Eucalyptus staigeriana essential oil in the control of postharvest fungal rots and on the sensory analysis of grapes

Óleo essencial de Eucalyptus staigeriana no controle de podridões fúngicas no período pós-colheita e na análise sensorial de uvas

Abstract

The objective of this work was evaluate the effect of Eucalyptus staigeriana essential oil on Colletotrichum gloeosporioides and Greeneria uvicola mycelial growth and conidia germination on grapes, as well as its potential for the control of postharvest rot diseases and its effect on the organoleptic properties of grapes. The essential oil (EO) showed in vitro antifungal activity against both pathogens, with fungicidal effect on mycelial growth and on conidia germination at the concentrations of 1.0 and 0.5 μL mL⁻¹, respectively. The EO volatile compounds had a fungistatic effect on the mycelial growth of C. gloeosporioides and a fungicidal effect on G uvicola. At postharvest, the EO reduced the incidence of ripe rot up to 75% and 86% in the preventive and curative treatments, respectively, and the incidence of bitter rot up to 54% in the curative treatment. Since the EO does not affect significantly grape sensory properties, it does not affect the consumption intention of grapes treated with the EO. The EO of E. staigeriana is efficient in the in vitro control of both pathogens; moreover, it is also efficient in the control of the incidence of postharvest fungal rot diseases, mainly in the curative treatment.

Index terms:
Colletotrichum gloeosporioides ; Greeneria uvicola ; alternative control; bitter rot; ripe rot