POSTHARVEST TREATMENTS TO INCREASE WATER-UPTAKE AND THE VASE LIFE OF LEPTOSPERMUM-SCOPARIUM FORST

Postharvest stem treatments and vase-solution treatments were assessed to determine the basis of the short vase-life of detached Leptospermu m scoparium Forst. stems. Stem cutting or heat treatments had little e ffect on water uptake or vase life. 8-hydroxyquinoline sulphate (HQS) delayed the decline in water uptake and leaf moisture content, and ext ended the vase life by 1-2 days. Cycloheximide (CHI) also extended the vase life by 2 days. However, the water uptake pattern and changes in leaf moisture content were different from those observed with HQS. Al though the rate of flower senescence was similar, CHI treatment result ed in a marked reduction in the rate of decline of water uptake and lo ss of leaf moisture content. Silver thiosulphate purse treatments had little effect on flower senescence. Sucrose reduced the rate of Bower senescence and when combined with HQS extended the vase life from 3 to 9 days. This suggests that the short vase-life of L. scoparium is the result of both the sugar status and water relations of the cut stems.