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

Objectif: l’objectif de l’etude est de contribuer au diagnostic du dessechement du manguier au Burkina Faso. Il s’agit d’une part d’evaluer l’incidence et la severite de la maladie sur cinq varietes commerciales provenant du  Nahouri, de la Sissili, du Houet, de la Comoe, du Kenedougou et de la Leraba et d’autre part d’inventorier les especes de champignons associees aux symptomes de la maladie. Methodologie et resultats: Une echelle de 1 a 5 a ete utilisee pour l’evaluation de l’incidence et de la severite du dessechement du manguier dans six provinces du Burkina Faso. Sa prevalence a ete evaluee sur cinq varietes commerciales du pays. Les taux d’infections des especes de champignons ont ete calcules a partir des echantillons des manguiers malades. Les resultats revelent une forte incidence du dessechement de manguier dans le Nahouri (86%) et une forte severite (58,2%). Cependant, les plus faibles valeurs ont ete constatees dans la Leraba avec 42,8% d’incidence et 29,8% de severite. Le Kenedougou, le Houet, la Comoe et la Sissili ont enregistre des incidences moyennes comprises entre (43,6%) a (81,6%) et de severites moyennes entre (30,88%) a (50,8%). La plus forte prevalence (77%) a ete enregistree sur la variete Amelie, suivie de Kent, Keitt, et Lippens. Le plus faible taux (34%) a ete observe sur Brooks. Sept especes de champignons ont ete inventoriees. Le plus fort taux d’infection a ete enregistre pour le champignon P estalotiopsis microspora (53,5 %), suivi de Botryodiplodia theobromae , Fusarium sp, Curvularia sp, Aspergillus niger , et de Botrytis cinerea . Le plus faible taux (1.25%) a ete note pour Colletotrichum gloesporiodes . Conclusion et Application: Ces resultats renseignent de l’importance du dessechement des manguiers ainsi que les especes de champignons associees a la maladie au Burkina Faso. Des etudes de caracterisation moleculaire couplees au test de pathogenie devraient permettre d’incriminer les especes fongiques responsables de la maladie pour mieux la controler. Mots cles: Dessechement, Manguier, Incidence, Severite, Champignons, Burkina Faso English Title: Prevalence of mango tree decline and evaluation of fungi frequency associated disease in Burkina Faso English Abstract 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, Comoe, Kenedougou and Leraba 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, Amelie 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 Leraba. Intermediate values of incidence and severity of the desease were observed in Kenedougou, Houet and Comoe. Maximum prevalence of disease (77%) was calculated on cultivar Amelie 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. Keywords: decline, mango, incidence, severity, fungi, Burkina Faso