栽培時期と潅水点がバラの生長，水消費量および切り花収量に及ぼす影響

Abstract

The effects of growing season and irrigation regime on growth, water use (soil evaporation and transpiration), and yield of rose plants were investigated. Rooted cuttings of 'Carl Red' roses were grown in a greenhouse and watered at the four following soil moisture tensions, i. e. 3, 10, 32, and 50 kPa (pF 1.5, 2.0, 2.5, and 2.7, respectively) during summer, fall-winter, and winter-spring seasons.In all seasons the best plant growth was obtained with the 3 kPa treatment which simultaneously coincided with the largest amount of water use. In the other treatments, as the soil moisture tension was increased, the amount of water use decreased and growth was inhibited. There was no effect of irrigation regime on water use per unit plant growth.The amount of water use per ten days varied within and among seasons. We postulate that the variations among seasons were caused by irradiation and temperature changes; whereas, those within season were caused by the difference in plant size, especially the leaf area.As the soil moisture tension was increased, the days to flowering from pinching or harvest increased, and the number, quality and marketability of cut flowers decreased.Based on these results, we recommend that the optimal soil irrigation tension for greenhouse rose production is kept at 3 kPa throughout the growing season.