加温栽培‘ デラウェア’ の隔日変温管理方法が生育と果実品質に及ぼす影響

We investigated the effect of time-dependent temperature management conducted every other day (TTMD) on the growth and berry quality of ‘Delaware’ grapes under forcing culture from January to May in order to reduce fuel consumption. This method involved lowering the standard temperature setting for forcing (control) by 5°C on alternate days. Grapevines that were grown under TTMD at night exhibited no significant differences in development (veraison, maturity), leaf color, berry growth, or berry quality compared with the control. However, fuel oil consumption was reduced by 8%. Grapevines that were grown under TTMD during the day showed no difference in the developmental period of berries or leaf color compared with the control. However, they showed lower levels of berry growth than the control from 14 days after the TTMD treatment to maturity; furthermore, they showed lower cluster and berry weights than the control. Therefore, it was concluded that TTMD is a suitable option for viticulturists if used at night from the time of berry set until the end of forcing.