Studies on the Efficacy of Non-Pathogenic Fusarium Oxysporum Isolate to Control Fusarium Wilt of Tomato Plants in Saudi Arabia

Nonpathogenic Fusarium oxysporum endophytes from tomato rhizosphere were evaluated for ability to reduce Fusarium wilt of tomato. Isolation from tomato, green bean and squash diseased plants revealed the association of one or more of the following fungal species, i. e. , Alternaria tenuis, Aspergillus flavus, A. niger, A. tamarii, Cephalosporium maydes, Fusarium moniliforme, F. oxysporum, F. solani. Penicillium spp. , Rhizoctonia solani and Sclerotium rolfsii. Upon testing the pathogenicity of isolates belong to Fusarium oxysporum on tomato, green been and squash plants were found more or less able to attack plants causing pre and post -emergence damping-off. Tomato plants was highly vulnerable to attack by isolate of F. oxysporum (F. o-T2) caused a pre-emergence (57.50 %), post emergence (61.60 %) and 72.50 % death of the survival tomato plants. The data also show that tomato plants inoculated with F. oxysporum (F. o-T5) isolate did not show symptoms of vascular disease and developed normally as plants in the control treatment. The in-vitro antagonistic effect of nonpathogenic of F. oxysporum isolate (F. o-T5) showed different level of antagonistic effects against 4 fungal isolates of plant pathogens. The non pathogenic isolate of F. oxysporum isolate (F. o-T5) was highly antagonistic to the pathogenic isolate of F. o-T2. Tomato seedling grown in soil inoculated with both the pathogenic and non-pathogenic F. oxysporum isolates, the non-pathogenic isolate F. o-T5 was efficient in controlling the disease incidence, as the disease incidence was significantly reduced by the non-pathogenic F. oxysporum (F. o-T5) from 80 to 28 % (65.0 % reduction) in soil infested with wilt pathogen and non-pathogenic respectively. Hence, the non-pathogenic F. oxysporum offer a very good prospects for integrated management of root disease in greenhouse crops