Combined Efficacy of Neem and Insecticides against Brinjal Mealy bug, Coccidohystrix insolita (Green)

摘要

Efficacy of Neem Seed Kernel Extract (NSKE) and Azadirachtin in combination with chemical insecticides (Dimethoate 30EC, Profenofos 50EC and Imidacloprid 200SL) was evaluated under field condition on the brinjal mealybug Coccidohystrix insolita (Pseudococcidae: Homopteraj. Dimethoate 30EC @ 0.5ml/lit + NSKE 3% recorded the minimum per cent plant infestation of 14.97 and mealybug population of 0.78/cm~2. But dimethoate 30EC @ 1 ml/lit alone recorded 17.56 per cent plant infestation and 0.89 mealybug/cm~2. Efficacy of profenofos 50EC was enhanced by Azadirachtin 1EC. Profenofos 50EC @ 1 ml/lit recorded 36.84 per cent plant infestation and 1.86 mealybug/cm~2. When Azadirachtin 1 EC @ 1 ml/lit was combined with half the dose of profenofos, the per centplant infestation and population were 32.80 and 1.61, respectively. But, in control they were 77.17 and 14.50 respectively. The fruit yield and return per rupee invested on plant protection were also high in dimethoate 30EC @ 0.5ml/lit + NSKE 3% (17.13 t/ha and 20.08) followed by profenofos 50EC @ 0.5ml + Azadirachtin 1EC @ 1 ml/lit (15.67t/ha and 15.18).