Effects of Voen Cover on the Growth and Yield of two Sweet Cherry Cultivars

In 1998, a trial was established with cultivars ‘Iputj’ and ‘Krupnoplodnaya’ at the Latvia State Institute of Fruit-Growing. A VOEN covering system was installed on part of the orchard in summer 2008. Considerable lowering of the canopy and renewed pruning were carried out throughout the trial. During 2009-2012, sweet cherry growth, yield and fruit quality were monitored. The cover was installed before flowering in each spring and uncovered after harvest. The cultivar ‘Krupnoplodnaya’ had a tendency for faster canopy growth under VOEN. Influence of VOEN cover on total yield was not significant, but had a positive tendency on marketable yield. In 2012, the marketable yield was 85% under VOEN, but only 53% without cover due to high precipitation. The cover decreased fruit decay significantly. Fruits damaged by birds (bird pecks) varied year by year. In the first part of the observation period, many damaged fruits were observed also under VOEN, but later the damage was decreased due to installed bird control devices. The fruits of sweet cherries were larger under cover. A positive effect of cover on amount of soluble solids and phenols in fruits was observed for cultivar ‘Krupnoplodnaya’ in 2011.