Influence of Light Intensity during Fruit Growth on Susceptibility of Hassaku Fruit to Kohansho

Abstract

Effects of light intensity during fruit growth on the occurrence and development of Kohansho in Hassaku (Citrus hassaku Hort. ex Tanaka) fruit were determined when the fruit was stored at 15°C or at 20°C following 5°C storage. Fruit harvested from the sun-exposed exterior canopy developed more Kohansho during storage than those from the interior canopy or covered with a cloth. The sun-exposed side of the exterior canopy fruit was more susceptible to Kohansho than the shaded side of the same fruit. L-Ascorbic acid (AsA) content in the flavedo was higher in fruit from the exterior canopy than from the interior canopy or those that were covered. AsA and total phenol contents in the flavedo were higher on the sun-exposed side than the shaded side of fruit that were taken from the exterior canopy. These results indicated that Kohansho of Hassaku fruit was mainly affected by light condition during fruit growth.