Flowering of zantedeschia rehmannii engl. as affected by combination of tuber storage temperature and duration

In Zantedeschia rehmannii Engl. tuber storage at 1-5° for 30 days is suitable for breaking dormancy, and a temperature of 10° is suitable for flower bud initiation. Thus, effects of the combination of 1° and 10° during tuber storage on growth and flowering were investigated. Tubers which were not given low temperature (<15°) were stored for 50 days. Initial storage temperature was either 1° or 10°, and tubers were moved to alternate temperatures 10, 20, 30, and 40 days after storage. There were no significant differences among treatments in days to emergence, although days to flowering of plants stored at 10° 20 days followed by 1° 30 days were shorter than those of other treatments. Storage temperature and duration had no significant effect on anthocyanin content, cut flower weight, malformed flower percentage, cut flower length, and bract length. Percentage of flowering and number of flowers per plant decreased as storage duration at 10° decreased. Flower production increased remarkably in plants stored at 1° for 10 days followed by 10° for 40 days and at 1° for 20 days followed by 10° for 30 days because secondary flowers were harvested. It is thought that dormancy is broken at any temperature for 50 days, however, storage at 10° for >30 days is suitable for increase in flowering. Our results suggest that tuber storage at 1° then 10° may be desirable when Z. rehmannii is forced in summer.