Medicinal plant extracts of five plants; Adhatoda vasica, Eucalyptus globulus, 
Lantana camara, Nerium oleander and Ocimum basilicum collected from Cairo, Egypt 
were evaluated against Fusarium oxysporum f. sp. lycopersici race 3 in vitro 
conditions using water and certain organic solvents. The results revealed that 
cold distilled water extracts of O. basilicum and E. globulus were the most 
effective ones for inhibiting the growth of F. oxysporum f. sp. lycopersici. 
Butanolic and ethanolic extracts of the tested plants inhibited the pathogen 
growth to a higher extent than water extracts. Butanolic extract of O. basilicum 
completely inhibited the growth of F. oxysporum f. sp. lycopersici at 
concentrations 1.5 and 2.0% (v/v). Butanolic extracts (2.0%) of tested plants 
had a strong inhibitory effect on hydrolytic enzymes; β-glucosidase, pectin 
lyase and protease of F. oxysporum f. sp. lycopersici. This study has confirmed 
that the application of plant extracts, especially from O. basilicum for 
controlling F. oxysporum f. sp. lycopersici is environmentally safe, cost 
effective and does not disturb ecological balance. Investigations are in 
progress to test the efficacy of O. basilicum extract under in vivo conditions.