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Effect of Diurnal Temperatures Alternations on the Growth of Annual Flowers at the Nursery Stage

1997; Japanese Society for Horticultural Science; Volume: 65; Issue: 4 Linguagem: Inglês

10.2503/jjshs.65.809

1880-358X

Akiko Itol, Tamotsu Hisamatsul, Norio Soichil, Mizuo Nonaka, Masayuki Amanol, Masaii Koshiokal,

Seedling growth and survival studies

The effect of difference between day temperture (DT) and night temperature (NT) and constant temperature regime ranging from 15° and 25 °C on the elongation and development of Matthiola incana (stock), Antirrhinum majus (snapdragon), Viola × wittrokiana (pansy) and Impatiens walleriana (Impatiens) seedlings was investigated.The 25 °/15 °C (DT/NT) treatment (positive DIF) promoted plant height and internode and petiole lengths more than did constant 20 °C (zero DIF), on all four species, whereas 15 °/25°C treatumet (negative DIF) suppressed growth compared to zero DIF. On the other hand, the increment of growth during rapid elongation stage was more influenced by average temperature than by DIF. Leaf length and leaf unfolding rate responded to average temperature rather than to DIF.By taking advantage of DIF effects, production of compact seedlings might be facili-tated because DIF regulates tha final height of seedlings, whereas average temperature controls elongation speed. Our data indicate that controls of elongation for a short period may be easier by altering temperature than by changing DIF.