Seasonality of the mycoflora of the crown disease complex of the vegetative organs of the grapevine Vitis vinifera cvar Anap-e-Shahe

Abstract

The mycoflora associated with lesions on the vegetative organs of Anap-e-Shahe cultivar of grapevine in Zaria were monitored for 3 years. The symptoms varied with the seasons but were the same over the
years studied. The mycoflora detected on the lesions were consistent with the symptoms. Except for pruning interruptions, Epicoccum sp., Penicillum sp., Aspergillus sp. and Curvularia sp. was regularly
detected on lesions of all growth seasons. Alternaria sp., Drechslera sp. and Pestalotiopsis aff. uvicola occurred only on lesions of the rainy season growths. Phoma aff. multirostrata, Colletotrichum
gloeosporioides, Phomopsis sp. and Phoma sp. were the dominant group on lesions of rainy season growth and were detected from the beginning of the rains in May until the close of the rains in October,
which corresponded with the prevailing period of anthracnose, tip die back, commencement of canker development and blight. The occurrence of Plasmopara viticola commenced during the downy mildew
epiphytotic late in July or early August, a time which corresponded with high relative humidity and a drop in maximum temperature at the peak of the rains. P. viticola and Curvularia sp. with other regularly
occurring fungi detected from the late rainy season persisted into the dry season. The seasonal variability in the mycoflora of the crown disease complex of grapevine provided information which
could be exploited in disease diagnosis and management.