Full Text
(47 K)

Utilization of Biopesticides in Managing the Cotton Pest Complex in India

G.P. Gupta, Kirti Sharma


Field trials were conducted with upland cotton (Gossypium hirsutum Var. Pusa 31) during the 1992, 1993 and 1994 crop seasons at the Indian Agricultural Research Institute, New Delhi, to evaluate the bioefficacy of neem products and Bt. formulations and their possible combinations with synthetic insecticides in a spray schedule for the management of cotton bollworms with the ultimate aim to reduce the load of synthetic insecticides and producing cost effective quality cotton. Observations were recorded on the incidence of bollworms viz., spotted (Earias spp.) , pink (Pectinophora gossypiella), American bollworm (Heliothis armigera) in green bolls and open bolls on loculi basis, quality of cotton, and total yield of seed cotton. The impact of insecticidal sprays was also noted on population build-up in whitefly, which was recorded on 30 leaves per plant basis after termination of all the rounds of spraying. Result shows that application of neem products or Bt. formulations alone or in combination with each other or with conventional synthetic insecticides failed to suppress bollworm complex in cotton under field conditions. However, neem or Bt in combination with at least one spray of synthetic pyrethroid in a 4-spray schedule proved effective in managing the bollworm complex and increasing quality of cotton produced. Our studies also showed satisfactory control of bollworm complex and cotton yield response by applying combinations of neem, Bt. and a 84% reduced rate of synthetic pyrethroid under field conditions. This management strategy will reduce the load of synthetic insecticides up to 75 percent and also safe to the environment with no resurgence problem of whitefly. The seed cotton yield in such a spray schedule was more (1910 kg/ha) as compared to spray schedules in vogue (1565 kg/ha, 1370 kg/ha). It shows that biopesticides (neem and Bt.) can replace conventional synthetic insecticides in a spray schedule and can effectively manage the bollworm complex in cotton without resurgence problem of whitefly, and will also minimize environmental exposure to toxic pesticides.

Reprinted from Proceedings of the 1996 Beltwide Cotton Conferences pp. 1135 - 1140
©National Cotton Council, Memphis TN

[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page
Document last modified Sunday, Dec 6 1998