EFFICACY OF PHENOLICRICH EXTRACTS FROM LEAVES OF PEPPER LANDRACES AGAINST ALTERNARIA LEAF BLIGHT OF TOMATO
C. Pane, F. Fratianni, F. Raimo, F. Nazzaro, M. Zaccardelli
Plant-derived antifungals have an interesting potential to be used for the sustainable management of plant diseases. In this work, seven different local genotypes of Capsicum annuum, diffused in agricultural areas of Campania Region (Italy), were explored for their potential in providing phytochemical extracts suitable for antifungal applications. Bioactive hydro-methanolic extracts has been assessed for phenolic composition and antioxidant capacity and, then, assayed both in vitro and in planta for the suppression of Alternaria alternata, the causal agent of early blight of tomato. Ultra high-performance liquid chromatography-diode array detection (UPLC-DAD) analysis showed phenolic profiles of each extract, identifying and quantifying the individual known components, including gallic acid, chlorogenic acid, epicatechin, cumaric acid, rutin, ferulic acid and luteolin. The phenolic-rich extracts of all peppers varieties proved to be active against in vitro mycelial development of A. alternata. Dipping artificially infected tomato leaves using extracts at 10 µg GAE ml -1 of total phenolics, reduced foliar early blight disease severity closely to 50%, on average. The role played by the phenolic complex in the antifungal activity and in disease control efficacy of the extracts, has been discussed.