Antifungal Activity of Essential Oils from Five Piper Species against Botrytis cinerea from Strawberry

Strawberry (Fragaria × ananassa Duch.) is susceptible to several fungal diseases, such as gray mold, caused by Botrytis cinerea, that compromise fruits during and after harvest. Disease control usually involves synthetic fungicides; however, the frequent selection of isolates resistant to fungicides and the risk of chemical residues in fruits have motivated the search for more sustainable alternatives. Plant essential oils are promising due to their antimicrobial properties. This study analyzed the seasonal composition of the essential oils of five Brazilian Piper species (Piper aduncum, Piper amalago, Piper caldense, Piper mikanianum, and Piper mollicomum) and their effectiveness in controlling Botrytis cinerea. The chemical composition, determined by Gas Chromatography–Mass Spectrometry, revealed the main compounds as a function of seasonality, with myristicin and germacrone being the most prominent. The essential oils of Piper caldense and Piper mikanianum were the most effective in controlling Botrytis cinerea, with a minimum inhibitory concentration of 20 μL mL–1, surpassing that of the commercial fungicide mancozeb. These results suggest a sustainable alternative for fungal disease control in agriculture.