Antifungal Effect of Leaf Extracts on the Groundnut Late Leaf Spot Pathogen Cercosporidium personatum.

Late leaf spot of groundnuts is caused by the fungal pathogen Cercosporidium personatum. Efforts to prevent this disease generally use synthetic fungicides that can pollute the environment. This study aims to identify the fungal pathogen of groundnut late leaf spot and determine the antifungal effect of leaf extract from several plants on leaf spot disease suppression. Late leaf spot pathogen was identified based on hyphae and conidia morphological characteristics. Growth inhibition of leaf extracts from butterfly pea (Clitoria ternatea), Mexican sunflower (Tithonia diversifolia), basil (Ocimum gratissimum), and sugar apple (Annona squamosa) at aconcentration of 25%were tested against C. personatum in vitro. The growth and intensity of groundnut disease attackswere assessed for seven weeks by inoculating C. personatum and applied with several leaf extracts. Results showed that the pathogen was identified as C. personatum with conidia characteristics of cylindrical to obclavate, short and slightly curved with four septa, and 35.75 × 7.11 µm in size. The inhibition percentage of C. personatum in vitro reached 94.03% by leaf extract of C. ternatea, 88.56% by T. diversifolia, 87.20% by O. gratissimum, and 84.10% by A. squamosa. Treatment of C. ternatea increased plant height by up to 12.85% and showed the highest reduction of infected leaves by up to 61.53%. C. ternatea leaf extract was found to be the most effective leaf extract to suppress C. personatum infection by 77.94%, while T. diversifolia, O. gratissimum, and A. squamosa reduced disease severity by 70.15%, 65.43%, and 57.76%, respectively. [ABSTRACT FROM AUTHOR]