Major Fungi Diseases of Cashew Trees (Anacardium occidental L.) in Cameroon

Abstract

The culture of cashew (Anacardium occidentale L.) is increasing in the Far North Cameroon. But, the productivity is threatened by the development of diseases in orchads. Therefore, the aim of this study is to identify diseases and pathogens involved in cashew cultivation. The diseases were identified under the basis of the identification keys. The fungal structures were characterized using an optical microscope and the pathogenicity test were carried out. Incidence, severity and prevalence of diseases were assessed in the dry season and the rainy season. Seven diseases and seven pathogens have been identified: anthracnose (Colletotrichum gloeosporioides Penz), pestalotia leaf spot (Pestalotia heterocornis), alternaria (Alternaria solani), drying of buds (Colletotrichum gloeosporioides, Phomopsus anacardii and Curvularia lunata), dieback (Colletotrichum sp. and Lasiodiplodia sp.), blight of leaves (Pestalotia heterocornis and Colletotrichum gloeosporioides) and powdery mildew (Oidium anacardii Noack). Whatever the season; anthracnose, pestalotia leaf spot an drying of buds are diseases with higher incidence (more than 85, 60 and 75% respectively) and higher prevalence. The severity of the diseases varied according to the location and season. Pathogenicity test revealed that all the test fungi were pathogenic to their respective host parts except cashew powder mildew and alternaria. The results of this study represent database for implementation of integrated disease management approaches in Cameroon.