Prévalence du dessèchement du manguier et evaluation de la fréquence des champignons associés à la maladie au Burkina Faso

Abstract

Prevalence of mango tree decline and evaluation of fungi frequency associated disease in Burkina Faso Objective : The objective of the study is to contribute to the diagnosis of the mango tree decline in Burkina Faso. It is to evaluate incidence and severity of this disease in five commercial varieties from Nahouri, Sissili, Houet, Comoé, Kénédougou and Léraba and to inventory the fungal species associated with the symptoms of the disease. Methodology and results : Incidence and severity of mango tree decline symptoms were calculated according to allotted scale from 1 to 5 on diseased trees. Prevalence was also assessed on Kent, Keitt, Amélie Lippens and Brooks commercial varieties from the six previously mentioned producing provinces of Burkina Faso. Samples of infected plant were collected and incubated for the inventory and infection rate of the fungal species. The frequency of fungal species were also carried out from the different organs of the mango tree. Survey results showed highest mango decline incidence (86%) and severity (58.2%) in the visited orchards of Nahouri. However, least incidence of (42.8%) and severity of (29.8%) were observed in Léraba. Intermediate values of incidence and severity of the desease were observed in Kénédougou, Houet and Comoé. Maximum prevalence of disease (77%) was calculated on cultivar Amélie followed by Kent ; Keitt, and Lippens. The minimum disease incidence (34%) was noted on Brooks. Seven species of fungi were inventoried. The highest frequency was recorded in Pestalotiopsis microspora (53.5%) followed by Botryodiplodia theobromae, Fusarium sp, Curvularia sp, Aspergillus sp and Botrytis cinerea. The least rate (1.25%) were noted in Colletotrichum gloesporiodes. Conclusion and application : These results indicate the importance of the mango decline and the species of fungi associated with the disease in Burkina Faso. Pathogenicity and molecular analyzes should allow to incriminate the fungal species responsible for the disease to better control.