Forcing Culture of Blueberry Grown in a Container Using a Hydroponics System Suitable for Use in Hilly and Mountainous Areas

We developed a sloped greenhouse and a hydroponics system suitable for use on sloping land. To use the greenhouse and the system effectively during the winter season, we investigated forcing culture of blueberry. We transplanted 15 cultivars of blueberry plants in containers filled with a peat-moss and supplied nutrient solution by the hydroponics system. Ten to 17 months after transplanting to the container, we investigated the death rate among plants of each cultivar. The death rate of plants was the highest in ‘Earliblue’. We considered that ‘Earliblue’ was unsuitable for the hydroponics system. In forcing culture, the plants experienced a term of cold temperature when placed outdoors in hilly and mountainous area (about 300 m above sea level) in Mikamo, Tokushima until 3 February, 2004. After 3 February, the plants were brought into a heated greenhouse near the field. Flowering of plants in forcing culture started at the end of February, which was 35–40 days earlier than flowering of plants under standard culture in Zentsuji, Kagawa. Harvesting from plants in forcing culture started at the end of April, which was about 35 days earlier than that from plants in standard culture. In forcing culture, at the beginning of harvesting term, fruit yields from ‘Patriot’ and ‘Weymouth’ were higher than those from other cultivar. However, for the experimental term, the yields from ‘Northland’ and ‘Sharpblue’ were higher than those from other cultivars. ‘Sunshineblue’ was unsuitable for forcing culture because of the late harvest period. The average price of shipped fruits from forcing culture was higher (¥3,389 kg) than that during other seasons. We supposed that forcing culture of blueberry using the greenhouse and the hydroponics system was promising culture method in hilly and mountainous areas.