Uso de cinco extractos botánicos en el control de moniliasis (moniliophthora roreri, cif y par) en el cultivo de cacao.

Abstract

Cacao (Theobroma cacao L) is one of the most important crops of agricultural importance in Ecuador. Cocoa production is located in 23 provinces of the country, however, the crop's yield is affected by one of the main diseases that affect production. The fungus Moniliophthora roreri, Cif y Par, the causal agent of moniliasis in cocoa beans, produces losses of up to 80%, which has a significant impact on the producer's economy. The significance of this disease is that the symptoms appear in the fruit, the first month there is a necrosis and deformation, the second month there are observed long brown necrotic males and fruits from the third month are covered with pseudoestroma of the fungus, it is the most contagious stage. This leads to the application of chemicals that are highly toxic to humans and the environment. To provide an answer to the problem of the use of fungicides, less toxic and easily degradable alternatives arise to control moniliasis. Plant species that produce secondary metabolites and have a regulatory action on pathogens affecting the crop of economic interest are of great help. With the above mentioned, the objective of this trial is: To determine the antifungal effect of the five botanical extracts on moniliasis in cacao. The plants used are: Llantén (Plantago major L.), Moringa (Moringa oleifera Lam), Tobacco (Nicotiana tabacum), Cinnamon (Cinnamomum verum), Hierba Luisa (Cymbopogon citratus (DC) Stapf.), on M. roreri. This research was carried out in the laboratory of phytopathology of the Technical University of Machala. In the assay, leaves of plant species were dried in an oven at 60 degrees Celsius for 48 hours, then they were sprayed and placed in glass vials with alcohol (96%), moniliasis fungus was isolated using PDA as culture medium. Seven treatments were carried out, taking as variable, the radial growth of fungus mycelium (Moniliophthora roreri, Cif and Par). The evaluated treatments were T1 ;T2; T3 ;T4 y T5 97 ml PDA + 3 cc of botanical entanolic extract, T6 97 ml PDA + 3 cc of alcohol (Control) and T_7100 ml PDA (Control). Under controlled laboratory conditions, treatment 4 (cinnamon ethanolic extract at 3%) showed better results in inhibiting radial growth of M. roreri. The treatments 1,2,3,5 did not present antifungal activity on M. roreri, in in vitro conditions. Treatment 6 (control plus alcohol 3%) and treatment 7 (control without alcohol), presented statistical differences, indicating that alcohol is interfering on the mycelial growth of the phytopathogenic fungus. The results evidenced in this study are considered promising and lead to future research, to evaluate the ethanolic extract of cinnamon on M. roreri, at field level; to determine the minimum inhibitory doses of the extracts for the control of M. roreri, and to evaluate the ethanolic extract of cinnamon against other species of phytopathogens.