Changes of Tree Growth and Fruit Characteristics on Different Temperature Conditions during Growth Stages in Grapevine (cv. Kyoho)

Changes of the growth patterns and fruit quality of ‘Kyoho’ grapevine in response to four different temperature conditions using the temperature gradient chamber were investigated. The temperature conditions consisted of 20.4°C (group I), 21.1°C (group II), 22.0°C (group III), and 23.4°C (group ‡W) during the growth period (April~October). Shoot diameter was the highest in group III, and it was decreased in group ‡W, group II, and group I. Berry setting density was the highest as 4.1 berry·cm-1 in group I, but was lowest as 2.2 berry·cm-1 in group ‡W. In the results of investigating the fruit characteristics, cluster weight was the highest in group II as 527.5g, it was decreased in group I as 495.3g, group III as 449.8g, and group ‡W as 431.2g. Total free sugar content was remarkably decreased in high temperature condition, and Tartaric acid was similar value in entire treatments except group III. Regarding sun burn and berry cracking at harvest, sun burn rate was remarkably increased in group ‡W as 8.3%, and berry cracking rate through water immersion was the lowest in group I as 20.0%, but it was relatively increase in high temperature conditions such as group II, group III, and group ‡W.