Studies on the Comparative Efficacy of Trichogramma chilonis Ishii (Hymenoptera:Trichogrammatidae), Insecticides and Integration of Trichogramma with Insecticides for the Suppression of Cotton Bollworms


Abstract

The comparative efficacy of Trichogramma chilonls Ishii (8 releases @ 1,50,000 parasitized eggs/ha), T. chilonis 8 releases +5 Insecticidal sprays (3 of oxydemeton methyl 0.075% and one each of cypermethrln 0.016% and carbaryl 0.4%) and insecticide treatments having seven sprays (3 of oxydemeton methyl, 2 of cypermethrin and one each of carbaryl and fenitrothion 0.34%) against cotton bollworms was studied. The number of bolls per plant In T. chilonis, T. chilonis + insecticides and insecticide treatments was 38.8, 46.3 and 47.2 respectively and they were significantly higher than in control (19.4). The damage to loculi was significantly higher in control (47.5 per cent) while In T. chilonis, T. chilonis + insecticide and insecticide treatments it was 30.2%, 13.1% and 10.1% respectively and the latter two treatments were on par with each other. The highest yield was obtained with insecticide treatment (19.7 Q/ha) followed by T. chilonis + insecticide treatment (18.6 Q/ha) and T. chilonis treatment (12.1 Q/ha). The yield in control was 8.6 Q/ha.

Keywords

Cotton Bollworms, Trichogramma chilonis, Insecticides, Integrated Control.

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