MICROORGANISMOS DEL GÉNERO Trichoderma PRODUCTORES DE FITOHORMONAS Y ANTAGONISTAS DE FITOPATÓGENOS

Chemical products applied indiscriminately in agriculture have caused serious imbalances to the environment; thus, there is a need to use sustainable tools such as bioinoculants. Five strains of Trichoderma spp. were evaluated as producers of organic acids, auxins and gibberellins, as well as its antagonistic capacity and the radial growth inhibition percentage (RGIP) against the plant pathogens Fusarium oxysporum, Alternaria spp. and Helminthosporium spp. of Northern Mexico. Results showed that all strains segregated organic acids, with its maximum production attained at 72 hours. All of them synthetized auxins and gibberellins, with TF showing the highest production of auxins (35.3 μg∙mL^-1), while no statistical differences among the strains were found for gibberellins. The highest value of RGIP against Fusarium oxysporum was found in TB (83.3 %) and TJ3 (81.5 %), while against Alternaria spp. the values ranged between 87.7 % in TB and 86.7 in TM, without significant differences between them. The strain TJ3 got the highest value (76.6 %) against Helminthosporium spp. The five strains showed class 1 and 2 of antagonistic capacity against the pathogens, showing a potential to be tested as biological cont rol agents and plant growth promoters, a promising combination for a biotechnological product and sustainable tool in agricultural areas of Northern Mexico.