POTENTIAL OF SOME BIORATIONAL INSECTICIDES IN CONTROLLING BEAN APHID OF COUNTRY BEAN

Abstract

The experiment was conducted at the central farm of Sher-e-Bangla Agricultural University (SAU), Sher-e-Bangla Nagar, Dhaka, Bangladesh to evaluate the potential of some biorational insecticides in controlling bean aphid of country bean (BARI seem1) during the period from October 2019 to February 2020. The experiment consists of

the following management practices: T 1 : Azadirachtin (Bioneem plus 1 EC) + Spinosad (Success 2.5 SC); T 2 : Thiamethoxam (Aktara 25% WG) + Spinosad (Success 2.5 SC); T 3 : Imidacloprid (Imitaf 20 SL) + Spinosad (Success 2.5 SC); T4: Farmers’ practice (spraying Malathion 57 EC weekly); T5: Control. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications. In consideration of total growing period, the %pod infestation by number, the lowest number of infested pods plant -1 was observed from T 3 (7.65), whereas the highest pod infestation was found from T 5 (17.75). The highest no. of healthy inflorescence plant ii -1 was observed from T 3

(55.75) while the lowest no. was observed from T 5 (39.00) treatment. The highest yield hectare -1 was found from T 3 (21.25 ton/ha), while the lowest yield hectare was found from T 5 (16.675 ton/ha) treatments. From this study it may be concluded that the treatment T 3 which consists of spraying of Imitaf 20 SL @2 ml/L of water at weekly interval and Success 2.5 SC @0.1 ml/L of water at alternate week was more effective among the management practices for controlling bean aphid of country bean which was followed by spraying Aktara 25% WG @0.5 g/L of water at weekly interval and Success 2.5 SC @0.1 ml/L of water at alternate week.