Abstract:
The application of botanical insecticides is one of the alternative ways to reduce the use
of harmful insecticides in agricultural pest management. The aqueous extracts of
Azadirachta indica seed kernel, Lasiosiphon eriocepalzcs leaves and bark, Ocimum
sanctum leaves, Allium sativum bulbs, and Cinnamomum zeylanicum leaf oil extract
effluent were investigated for efficacy in the management of three major leaf eating
caterpillars (Plutella xylostella (L.), Chrisodeixis eriosoma (Doubleday), and
Spodoptera litura (Fabricius)) of cabbage at the organic farm site in Regional
Agricultural Research centre, Bandarawela. The results revealed that in both seasons
(Yala 2006 & Maha 2006/2007) caterpillar population was reduced significantly in
plant extract treated plots compared with untreated control. A. indica seed kernel was
the superior plant extract and comparatively lowest larval population was recorded in
this treatment. However, plant extracts other than O. sanctum also recorded low pest
population without significant difference with A. indica.
