Antifungal potential of essential oils from Pectis brevipedunculata and Dizygostemon riparius in anthracnose control in mango

Abstract

Essential oils have been widely studied because they are natural sources of substances that have antimicrobial properties. In fruit growing, especially in mango crop, anthracnose (Colletotrichum gloeosporioides) is considered the main disease because it causes series of damages in the fruit production chain and, in this sense, essential oils can be an option in this disease control. The objective of this study was to evaluate the effect of essential oils obtained from the leaves of Chá-de-moça (Pectis brevipedunculata) and Melosa (Dizygostemon riparius) in the in vitro and in vivo control of the C. gloeosporioides fungus, in seedlings and mango fruits. The in vitro bioassays were performed by testing the effect of different concentrations of essential oils (0, 1, 2, 3 and 4 µl/mL) on the reduction of mycelial growth of the C. gloeosporioides fungus. Additionally, the anthracnose control in mango seedlings (Tommy Atkins, Constantina, Comum and Rosa cultivars) was evaluated by foliar application of essential oils at 4 µl/mL concentration. Disease control in fruits of the same mango cultivars was evaluated at 3 µl/mL concentration of essential oils. The evaluation was carried out by measuring the average diameter of the colonies, for the in vitro treatment, and the lesions for the in vivo treatments, in two diametrically opposite directions. There was a decrease in the fungus mycelial growth in all tested concentrations. There was a decrease in the disease severity from the sixth day after the oils application in Tommy Atkins cultivar seedlings, when treated with both essential oils at 4 µl/mL concentration. As for preventive treatments with fruits, it was observed that all cultivars achieved a reduction in severity from 54.83% at 3 µl/mL concentration with the use of both essential oils. Given the results obtained, it was observed that the essential oils P. brevipedunculata and D. riparius can be a viable alternative in the anthracnose control in mango culture.