No abstract

No abstract

No abstract

An experiment was conducted to measure the effects of pulse treatments of BA, sucrose, and BA before, after, or with sucrose, on the vase life of cut Eustoma flowers. A BA pulse at 50 mg·L-1 before 4% sucrose promoted the longevity of cut Eustoma flowers better than other treatments. Simultaneously, sucrose, glucose, and mannose concentrations in flowers during vase periods were maintained at higher levels in double pulse treatments than in the single pulses. Ethylene production in flowers 2 days after vase treatment was highest in the BA-treated flowers; intermediate in flowers pulsed with BA before, after, or with sucrose; and lowest in sucrose-treated flowers. Although a BA pulse increased ethylene production over that of controls, it inhibited senescence in cut Eustoma flowers. Respiration in flowers pulse-treated with sucrose or with BA before, after, or with sucrose, was significantly higher than that in controls. Results suggest that the vase life of cut Eustoma flowers is improved by either BA or sucrose in vase solution and especially when BA was pulsed before the sucrose pulse. Chemical name used: N6-benzyladenine (BA).

Abstract.-Cut Oncidium flowers were kept in open solutions. Kinetin at 50 mg.l· 1 plus sucrose at 40 g.l· 1 appeared to be more efficient in maintaining flower longevity than kinetin or sucrose alone. The flower longevity was longer with a kinetin pulse followed by a sucrose treatment than a continuous kinetin plus sucrose treatments. Gibberellic acid (GA3) had little effect on keeping flower longevity in Oncidium. Ethylene production was inhibited by the presence of sucrose. However, ethylene production was slightly stimulated by treatments of kinetin or GA3 alone as compared with HQS (8-hydroxyquinoline sulfate) controls. Similarly, ethylene production in kinetin plus sucrose, kinetin plus GA3 plus sucrose and GA3 plus sucrose was slightly enhanced compared with sucrose alone.Key-words: cut flower-flower longevity-kinetin-sucrose-Oncidium.Resume.-La kinetine a 50 mgJ·1 plus le sucrose a 40 g.l-1 apparaissent plus efficaces pour le maintien de Ia longevite de !leurs coupees d'Oncidium que Ia kinetine ou le sucrose seuls. Cette longevite s'avere aussi plus longue avec une alternance de kinetine suivie d'un traitement au sucrose qu'avec Ia kinetine en continu suivi du meme traitement. L'acide gibberellique (GA3) a un eifel reduit sur cette longevite. La production d'ethylene est inhibee en presence de sucrose. Cependant cette production est legerement stimulee par des traitements a Ia kinetine ou au GA3 seuls comme le montrent des comparaison avec I'HQS (ahydroxyquinoline sulfate). De meme, cette production d'ethylene en presence de kinetine plus sucrose, de kinetine plus GA3, de sucrose plus GA3 est legerement augmentee par rapport au sucrose seul.Mots-cles : extraits de !leur -longevite florala -kinetine -sucrose -Oncidium. 178