Trichoderma Asperellumstrains as potential biological control agents againstFusarium verticillioidesandUstilago maydisin maize

Globally, corn is the most economically important crop, surpassing crops such as wheat, rice and barley. However, the presence of pathogenic fungi associated with corn, have favoured the appearance of diseases that cause economic loss. Therefore, the aim of the present study is to assess the efficacy of treatments in vitro and in vivo with Trichoderma asperellum in controlling the disease severity and the yield reduction in corn plants caused by Fusarium verticillioides and Ustilago maydis. In vitro confrontation experiments demonstrated the high antagonistic capacity of the T. asperellum strains, which is able to reduce the radial growth of the pathogen's colonies from 88.71% up to 100%. In the field experiments treatments 6 and 7, where T. asperellum was confronted with F. verticillioides and U. maydis, showed a significant reduction in the average damage of the disease by 8.3 ± 6.7 and 9.5 ± 3.0, and an increase in their grain yield by 4.43 ± 0.33 and 4.11 ± 0.15 t/ha, respectively. Similarly, the percentage of good ears of 66.75 ± 5.4 and 70.37 ± 5.4, obtained in treatments 6 and 7, was higher than those values obtained in treatments 2 and 3 without Trichoderma confrontation. These results indicate that the selected Trichoderma strains isolated from Zea mays could effectively control these phytopathogenic fungi in field.