ROLE OF PRESSURE POTENTIAL IN KEEPING QUALITY OF CUT GERBERA INFLORESCENCES

Ageing of cut Gerbera inflorescences in a vase is accompanied by an increased leakage of ions from petal tissue, causing a decrease of water content and pressure potential of the petals.
The increase in ion leakage is absent when inflorescences remain on the plant.

Lowering pressure potential of excised petals hastened the increase of ion leakage.
Increasing pressure potential by placing flower stems in KNO₃-solutions delayed the increase of ion leakage.
For the 3 cultivars used, there existed a correlation between the moment at which the increase of ion leakage started and pressure potential of the petals on the day of harvest.
Time of year influenced the moment of increasing ion leakage and also the pressure potential of petals.
Pretreatment (24 h) of the cut inflorescences with a 20% sucrose solution delayed the increase of ion leakage and increased pressure potential of petals.
However, the effects of 4% sucrose as a constant additive to the vase water varied greatly in different experiments, probably due to seasonal influence on the internal water relations of the petals.

It is suggested that pressure potential of petals on the day of harvest might give a good indication for potential keeping quality.

II International Symposium on Post-harvest Physiology of Cut Flowers

U. van Meeteren

https://doi.org/10.17660/ActaHortic.1981.113.19