Study of Different Levels of Chlorantraniliprole 10%+Thiamethoxam 20% Mixture Against Major Insect-pests of Tomato

Experiments were conducted at Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India to evaluate the efficacy of chlorantraniliprole 10%+thiamethoxam 20% @ 105, 128 and 150 g a.i. ha⁻¹ along with other insecticides against major pests of tomato under field condition. Tomato crop was raised in Randomized Block Design during 2010−11 and 2011−12 crop seasons. One soil drench application of all the treatments was given at 10 days after transplanting @ 100 ml water plant⁻¹ except λ-cyhalothrin 5 EC that was given as foliar spray at the same time with three replications. Observations of whitefly, leaf miner and fruit borer were taken on 5^th, 10^th, 15^th, 20^th and 30^th days after soil drench application. Yield was recorded separately for each treatment during both the seasons. The per cent reduction or increase (+) of parasitoids (Encarsia sp. and Apanteles sp.) were recorded only on 30^th day after application. Results revealed that chlorantraniliprole 10%+thiamethoxam 20% mixture @ 150 g a.i. ha⁻¹ gave excellent control of the two sucking pests, viz. leaf miner (5.09 and 5.75%) and whitefly (0.50 and 0.41 scale) as well as of Helicoverpa armigera (0.46 and 0.61 larvae plant⁻¹) for both the seasons. The yield increases were also significantly higher in Chlorantraniliprole 10%+thiamethoxam 20% mixture treatments as well as it showed remarkable specificity to two important natural enemies associated with tomato ecosystem.