Willows in the vase
Experimental

Five twigs of each species or cultivar were put in containers of tap water and five in floral preservative. This contained 1% sucrose, 0.2% ctiric acid and 0.02% hydroxyquinoline citrate and was adjusted to pH 3.5. The twigs were kept in a room at 25°C with continuous fluorescent light at 10 μmol m^-2s^-1. Additional twigs of S. chaenomeloides and S. pentandra were exposed to treatments that were thought to possibly affect bud opening. Some were sprayed with GA₃ at 0.5 g l^-1, some were exposed to 10 μl l^-1 ethylene and some were kept in continuous darkness. Every 3 or 4 days each twig was weighed for a measure of bud enlargement and maintenance of tissue hydration. Each weight recorded during the experiment was divided by the weight of the same stem at the beginning and the average of these relative weights was calculated for the 5 twigs in each treatment unit.

Results

Except for S. gilgeana and S. schwerinii the willow twigs generally showed an increase in fresh weight in the first few days and this was more pronounced in the floral preservative than in water. However, only S. chaenomeloides and S. pentandra in water showed a sustained increase and all fresh weights declined in floral presevative after about 10 days. Fresh weight changes in S. chaenomeloides and S. pentandra were not affected by ethylene, GA or continuous darkness.

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