Managing pests in cotton

PESTICIDE USE on cotton is both extensive and intensive. With the advent of hybrids and high yielding varieties, the pest problem is more and farmers are relying heavily on chemical pesticides for plant protection.

. Seed treatment with insecticide is becoming a standard agricultural practice instead of foliar spray in the early stage of crop growth. Seed treatment with chemicals is an eco-friendly approach with least disturbance to the environment.

Smaller amounts of the chemical are treated with seeds and seeds sown with treated chemicals gives protection in the early stages. While the insect sucks the sap, the pest ingests the chemical compound that is deadly for them with the plant sap.

The seed dressing chemicals viz, imidacloprid 70 WS (Gaucho) at 7.5 g/kg of seed, thiamethoxam 70 WS (Cruiser) at 5 g/kg of seed and chlothianidine 600 FS (Poncho) at 9 ml/kg of seed are effective in keeping the population of sucking pests below Economic Threshold Level (ETL) upto 40 days after sowing.

Seed treatment also reduces leaf curl viral disease in the northern zone where it is prevalent. Seed treatment in addition to protection of sucking pests, gives initial vigour and early establishment to the plant.

V. G. Mathirajan, K. Natarajan & B. Dhara Jothi

Central Institute for Cotton Research Coimbatore-641003