2004 Volume 42 Issue 4 Pages 349-352
We examined the relationship between the timing of heating the greenhouse in autumn and winter period and flowering of Disa orchid as part of efforts to develop and establish a stable method of growing with the suitable cultivars at the Yatsugatake Farm of the Yamanashi Agricultural Research Center (955 m above sea level, Takane, Hokuto) . In the 2001 experiment, flowering were promoted by rising the night temperatures from February 8. Heating treatment hastened flowering by about 20 days in D. Kewensis and about 40 days in D. Helmut Meyer. Flower stalks of the two cultivars were longer in heat-treated plants than in control plants. The number of flowers per flower stalk was not affected by the heating treatment except for D. Helmut Meyer which had fewer flowers in treated plants than in control. In the 2003 experiment, heating the greenhouse at night hastened the flowering in D. Cardior × D. uniflora and D. Helmut Meyer, but not affected in D. uniflora and D. Helmut Meyer. Only in D. uniflora, the length of flower stalk was shortened by earlier heating. The other three cultivars, (D. Cardior × D. uniflora, D. Margaret Ann Rundle and D. Helmut Meyer), were not affected by heating.