Chemical Control of Whitefly and Aphid Insect Pest of French Bean (Phaseolus vulgaris L.)

An experiment was conducted at Sher-e-Bangla Agricultural University farm to study the efficacy of some insecticides against major insect pests of French bean (Phaseolus vulgaris L.). The treatments of the experiment were T1: Bamper 20SL (Imidacloprid) @ 0.5 ml L -1 , T2: Shobicron4 25EC @ 2 ml L -1 , T3: Actara 25WG (Thiamethoxam) @ 0.3 g L -1 , T4: Chlorpyriphos 20EC @ 3 ml L -1 , T5: Sinothrin 10EC (Cypermethrin) 1 ml L -1 , T6: Fortap 50SP (Cartap) @ 3 g L -1 and T7: Control treatment. Results showed that the lowest number of whitefly plant -1 (3.28 at 60 DAS) and aphid plant -1 (4.82 at 60 DAS), the lowest infestation intensity by whitefly (5.92%) and aphid (14.25%), the lowest infested bean yield plant -1 (52.80 at 60 DAS), highest healthy bean yield plant -1 (166.40 g at 60 DAS), highest total healthy yield (11.28 t ha -1 ), lowest total infested yield (0.64 t ha -1 ) and highest gross return (Tk. 232000.00 ha -1 ) were obtained from the use of Chlorpyriphos. The highest percent reduction of whitefly plant -1 (81.44 % at 60 DAS) and aphid plant -1 (80.15 % at 60 DAS), highest percent reduction of infested bean yield plant -1 (81.82 % at 60 DAS) and highest increase of healthy bean yield plant -1 over control (215.20 % at 60 DAS) were achieved from the same treatment. Hence Chlorpyriphos 20EC performed best to suppress the whitefly and aphid of French bean followed by Fortap 50SP.