Symptomatology of Fungal Diseases of Cultivated Ginger (Zingiber officinale Roscoe) in the Main Production Areas in Côte D’ Ivoire

Abstract

Ginger (Zingiber officinale) is a plant widely recognized worldwide for its nutritional and medicinal qualities. However, its cultivation faces various challenges, including fungal diseases, which are responsible for significant losses. This study aims to assess the symptoms of diseases caused by fungi in ginger cultivation in Côte d’Ivoire. To achieve this, a phytosanitary survey was conducted in five major ginger production areas (Tiassalé, Hermankono, Koun-Fao, Soubré, and Bongouanou). The observed symptoms were described, and their prevalence and severity were evaluated. Subsequently, the fungi associated with these symptoms were isolated and identified. The results obtained allowed the identification of four different types of symptoms: chlorosis, necrosis, wilt, and leaf spot. All these disease symptoms were observed in all the ginger plots in the surveyed localities. The leaf spot symptom was the most frequently observed, with the highest prevalence of 87.15% in the Soubré area and a lower prevalence in Bongouanou which was 45.17%. Symptom severity varied by locality. Fourteen genera of fungi were isolated from symptomatic ginger leaves and stems. These included Aspergillus, Colletotrichium, Curvularia, Fusarium, Leptosphaeria, Penicillium, Pestalotiopsis, Pythium, Rhizoctinia, Rhizopus, Sclerotium, Trichoderma, and two unidentified genera, referred to as unknown 1 and unknown 2. The isolation frequencies of fungal genera varied by locality, with Fusarium having the highest isolation frequency among all the isolated fungi. This initial study on fungal diseases in ginger cultivation in Côte d’Ivoire could provide valuable insights for guiding control methods.