Insect pest management of winter planted cotton in coastal rice‐fallows of West Bengal†

Abstract

Abstract Efforts to grow some Indian strains of G. hirsutum cotton in the dry winter season, with the residual soil moisture of rice‐fallows in tropical coastal West Bengal, including the sundarbans (India), were initiated in 1969–70. Earias vitella (Stoll) was the ‘key’ insect pest from the presquaring to the boll maturing stage, while Heliothis armigera (Hubner) was an occasional mid‐and late‐season pest. Earis activity is low during December‐January, increasing with rising temperature from February, and becoming a maximum in May‐June. In the early 1980s ten glanded, including one nectariless, and two glandless including one nectariless American medium‐staple rapid fruiting and early maturing hirsutum varieties from the USA were tried in the short‐season production system at high planting density, together with integrated pest management. These American varieties matured an economic load of bolls from the first flush of flowers before the peak Earias infestation and yielded, 841–1930 kg/ha and 767–1162 kg/ha seedcotton from direct‐seeded and transplanted crops, respectively.