pre emergence followed by Post emergence application.
Ex: Application of Atrazine as Pre-emergence followed by 2,4-D as Postemergence.
Meaning of sequential application of herbicides
Importance of Sequential application
Provides enough weed control to prevent major weed problems in maize.
More consistent weed control of late emerging weeds
Greater control and biomass reductions allow greater maize yield
More consistent weed control in SEQ than PRE or Post alone
Principles
To control broad spectrum / late emerging weeds
To control weed flora throughout the growing season
Difficulty in inter-culture operations due to unfavorable weather
Pre emergence alone and Post emergence alone are
not much effective.
Research studies
Treatments Cyperusesculentus
Convolvulus arvensis
Chenopodiumalbum
Amarantusspp
Foramsulfuron 26.94 71.47 91.20 100
Nicosulfuron 55.63 74.42 100 93.80
Atrazin+lasso 27.92 36.70 84.88 56.01
Weedy 0 0 0 0
Table-1- Weed control (percent) with herbicides
NURAKY et al, 2011
Treatments Cyperusesculentus
Convolvulus arvensis
Chenopodiumalbum
Amarantusspp
Foramsulfuron 1.56 1.28 0 0
Nicosulfuron 1.25 0 0 0
Atrazin+lasso 3 1.41 0 0
Weedy 9.48 2.31 9.25 6.91
Table 2- weed density (number) at 26 days after sowing
NURAKY et al, 2011
TreatmentPlant height at maturity (cm)
Ear height aboveground (cm)
Leaf area indexNo. of
leaves/plant (at maturity)
Atrazine Trazine Callitraz
125.0130.2
49.046.8
1.1601.123
13.512.2
2,4-DCalliherbeBextra
121.8135.7 0
47.851.4
0.9801.41
12.113.1
GlyphosateKalach 360LFireWeed Out
120.1143.6128.5
66.356.748.5
1.1101.4901.343
12.713.413.7
ParaquatBenaxoneGramoxone Super
140.5126.1
59.948.6
1.071.0133
13.112.8
Control (No herbicide)LSD (P = 0.05)
126. 6NS
44.8NS
0.935NS
13.2NS
Table 3. Maize plant heights, height of ear above ground, leaf area index number of leaves per plant measured at 10 WAP.
Ghana. Larbi,2013
Treatments Weed index
(%)WCE (%) Grain yield
(kg/ha)
1.Atrazine 1.25 kg/ha +1 IC at 30DAS 24.75 75.37 5297
2.Atrazine 1.25 kg/ha fb Atrazine 0.50 kg/ha 16.53 84.85 5876
3.Atrazine 1.25 kg/ha fb Atrazine 1.00 kg/ha 10.86 88.32 6275
4.Butachlor 1.00kg/ha + 1 IC at 30DAS 30.42 74.47 4898
5.Butachlor 1.00kg/ha fb Atrazine 0.50 kg/ha 17.37 83.40 5817
6.Butachlor 1.00kg/ha fb Atrazine 0.50 kg/ha 14.84 85.18 6020
7.Atrazine 1.25 kg/ha fb 2,4-D 0.5 kg/ha 8.52 91.58 6440
8.Butachlor 1.00kg/ha fb 2,4-D 0.5 kg/ha 10.22 89.72 6320
9.Farmers practice (1 IC at 20 and at 1 HW30 DAS) 20.69 76.75 5583
10.Weed free check 0.00 94.67 7040
11.Weedy check 40.4 0.00 4195
SEm± 3.80 2.84 285
CD(0.05) 11.27 8.40 841
Table 4: WCE, WI and grain yield at different growth stages as influenced by sequential application
ARS, Devihosur Mallikarjun, 2008
TreatmentsPlant height
(cm)LAI Net
returns(Rs ha-1)
B: C ratio
