Effect of exogenous growth regulators on quality and longevity of cut tulip flowers

摘要

Effects of pulse treatments with calcium nitrate, gibberellic acid, benzyladenine, sucrose (S) and ethephon on postharvest longevity and stem length of cut tulips 'Fantasy' and 'Aladdin' were investigated. The vase life of flowers was improved by using 0.1 mM GA_3, 0.1 mM BA and 2 mM Ca(NO_3)_2. Pulse treatment with ethephon at five concentrations from 2.5 to 50 mg centre dot l~(-1) significantly reduced the length of the last internode of Fantasy cv., when compared to water control. The addition of 10 mg centre dot l~(-1) ethephon to the preservative solution completely inhibited, caused by GA_3 and S, undesirable stem elongation without any negative effect on flower longevity. Ethylene production was higher in tulips pulsed with ethephon (10 mgcentret dot l~(-1)) than in those untreated. For a short 24-h pulsing both Ca(NO_3)_2 + BA + S + ethephon and Ca(NO_3)_2 + GA_3 + S + ethephon solutions were effective, resulting in a longer vase life of either freshly cut or dry-stored flowers. To protect tulips against an excessive stem elongation after harvest, the addition of ethephon to the pulse treatment with a preservative solution is preferable.