Fungicida biológico a base de una cepa del hongo Trichoderma harzianum: su supervivencia en el suelo

An alternative to the indiscriminate use of phytosanitary products is the incorporation of competing antagonistic microorganisms for the protection of the crops of soil-borne pathogens. In this work the potentiality of the establishment of Trichoderma harzianum Rifai (strain Th5cc) in the soil under different formulations was evaluated, in order to know which is the most effective in maintaining the population of the antagonist at moderate levels. The population was quantified using the soil dilution plate technique with a selective medium for Trichoderma. The results show that both the liquid formulation and the coated seeds increase the Th5cc population until 90 days after the formula was incorporated into the soil (1.4 x 104 colony forming units / g of soil). In contrast, with the application of solid formula, the population of the antagonist begins to decrease after 90 days. In the case of incorporation in the seed, the population of T. harzianum at the beginning was lower than that of the control, but at 60 and 90 days they reached higher values than the original soil population (control). The efficiency of the application of T. harzianum as an antagonist in plants is closely related to its formulation, which clearly influences survival in the soil.