T1: Atrazine 1.25 kg/ha +1 IC at 30DAS 180.52 1.82 19602 2.27
T2: Atrazine 1.25 kg/ha fb Atrazine 0.50 kg/ha 185.55 2.21 22991 2.45
T3: Atrazine 1.25 kg/ha fb Atrazine 1.00 kg/ha 190.76 2.37 25130 2.55
T4: Butachlor 1.00kg/ha + 1 IC at 30DAS 179. 16 1.75 17526 2.17
T5: Butachlor 1.00kg/ha fb Atrazine 0.50 kg/ha 182.78 2.07 23005 2.48
T6: Butachlor 1.00kg/ha fb Atrazine 0.50 kg/ha 186.34 2.29 23962 2.52
T7: Atrazine 1.25 kg/ha fb 2,4-D 0.5 kg/ha 193.38 2.54 26601 2.67
T8: Butachlor 1.00kg/ha fb 2,4-D 0.5 kg/ha 191.48 2.46 26224 2.70
T9: Farmers practice (1 IC at 20 and at 1 HW30 DAS)
181.76 1.96 21082 2.33
T10: Weed free check 196.46 2.69 27821 2.50
T11: Weedy check 173.32 1.70 14046 2.01
CD at 5% 8.68 0.41 3903 0.26
Mallikarjun, 2008
ARS, Devihosur
Table 5 : Effect of weed control treatments on growth parameters and economics as influenced by sequential application
TreatmentWeed count (per 0.5 m2)
Weed dry weight (per
0.5 m2)
Weed control index (%)
TDMP at harvest of maize (g/plant)
T1 : Atrazine 1.25 kg a.i./ha (PRE) fb. Atrazine 1.50 kg a.i./ha (POST)
4.43 3.87 75.9 292
T2 : Atrazine 1.25 kg a.i./ha (PRE) fb. Atrazine 1.75 kg a.i./ha (POST)
4.33 4.47 67.4 327
T3 : Atrazine 1.25 kg a.i./ha (PRE) fb. Paraquat 1.0 kg a.i./ha (POST)
3.93 3.10 84.8 304
T4 : Atrazine 1.25 kg a.i./ha (PRE) fb. Paraquat 1.5 kg a.i./ha (POST)
4.10 3.40 81.5 317
T5 : Atrazine 1.25 kg a.i./ha (PRE) fb. Glyphosate 2.5 kg a.i./ha (POST)
3.08 3.29 82.7 332
T6 : Atrazine 1.25 kg a.i./ha (PRE) fb. Glyphosate 3.0 kg a.i./ha (POST)
3.43 3.36 82.0 284
T7 : Atrazine 1.25 kg a.i./ha (PRE) fb. 2,4-D Na salt 2.0 kg a.i./ha (POST)
4.10 3.84 76.2 277
T8 : Atrazine 1.25 kg a.i./ha (PRE) fb. 2,4-D Na salt 3.0 kg a.i./ha (POST)
3.89 3.91 75.3 292
T9 : Atrazine 1.25 kg a.i./ha (PRE) fb. (2 IC @ 30 and 45 DAS) + 1 HW (between 30 and 45 DAS)
3.29 3.70 77.5 310
T10 : Weedy check 6.23 7.78 0 298SEm+ 0.2 0.0 0.53 3.26CD at 5% 0.6 0.1 1.56 9.68
Ishrat, 2010
Table 6 : Weed dynamics as influenced by pre and post emergence application of herbicides in maize
Ramdurg
Treatment100-seed
weight (g)Grain yield
(kg/ha)Net income
(Rs./ha)B:C
T1 : Atrazine 1.25 kg a.i./ha (PRE) fb. Atrazine 1.50 kg a.i./ha (POST)
36.5 4637 51802 3.48
T2 : Atrazine 1.25 kg a.i./ha (PRE) fb. Atrazine 1.75 kg a.i./ha (POST)
38.8 4534 50822 3.41
T3 : Atrazine 1.25 kg a.i./ha (PRE) fb. Paraquat 1.0 kg a.i./ha (POST)
32.8 4791 54725 3.56
T4 : Atrazine 1.25 kg a.i./ha (PRE) fb. Paraquat 1.5 kg a.i./ha (POST)
37.6 4752 52488 3.38
T5 : Atrazine 1.25 kg a.i./ha (PRE) fb. Glyphosate 2.5 kg a.i./ha (POST)
43.6 5305 59139 3.70
T6 : Atrazine 1.25 kg a.i./ha (PRE) fb. Glyphosate 3.0 kg a.i./ha (POST)
35.7 5283 60702 3.76
T7 : Atrazine 1.25 kg a.i./ha (PRE) fb. 2,4-D Na salt 2.0 kg a.i./ha (POST)
34.7 3457 39411 2.90
