Dieback of Mango and Cutting Method Impact on the Regeneration of Tree in the Sudano-Sahelian Zone

Abstract

Background and Objective:The dieback of mango (Mangifera indica) has become an increasing threat to mango production in Tchad and Cameroon. The present study was conducted to characterize and identify pathogens associated with the mango quick decline tree for the first time in both countries. Materials and Methods: Investigations were carried out through field observations of the symptoms. A simple block experimental design was adopted and the scale was used to assess the incidence, severity and prevalence at the two sites during the dry and rainy seasons. Pathogens associated were isolated using a Potato Dextrose Agar (PDA) medium. The control strategy was evaluated. Results: During the survey, symptoms of this disease were wilting of leaves and branches which gradually progress into dieback, gummosis, rotting of the stem and vascular discolouration. Six fungi, Lasiodiplodia theobromae, Colletotrichum sp., Aspergillus niger and Botrytis cinerea were present in the dry season and the two sites, Curvularia sp. and Schizosaccharomyces pombe occurring in the rainy season only in Cameroon were isolated. The highest incidence and severity rates were obtained during the rainy season, 43.94 and 14.03%, respectively. Kassai variety (25%) was the most susceptible to dieback. The percentage of tree regeneration from the cutting method depends on the attack percentage of the tree. Conclusion: This study suggested that several fungi are associated with this disease in Cameroon and Chad. Molecular analysis and pathogenicity are necessary to upset the control strategy (cutting method) which is efficient when the attack tree is under 50%.