Coffee Berry Disease in Kenya. II. The Role of Glomerella cingulata in the Colletotrichum Population, Colonizing the Bark of Coffea arabic a

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Vermeulen, H.
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On the maturing bark of cut branches of Coffea arabica previously sprayed with copper fungicides perithecia of Clomerella cillgulata were easily found after two to ten days of incubation. Without fungicides the number of perithecia was decidedly lower. On prunings left on the ground under the coffee trees for 6 to 24 weeks the perithecia could also be found, but the numbers declined rapidly with time. Perithecia of C. cillguiata could forcibly discharge ascospores under laboratory conditions. Monospore cultures obtained by catching ascospores on agar, invariably belonged to three Colletotrichum ypes. It was rarely possible to isolate a Colletotrichum able to infect green coffee berries. Growthrate, colour of the mycelium, number of conidia produced ill vitro and infectivity on green coffee berries, however, differed substantially from C. coffeanum, the cause of coffee berry disease. In Kenya no evidence has been obtained that ascospores from perithecia on bark could infect wounded or unwounded green coffee berries. Neither has any infection been obtained with ascospores from perithecia grown ill vitro. Possible explanations for the difference with previous findings are offered. Based on the data presented in this paper, it is concl'-1ded that C. cingulata is not likely to play role in the epidemiology of the coffee berry disease in Kenya.
East African Agricultural And Forestry Journal, 76, pp. 285-292