Improving the yield and cut flower quality of autumn flowering Alstroemeria by a soil cooling system.

摘要

Plants of Alstroemeria cultivars Regina and Carmen (syn. Cana), when kept at a minimum of 10deg C in winter, continually produced flowering shoots if they were planted by 21 May and 20 June, respectively, provided that the soil temperature was maintained at 14deg C at night. After these critical dates it became almost impossible to keep Regina and Carmen below 15deg C and 17deg C, which are the critical and threshold temperatures for flowering. Cut flower yield and quality obtained by this method were poor. Potted ReginXa plants which were previously exposed to chilling at 2deg C for 10 weeks and then transplanted to a chilled soil bed on 10 June produced flowering shoots in autumn. When plants were raised at a minimum of 20deg C prior to chilling, they produced more vegetative shoots after transplanting than plants raised at a minimum of 10deg C. The former plants also produced more flowering shoots and high quality cut flowers in early autumn. Carmen plants grown in a chilled soil bed, kept below 17deg C for only 6 hat night, produced more vegetative shoots and higher quality cut flowers in autumn than plants grown in a bed which was cooled continuously. By maintaining the soil at 20 deg C for 8-20 weeks prior to cooling to 17deg C on 12 June, a large number of vegetativeshoots were produced in summer and autumn and the cut flower yield and quality of autumn-flowering 2-year-old Carmen plants were improved.