CONGABA FITOQUÍMICA E ATIVIDADE ANTIFÚNGICA DO EXTRATO DE FOLHAS DE Piper marginatum NO CONTROLE DE FITOPATÓGENOS

The use of plant extracts with antifungal potential may be an option to reduce the use of agrochemicals, to avoid environmental problems, as well as the resistance of phytopathogens. The objective of this study was to characterize and evaluate the antifungal activity of the ethanolic extract of Piper marginatum leaves on phytopathogenic fungi Alternaria sp and Colletotrichum musae. The ethanolic extract was obtained by Soxhlet and the chemical profile was characterized by thin layer chromatography (CCD). In the antifungal assays, the extract was diluted in potato-dextrose-agar (BDA) medium to obtain 10%, 20%, 30%, 40% and 50% and poured into Petri dishes containing BDA for phytopathogen deposition after solidification. The control consisted in the sowing of the fungi in medium without addition of the extracts. The phytopathogens Alternaria sp. and C. musae were obtained from eucalyptus and banana, respectively. The experimental design was completely randomized (DIC), in a factorial scheme, with four replications. Evaluations were scheduled for the medium term of the colonies daily for five days. The identification of the chromatographic profile of P. margintatum evidenced the presence of hydrolysable tannins, phenylpropanoids, flavonoids and terpenes. The phytopathogen most affected by the extract was C. musae, from the 10% concentration. As concentrations of 40% and 50% were responsible for reductions of 10.9% and 20.2% no mycelial growth of this fungus. With this, the ethanolic extract of Piper marginatum can be considered a promising one for the production of a natural antifungal in the reduction of the use of agrochemicals.