Isolate of Trichoderma brevicompactum for the control of cocoa witches' broom disease: preliminary results. In: Agrotrópica v. 24 p. 21-26, 2012.

Abstract

The aim of this paper was to study in vitro and in vivo the effects of one isolate of Trichoderma brevicompactum as a possible biocontrol agent for witches' broom disease. The antagonist was isolated from inner trunk tissues of cocoa, after surface desinfestation with sodium hipochlorite solution, rinsed once in 70% ethanol and then twice in sterile distilled water. The isolate of Trichoderma produced in liquid medium metabolites capable of preventing the germination of basidiospores and the mycelial growth of Moniliophthora perniciosa when culture filtrate was used at 2% and 10% concentrations respectively. The production of basidiocarps was significantly reduced by one application of spore suspension (2 x 107 spores/ml) of T. brevicompactum on dried brooms. Experiments carried out in greenhouse showed that spore suspension (2 x 107 spores/ml) and culture filtrate at the concentration of 5% were able to reduce the incidence of witches' broom in cocoa seedlings and also the number of diseased pods in field.