Estudo in vitro do potencial de Trichoderma asperellum e Pichia sp. no controle de Macrophomina spp.

Abstract

The use of Trichoderma asperellum and Pichia sp. to control Macrophomina spp., can reduce the incidence of diseases caused by the phytopathogen, as the control in the field is difficult to handle. The present work aimed to evaluate the ability of the antagonists T. asperellum and Pichia sp. to control in vitro the phytopathogen Macrophomina spp., with isolates from soybean and corn, using the pairing method, with 5 replications per treatment on plates using Potato-Dextrose-Agar (PDA) medium and incubated in a B.O.D. growth chamber, in the dark at 25° C ± 2°C. The variables analyzed were mycelial growth, and percentage of growth inhibition. After 21 days of incubation, notes were assigned based on the scale proposed by Bell et al. (1982) and adapted by Nascimento et al. (2016). The antagonists T. asperellum and Pichia sp. showed efficacy control of the phytopathogen Macrophomina spp. in vitro. However, the yeast Pichia sp. showed lower control efficiency, but the formation of inhibition halo was observed. It is concluded that the isolates, Macrophomina phaseolina (isolated 2, soybean) and Macrophomina phaseolina (isolated 4, corn), exhibit the highest mycelial growth in vitro. The antagonist T. asperellum stands out in this work due to its antagonistic potential on Macrophomina spp. isolates, as an antagonist showing inhibition of the phytopathogen isolates.