Mortality of the soybean cyst nematode in aqueous extracts of neem plant

Abstract

The effect of an aqueous extract (10 g/200 ml of distilled water) of vegetative and propagative parts of neem (Azadiractina indica) was tested on the mortality of juveniles of Heterodera glycines. Mortality induced by aqueous extract of the branches, leaves and seeds was 99, 97 and 99.9% respectively, not statistically different among them. In a second test, the number of females on the root system was determined thirty days after the incorporation of 15 g of whole leaves/kg of soil or 10 g of each of ground branches, whole seeds and ground seeds/kg soil. The number of females recovered after incorporation of whole leaves, ground branches, whole seeds and ground seeds was 1, 32, 9.1 and 0.8/root system respectively, the differences being statistically different (5%). The number of females in the control roots was 61, indicating the presence of toxic compounds in neem.