Abstract
This study investigated the effect of the minimum air temperature on the occurrence of abnormal inflorescences in Gypsophila paniculata ‘Altair’. Abnormal inflorescences could be classified into three types: Type 1 (short flower stalk), Type 2 (coalescent two-flower stalk), and Type 3 (looping and irregular flower stalk). Abnormal inflorescences increased from early winter to early spring. Type 1 and 2 inflorescences could be observed at a constant rate, regardless of the flowering time, whereas markedly abnormal inflorescences (Type 3) increased significantly in March. Subsequent investigation of the effect of the minimum air temperature (7, 11, and 15°C) revealed that Type 3 increased at a lower air temperature; however, a lower air temperature improved the volume, length, and weight of cut flowers. In conclusion, a minimum air temperature of 11°C may be optimum to produce high-quality cut flowers of ‘Altair’. The cumulative number of chill hours (<9°C) from pinching to budding was more strongly correlated with the incidence of Type 3 abnormalities than that from budding to flowering. Thus, the occurrence of Type 3 abnormalities is affected by the minimum air temperature from pinching to budding.
