Application of Biplot Techniques to Evaluate the Potential of Trichoderma spp. as a Biological Control of Moniliasis in Ecuadorian Cacao

Abstract

Cocoa, a crop with great socioeconomic impact in Ecuador, faces continuous challenges that undermine the quality and yield of the crops. Moniliasis, a phytosanitary problem that is difficult to control, is the main limiting factor in cocoa production. This disease is caused by the phytopathogen Moniliophthora roreri, which causes premature maturation and necrosis of the ears. In this study, 50 strains of Trichoderma spp. in two-culture media, PDA and MEA, were used to evaluate the mycelial characteristics and antagonistic capacity of the strains in individual situations and in circumstances of confrontation against the phytopathogens Moniliophthora roreri (MRCP) and Moniliophtora roreri (MMCA). The data from the parameters obtained in the in vitro experimental practice were subjected to the multivariate PCA biplot method; the results indicated that five strains exhibited a notable antagonism capacity against the two specific strains of M. roreri: strain E22 grown on PDA medium, and the other four (E25, E29, E30, E39) cultivated on MEA medium. The open field trial showed that all treatments based on Trichoderma spp. improved productive performance compared to control plantations to which no biopreparation was applied. Significant differences (p < 0.05) were reported for all treatments. The efficiency of the biopreparations ranged between 51.26% and 72.46% with yields of 677.86 kg/ha to 976.90 kg/ha, respectively. The Trichoderma strain E29 showed the greatest potential for the biological control of M. roreri under field conditions. The findings validate the effect of diversified Trichoderma biopreparations in the biological control of moniliasis, providing concrete data on the efficacy of the biopreparation under real cultivation conditions and supporting its practical viability.