Susceptibility of certain varieties and genotypes and control of wilt and root rot diseases of sesame attributed to fusarium oxysporum f sp sesami and macrophomina phaseoli.

ABSTRACT

Eight fungal isolates were obtained from naturally diseased sesame plants suffering from wilt and root rot diseases. These isolates were identified as Fusarium oxysporum f. Sp. Sesami and Macrophomina phaseoli. Fusarium isolates infected sesame plants causing wilt symptoms and Macrophomina isolates infected sesame plants causing root rot and charcoal stem rot. Varietal resistance on different varieties and genotypes revealed that Giza 32 was less susceptible to infection with F. oxysporum and M. phaseoli than other tested cultivars. Among the tested fungicides, Benlate was the most toxic in vitro. Furthermore, the application of Benlate and Rhizolex-T as soil treatment at concentrations of 0.04-0.1% decreased the percentage of wilt and root rot diseases. Additionally, in a field trial, Benlate proved to be a very effective fungicide in decreasing infection with M. Phaseoli and F. oxysporum when applied at 0.5 g/hill. Bacillus subtilis was isolated from the rhizosphere of sesame plants and showed inhibitory effect against the fungi tested in vitro. The antagonists were able to suppress wilt and root rot diseases when applied to artificially infested soil. Moreover, the addition of 1% organic manure resulted in a greater reduction in infection with wilt and root rot diseases