Biocontrole de Fusarium oxysporum F. Sp. Cubense a partir de Trichoderma spp.

Abstract

Banana is one of the most important crops in the world agricultural scenario. The cultivated area corresponds to 4.8 million hectares, of which food base of millions of people worldwide. Fusarium oxysporum f. sp. cubense (Foc), is a fungus that causes Panama disease, which is considered the most destructive disease of the banana crop. A factor which complicates the control of Foc is the presence in their structure of the chlamydospores, which are units that provide resistance to the fungus establish for over 30 years in soil. In this contest the present study aimed to evaluate the efficiency of Trichoderma spp. Foc for biocontrol. For this, two experiments were conducted using two isolates of Trichoderma spp. In the first experiment antibiosis was tested by direct confrontation in Petri dishes. The colonization of the isolates was assessed by grading scale. In the second experiment, the antagonism between isolates of Trichoderma spp. and Fusarium oxysporum f. sp. cubense was evaluated on banana seedlings Silver dwarf in a greenhouse. The infestation of the substrate was carried out with inoculum of Trichoderma spp. 81 and 82, and inoculum of Foc. As controls, seedlings were used planted in soil infested with Foc, with isolated 81 and 82 and seedlings no inoculated. The strain Trichoderma 81 has the potential for biocontrol of Fusarium oxysporum f. sp. cubense as it was effective in in vivo antagonism. Subsequently to this study, testing is possible under natural conditions of production with the use of this isolated for control of Panama disease. The isolate of Trichoderma spp. 82 has potential as banana growth promoter.