POPULATION DYNAMICS OF INSECT PESTS INFESTING BROCCOLI AND TO EVALUATE MAJOR INSECTICIDES FOR THEIR BIOEFFICACY AND RESIDUES
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Date
2024-07-24
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UHF Nauni
Abstract
The present investigation entitled “Population dynamics of insect pests infesting broccoli and to evaluate major insecticides for their bioefficacy and residues” was carried out during 2021-2022 and 2022-2023 at Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan (HP). Results of this investigation revealed that broccoli was found to be infested mainly with aphid, Brevicoryne brassicae (L.), diamondback moth, Plutella xylostella (L.) and flea beetle, Phyllotreta cruciferae (Goeze). Incidence of aphid and flea beetle was found to be present throughout the cropping season of broccoli (48th SMW to 10th SMW) while diamondback moth appeared from 4th to 6th SMW which persisted till 10th SMW. Weather parameters showed non-significant correlations with aphid population buildup; maximum and minimum temperature significantly affected diamondback moth larvae population; and maximum temperature, minimum temperature and rainfall significantly affected population buildup of flea beetles. Bioefficacy studies indicated that acetamiprid 20% SP at recommended dose (X) resulted in 75.50-76.52 per cent efficacy in controlling aphid populations, flubendiamide 20% WG at X dose showed efficacy of 76.97-79.62 per cent against diamondback moth and lambda-cyhalothrin 4.90% SC at X dose showed highest efficacy to the tune of 73.95-76.12 per cent in managing flea beetle populations. The average initial residues of cyantraniliprole (60 and 75 g a.i./ha), acetamiprid (15 and 18.75 g a.i./ha), flubendiamide (18.24 and 22.80 g a.i./ha), lambda-cyhalothrin (15 and 18.75 g a.i./ha) and novaluron (75 and 93.75 g a.i./ha) were in the range of 0.562-0.762, 0.757-1.069, 0.231-0.358, 0.473-0.687 and 1.172-1.494 mg/kg, respectively with a half-life of 1.873-2.354, 1.525-1.930, 1.371-1.620, 1.975-2.484 and 1.678-2.170 days in broccoli heads, respectively. No residues were detected in broccoli cropped soil at harvest time. No appreciable risk to consumers from rural and urban households was observed on the basis of acute hazard quotient (HQ) and chronic HQ values being less than 1 for all the insecticides