Effective control of anthracnose (Colletotrichum gloeosporioides) in postharvest tomato under different storage temperatures using essential oils from eucalyptus (Eucalyptus globulus) and lemongrass (Cymbopogon citratus)

Abstract

Anthracnose is a postharvest disease of tomato fruit caused by the pathogenic fungus Colletotrichum gloeosporioides, which causes significant losses during storage. Nowadays, it is necessary to search for new environmentally and health friendly alternatives to prevent the disease, being essential oils (EOs) a tool with great antifungal potential. In this work, EOs were obtained from eucalyptus (Eucalyptus globulus) and lemongrass (Cymbopogon citratus) leaves by hydrodistillation, which were characterized physicochemically, presenting mainly the compounds eucalyptol (1,8-cineole) and carveol, respectively. The in vitro antifungal activity of these EOs was analyzed by inhibition of micellar growth and inhibition of conidial germination in C. gloeosporioides. Both EOs inhibited mycelial growth and conidial germination of the pathogen, but the one from lemongrass showed a higher antifungal capacity. Lemongrass EOs were also applied to tomato fruits stored at room temperature (25 °C) and cold (8 °C), infected with C. gloeosporioides, reporting a significant reduction in the incidence (until 63 %) and severity (until 9 %) of anthracnose developed at room temperature (in 7 days), and an absolute elimination of the disease (0 % incidence and severity) in cold (in 40 days), due to the antimicrobial action of the EOs. Therefore, EOs obtained from lemongrass leaves by hydrodistillation are an effective tool in the control of anthracnose in tomato fruits, with absolute effectiveness in cold storage.