1EVALUATION OF NATURAL PRODUCTS AS POSSIBLE ALTERNATIVES TO METHYL BROMIDE IN SOIL FUMIGATION

Crude extracts from Warburgia ugandensis Sprague, Azadirachta indica, Tagetes minuta and Urtica massaica have been tested against soil pathogens; Fusarium oxysporum, Alternaria passiflorae and Aspergillus niger. The results obtained showed biological activity against these pathogens except for U. massaica extract, which was not active. Separation of the crude extract from W. ugandensis yielded two pure compounds; Muzigadial and Muzigadiolide whose structures were confirmed by spectroscopic techniques and comparing with already existing spectroscopic data. The minimum inhibitory concentration (MIC) for those two compounds from W. ugandensis have been obtained. Green house experiments using W. ugandensis crude extract against F. oxysporium that causes wilting in Lycopersicon esculentum (tomato plant) have been carried out. Data interpretation carried out by Analysis of variance and comparison of various treatments through LSD and DMRT tests showed that this crude extract controlled the pathogen F. oxysporum