Abstract: Commercial management of soilborne pathogens is often reliant on use of synthetic chemicals. These chemicals are expensive and not easy to use for most resource poor farmers. Biofumigation represents a potential alternative because of its less heath impacts, less cost and its less harm to the environment. This work was initially done in the laboratory and then continued in the greenhouse tunnel and field. The study aimed to determine the efficacy, produced by Cleome gynandra species, on soil borne fungal pathogens. In the laboratory, green C. gynandra was effective against purple C. gynandra. In the greenhouse seedlings inoculated with Rhizoctonia solani and Pythium ultimum were effectively controlled by purple C. gynandra and it was comparable to the control treatments. Statistical differences gave major evidence of disease suppression in plots amended with purple C. gynandra species in yields of both tomato and sweet pepper grown in the field. The results also show that the two C. gynandra specie types had potential as control for soilborne pathogens. The results are discussed in detail in this paper.
Keywords: biofumigation, glucosinolates, isothiocyanates, Cleome gynandra, pathogens