Weed Control in Maize and Sorghum Field
Cyperus rotundus, Nut grass annual grasses Digtaria spp., Cynodon dactylon are important grasses. Diagera arvensis. Phyllantus hiruti. Eqphoribia sp, Commelina beqalensis etc.
Methods of Control:
1. 2 – 3 hand weeding in early growth stage along with row cultivation with tooth harrow.
2.Atrazins and simazine (@ 0.5 to 2 kg/ha) on bread leaved weeds. Pre planting herbicides. Pre – emergence chemicals for maize are atrazine. Zimazine (0.5 to 1 kg/ha), 2,4-D MCPA and alachlor (3.5 kg/ha) to control annual grasses. Nut sedges and some broad leaved weeds.
3. Post emergence spray of 2.4-D or MCPA (0.5 kg/ha) controls nut sedge and dicot weeds. 2.4-D should be applied as directied spray at 8 to 25 cm height stage.
Dicamba can be used 10 days before teaseling for control of Portulaca sp., Conoulvates spp. direct spray is preferred over its blanket application. Atrazine may be applied as its blanked emulsion spray.
1 to 2 hand weeding and hoeing pre emergence herbicides are recommended as propazine as (1 to 2 kg/ha) which has long residual effect, in dry farming areas. Atrazine or Simazine (0.25 to 1 kg/ha) is also used. On medium and heavy soils Terbutry 1 – 2 kg/ha and Propachlor (1-2 kg/ha) applied at 1 1-1 ½ kg when crop is 15 cm tall. To control germinating weeds simazine is used while Attrazinc, 2, 4-D and Dicamba are used when crop is at 10-30 cm height.