INCOPED 5th International Seminar on Cocoa Pests and Diseases held on 15th-17th October, 2006 in San Jose, Costa Rica was jointly organized by CATIE and INCOPED.

Abstract:

Witches’ broom caused by the basidiomycete fungus Crinipellis perniciosa (Stahel) Singer is the most important factor constraining cocoa production in the main cocoa growing regions of Brazil. Pod losses of up 90% are experienced in affected areas in Bahia and Amazon regions. Biological control by means of microrganisms is a powerful tool that could contribute substantially as an alternative or a part of an overall integrated management strategy of the witches’ broom disease. The aim of this paper was studying in vitro and in vivo the effect of one isolate of Trichoderma sp. as a possible biocontrol agent for witches’ broom disease. The antagonist was isolated from inner trunk tissues of cocoa, after surface desinfection with sodium hypochloride solution, rinsed once in 70% ethanol and twice in sterile distilled water. The isolate of Trichoderma sp. produced in liquid medium metabolites capable of inhibiting in 100% the mycelium growth and the germination of basidospores of C. perniciosa when culture filtrate was used in the concentrations of 2% and 10%, respectively. The production of basidiocarps on dead brooms was significantly reduced by one application of spore suspension (2 x 107 spores/ml) obtained from Trichoderma sp. grown on autoclaved rice grains. Experiments carried out in greenhouse showed that spore suspension (2 x 107 spores/ml) and culture filtrate in the concentration of 5% were able to reduce over 70.8% the incidence of witches’ broom disease in cocoa seedlings, when applied six days before inoculation with the pathogen. These results suggest that this isolate of Trichoderma sp. is promising to be used as a …

Año de publicación:

2007

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