Evaluación in vitro de fungicidas químicos para el control de Moniliophthora roreri agente causal de la moniliasis del cacao (Theobroma cacao L.)

Abstract

Cacao cultivation represents an important sector for the Ecuadorian economy, as it is one of the country’s main export products; however, diseases such as Moniliophthora roreri cause significant losses, and their control continues to be a challenge for producers. One solution to counteract this disease is the in vitro evaluation of chemical fungicides, as it allows for the characterization of phytopathogenic isolates and the estimation of chemical molecule dosages for phytosanitary management. For this reason, this study consisted of evaluating two fungicides: copper sulfate pentahydrate at 200, 2000, and 20000 mg·L⁻¹ and azoxystrobin at 1.0, 0.1, and 0.01 mg·L⁻¹ using two isolates of M. roreri under in vitro conditions. A completely randomized factorial design with seven replications was used. The radial growth of the fungus was evaluated to estimate the percentage of growth inhibition (PIC). The results showed that azoxystrobin achieved 100% PIC at 1 mg·L⁻¹ and was highly sensitive, regardless of the M. roreri isolate, although statistically the PIC between strains was significant. Copper sulfate pentahydrate reached maximum PIC at a dosage of 20000 mg·L⁻¹ and was classified as insensitive, with no significant differences in PIC between isolates of M. roreri. It is concluded that M. roreri is highly sensitive and insensitive to azoxystrobin and copper sulfate hydrate, respectively. The doses tested provide the basis for analyzing a larger number of isolates and subsequently applying trials under field conditions.