In vitro Control of Anthracnose Disease of Cowpea (Vigna unguiculata L. Walp) caused by Colletotrichum destructivum with Cyathula prostrata L and Diodia scandens SW leaf extracts

Abstract

Aim/Background: Colletotrichum destructivum is one of the most important causes of anthracnose disease of cowpea leading to a great reduction in their production and yield potentials. The constant application of chemicals to control these phytopathogens poses potential threats to human health and the environment. Potential non-chemical control strategy such as the use of botanicals would be a better alternative. Botanicals are readily available, safe, efficacious and eco-friendly. This study was undertaken to investigate the potentials of Cyathula prostrata and Diodia scandens leaf extracts to control the in vitro mycelial growth and sporulation of C. destructivum, causal agent of anthracnose disease of cowpea (Vigna unguiculata L. Walp). Methods: The leaves of both plants were air dried, pulverized, and the fine powder extracted by conventional maceration techniques using aqueous solution. Prepared concentrations (40-100%) of the extracts were then tested against the in vitro mycelial growth and spore germination of the purified test pathogen (C. destructivum) isolated from infected cowpea pods. Benomyl (3%) was used as reference fungicide drug. Results: It was observed that the extract treatments at 60, 80 and 100% significantly (P 0.05) than that of benomyl fungicide (3%). Conclusion: These findings suggest that C. prostrata and D. scandens leaf extract have the potentials as veritable control agents of anthracnose disease of cowpea in Africa.