Induction of systemic resistance in Theobroma cacao L. for the management of “witches’ broom” caused by Moniliophthora perniciosa

Abstract

The pathogen Moliniophthora perniciosa can cause losses in the cocoa crop of more than 90% when integrated disease management is not carried out in the crop. In the present study, the effect of sucrose as a resistance inducer in cocoa trees (Theobroma cacao L.), was evaluated for the management of the “witches’ broom” disease caused by Moniliophthora perniciosa. The experiment was developed in the municipality of Chaparral, Tolima, Colombia (854 m.a.s.l.). The treatments corresponded to 0.9 M sucrose: injected (T1), foliar spray (T2) and without sucrose (T3). A completely randomized block design with three treatments was established. The results showed that the incidence and severity of the disease in the trees treated with sucrose were lower. The polyphenol oxidase enzyme presented its highest activity in T3, while peroxidase and superoxide dismutase in T2. It was observed that sucrose as an inducer, can alter metabolic pathways involved in the defense mechanisms of cocoa trees, reducing the incidence and severity, thus establishing an alternative for the management of “witches' broom” disease in producing countries.