The effect of crude extracts of neem (Azadirachta indica) leaf, neem seed and garlic (Allium sativum) at concentrations ranging from 5% to 30% of the material in 100 ml of Potato Dextrose Agar on mycelial growth of Fusarium oxysporum f. sp. lycopersici was assessed. All the extracts inhibited mycellial growth at various levels. Dry neem seed extract gavel 100% inhibition of mycelial growth. Fresh neem leaf extract reduced mycelial growth with increasing concentration while in garlic there were no differences in growth inhibition among the various concentrations used. However garlic extracts decreased sporulation with increasing concentration and cultures grown on extract amended agar plates remained viable.

This paper presents a preliminary report of Fusarium wilt of Roselle in the Nigerian savanna. Soil and plant samples were collected from eight experimental plots where plants showed Roselle wilt symptoms. Samples were analyzed for the presence of nematodes and wilt pathogens. The wilt causative organism Fusarium oxysporum was isolated together with nematodes of different genera. However, nematodes of the genus Helicotylenchus, Scutellonema and Hoplolaimus appeared to occur in higher densities than the others.