ニホンナシ'幸水'の生育相および果実品質の年次変動と気象要因との関係(栽培管理・作型)  [in Japanese] Relationships between the Yearly Variation in the Developmental Phase and Fruit Qualities of Japanese Pear 'Kosui' and Climatic Factors(Crop Production & Cropping Type)  [in Japanese]

三重県で栽培されているニホンナシ'幸水'の生育相および果実糖度の年次変化と気象要因との関係を解析した.データを解析した1981年から2004年までの24年間で, 年平均気温は1年間に約0.07℃の割合で上昇していた.気温の上昇は, 9月から2月の間で大きかった.自発休眠覚醒期の推定値は, 1年間に0.49日の割合で遅くなった.満開期は年々早くなっており, その程度は1年間で0.37日であった.満開期は, 2月上旬から4月中旬の旬平均気温と負の相関を示し, これらの旬平均気温の中には年次と正の相関を示すものがあった.収穫最盛期は, 満開期と正の相関を示し, また, 1年間に0.32日の割合で早くなった.果実生育期間の長さの年次変動には傾向は認められなかった.これらのことより, '幸水'の生育相は, 地球温暖化の影響を受けていると推察された.一方, 果実糖度は, 7月中旬から8月中旬の旬平均気温および日射量と正の相関を示し, 7月下旬から8月上旬の降水量と負の相関を示した.しかし, 果実糖度と年次との間には相関が認められなかった.

We analyzed the relationships between the yearly variation in the developmental phase and fruit quality of the Japanese pear 'Kosui'(Pyrus pyrifolia Nakai) and climatic factors in Mie Prefecture between 1987 and 2004. The annual mean air temperature tended to rise at an annual rate of 0.07℃. This uptrend in the mean temperatures was especially remarkable from September to February. Along with the rise of temperature, the estimated date of breaking of bud endodormancy in 'Kosui' pear tended to be delayed at a rate of 0.49 day per year, possibly due to the rising temperatures during late autumn and winter. The dates of full bloom were negatively correlated with mean air temperatures at 10-day intervals from early February to mid-April and some of these mean air temperatures increased with advancing years. As a result, the dates of full bloom became earlier each year at a rate of 0.37 day per year. The date of peak harvest was positively correlated with the annual and became earlier each year at a rate of 0.32 day per year. The number of days from full bloom to peak harvest was not correlated with the annual. These results suggest that the developmental phase of 'Kosui' pear in Mie Prefecture is being influenced by global warming. However, the sugar concentration in the fruit was influenced by mean air temperature and mean solar radiation from middle July to middle August and mean precipitation from late July to early August, although, the yearly variations in sugar concentration in the fruit did not parallel the variations in annual mean air temperature.