Bio-efficacy of some botanical leaf extracts against mustard aphid, Lipaphis erysimi (Kaltenbach) and their influence on the yield and yield attributes of Indian mustard (Brassica juncea)

Abstract

The current study was undertaken to assess the bio-efficacy of leaf extracts of Neem (Azadirachta indica A. Juss), Tobacco (Nicotiana tabacum L.), African marigold (Tagetes erecta L.), a mixture of the three extracts, imidacloprid, and a control (water spray) against mustard aphid during two consecutive Rabi seasons of 2022-23 and 2023-24. The percentage reduction over control (PROC) values were calculated for each botanical extract to ascertain their effectiveness at 1, 3, 7 and 10 days after treatment. The pooled efficacy at 10 days after treatment revealed that Imidacloprid was the most potent, recording 100.0% reduction, followed by neem leaf extracts (82.79%), tobacco leaf extracts (78.76%), and the mixture treatment (77.41%), with marigold leaf extract displaying the lowest efficacy at 69.01%. A parallel trend was observed in seed yield, affirming the efficacy of these treatments in mitigating aphid-induced losses in mustard crops. The botanical extracts showed significant efficacy potentials and so can be used as substitutes for imidacloprid insecticide to manage the aphid in an eco-friendlier manner.