Isolados de Trichoderma spp. na inibição de fitopatógenos, na germinação de sementes e no desenvolvimento de plantas de tomateiro

Abstract

Tomato culture is susceptible to several phytopathogenic diseases, and biological control becomes an important tool to combat these adversities, and thus, reduce the chemical control that is widely used in culture. Thus, the objective of this work was to isolate species of the genus Trichoderma, and to evaluate the in vitro antagonism and mycelial growth by means of secondary metabolites of Trichoderma, as well as its action under the development of the tomato. Two Trichoderma spp. of native forest, termed TH1 and TH2. In the in vitro assays, antagonism was evaluated by direct pairing to Alternaria solani, Sclerotinia sclerotiorum and Fusarium sp. and also mycelial growth of the last two fungi mentioned under the effect of the exudate of the isolates of Trichoderma spp. The effect of exudates on germination and seedling growth, as well as the influence of microbiolization of seeds at different concentrations, was also verified. For the in vivo assay tomato plants were treated with Trichoderma ssp. And in another test the solution was applied to the seedlings in order to verify the growth promotion. The isolates presented antagonism to pathogens as well as the reduction of mycelial growth through the exudates. The tomato seeds had a positive effect in relation to the Trichodema exudate, however the opposite was observed in relation to the microbiolized seeds, in which they had inhibition of the germination and growth of the seedlings. There was no promotion of tomato growth through the isolates.