<%if Instr(1,Request.ServerVariables("Script_name"),"home.asp")=0 then %> <%else%> <%end if%>
   
General
Soils
Seed Material
Cultivation Practices
Nutrients
Irrigation
Pests
Post Harvest
Growth Regulators
Crop Specific
  Weed Management

Introduction > Why the weed menace is more in Maize > Common Grasses > Common Sedges > Common Broad Leaved Weeds > Methods of Weed Control > Weedicides used in Maize >


Ikisan - Introduction to weed management in Maize

Introduction

  • Weed infestation drastically reduces the grain yield of maize.
  • Crop responds very well to mechanical weeding done by bullocks or tractor drawn implements between the rows and hand weeding with in the rows.
  • The weeding operation may be repeated two to three times but not after knee high stage of the crop.
  • Losses caused by weeds are more during the early stages than in the later stages.
  • Mechanical weeding is good for root aeration but continuous rains in kharif season posses a serious problem in which the soil becomes wet and any agricultural operation cannot be done.
  • Under such conditions weed grow luxuriantly and they do permanent harm to the crop before thy are controlled. Therefore integrated weed control measure is essential for taking care of weeds from initial stage of growth.
  • Mechanical weeding in any case should not be done after knee height stage as it damages the leaves.

 
Top  


Ikisan - Why the weed menace is more in Maize

Why Weed Menace Is More In Maize

  • The crop is heavily fertilized
  • The crop is a wide spaced crop
  • Slow initial growth

 
Top  


Ikisan - Grass weeds of maize Grass weeds found in maize

Cynodon dactylon

V.N: Garika


Dactyloctenium aegypticum

V.N:Nakshatra gaddi


Echinocloa crusgalli

V.N:Ooda

 


 
Top  


Ikisan - Common Sedges in maize

Common sedges in maize


Cyperus deformis

V.N:Tunga(Common Sedge / Annual sedge)


Cyperus rotundus

V.N: Tunga(purple nut sedge / nut grass)


 
Top  


Ikisan - Broad leaved weeds in maize

Broad leaved weeds


Amaranthus viridis

V.N: Chilaka thotakura.


Chenopodium album

V.N: Pappu kura


Parthenium hysterophorus

V.N: Macharla kampa/Vayyari bhama

Trianthema portulacastrum

V.N: Ganjeru

 

 

 
Top  


Ikisan - Methods of weed control in Maize

Methods Of Weed Control

  • Maize is most sensitive to weed competition during its early growth period.
  • The growth of maize plants in the first week is rather slow and it is during this period that weeds establish rapidly and become competitive.
  • Maximum weed competition in maize occurs during the period of 2 to 6 weeks after sowing. This suggests the importance of maintaining the field weed free during this critical period of weed competition.
  • The integrated weed control measures are to be followed for efficient weed control

Weed Control Through Efficient 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.

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.

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.

Chemical Weed Control

  • Incessant rains and dry spells prevent weed control on time by traditional methods. Non-availability of manual labour due to competition from other crops or high wages of manual labour also come in the way of timely weed control in maize.
  • Weed control by mechanical means is possible only when crop grows upto certain stage and crop has to compete with weeds till such period. Chemical weedicides are boon in such a situation.
  • Atrazine or Simazine @ 1.5 to 2 kg / ha dissolved in 500-600 litres of water, sprayed uniformly on the soil 2-3 days after sowing and followed by irrigation control most of the weeds efficiently. Moisture in the soil is essential for efficient weed control.
  • In case of intercropping with legumes Pendimethalin should be used instead of Atrataf in the same proportions.

Weed Control By Mechanical And Manual Means

  • When maize crop attains Knee high stage (30 days after sowing), weeds can be controlled by working cultivator or blade harrow in between the rows of the crop.
  • Withholding irrigation for a week after the operation controls most of the weeds. Manual Weeding, only within the crop rows (between the plants) makes weed control efficient and economical.

Weed Control By Intercropping

  • Slow initial growth nature of crop and wide inter row spacing creates congenial conditions for growth of weeds.
  • Inter cropping of compatible and non-competitive crops like pulses, oil seeds and rooted vegetables not only prevent growth of weeds but also results in profitable utilization of natural and applied resources resulting in higher returns.

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.

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.

 
Top  


Ikisan - Herbicides Used In Maize

Herbicides Used In Maize

Weedicide
Tradename
Weeds Controlled
Mode of action
Dosage
i)Pre emergence Atrazine Simazine

Atrataf

Taphizin

Contols several broad leaved and grasses

Abrobed by weeds through roots

Acts on Hill reaction and stops the production of oxyzen and thus interferes with photosynthesis and effects the weed grwoth.

2.0-2.5
kg/ha

Alachlor:

Lasso

annual grasses and certain broad leaved weeds.

Absorbs mainly near the first node of germinated shoots, secondarily by roots and translocated throughout the plant and then metabolized with in 10 days.

2-3 kg/ha.

Linoron
---
Besides annual grasses, it is also reported to suppress the growth of bermudagrass to some extent
---
1 kg/ha

ii) Preplant incorporation

Fluchloralin

---
Effective against commom annual weds
---
05-0.67
kg/ha
EPTC
---
Effective in the control of cheifly annual grasses
---
3-4 kg/ha

iii) Post emergence

2,4-D

---
Applied as direct spray, it can control sedges and young broadleaf weeds when the crop height is 8.25 cm. Dicamba can be added to 2,4-D to improve control of Trianthema and other difficult weeds
---
0.5-0.8
kg/ha

iv) Herbicide combinations

Tank mixture of Atrazine, alachlor and phytobland oil

---
Effectively control sedges
---
0.25kg/ha
+0.42kg/ha
+5%

 
Top  



Site Powered By
  ©Copyright ikisan.com 2000. All Rights Reserved.