ISHS Acta Horticulturae 430: VII International Symposium on Flowerbulbs
IMPROVING FLOWERING RATES IN NERINE BOWDENII BY MODERATING SUMMER TEMPERATURES |
| Authors: | R. Shillo, A. Ronen, J. Muchnik, M. Zaccai |
| Keywords: | synanthous, hysteranthous, evergreen |
| Abstract:
Nerine bowdenii W. Watson was introduced into Israel many years ago, but was not commercialized due to the problem of inflorescence abortion. The tendency of the flower bud to abort is apparently linked to the 18–24 month interval between flower initiation and anthesis. Our working premise was that the low blooming rate of N, bowdenii growing on sandy soils in Israel was due to high temperatures and possibly low humidity during the summer. Accordingly, we examined the possibility of forcing the plant to flower by improving growing conditions. Bulbs were planted in October 1994 in a plastic greenhouse in which air humidity was kept at 70–80% and the temperature within 14–16°C and 26–31°C during the night and day, respectively. Under these conditions, the plants became evergreen, and in August-September 1995 flowering occurred in most bulbs of size 8 plus, and in 60% of bulbs size 6/7. In addition, flowering of daughter bulbs began in early November. In a field experiment, bulbs were transplanted from sandy to loess soils in October 1992. Soil and ambient summer temperatures were lowered by applying a 2 cm vermiculite mulch and by continuous irrigation. In the first year, bulbs multiplied but produced few inflorescences. In the second year, scattered flowering occurred in late spring to early summer. In autumn, which is the natural flowering season, there was a burst of bloom from mid-August to the beginning of October during which about 44% of the shoots produced flowers and the yield per square meter was approximately 55 inflorescences. A similar phenology was observed during the third year, but the number of flowers in autumn was much lower, apparently because of plant overcrowding. | |
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