Obtenção de isolados nativos de Trichoderma de Laranjeiras do Sul - PR e avaliação de seu efeito inibitório sobre Sclerotinia sclerotiorum

Abstract

The fungus Sclerotinia sclerotiorum is the causal agent of white mold, a disease of great importance in many species of cultivated plants. It is a pathogen that is difficult to control and forms resistance structures (sclerotia), capable of remaining in the area for many years. Seeking more sustainable methods of controlling this disease, biological control stands out, such as, for example, with the antagonistic fungus Trichoderma. The present work aimed to evaluate the presence and inhibitory effect of Trichoderma isolates native to the region of Laranjeiras do Sul/PR, on Sclerotinia Sclerotiorum. Different bioassays were carried out to evaluate the effect of the isolates on S. sclerotiorum in vitro and also the protective effect in vivo on lettuce plants. Three Trichoderma isolates were identified that promoted significant inhibition of the mycelial growth of S. sclerotiorum, as well as the formation of sclerotia in vitro. The isolates also promoted a reduction in the severity of white mold on lettuce plants. The results obtained demonstrate the natural occurrence of Trichoderma isolates in Laranjeiras do Sul with significant effect on the control of S. sclerotiorum.