This study aimed to determine the chemical composition of Eucalyptus staigeriana essential oil (EO) and its effect in vivo against Botrytis cinerea and Colletotrichum acutatum in postharvest of grapes and in a vineyard. Moreover, grapes collected from de field experiments were used to evaluate the impact of the alternative control on the alcoholic fermentation and wine composition. The major compounds of E. staigeriana EO were citral (30.91%), 1,8-cineole (24.59%), and limonene (19.47%). In the postharvest experiment, EO was efficient, reducing the incidence and severity of disease caused by B. cinerea and the incidence of disease caused by C. acutatum, both in preventive and curative treatment. Moreover, this EO reduced the incidence and severity of gray rot caused by B. cinerea and the severity of ripe rot caused by C. acutatum in the field. The alternative control did not significantly influence the alcoholic fermentation and volatile composition of wines, except for the residual presence of 1,8-cineole that can contribute to the aroma complexity of 'Isabella' wine. These results are promising and indicate that E. staigeriana EO might be further investigated as a natural alternative to control fungal rots on grapes.
Keywords: Botrytis cinerea; Colletotricum acutatum; alternative control; eucalyptus; wine.