Sensitivity In Vitro Of Isolates Of Moniliophthora Roreri Against Fungicides With Different Modes Of Action

Abstract

The mush room Moniliophthora roreri, the causative agent of Moniliasis, is the main problem in cocoa cultivation in Ecuador. The objective of this study was to evaluate the sensitivity of 23 strains of M. roreri against fungicides of different modes of action; The strains were isolated from cocoa fruits with symptoms of the disease collected from cocoa plant samples of the Super Tree, National Type and CCN51 ecotypes in the Francisco de Orellana, Loreto and Joya de Los Sachas cantons of the Orellana province. Three systemic fungicides were evaluated: Azoxystrobin, Difenoconazole and Boscalid; and a protectant, copper sulfate pentahydrate 240 g/L-1, at different concentrations (100, 10, 1, 0.1, 0.01 ppm) in PDA culture medium with three replicates for each treatment. The results obtained show that the pathogen is sensitive to systemic fungicides; 82.60% of the evaluated strains are sensitive to Azoxystrobin at a concentration of 10 ppm with a percentage of growth inhibition (PIC) above 50%; On the other hand, 82.60% of the evaluated strains are sensitive to Difenoconazole from the concentration of 1 ppm with a PIC greater than 50%; and, 86.96% of the evaluated strains are sensitive to Boscalid at a concentration of 10 ppm with a PIC above 50%. However, M. roreri It is insensitive to copper sulfate pentahydrate in all concentrations tested. The fungicides Difenoconazole, Boscalid and Azoxystrobin can be used for chemical control in the management of Moniliasis disease in cocoa.