Field Evaluation of Botanicals for the Management of Cruciferous Vegetable Insect Pests

  • F. P. Neupane

Abstract

In field tests conducted for four cropping seasons, crude water extracts of green neem leaves (Azadirachta indica A. Juss), chinaberry (Melia azedarach L.), malabar nut (Justicia adhatoda L.) and Indian privet (Vitex negundo L.) all at 200 g of leaves per litre of water; were superior to the crude water extracts of the green leaves of mug-wort (Artenzisia vulgaris L.), yellow lantana (Lantana camara L.), crown plant (Calotropis gigantea (L.) R. Br.) and dry fruits water extract of chinabeny, all at the same rate as above, and neem seed kernel-based water dispersable powder at 0.1 %; in suppressing the cruciferous insects, namely the cabbage butterfly (Pieris brassicae nepalensis Doubleday), the soyabean hairy caterpillar (Spilarctia casigneta Kollar), the tobacco caterpillar (Spodoptera litura Fab.) and the diamondback moth (Plutella xylostella L.) on cabbage and increasing its yield. Synthetic organic insecticides, namely malathion (0.05% and monocro tophos (0.05%) were superior to all the botanicals in suppressing the above insects and increasing the cabbage yield. However, the health and environmental risks involved and high prices of these chemical insecticides should discourage the farmers for their use