Evaluation of the Sensitivity of Strains of phytophthora spp Cause of Brown Rot of Cocoa (Theobroma cacao l.) against to Limocide 60 ME (An Extract of Sweet Orange Essential Oil)

Abstract

Ivory Coast produces nearly 2 million tons, which represents 15% of the Gross Domestic Product (GDP), more than 50% of exports and provides seven million jobs to Ivorians. However, its production is severely limited by the brown rot disease of cocoa pods. In order to increase production and improve public health and environmental problems, sweet orange essential oil extract was used to combat cocoa brown rot disease caused by Phytophthora spp. A morphological description of the pathogen was carried out. The effectiveness of Limocide was tested at doses of 100, 200, 400, 800 ppm and compared to NECO and Callomil super. Limocide, Callomil super and NECO significantly inhibited the in vitro mycelial growth of Phytophthora spp with 29.76, 89.41 and 100% respectively after six days of incubation. The minimum concentrations that inhibit 50% (IC 50 ) the growth of the fungus were, respectively, 929, 1521 and 348 ppm for Limocide , Callomil super and NECO. The biofungicide Limocide has proven its ability to control brown rot of cocoa pods under controlled conditions.