Evaluation of Insecticides Against Amrasca Biguttula biguttula (Ishida) in Cotton

Abstract

This field experiment on the evaluation of insecticides against cotton leafhopper Amrasca biguttula biguttula (Ishida) in Gossypium hirsutum L. was conducted at Hisar (Haryana) during kharif 2019. Based on mean of both sprays, the least counts of nymphs and adults was observed with flonicamid 50%WG @ 150 g ha-1 (0.84 nymphs and 1.73 adults/3 leaves) followed by dinotefuran 20%SG @ 150 g ha-1 (1.49 nymphs and 2.06 adults/3 leaves) and diafenthiuron 50%WP @ 500 g ha-1 (1.65 nymphs and 2.25 adults/3 leaves). Imidacloprid 17.8%SL @ 100 ml ha-1, thiacloprid 21.7% SC @ 125 ml ha-1, thiamethoxam 25% WG @ 100 g ha-1 and buprofezin 25% SC @ 1000 ml ha-1 were moderately effective. Insecticide sprays reduced the occurrence of natural enemies (spiders, coccinellids and Chrysoperla) only insignificantly. The maximum seed cotton yield was obtained with flonicamid (21.60 q ha-1) followed by dinotefuran (20.99 q ha-1), diafenthiuron (20.71 q ha-1), imidacloprid (20.41 q ha-1), thiacloprid (20.12 q ha-1), buprofezin (19.87 q ha-1), thiamethoxam (19.83 q ha-1) and monocrotophos (19.37 q ha-1). The incremental cost-benefit ratio was maximum with imidacloprid (1:6.36) followed by thiacloprid (1:5.64), thiamethoxam (1:5.29), monocrotophos (1:4.74), dinotefuran (1:4.38), flonicamid (1:3.99), buprofezin (1:3.86) and diafenthiuron (1:3.19).