Efficacy of neem leaf extract on root-knot nematode, Meloidogyne incognita infecting cowpea

A pot culture experiment was carried out to study the effect of soil and foliar application of neem leaf extract at two concentrations viz. 10 and 15 per cent on the root-knot nematode, Meloidogyne incognita. Soil application showed higher reduction in nematode population compared to foliar application. Soil application at 15 per cent recorded minimum number of nematodes in soil and root which was 90 and 90.3% decrease over control, respectively. The gall index was only 1.3 at 15% concentration, where as it was 5 in untreated control. The plant growth was promoted by soil application of neem leaf extract at 15 per cent followed by 10 per cent concentration. Numbers of pods were 3.8 at 15% while it was nil in control.