IN a previous paper1 it was demonstrated that adventitious-root formation, due to Fusarium vasinfectum metabolites, is confined to the wilt-resistant ‘Ashmouni’ cotton cut shoots, while the susceptible ‘Giza 26’ cotton variety fails completely to initiate any root development. The comparative readiness of a resistant variety to form adventitious roots in response to the metabolites of the specific fungal pathogen on host extract, and the failure of a susceptible variety to manifest such response, have been further tested and verified with other species of Fusarium as well as cotton and tomato varieties. The present work has been carried out in an attempt to elucidate the two following problems: (a) the metabolitic potentialities of Fusarium solani (cf. Snyder and Hansen) to stimulate adventitious roots in wilt-resistant ‘Karnak’ and susceptible ‘Giza 26’ cotton varieties, and (b) the metabolitic potentialities of two tomato-wilt Fusarium species, namely, F. oxysporum and F. moniliforme, to initiate adventitious roots in wilt-resistant ‘Myco. 1’ and susceptible ‘North Dakota’ tomato varieties.