KATNA, SAPNANIDHI2018-07-162018-07-162018-07-04http://krishikosh.egranth.ac.in/handle/1/5810060351ABSTRACT The present investigations on “Persistence of imidacloprid, lambda-cyhalothrin and spiromesifen on cauliflower” was carried out during 2016-2017 in the department of Entomology, Dr. Y S Parmar University of Horticulture and Forestry, Nauni, Solan. The objectives of the study were to evaluate the persistence of imidacloprid, lambda-cyhalothrin and spiromesifen in/on cauliflower curds and the cropped soil. The effect of decontamination methods in dislodging the insecticide residues from cauliflower was also studied. The study was conducted using Confidor 17.8 SL 140 and 280 mL ha-1), Reeva 5 EC (300 and 600 mL ha-1) and Oberon 240 SC (419 and 838 mL ha-1) at single and double dose, respectively. The persistence study on cauliflower curds recorded initial deposits due to single and double dose of imidacloprid (25 and 50 g a.i. ha-1) as 0.488 and 0.912 mg kg-1, lambda-cyhalothrin (15 and 30 g a.i. ha-1) as 0.303 and 0.610 mg kg-1 and spiromesifen (96 and 192 g a.i. ha-1) as 0.960 and 2.083 mg kg-1. Imidacloprid, lambda-cyhalothrin and spiromesifen residues persisted in cauliflower curds upto 7 and 10 days at single and double dose, respectively. The residues of imidacloprid, lambda-cyhalothrin and spiromesifen in curds reduced to half in less than 4 days. The initial deposits of 0.102, 0.063 and 0.062 mg kg-1 at single dose and 0.191, 0.121 and 0.115 mg kg-1 at double dose were observed for imidacloprid, lambdacyhalothrin and spiromesifen, respectively, in cauliflower cropped soil. Among various decontamination processes, microwave cooking after tap water washing was found most effective which provided up to 90.23 per cent relief followed by open pan cooking after tap water washing (83.41%), saline water washing (50%), lukewarm water washing (41.95%) and tap water washing (26.88%) from the three insecticide residues in cauliflower curds. Safe waiting period of 12.28 days for imidacloprid, 11.33 days for lambda-cyhalothrin and 11.12 days for spiromesifen was suggested to harvest cauliflower safely.ennullThesis