DEVELOPMENT OF MANAGEMENT PRACTICES AGAINST TOMATO FRUIT BORER, Helicoverpa armigera (Hubner) AND QUANTIFICATION OF RESIDUE OF CYPERMETHRIN AND CHLORPYRIFOS IN TOMATO

Abstract

The experiments were conducted in the experimental field of Sher-e-Bangla Agricultural University, Dhaka and Pesticide Analytical Laboratory, Entomology Division, BARI, Joydebpur, Gazipur during the period of November 2007 to May 2008 to evaluate the efficacy of some management practices against tomato fruit borer and residue level of insecticide in Tomato. Considering the effects of different management practices applied against tomato fruit borer at early, mid and late fruiting stages, the level of infestation followed more or less similar trend for both by number and by weight of tomato but at late stage the rate infestation by fruit borer was a little bit higher. Among the treatments T3 (Comprising Ripcord 10 EC @ 1 ml/L of water + Neem seed kernel (20 g /L) at 7 days interval + Mechanical) performed maximum number and weight of healthy fruit/plant and minimum number and weight of infested fruit. The lowest percent fruit infestation by number and by weight was also recorded in T3 whereas in T6 (Untreated control treatment) the situation is totally overturned in this trial. In considering the economic analysis of the different treatments in controlling tomato fruit borer, the highest cost benefit ratio (4.55) was recorded in the treatment T3 (Consisting Ripcord 10 EC @ 1 ml/L of water+Neem seed kernel (20 g /L) at 7 days interval+Mechanical).On the other hand, the minimum cost benefit ratio (1.08) was recorded in treatment T2. But no management cost was required for T6 treatment (Untreated control). The residue of the insecticide Cypermethrin (0.031 ppm ) was detected in the sample up to 5 Days after spray (DAS) and the quantities were over MRL up to 3 DAS. Chlorpyrifos residue 0.26 ppm was detected in the sample up to 7 DAS of which up to 5 DAS the quantity of residue were above MRL.