Introduction to Major Field Crops

Weed Management

Weeds have an inherent fast growing and fast multiplying capacity. They pose a serious threat in fields of wider spaced crops like maize. Most common weeds in maize are Cyperusrotundus, Cynadondactylon, Digitariasanguinalis among monocots and Tribulusterrestris, Trainthemaportulacastrum,Trainthememonogyna,Corchorusactangulus among dicots.

Weeding may be undertaken as soon as the crop germinate and attains 3-4 leaf stage (about 25 days after sowing) and may be continued till 75 days after sowing. Any delay in weed removal may cause fall in grain yield. Unweeded crop is likely to give 50 per cent less yields as compared to clean seed bed. Weeds are usually controlled by manual labourers in 2-3 operations. Atrazine at 2.5 kg/ha is one of the most efficient herbicides which remains effective for a maximum period of 30 days. In legume-cereal mixture, Pendimethalin at 2.5 l/ha has been found to be the most effective and protects both the legume and cereal crop in pre-emergence application.

Fig: Intercultivation.

Fig: Polythene mulching.