Articles
WATER-BALANCE ASPECTS OF CUT AND INTACT ‘SONIA’ ROSE PLANTS, AND EFFECTS OF GLUCOSE, 8-HYDROXYQUINOLINE SULFATE AND ALUMINIUM SULFATE
Weight, transpiration and water uptake were followed by twice-daily weighings through one blooming period.
Cut roses in water developed a characteristic pattern of weight fluctuations, losing ca. 10% weight in the light and regaining it in the dark.
After petal shedding, the pattern persisted on a roughly 50% reduced scale: thus both petals and foliage contributed to the phenomenon.
In the intact roses only the senescing petals lost some of their water-retaining capacity.
Total daily transpiration and uptake of the cut roses were identical to those of the intact ones in the first 24 h, but then rapidly declined, to about 10%. In the intact roses there was some 30% decline as well.
In the dark periods, uptake of the cut roses did not decline, as contrasted to that in the light, but remained constant and equal to that of the intact plants for a long time; this necessitates a revision of the vascular-plugging concept.
Glucose, in combination with 8-HQS or Al-sulfate, profoundly affected the above weight and water-turnover patterns, reducing water loss by stomate closure and improved water retention.
Currently,
-gauging is used to estimate the relative contributions of petals and foliage to the weight patterns described.
