THE EFFECT OF SUCROSE IN A VASE SOLUTION ON LEAF BROWNING OF PROTEA NERIIFOLIA R. BR.

Leaf browning of several Protea spp. after harvesting is one of the most important problems in the protea industry.

The use of a flower preservative is essential to retard leaf browning of proteas.
The objective of this study was to determine the effect of sucrose in a vase solution on leaf browning of harvested Protea neriifolia.
Sucrose is an easily assimilable substrate and replaces the depleted intracellular carbohydrates and also retards the degradation of other organic components.

P. neriifolia stems were placed in a vase solution containing labelled ¹⁴C-sucrose (U ¹⁴C) for 18 hours.
A greater amount of ¹⁴C accumulated in the flower heads than in the leaves.
When placed in a vase solution containing ¹⁴C-sucrose and 1% sucrose a significant quantity of ¹⁴C accumulated in the flower head within 12 hours.
A pulsing period of 12 hours would thus ensure an efficient distribution of sucrose throughout the whole inflorescence.

In experiments with only sucrose in the vase solution it was found that concentrations of up to 1% sucrose effectively delayed the onset of leaf browning of P. neriifolia inflorescences.
Concentrations greater than 1% sucrose were harmful to the leaves and enhanced leaf browning.

I International Protea Research Symposium

J.A. Brink, G.H. de Swardt

https://doi.org/10.17660/ActaHortic.1986.185.11