Control of damping-off diseases of vegetables by Trichoderma species
1995
Cuevas, V.C. | Soriano, J.M. | Bagunu, L.G. | Soniega, J.A. | Alfonso, A.L. (Philippines Univ. Los Banos, College, Laguna (Philippines). Inst. of Biological Sciences)
Studies were conducted to determine the species of Trichoderma that can be used as possible biocontrol agents of Sclerotium rolfsii, Rhizoctonia solani, and Fusarium oxysporum pathogens causing damping off in many crops. Screening of Trichoderma species was done in the laboratory using the dual culture technique. The most promising species, T. parceramosum Bissett, was studied in vitro to determine its mechanism of controlling the pathogen. Control by Trichoderma parceramosum and T. pseudokoningii of pre- and post- emergence damping off diseases caused by the above-mentioned pathogens in seedlings of tomato, pechay, mustard and lettuce were studied under screenhouse conditions. The antagonist were seeded in the soil either as spore suspension or by using pelletized carrier. Spores and sclerotia were used in seeding the soil with propagules of the pathogens. All the tested Trichoderma species can exert a certain degree of control in one or two of the pathogens tested. The more effective species, T. parceramosum and T. pseudokoningii, grew rapidly outpacing the growth of the pathogens. Microscopic examinations also demonstrated direct parasitism and coiling of T. parceramosum on hyphae of Sclerotium rolfsii. T. parceramosum and T. pseudokoningii significantly reduced the damage of damping off in tomato caused by Fusarium but did not completely control the disease. Both species can also effectively control the post emergence damping off disease of the test crops caused by R. solani and S. rolfsii in both sterilized and unsterilized soils
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