Control of bud sprouting and elongation in colored Zantedeschia tubers by low-temperature storage

The effect of low-temperature (LT) storage at 10 °C on dormancy relaxation and bud break was studied in tubers of colored Zantedeschia. LT storage for 35 or 64 days enhanced budbreak by about 80 days compared to tubers stored at 20 °C. Primary bud elongation did not occur at 10 °C for 143 days, but took place after the tubers were transferred to 20 °C. Prolonged LT storage enhanced the rate of bud elongation at 20 °C. It is proposed that LT storage enhances dormancy relaxation but, at the same time, inhibits bud elongation in nondormant buds. This dual effect can serve growers in programmed production of year-round forcing of colored calla lily flowers.