摘要:Sclerotinia stem rot is a plant disease caused by the pathogenic fungus Sclerotinia sclerotiorum, and considered as one of the most serious and devastating diseases that affect many crop plants in Jordan. Biological control has recently become a successful alternative to the chemical treatment. In this study, five bacterial isolates (U1-U5) were obtained from the external surface of none germinated Sclerotia collected from soil samples of infected cucurbit plants in the Jordan Valley. Bacterial isolates were evaluated for their potential antifungal activity against two S. sclerotiorumisolates; S23 and E15. Results showed significant inhibition of both sclerotial and mycelial formations, with highest antifungal activity observed for U2, U3 and U5 isolates. These three isolates were identified as Bacillus subtilisand subjected to an in vivo evaluation of antifungal activity on squash seeds under greenhouse condition. Results revealed a significant improvement in seedling growth parameters and high survival percentages, with normal overall appearance.