Climate change impacts
In the coastal region of Setouchi, the temperature during maturation is high, and grape coloration tends to be poor. This is particularly notable in the red variety "Aki Queen". The price of grapes with weak skin coloration drops dramatically even if the taste is unaffected. As a consequence of global warming, it is possible that areas of cultivation that have so far been unaffected by this issue, may develop this problem in the future. Although it has long been known that cincturing (i.e., selective bark removal) improves coloration, this may not be effective as temperatures rise.
Adaptation activity
A combination of cincturing and crop thinning has been explored in Hiroshima Prefecture, as a method of improving the coloration of grapes in warm climates.
Fig. 1 Results of combined crop thinning and cincturing.
(Source: Hiroshima Prefectural Technology Research Institute, Agriculture Research Center, “Methods for Improving "Aki Queen" Grape Coloration in the Setouchi Coastal Region”）
Fig. 2 Appearance of vine after annual cincturing.
(Source: “Methods of Increasing Grape Coloration in Warm Climates by Combining Cincturing and Crop Thinning”, Hiroshima Prefectural Technology Research Institute, Agriculture Research Center)
