Evaluation of some commercial and native isolates of Trichoderma harzianum for controlling Melon Fusarium wilt using seed coating method

The present paper tends to assess the inhibitory impacts of the three isolates of Trichoderma harzianum obtained from the commercial products of Trianum-P, Trichomix-HV and TricofungS and the two native isolates of T. harzianum, Th1 and Th2, applied to control melon Fusarium wilt using seed coating method under both laboratory and greenhouse conditions. Melon seeds were infected with pathogen and treated by T. harzianum isolates were assessed for germination in vitro. Research results showed that Trianum and Th1 were the most effective treatments for germination (with 95 and 92.5%, respectively), in comparison with the control sample 25% and they indicated significant difference. In greenhouse, disinfected seed by tested treatments were planted in pots containing soil infected by pathogen. Treatments included the three mentioned commercial products and two propagated isolates in bran at three concentrations of 0.5, 1.5 and%0 2.5 and two fungicides of Rovral TS and Thiabendazole in concentrations of 1.5,2 and %02.5. plant growth parameters and disease severity were measured. Trianum, Tricofung, Trichomix and Rovral in concentrations of 2.5, 1.5, 2.5 and %2 reduced disease severity by 80% and 67.5%, 67.5%, 67.5% respectively. In control samples, the percentage of plants with no wilt symptoms was 7.5%. For growth parameters, the plants treated by Rovral %ₒ2, Th1, Th2 and Trianum %ₒ2.5 were the most effective seed coatings. Research results indicated that commercial and native isolates of T. harzianum had the potential of controlling Fusarium wilt in melon using seed coating method as well as tested chemical fungicides. However, different isolates of T. harzianum had different biological effects.