T8 : Atrazine 1.25 kg a.i./ha (PRE) fb. 2,4-D Na salt 3.0 kg a.i./ha (POST)
38.5 4105 41853
T9 : Atrazine 1.25 kg a.i./ha (PRE) fb. (2IC 30 and 40 DAS) + 1 HW (between 30 and 45 DAS)
40.2 4826 52375 3.25
T10 : Weedy check 30.7 2342 20727 2.23SEm+ 0.9 1.91 2509 0.12CD at 5% 2.67 567 7454 0.36
Ramdurg Ishrat, 2010
Table 7 : Yield attributes and economics as influenced by pre and post emergence application of herbicides in maize
Table 8 : weed index, WCE and Grain yield of maize as influenced by application of herbicides in maize
Treatment Weed index (%)
WCE (%)
Grain yield (t/ha)
T1: Weedy check (no weeding, no intercultivation ) 33.25 0.00 5.13
T2: Mechanical weeding( at 25 DAS and at 45 DAS and IC at 30 DAS )
9.96 27.94 6.94
T3: Atrazine ( 1.00 kg ha—1 pre-em ) + IC at 30 DAS 18.09 16.05 6.31
T4: Atrazine ( 1.25 kg ha—1 pre-em ) + IC at 30 DAS 16.00 18.36 6.49
T5: Atrazine ( 0.75 kg ha—1 pre-em ) fb. 2,4- D ( 1.00 kg ha--1post- em) at 30 DAS
1.78 28.58 7.57
T6: Oxyfluorfen ( 0.25 kg ha—1
post – em) at 20 DAS29.37 24.45 5.45
T7: Weed free check ( IC at 20 DAS and 40 DAS + HW at 30 DAS and 50 DAS)
0.00 36.18 7.72
S. Em± 3.79 0.94 0.29 CD at 5% 11.26 2.79 0.87 MARS, Dharwad Shantveerayya, 2010
Treatments Grossreturns(Rs.ha-1)
Net returns(Rs.ha-1)
Benefit:cost ratio
T1: Weedy check ( no weeding, no intercultivation ) 69564 42670 2.59
T2: Mechanical weeding( at 25 DAS and at 45 DAS and IC at 30 DAS )
94156 64510 3.18
T3: Atrazine ( 1.00 kg ha--1pre-em ) + IC at 30 DAS
85562 56235 2.92
T4: Atrazine ( 1.25 kg ha--1pre-em ) + IC at 30 DAS
88048 58371 2.97
T5: Atrazine ( 0.75 kg ha--1pre-em ) fb. 2,4- D ( 1.00 kg ha--1post- em) at 30 DAS
102600 72993 3.47
T6: Oxyfluorfen ( 0.25 kg ha--1post – em) at 20 DAS
73899 44726 2.53
T7: Weed free check ( IC at 20 DAS and 40 DAS + HW at 30 DAS and 50 DAS)
104684 73785 3.39
S. Em± 3985.49 3985.49 0.14CD at 5% 11841.49 11841.49 0.42
Table 9 : Economics of maize as influenced by application of herbicides
MARS, Dharwad Shantveerayya, 2010
TreatmentsTotal dry weight of weeds (g m-2)
Weed indexWeed control efficiency (%)
1.Atrazine 1.00 kg a.i./ha (PRE) 6.69 13.20 50.15
2.Metribuzine 0.25 kg a.i./ha (PRE) 6.71 14.91 50.00
3.Alachlor 0.50 kg a.i./ha + Atrazine 1.0 kg a.i./ha (PRE)
6.36 11.74 52.62
4.Glyphosate 1.00 kg a.i./ha (PP) fb. Atrazine 375 g a.i./ha + Alachlor 0.50 kg a.i/ha
8.55 24.01 36.33
5.Glyphosate 1.00 kg a.i./ha (PP) fb. 2, 4-D @ 2.00 kg a.i./ha (POST)
7.54 19.75 43.83
6.Glyphosate 1.00 kg a.i./ha (PP) + Castor oil 4. ltr/ha 8.18 30.83 39.05
7.Atrazine 1.25 kg a.i./ha (PRE) fb. Atrazine 1.50 kg a.i./ha (PRE) to weeds
6.03 3.80 55.07
8.Atrazine 1.00 kg a.i./ha fb. 2, 4-D @ 2.0 kg a.i./ha 6.64 12.68 50.52
9.Alachlor 1.00 kg a.i./ha (PRE) fb. Oxyfluorfen 0.20 kg a.i./ha (POSt) directed spray
