In Vivo Antifungal Activity of South African Medicinal Plant Extracts against <i>Fusarium</i> pathogens and Their Phytotoxicity Evaluation

• Main Authors: Hlabana A. Seepe, Kafua E. Lodama, René Sutherland, Winston Nxumalo, Stephen O. Amoo
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Plants
• Subjects: <i>Fusarium </i>species; maize seeds; medicinal plant extracts; seed germination; smallholder farmers
• Online Access: https://www.mdpi.com/2223-7747/9/12/1668

Smallholder farmers play a major role in crop production towards household food security, particularly in resource-poor communities. Maize is a common crop produced in smallholder farming and it is cultivated from seeds that has been stored and re-used for years. Spoilage of stored grains is a major challenge, which leads to yield loss and poor seed quality. The objectives of this study were to evaluate in vivo antifungal activity of selected plant extracts against <i>Fusarium</i> pathogens on maize seeds, and to evaluate their phytotoxicity on seed germination and seedling growth. Fresh leaves collected from eight medicinal plants were dried and selectively extracted with water, ethyl acetate or acetone. The dried extracts were evaluated for antifungal activity against <i>Fusarium</i> pathogens (<i>F. proliferatum</i>,<i> F. oxysporum</i>,<i> F. subglutinans</i>,<i> F. verticilloides</i>,<i> F. semitectum</i>,<i> F. chlamydosporum</i>,<i> F. solani</i>,<i> F. equisite </i>and<i> F. graminearum</i>) inoculated on maize seeds. <i>Melia azedarach</i> acetone extract showed strong antifungal activity (97% inhibition) against <i>F. proliferatum</i> while combined acetone extracts from <i>Combretum erythrophyllum</i> and <i>Quercus acutissima</i> exhibited 96%, 67% and 56% inhibition against <i>F. verticilloides</i>,<i> F. proliferatum</i> and <i>F. solani</i>, respectively. With the exception of <i>Quercus acutissima</i> ethyl acetate, none of the extracts significantly inhibited seed germination when compared to untreated seeds. This study showed that plant extracts could control <i>Fusarium</i> diseases without any adverse effects on maize seed germination or plant growth.