Abstract
The effects of artificial shading in summer on photosynthesis, carbohydrate accumulation and fruit set in sweet cherry grown in warm areas were studied. Potted trees were grown in steel frame structures covered with woven shade cloth made of silvered polyethylene and providing 53% light reduction. Shading slightly increased the daily leaf net photosynthetic rate compared to control. Shading delayed leaf abscission. In another experiment, 1-year-old trees were grown under the same level of shade. Although dry weight was not influenced by shading, reserve carbohydrate concentration of the tree under shaded conditions was higher than that under unshaded conditions. Five-year-old trees were subjected to the same level of shading. Shading prolonged embryo sac longevity the following spring and resulted in increased fruit set. These findings suggest the possibility of applying artificial shading in summer to increase assimilate accumulation and fruit set the following spring in sweet cherries grown in regions with hot summers.
