Effect of essential oils on in vitro anthracnose and in fruits of the papaya plant.

ABSTRACT

Post-harvest papaya diseases are primarily responsible for the losses suffered during this process. Anthracnose is a disease caused by the Colletotrichum gloeosporioides fungus. This pathogen has the ability to settle in the immature fruit, remaining dormant until conditions become favorable for its development. The purpose of this study was to determine the fungicidal effect of essential oils on the C. gloeosporioides fungus. The experiments were undertaken in the Plant Health laboratory of the State University of Mato Grosso do Sul, at the University Unit of Cassilandia, where an evaluation was performed in three stages, namely: I) the effect of essential oils on spore germination, II) the in vitro action of oils on mycelium fungi, and III) the effect of essential oils on the fungus in papaya fruit. For the three phases, the experimental design was completely randomized in a 6 x 5 factorial arrangement (essential oils of rosemary, mint, lemongrass, anise, tea tree, and cinnamon) and five concentrations (0 uL, 10 uL, 30 uL, 50 uL, 100 uL) with five replications. The spore germination was drastically affected by the mint and tea tree oils. The fungitoxic effect of peppermint oil was confirmed in subsequent experiments in which this substance at a concentration of 100 uL completely inhibited the mycelial in vivo and in vitro growth of the C. gloeosporioides fungus. The rosemary and tea tree oils also affect the mycelial in vivo and in vitro growth of this fungus, albeit to a lesser degree.

Keywords alternative control; fruticulture; post-harvest diseases