Colletotrichum gloeosporioides can Overgrow Colletotrichum kahawae on Green Coffee Berries First Inoculated with C. kahawae

Abstract

Colletotrichum gloeosporioides is a weak pathogen of coffee that infects ripe berries at dark red stage causing necrotic lesions, but only penetrates up to the second superficial layers of the pericarp at the rose and pink stages. C. kahawae, the causal agent of coffee berry disease (CBD) and responsible for 70-80% of crop loss, infects berries at any stage of development. When green berries are first inoculated with C. kahawae and then at 2, 72 or 96 h later with C. gloeosporioides, the necrotic lesions were significantly larger than in the controls, and were much more evident when the berries were incubated at the optimum growth temperature of 28 degrees C for C. gloeosporioides. Isolations from the lesions induced by the first inoculations with C. kahawae followed by inoculation with C. gloeosporioides revealed that all or most of the time the recovered isolates of the latter. Thus, C. gloeosporioides can overwhelm C. kahawae under conditions of higher environmental temperature and humidity and may enhance the CBD infection process under field conditions.