EFFECT OF SOME SPECIES OF TRICHODERMA SPP. AND THE CHEMICAL FUNGICIDE TOPSIN M IN CONTROL OF THE DISEASE OF SEED ROT AND SEEDLING DAMPING OFF OF OKRA CAUSED BY FUSARIUM CULMORUM.

This study aimed to isolate and diagnose the pathogen of seed and seedling rot disease from infected okra roots [Abelmoschus esculentus (L.) Moench] and its control using the chemical fungicide Topsin M and some species of Trichoderma spp. [Trichoderma aspirelloides (1), Trichoderma atroviride (2), Trichoderma longibrachaitum (3), Trichoderma asperellum (4)]. The results showed the possibility of isolating 15 fungal isolates that were morphologically diagnosed as different species belong to Fusarium spp. The results of the pathogenicity test of 15 fungal isolates in plastic pots showed that all isolates were pathogenic and the rates of inhibition of seed germination ranged between 0.00% - 73.30% and significant difference from the percentage of seed germination in the control treatment, which reached to 100%. Among those isolates, the isolated fungus (5) was the most pathogenic compared to the other isolates by preventing seed germination (0.00%) compared to isolate (1) which had a little effect in reducing the percentage of seed germination (73.30%). The most pathogenic fungus (isolate 5) was molecularly diagnosed as Fusarium culmorum using the polymerase chain reaction technique (PCR). The results proved that all species of fungi Trichoderma spp. had a significant effect in inhibiting F. culmorum compared to the control treatment (pathogenic fungus alone). [ABSTRACT FROM AUTHOR]