Citrus Extract Found Potent in the Control of Seed-Borne Fungal Pathogens of Pearl Millet—A Recommendation for Farmers’ Seed Saving Systems

Abstract

Seed saving is crucial to ensure seed and food security, especially in developing countries. In Ghana, about 90% of pearl millet farmers utilise farmer-saved seed for production. Such seeds usually have a low germination rate, and may carry important seed-borne pathogens. In this study, the quality of farmer-saved seeds and the potential of botanicals to control seed-borne fungi were examined. A structured questionnaire was administered to 120 farmers from Garu, Bongo and Kassana-Nankana districts in Ghana. During the survey, 60 samples of farmer-saved seed were obtained for seed quality evaluation. Aqueous extracts of neem (Azadirachta indica) and citrus (Citrus sinensis) were prepared as seed treatments compared with a control. Fourteen (14) fungal species were associated with the seed samples, but the four dominant ones were Curvularia spp. (62%), Talaromyces spp. (53%), Aspergillus spp. (52%) and Exserohilum spp. (42%). The application of citrus extract inhibited fungal incidence (15–31.7%) compared to neem extract (33.3–93.3%) and the control (96.7–98.3%). The application of citrus extract resulted in a higher (74.7–82.8%) field germination rate compared to neem extract (62.3–73.2%) and the control (65.5–69.2%). The citrus extract was the most efficient treatment in reducing the incidence of fungi and enhancing the seed germination and vigour of pearl millet.