Investigation of fungitoxic activity in Momordica charantia L. to control Sclerotium rolsii Sacc. - DOI: 10.4025/actasciagron.v31i3.364

Abstract

The fungus Sclerotium rolfsii causes major economic losses in agriculture. Due to the resistance structures (sclerotia) production in soil, this pathogen is difficult to be controlled in field. Furthermore, new reports of active ingredients to control of this pathogen are scarces in literature. The objective of the present work was to verify the existence of fungitoxic activity in Momordica charantia (bitter gourd) with future potential of study to control S. rolfsii. Assays were carried out in vitro (laboratory) and in vivo (growth chamber). In vitro, sclerotia of the pathogen were placed in contact with hydroethanolic and aqueous extracts of leaves and stem of M. charantia for 7, 14, 21 and 28 days. To the control, sclerotia were placed in flasks without extract. After each time, the survival of sclerotia was evaluated in specific culture medium. In vivo, the activity of the extracts was investigated preventively and curatively (application at 6 and 3 days before the planting; at the day of planting, and at 3 and 6 days after the planting), and the extracts also were applied in seed treatment to the pathosystem common bean cv. Carioquinha versus S. rolfsii. The efficacy of the extracts was evaluated by disease severity. The hydroethanolic and aqueous extracts inhibited 100% of germination of sclerotia in vitro in a period from 0-7 days. When applied at 6 and 3 days before planting, the hydroethanolic extract reduced 74% of disease severity. These results showed fungitoxic activity in bitter gourd aerial part that could be potentially studied to control of S. rolfsii, preferably applied preventively.