Hendersonula dieback of mango in Niger.
Reckhaus P., Adamou I.
Author Affiliation: Deutsche Gesellschaft für Technische Zusammenarbeit, Niger.
Plant Disease 71 :1045
Abstract : Since the early 1980s, a dieback disease has caused severe damage on mango trees in the Republic of Niger. The fungus most commonly isolated was H. toruloidea a facultative, wound-invading pathogen with a broad host range. Symptoms, which develop only during periods of high RH and high day and night temp. include sudden wilting of young shoots, twigs, or whole branches. Leaves turn bright red-brown but do not fall off. Cankers develop on infected branches and exude clear drops of gum. Internal tissue is dark brown to black. During the rainy season, black carbonaceous pycnidia occur containing hyaline to light green, ellipsoid pycnidiospores. Wound inoculations of 2- to 3-month-old mango seedlings and twigs (1-1.5 cm diam.) of adult mango trees, using small discs of mycelium and arthrospores containing agar as inoculum, demonstrated the pathogenicity of H. toruloidea. It is suggested that stress factors, mainly water, enhance severity of the disease.