Activity and bioformulation of Trichoderma harzianum for management of tomato diseases caused by soilborne pathogens

Protected vegetable cultivation in Turkey, which is economically important for both domestic consumption and export facilities, is done on around 61696 ha of area with 5.9 million tons of production. Therefore, disease and pest management have become one of the major restricting factors on protected vegetable cultivation in Turkey. Root rot, wilt, damping off diseases caused by soil borne pathogens such as Fusarium spp., Rhizoctonia spp. and Pythium spp. result in considerable yield losses in greenhouse grown vegetables unless soil disinfestation prior to planting is applied. Pesticide applications conducted after disease onsets are neither effective nor economical. In this study, three Trichoderma harzianum isolated from soil collected from Eastern Mediterranean Region were bioformulated. Various supporting materials, drying temperatures and spore concentrations were tested in bioformulation process. Trichoderma isolates were applied to seedling medium after formulation, colonization of roots was done for one month, and pot and greenhouse trials were completed. Tomato seedlings were planted both in solarized and non-solarized soil in greenhouse. The disease incidence was 46-64% in control pots and 15-23% in three Trichoderma harzianum isolates applied pots. Disease incidence of seedlings in solarized soil was lower than in non-solarized control parcels. The disease incidence effect was 27-67% in solarized soil and 39-59% in non-solarized control parcels when Trichoderma treated tomato seedlings were planted. No statistical difference was observed between commercial preparation T-22 Planter box and our isolates.