Invitro Evaluation of Neem Tree Seed Oil Against Fungal Growth of Fusarium oxysporum. F. sp. lycopersici, the Causal Agent of Tomato Wilt Disease

Abstract

Fusarium wilt considered as one of the most important diseases of tomato in Sudan. The present investigation was undertaken under laboratory conditions to study the effect of different neem oil concentrations, and synthetic fungicide,(AmistarTop 200ml/100L Water), on growth of the fungus Fusariumoxysporumf. sp. Lycopersicithe causal agent of wilt disease on tomato. Three concentrations of neem oil (1.5, 2.5 and 3.5 %) and fungicide as recommended dose were tested in addition to control. The assessment of theirinhibitory effect against the pathogen was expressed as fungal growth inhibition percentage after six days of treatment. The results obtained showed that neem oil at alltested concentrations (1.5, 2.5, 3.5 (%) as well as the fungicide reduced significantly (P<0.05) the fungal growth (36.65%, 34.59%, 40.95, and 53.59 %) respectively compared to untreated control(100%). Moreover, the fungicideat100% concentration (0.2\100ml) demonstrated the highest inhibition of fungal growth (53.59%) followed in descending order by neem oil concentrations. Among neem oil concentration, the highest one (3.5%) reduced significantly the growth of the fungus (40.59%). Generally, the results showed that the antifungal activity increase with increase in extract concentration. Obviously, the test fungus differs in response to the different concentrations.