The effect of beneficial Trichoderma species isolated from sodic and saline soils to control Fusarium root rot of cucumber (Fusarium solani)

Trichoderma species are dominant organisms in most of soil microflora due to metabolic diversity and competitiveness and found approximately in all diverse habitats. In this study, four selected Trichoderma strains were evaluated to better control of cucumber stem and root rot disease caused by Fusarium solani. Cucumber germinated seeds were sown into inoculated soil with Trichoderma strains. Cucumber seedlings at forth leaf stages were inoculated with Fusarium. One month after inoculation by Fusarium, biocontrol effect of Trichoderma strains were evaluated by measuring the disease severity and cucumber growth factors. The results showed that Trichoderma strains were reduced disease severity and increased the growth factors in which both strains T189-4 (T. aureoviride) and T127-12 (T. harzianum) had the greatest impact on reducing infection with 91.67% in compare to untreated plants. The effect of Trichoderma strains on plant growth factors including root and stem length, dry and wet weight of root and stem, stem diameter and relative chlorophyll resulted that different Trichoderma strains have a posetive effects on increasing plant growth factors in which the strains T189-4 and T127-12 had the greatest effect on root dry weight in the presence of the pathogen, with 97% and 82%, respectively. These results indicated that the use of these Trichoderma native strains could be recommended for the control of Fusarium stem and root rot in the integrated management program of disease.