Antifungal Activity of Five Aqueous Extracts on <i>Rhizopus</i> sp., the Agent Responsible for Soft Rot of Cassava (<i>Manihot esculenta </i>Crantz) Tubers in Côte d'Ivoire

Cassava (Manihot esculenta Crantz) is the second most important food crop in Côte d'Ivoire after yams. However, its production is threatened by the fungus Rhizopus sp., which causes cassava tuber rot. The chemical pesticides used to control these microorganisms pose a threat to the environment, as well as to the health of those who use and consume them. To minimize the damage caused by these substances, a study was conducted to evaluate the biological efficacy of aqueous extracts of Syzygium aromaticum, Allium sativum, Artemisia annua, Zingiber officinale and Tithonia diversifolia against Rhizopus sp. The extracts were tested at concentrations of 30, 60 and 90 g/L for their effect on mycelial growth and spore germination. The direct contact method in PDA medium was employed, and the results revealed that all the aqueous extracts exhibited an antifungal effect on mycelial growth and spore germination. The highest inhibition rates of mycelial growth and spore germination were obtained at 90 g/L. Aqueous extracts of Syzygium aromaticum were the most effective, achieving a 100% inhibition rate, while those of Tithonia diversifolia had the lowest inhibition rates.