Aran Ngampongsai, Sunthorn Pipithsangchan, and Wipawadee Chamnan

pp. 307 - 316

Abstract

Tests on plant crude extracts of neem seeds, galanga and citronella grass at the rates of 200 ml/20 L of
water together with synthetic insecticides, cypermethrin, methamidophos, carbosulfan and carbofuran, at
the recommended rates showed that none of the treatments was effective in controlling plant damage caused
by adult of bean fly (Ophiomyia phaseoli Tryon). The application of the synthetic insecticide, methamidophos,
and plant crude extracts of neem seeds + galanga + citronella grass provided the highest effectiveness to
control aphids (Aphis craccivora Koch). Control of A. craccivora was not significantly different between the
synthetic insecticide and plant crude extracts, except methamidophos. Pod damage caused by pod borer
(Maruca testulalis Geyer) and yields were also not significantly different among treatments. However, the
highest yield of 1,224.7 kg/rai was recorded in plots treated with neem seed extracts and the synthetic insecticide, carbosulfan. In untreated plots, the lowest yield of 587.3 kg/rai was collected.