Efficacy of botanical extracts of indigenous plants against Brevicoryne brassicae infesting crucifers

Aqueous leaf extracts of Artemisia brevifolia Wall and Eupatorium adenophorum Spreng, both sprayed at the rate of 0.075 and 0.1125 per cent, were evaluated against Brevicoryne brassicae L. on cabbage at research farm of Highland Agricultural Research and Extension Centre, Kukumseri, Lahaul and Spiti, Himachal Pradesh (2772 m AMSL). The results revealed that two sprays of Artemisia and Eupatorium leaf extracts (0.1125%) at fortnightly interval reduced the B. brassicae population to the tune of 88.8 to100.0 and 89.1 to 90.2 per cent over pre-treatment, respectively as observed at 14 days after second spray (DAS₂). While, reductions in plant infestations were to the tune of 84.5 to 93.9 and 94.9 to 96.8 per cent over pre-treatment, respectively after the same duration. Artemisia and Eupatorium leaf extract (0.1125%) sprayed plots recorded 29.6 to 35.7 and 27.7 to 29.8 per cent higher yield of cabbage heads over control, respectively.