We studied stem bending in cut Gerbera flowers (Gerbera jamesonii cv. Tamara). Bending might be due to
turgor loss. During vase life water uptake decreased more rapidly than transpiration, hence the flowers
lost water. Net water loss did not occur in the floral head, but was found in the stem. It was largest in
the segment (10–15 cm below the floral head) where bending was localised. When comparing flowers
that showed stem bending with those that did not, on day 7 of vase life, the fresh weight loss of 5 cm
stem segments was higher in the stems that had bent. Covering the stems with a flexible, thin sleeve of
polypropylene plastic reduced transpiration and increased the time to stem bending from d 7 to d 14
of vase life. Additionally, stem bending might relate to stem elongation and to stem morphology and
anatomy. Stems elongated by 1–1.5 cm, in the uppermost 10 cm, during the first two days of vase life. No
relationship was found between stem elongation and bending. At harvest, the stems contained a large
central cavity, starting at about 5 cm from the root–shoot junction, and ending about 10 cm below the
floral head. The cavity extended upwards and laterally during vase life, but no relationship was found
between cavity formation and stem bending. A cylinder of sclerenchyma in the stems was found to end
about 20 cm below the floral head, in summer. Bending was correlated with the extent of sclerenchyma
formation and stem lignin levels. It is concluded that stem bending is due to net water loss from the stem,
particularly in the area of bending, and to low mechanical strength in the upper part of the stems, which
lack a sclerenchyma cylinder.
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