Evaluación in vitro de la capacidad antagónica de Trichoderma comercial (Trichoderma harzianum) y Trichoderma nativo (Trichoderma sp.) frente a los patógenos Alternaria sp., Fusarium oxysporum y Heterosporium echinolatum del cultivo de clavel (Dianthus caryophyllus)

Abstract

The present research aimed to evaluate the antagonistic capacity of commercial Trichoderma (Trichoderma harzianum) and native Trichoderma (Trichoderma sp.) In vitro, against the pathogens Alternaria sp., Fusarium oxysporum and Heterosporium echinolatum of the cultivation of carnation (Dianthus caryophyllus). Strains native to the rhizosphere of the crop were isolated. The isolated strains were purified by means of the successive re-planting method and the strains were identified based on their morphology and physiology as apparently Trichoderma viride and Trichoderma harzianum. After characterization, the native strains were compared with the commercial strain (Trichoderma harzianum) against the aforementioned phytopathogens. A completely randomized experimental design with 9 treatments was used. It was concluded that the native Trichoderma strains acted more aggressively than the commercial strain before the phytopathogens under study. Alternaria sp., Fusarium oxysporum and Heterosporium echinulatum were controlled on 36%, 55% and 50%, respectively. The control mechanisms of the species with appearance to Trichoderma harzianum and Trichoderma viride against pathogens were: competition for space and nutrients, parasitism and antibiosis. With the antibiosis test, 76% of control was achieved, when Trichoderma was present in the medium before the same.