5.15 12.79 61.62
10.Atrazine 1.50 kg a.i./ha 6.69 13.51 50.1511.Oxyfluorfen 0.15 kg a.i./ha (PRE) 5.64 22.32 57.9612.Maize + cover crop (cowpea) 5.97 31.42 55.5013.Maize + cover cropp (mung bean) 6.55 25.39 51.1914.Weed free check 1.25 - 90.7315.Weedy check 13.42 49.73 -S.Em + 0.44CD at 5% 1.27
Table10 : Total dry weight, weed control efficiency and weed index in maize as influence by weed control treatment
Shailendra singh, 2011ARS, Arabhavi
TreatmentsGrain weight per plant (g)
Grain yield Stover yield
Atrazine 1.00 kg a.i./ha (PRE) 102.97 48.99 70.94Metribuzine 0.25 kg a.i./ha (PRE) 106.00 47.85 72.81Alachlor 0.50 kg a.i./ha + Atrazine 1.0 kg a.i./ha (PRE) 108.40 49.12 69.38
Glyphosate 1.00 kg a.i./ha (PP) fb. Atrazine 375 g a.i./ha + Alachlor 0.50 kg a.i/ha
96.67 42.35 57.40
Glyphosate 1.00 kg a.i./ha (PP) fb. 2, 4-D @ 2.00 kg a.i./ha (POST)
96.70 44.92 62.81
Glyphosate 1.00 kg a.i./ha (PP) + Castor oil 4. ltr/ha 85.87 38.54 58.44
Atrazine 1.25 kg a.i./ha (PRE) fb. Atrazine 1.50 kg a.i./ha (PRE) to weeds
110.17 54.02 74.06
Atrazine 1.00 kg a.i./ha fb. 2, 4-D @ 2.0 kg a.i./ha 105.20 48.91 68.13
Alachlor 1.00 kg a.i./ha (PRE) fb. Oxyfluorfen 0.20 kg a.i./ha (POSt) directed spray
106.50 48.86 68.44
Atrazine 1.50 kg a.i./ha 103.90 48.41 68.44Oxyfluorfen 0.15 kg a.i./ha (PRE) 97.17 43.16 58.96Maize + cover crop (cowpea) 84.63 38.34 48.75Maize + cover cropp (mung bean) 91.80 41.59 60.63Weed free check 117.67 56.01 76.25Weedy check 83.67 28.11 45.31S.Em + 5.22 3.16 2.67CD at 5% 15.11 9.17 7.73
Table 11: Grain yield and yield components of maize as influenced by weed control treatments
Shailendra singh, 2011ARS Arabhavi
Conclusion
Sequential application of herbicides helps to control
weeds on time and for longer period. Pre-emergence application of
atrazine 1.50 kg ha-1/simazine 1-1.5 kg ha -1 helps to control weeds up
to 30 days followed by atrazine 1.50 kg ha-1 (pre-emergence to weed
and post emergence to crop)/2, 4-D @ 1 kg ha-1/ paraquat 1 kg ha-1
(Directed spray)/glyphosate 0.1 kg ha-1 (Directed spray) control after
the new emerging weeds. This will help the farmer in reducing the
burden of labour problem.
FUTURE LINE OF WORK Continuous studies are required on the effectiveness and bio-efficacy
of new generation herbicides and herbicide mixtures in maize crop.
Studies on residual effect of herbicides on crop grown in sequence and also on the environment in long-run needs to be initiated.
The studies are needed on the use of herbicide in granular form.
Use of different new methods of weed control like electromagnetic radiations.
Use of encapsulated herbicides.
“Knowledge is like a garden: if it is not cultivated, it cannot be harvested”“Knowledge is like a garden: if it is not cultivated, it cannot be harvested”