Leaf and stem extracts of some selected medicinal plants to inhibit fungal growth and conidia formation of Colletotrichum capsici

Anthracnose is a disease caused by Colletotrichum capsici in Capsicum species. This disease leads to a decrease in product quality after harvest, which results in significant yield losses. Fungicides are used to control post-harvest diseases. As a result, efforts have been concentrated on finding alternatives to synthetic fungicides. To evaluate the antifungal potentials of Alternanthera sessilis, Cocculus hirsutus, Mitragyna parvifolia and Terminalia bellerica, the leaves and stems of the medicinal plants were used. The extract was prepared in three distinct solvents viz. aqueous, ethanolic and methanolic. The C. capsici radial growth (86.96 ± 2.92 and 87.70 ± 2.41 %), germination of conidia (77.88 ± 0.96 and 54.79 ± 1.92 %) and appressorium were strongly inhibited by the ethanolic extract from the leaves and stem of A. sessilis, but the methanolic leaf extract (32.22 %) and stem (27.59 %) of M. parvifolia showed the least inhibition activity. The aqueous extracts of both plant parts did not show significant results. In the present study, A. sessilis is a bio-fungicide that is eco-friendly and potentially useful for preventing anthracnose disease in chili. Different antimicrobial compounds have been found in ethanolic leaf extract of A. sessilis via high resolution-liquid chromatography-mass spectroscopy and these compounds have been reported to show antimicrobial activity. Significant effects of the A. sessilis crude extract showed the changes in morphological traits of conidia and germination failure of C. capsici by scanning electron microscope. The current investigation verified that A. sessilis is a promising environmentally friendly biocide for C. capsici in an in-vitro condition. Phytochemical analysis of selected plant extracts has revealed the presence of organic compounds as their constituents and they are biologically active molecules, including antibacterial and antifungal compounds.