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1. DEPARTMENT OF AGRONOMY
AN ASSIGNMENT ON Weed Management In C4 Plants (Maize,
Sorghum And Perl Millet)
SUBMITTED TO: - DR. M.L.
Kewat Sir
(DEPARTMENT OF AGRONOMY)
SUBMITTED BY:- MAHENDRA
ANJNA
ENROLLMENT NO: 170111010
CLASS: - M.SC. (Ag.) PREVIOUS
YEAR
DEPARTMENT OF AGRONOMY

2. Weed Management In C4 Plants (Maize,
Sorghum and Perl Millet)
A. Weed flora:-
•Common broad-leaf weeds:- Abutilon indicum, Argemone
Mexicana,Celosi argentina,Borreria articularis,Gynondropis(Cleome)
supp.,Digeria arvensis,Corchorus olitorius,Portuala spp.Veronica
cinerea,Leucaaspera,Xanthium strumarium,Anagallis arvensis,Bidense
pilosa,Eclipta spp.,Ipomea spp.,Tridax procumbence,Euphorbia spp.
,Amaranthus spp.
•Common Grass (Monocot) Weeds:- Chloris spp.,Digetaria
sanguinalis,Dactyloctenium aegyptium,Echinocloa spp.,Commelina
spp.,Paspalum distichum,Eleusine indica,Eragrostis spp.,Setaria
spp.,Cynodon dactylon.
•Common Sedges:-Cyperus rotundus,Cyperus esculentus,Cyperus
defformis,Cyperus compressus.

3. 1. Perennial weeds :-
Grasses:-Cynodon dacrylon, Sorghum halepense, Sorghum
sudanense. Plantago lanceolata (simple perennial).
Broad leaved weeds:- Convolvulus arvensis, Launaea cornuta,
Polygonum convolvulus, Pluchea lanceolata Oralis latifolia
corniculata (simple perennial).
Parasitic weeds:- Striga hermonthica predominant in Africa, Striga
asiatica (lutea).
B. Yield Reduction :- 20-30%, but variable with management
practices,condition,varieties and across locations.
C. Critical period :- Early crop establishment to early reproductive
stages ,Generally 30-60 DAS (Day After Sowing).
D. Weed Management :-

4. a) Pure and clean seeds
b) Use of well decomposed manures
c) Time of sowing:- Time of sowing is another important
consideration for rainy season crops towards avoiding early/initial
weed competition.
d) Weed Control By Crop Rotation:- Maize followed by redgram,
groundnut and safflower in rotation not only control weeds but
improves productivity of maize.
Maize preceded by green manure crops like Dhaincha and Sunhemp
not only exterminate weeds due to rank vegetative growth but also
improves the fertility of soil.
e) Intercropping practices :- With soybean,green gram, black
gram, cow pea.
f) Weed Control Through Seed Treatment:- Soaking the maize seed
for 24 hours in water and sowing after shade drying makes the seed
to germinate early compared to weed seed and gives upperhand to
maize crop over weeds. This practice besides providing optimum
plant stand and reduces crop duration.

5. g) Proper Seed bed preparation:- Two to three ploughings by
country or mould board plough or ploughing by disc or mould board
plough followed by 2 to 3 harrowings not only brings desired tilth but
makes weed free seed bed preparation.
Ridge and furrows layout further reduces weed intensity.
h) Hand weeding :- Two hand weeding at 25-30 and 45-60 DAS
i) Mulching:-
J) Weed Control Through Improved Fertilizer Practices:-
Chemical fertilizer application in bands 5 to 10 cm. From the seed
instead of broadcasting, makes it available more to the crop and less
to the weeds and hence more dominance of crop over weeds.
Top dressing of fertilizer at knee high stage after inter culture 15-20
cm. From crop rows, with holding irrigation for a week and covering
the fertilizer by operation of ridger also reduces crop competition
from weeds.
k) Soil solarization:- Soil solarization practised during hot summer
months (April-May) for a period of 4-6 weeks with transparent film of
50-100 micron.

6. l) Deep ploughing:-
m) Weed Control By Harvesting At Physiological Maturity:-
Harvesting of maize at physiological maturity (as indicated by black
layer formation) leaves the soil with moisture content sufficient
enough to take up post harvesting ploughing and duration of crops
reduced by 8-10 days.
Exposure of soil to solar radiation by post harvest ploughing kills
most of the deep-rooted weeds and a good seedbed is prepared by
natural means.
n) Chemical control :-
1.Atrazine as PEm @ 1-1.5kg/ha
2.Alachlor(lasso) as PEm @ 2-2.5 kg/ha –many Annual grasses & some
BLW.
3.Metolachlor(Dual) as PEm @ 1.5-2 kg/ha -–many Annual grasses and
Cyperus.
4.Pendimethalin as PEm @ 1-1.5 kg/ha- many Annual grasses & some
BLW.
5.Bentazon @ 1-1.5kg/ha at 2-3 leaf stage of crops –control of BLW
6.2,4-D @ 0.5-0.75 kg/ha as post emergence - control of BLW
7.Alachlor + Atrazine @ 4-5 kg/ha as PEm - many Annual grasses &
BLW.

7. 8.Atrazine + Metolachlor @3-4 kg/ha PEm and up to 3 leaf stage of
crop
9.Cyanazine+ Atrazine@ 3-4 kg/ha PEm and up to4-6 leaf stage of
crop.
10.Halosulphuron (Sempra 75%) @ 80-100 gm/ha – 20-30 DAS-
Control Sedges
11.Topramezon %) @ 80-100 gm/ha – 15-20 DAS –BLW and Grasses
12.Tembotrione 285gm/ha ha – 15-20 DAS –BLW and Grasses