Research on the prevention of bunch rot disease caused by Aspergillus spp. on sultanina seedless grapes in Aegean region vineyards

Seedless sultana grapes are cultivated across large areas of the Aegean region. Generally in grapes, fungi such as Alternaria spp. and Aspergillus niger, as well as Botrytis cinerea, are the causes of the rot bunches. In Turkey there is no directive for combatting the factors which lead to the rotting of bunches in grapes, other than for B. cinerea. In this study, samples were taken from leaves, flowers, stem, shoots and other parts at almost every stage of vineyard development. In the isolations carried out, above 400 Aspergillus spp. isolates were collected. 20 isolates were randomly chosen from these and their levels of sensitivity to different 17 fungicides were tested under in vitro conditions. In order to determine the effectiveness of fungicides on 2 Aspergillus spp. isolates, which is known as the most sensitive and most resistant to all fungicides, fungicides were prepared in doses in 0.1, 0.3, 0.01 and 0.03 ppm and tested on germination of spores, the effects of grain and clap under in vivo conditions. In another aspect of our study, fungicide applications were made against Aspergillus spp. and other factors, taking note of infection times. During two years the yeast granular formulation number 173/6 was applied to some vinestocks in experimental vineyard on 60 vine stock of using pesticides. The harvested grapes were stored during 3 months. The grapes were prepared as full, half dose SO2 paper and control, with four repetitions per application, and then put into storage for three months. Development of decomposition, yeast population dynamic and quality analysis tests were conducted on grape samples taken from the storage at the end of every month. Key words: Seedless sultana grapes, fungicide, epiphytic yeast, storage, SO2 paper.