Evaluation of plant extracts against insect pests of cabbage

A field experiment was conducted to study the bioefficacy of plant extracts against diamond back moth, Plutella xylostella L. cabbage butterfly, Pieris brassicae L. and cabbage aphid, Brevicoryne brassicae L. and their toxic effect on the predatory coccinellid beetle, Coccinella septempunctata L. in cabbage var. “Pride of India”. Against P. xylostella Margosom (Azadirachtin 300 ppm) @ 0.3% proved to be the most effective closely followed by Melia azedarach, extract applied at 5%. Against P. brassicae also Margosom registered significantly the lowest damage closely followed by M. azedarach extract @ 5% and Artemisia nilagirica extract@ 5%. A similar trend of Margosom was also observed against B. brassicae maintaining its superiority. It was at par with the treatments with M. azedarach, A. nilagirica, Ageratum conyzoides and Chinnamomum tamala. Against C. septempunctata among the tested insecticides, M. azedarach @ 5% conc. proved to be the safest which was at par with A. nilagirica C. tamala and Aralia armata. Maximum cabbage yield was obtained with Margosom followed by M. azedarach and A. nilagirica.