Abstract
Application of pesticides to control downy and powdery mildew is indispensable for almost all Vitis vinifera varieties. Recently, fixed spraying systems are in increasing demand as an alternative to airblast sprayers and hand-held spray guns. A prototype of a fixed spraying system was mounted in 2014 at Laimburg Research Centre; fungicides were applied using two spraying lines, which were equipped with micro-sprinklers and cooler nozzles. Biological efficacy of treatments against downy and powdery mildew was evaluated over four grapevine seasons. With this prototype, grape bunches were successfully protected to a similar degree as with the airblast sprayer. However, in years when weather conditions were favorable for downy mildew infections later in the season, the fixed spraying system was not as effective in leaf treatments as the airblast sprayer. This study provides the basis for future work towards developing the economic and engineering aspects of fixed spraying systems.