Anthracnose and Berry Disease of Coffee in Puerto Rico

Abstract

A survey revealed that Anthracnosis (Glomerella cingulata asex. Colletotrichum gloeosporioides) was the principal aboveground disease of field coffee in Puerto Rico. Isolates of C. gloeosporioides from both diseased soybeans and coffee caused typical branch necrosis in coffee after in vitro inoculation. Noninoculated checks showed no symptoms of branch necrosis or dieback. Necrotic spots on coffee berries collected from the field were associated with the coffee anthracnose fungus (C. gloeosporioides), the eye spot fungus (Cercospora coffeicola) and the scaly bark or collar rot fungus (Fusarium stilboides). Typical lesions were dark brown, slightly depressed and usually contained all three fungi. Fascicles of C. coffeicola conidiophores formed a ring inside the lesion near its periphery. Acervuli of C. gloeosporioides and the sporodochia of F. stilboides were mixed in the center of the lesions. Monthly fungicide sprays (benomyl plus captafol) and double normal fertilization (454 g 10-5-15 with micronutrients/tree, every 3 months) partially controlled berry spotting. Double normal fertilizer applications alone appeared to reduce the number of diseased berries by approximately 41%, but fungicide sprays gave 57% control. Combining high rate of fertilization and fungicide applications resulted in a reduction of approximately 85% of diseased berries.