PANDEY, R. R. (Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi221005, India). Succession of microfungi on leaves of Psidium guajava L. Bull. Torrey Bot. Club 117: 153-162. 1990.-The phylloplane mycoflora of guava (Psidium guajava L.) was studied from the bud stage to leaf fall stage in summer, rainy and winter seasons using a combination of cultural methods. In general, the number of fungi/cm-2 on leaves increased from the time of bud opening to senescence, but declined at leaf fall. The bud (unexpanded leaves) and newly expanded leaves were colonized by a limited range of fungi such as Alternaria alternata, Aureobasidium pullulans, Aspergillus niger, Cladosporium cladosporioides, Epicoccum purpurascens, pink yeasts and white yeasts. The number of fungal species was maximal at the senescent leaf stage in each season. Qualitatively, three categories of fungi, viz., early leaf fungi, mature leaf fungi, and dying and dead leaf fungi were recognized. On average, more fungal species were found in the rainy season and fewer in the summer. Some species were common to all seasons. Three main seasonal groups of fungi were observed: season specific, season sensitive, and season insensitive. Four potentially pathogenic species (Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. psidii, Pestalotia psidii, and Phoma psidii) were consistently present during all seasons. Most fungi were isolated by dilution plating, followed by the moist chamber method, and the fewest by the washed disk technique.