Studies on the mycoflora of coffee leaf surfaces

Abstract

Several methods, including disk plating, leaf washing, leaf maceration, sporefall, and sellotape impression techniques were used in isolating coffee leaf surface mycoflora. Leaf surfacesof cultivars of Coffea arabica L. in Kiambu, Kenya, support a wide range of mycoflora, the commonest of which are species of Aureobasidium, Cladosporium, Colletotrichum, Phyllosticta and Epicoccum. Factors affecting distribution of the fungal isolates were investigated. Seasonal variation, leaf age, coffee variety, temperature, relative humidity, presence of coffee pollen, etc. app ear ed to influence the mycofloral populations. The effect of captafol (Difolatan) on the phylloplane mycoflora as well as its "tonic" effects were demonstrated and discussed. ~ vitro antagonism between some of the isolates was studied. Fusarium stilboides strongly exhibited antagonism against other :Lsolates. The possibility of using such antibiosis as a meanp of biological disease control is discussed. A pathogenicity test suggests that Alternaria alternata is a weak pathogen of young coffee leaves.