Efficacy of nine different botanical nematicides were tested against root-knot nematodes,
Meloidogyne Incognita affecting cowpea (Vigna unguiculata) cultivar oloyin in an open field experiment
in a randomized complete block design with five replicates. The known effective synthetic nematicide,
Furadan and the cowpea which bore no nematicides were included as controls. Based on comparism
with known effective nematicide (Furdan), three nematicides Azadirachta indica (bark), Salvadora
persica, and Chromolaena odorata were rated more effective as they showed 55% reduction in
percentage number of eggs and percentage root galling over the control which were significantly same
as the furadan. The remaining nematicides, Capsicum annum, Zingiber officinale, Azadirachta indica
(leaf, seed and husk) and Manihot esculenta were moderately effective in reducing the percentage
number of eggs and percentage root galling over the control which in turn differ significantly from the
known effective nematicide furadan. Amongst the neems (neem leaf, neem seed, neem husk and neem
bark) neem bark was the most effective and neem husk was the less effective. In terms of vigour, all the
botanical nematicides were significantly same as the furadan control, except Manihot esculenta which
differ significantly.