2017 Volume 17 Pages 34-45
Although climatic conditions had hindered the introduction of Pinot Noir, a cultivar of wine grape (Vitis vinifera), to areas such as Yoichi and Sorachi, Hokkaido, northernmost Japan, the growing region of the cultivar has recently extended. We analyzed meteorological data to obtain the rationale for the successful cultivation of Pinot Noir in Hokkaido; climate shift since 1998 pointed by Kanno (2013), i.e., rise in summer temperature, facilitated cultivation of the variety. Today, Yoich and Sorachi have become the right locations for growing the cultivar, and it has also been grown in other areas. Indeed, the vintage chart in Tokachi indicated the consistent, good harvest of grape since 1998. There is negative correlation in the average monthly temperature between April and August, and positive correlation between August and September ever since the climate shift. We hypothesize the benefits of the climate shift in terms of wine production as follows: 1) in years with low April temperature and high summer temperature, the growth rate in early stage delays, but the temperature required for grape maturation is secured by high temperature in August and September; and 2) in years with warm April and subsequent cool summer, early growth start keeps the growing season long enough, which may have compensated the risk of poor grape maturation in cool summer. Thus, climate change is considered to have favored the cultivation of Pinot Noir in Hokkaido.
