In order to save the Egyptian ecosystem from poUution with pesticides. Five
bioagents were Isolated from the Egyptian soil. These bioagents were identified as
Trichodenna hamatum, Gliocladium virens, BaciHus suM/is, Pseudomonas
truo19scens and Streptomyces sp. The isolates proved to be antagonistic to
Rhizoctonia so/ani, Pythium sp. and Fusarium sp. in vitro. Under field conditions,
good control of soil borne diseases of cucurbits was achieved as a result of these
bioagents. The application of bloagents as seed coat resulted in higher efficiency
than applying them as soil drench. The bioagents affected positively the root system
and the foliage. A new method to asses the bioagent antagonistic potency in vitro, was developed.
The bloagents showed satisfactory control of downy mildew disease on cucumber
and powdery mildew on squash, with significant Increasing in the yield. In all cases
the fungicides showed better results.