Studies on Shading System in Sweet Cherries (Prunus avium L.) to Prevent Double Fruit Formation under Subtropical Climatic Conditions

In this study, the performances of cherries grown under subtropical conditions and the effects of shading systems on the prevention of double fruit formation were investigated. The experiments were carried out at Pozmer Agricultural Research and Application Center in Adana (50 m a.s.l.) during 2006-2008. 'Na-1', 'Early Van Compact', 'Bing Spur', 'Lapins' and 'Cristobalina' cherry cultivars fruited earlier and had good yielding, however double fruiting especially in 'Na-1' cherry cultivar seemed to be a serious problem under warm climatic conditions. The shading system was applied to reduce the high temperature affect to double fruit formation. Shading system with 55% of light transmission reduced air temperature about 1.9-3.1 degrees C compared to the full exposure. As a result of temperature reduction, double pistil formation was also reduced to 60.89 and 27.81%. The temperatures over 30 degrees C affected the promotion of double fruit formation during the physiological bud differentiation period at the beginning of June while morphological differentiation period of cherries will be initiated on 20th June and continued until the end of July to the beginning of August.