Atividade antifúngica de óleos essenciais contra isolados de Fusarium sp. do mamão (Carica papaya L.)

Abstract

Papaya stands out among the crops of relevant economic importance for fruit production. Characterized by rapid ripening and being very perishable, its fruits are highly susceptible to diseases caused by post-harvest fungi. Their control is usually done through the use of fungicides, which when used improperly lead to risks to the environment and to human health. Thus, in the search for reducing these effects, the use of essential oils comes as an alternative control of diseases in post-harvested fruits. The objective of this study was to evaluate the antifungal effect of essential oils extracted from plants (Cymbopogon citratus, Lippia sidoides, Ocimum micranthum and Ocimum gratissimum) on mycelial growth of isolates of Fusarium sp., a causal agent of rot in papaya fruits. The experimental design was completely randomized with seven concentrations of four oils to each isolate, with three replicates. The percentage of mycelial growth inhibition was calculated, and the means were submitted to analysis of variance and the Tukey test at 5% probability. Light microscopy images were used to visualize the effect of the treatments on the germination of the isolate more sensitive to the treatments. The results indicate that the most effective essential oils to reduce mycelial growth were from L. sidoides, O. gratissimum, O. micranthum and C. citratus, respectively. The isolates presented distinct responses for the same treatments, and the LPPC 81 isolate was the most sensible to the oils.