Bio-effectiveness and non-target toxicity of an IPM compatible thiourea compound diafenthiuron against cardamom thrips and capsule borer under hill zone of West Bengal

Field evaluation at progressive farmer's holdings in Kalimpong, darjeeling, West Bengal in a seven years old large cardamom plantation with a local cultivar “Varlangey” was carried out to investigate the bio-efficacy of a non-organofluorine benzyl urea compound diafenthiuron 50% WP along with standard checks against cardamom thrips Sciothrips cardamomi (ramk.) and capsule borer Conogethes punctiferalis (Guen.) during two winter seasons. the treatment at higher dosages (800 and 1600 g ha⁻¹) found superior over standard checks quinalphos 25% ec, chlorpyrifos 20% ec and carbosulfan 25% ec. the highest biological yield was obtained with higher dosages (32.45 and 33.00 q ha⁻¹). the infestation of thrips and capsule borer was minimum in treatments with higher dosages with an overall mean ranging from 9.05–9.53% mean capsule damage and 19.29–19.64% mean shoot and 11.54–12.03% mean capsule damage respectively.