• Milena Dimova Agricultural University, Plovdiv, Bulgaria
• Miroslav Titjnov University of Forestry, Sofia, Bulgaria
• Veselin Arnaudov Fruit Growing Institute,Plovdiv,Bulgaria
• Stephan Gandev Fruit Growing Institute, Plovdiv, Ostromila, Bulgaria

Abstract

The experiment was carried out in 2007-2012 in a sour cherry orchard with three cultivars – ‘Oblachinska’, ‘Schattenmorelle’ and ‘Heiman Ruby’- established in the region of the town of Hisar. In 2007 the control of cherryleafspot(Blumeriellajaapii) was conducted at improper time and inaccurate rates. That induced leaf defoliation in August. In the next vegetation periods (2008-2012) the control of cherry leaf spot was carried out by applying fungicides at definite rates at the most critical time for the host-pathogen system. During the next years (2009-2012) the trees of ‘Oblachinska’ cultivar yielded normally – 1300 kg/dekar, while the trees of the other two cultivars started improving their health status and the yield gradually increased, reaching up to 1600 kg/dekar(da) for ‘Heiman Ruby’ and 1100 kg/da for ‘Schattenmorelle’.