Antagonism of Trichoderma on the control of Fusarium spp. on Phaseolus lunatus L.

Abstract

Biological control strategies have become an important tool in the sustainable management of plant diseases. This paper aims to report the Fusarium species that affect fava beans (Phaseolus lunatus L.) grown in Paraíba, Brazil, and determines the potential of Trichoderma isolates to control these fungi. Two Trichoderma and ten Fusarium isolates from fava bean seeds were selected. The beans were obtained from cultivated areas in the municipalities of Remígio, Alagoa Grande and Campina Grande, in Paraíba state. Phylogenetic analyzes based on DNA sequences of the translation elongation factor 1-α (TEF1) gene resolved the Fusarium isolates into four species belonging to the F. fujikuroi and F. incarnatum-equiseti species complexes. In vitro tests showed that the two isolates of Trichoderma tested presented antagonistic potential against the pathogens from the fava beans evaluated. In the direct comparison test, the growth of the pathogens was reduced from the seventh day in both treatments. Sporulation also showed a reduction, but only for 40% of Fusarium isolates. This work demonstrates that Trichoderma isolates can be used as a sustainable alternative to manage Fusarium spp. infection of fava beans.