Antagonismo enzimático de Trichoderma spp. sobre Fusarium oxysporum y Phytophthora parasitica en Hibiscus sabdariffa L.

Mexico is the seventh largest producer of jamaica (Hibiscus sabdariffa), and Guerrero State agglomerates more than 70 % of the national production. The crop presents important phytosanitary limitations, highlights the "black leg" associated with a complex of pathogens (Fusarium oxysporum and Phytophthora parasitica). Losses up to 100 % are reported in areas without phytosanitary management. Due to the nature of the consumption of the final product, it is necessary to implement ecological strategies to manage the disease. The objective of the study was to quantify the chitinases and glucanases activity of Trichoderma spp. isolates, and to evaluate their inhibitory effect in vitro on F. oxysporum and P. parasitica. Strains Ta10, Ta11, Ta6 and Ta9 of T. asperellum and Ti14 of T. inhamatum from soils cultivated with jamaica and high incidence of the pathogens were evaluated. The levels of chitinases and glucanases produced in all Trichoderma spp. were significant (P0,05), and it was found that Ta9 had the highest specific chitinase activity, and Ti14 the highest for glucanase. All the filtrates from the different isolates of Trichoderma spp. generated a substantial inhibition of mycelial growth of F. oxysporum and P. parasitica. Consistently, the strain Ta9 produced inhibition percentages greater than 90 % in both tests. A significant correlation was detected between the enzymatic activity and the inhibition of the growth of the Trichoderma spp. isolates on pathogens