Phenotypic Characterization of Fungal Pathogens Associated with the Main Mycoses of Cashew (Anacardium occidentale L.)

Abstract

Aims: To study the diversity of fungal pathogens associated with cashew mycoses in Togo. Study Design: This research project was initiated by the Mycology Research and Applications Unit of the Botany and Plant Ecology Laboratory (LBEV) in order to have adequate information on cashew mycoses in Togo. Place and Duration of Study: Laboratory of Botany and Plant Ecology (LBEV) of the University of Lome (UL) and of Crop Protection and Biosafety Laboratory of Togolese Institute of Agronomic Research (ITRA), February to August 2020. Methodology: A total of 148 symptomatic samples (leaves, buds, inflorescences, nuts, and apples) were collected from cashew trees in the East Mono prefecture of Togo. Malt-agar medium supplemented with chloramphenicol at 0.5 g/l was used for the isolation of fungal pathogens. The characterization of these fungal pathogens was carried out from the 7th day based on their macroscopic (texture, color, diameter of growth) and microscopic (hypha, spore, fruiting body) characters. Results: This study revealed the presence of five mycoses in cashew orchards in the East Mono prefecture. These are leaf anthracnose, bud’s dieback, black rust, leaf yellowing, and powdery mildew. In total, 12 fungal genera were encountered and 14 species of fungal pathogens were identified on all the samples collected: Rhizopus sp., Penicillium sp., Mucor sp., Sporotrichum sp., Fusarium nivale, Fusarium moliniforme, Fusarium moliniforme var. subglutinans, Curvularia lunata, Curvularia geneculata, Alternaria tenuissima,  Alternaria brassicisola, Beltrania rhombica Penz., Thielavia coactilis Nicot, Helminthosporium avenae, Helminthosporium siccans, Phoma eupyrena, Aspergillus flavus, Aspergillus niger. Conclusion: It would be of great interest to train cashew producers in the East Mono prefecture on the recognition of the symptoms of these mycoses and their management.