Production and postharvest treatment of cut stems of Eucalyptus L. Her. foliage

Abstract

<jats:p>Optimum pruning height for cut foliage production was investigated for 3-year-old trees of <jats:italic>Eucalyptus globulus</jats:italic> Labill. Trees cut at a height of 1.0 m above ground level had most stems resprouting from the trunk, but a pruning height of 0.5 m produced the longest stems. Postharvest trials were conducted to assess the vase life of cut stems, and the effect of pulsing and simulated transportation on vase life. Holding solutions containing 1% or 2% sucrose and 8-HQC at 200 mg·L<jats:sup>–1</jats:sup> significantly increased vase life of <jats:italic>E. globulus</jats:italic> and <jats:italic>E. cinerea</jats:italic> F. Muell. ex Benth. over the control, but pulsing <jats:italic>E. cinerea</jats:italic> in 1%, 5%, or 10% sucrose plus 8-HQC for 2 hours at 24 °C or 24 hours at 3 °C had no effect. In simulated transport trials, pulsing overnight in 1% or 5% sucrose plus 8-HQC at 3 °C followed by 1 week dry storage at 3 °C had no effect on the vase life of cut stems of <jats:italic>E. sideroxylon</jats:italic> Cunn. ex Wools., <jats:italic>E. platypus</jats:italic> Hook., <jats:italic>E. spathulata</jats:italic> Hook., <jats:italic>E. cladocalyx</jats:italic> F. Muell. <jats:italic>E. platypus,</jats:italic> or <jats:italic>E. spathulata E. sargentii</jats:italic> Maiden, but a 5% sucrose pulse plus 8-HQC significantly increased the vase life of <jats:italic>E. spathulata E. platypus</jats:italic>. A long pulse at low temperature (24 hours/3 °C) followed by 1 week dry storage was more effective than a short pulse at high temperature (2 hours/24 °C) for <jats:italic>E. albida</jats:italic> Maiden &amp; Blakely stems and no sucrose was more effective than 1% or 5%. Thus, a pruning height of 0.5 or 1.0 m was optimum for cut foliage production of <jats:italic>E. globulus</jats:italic>, and a 2% sucrose holding solution extended vase life. There was no advantage of sucrose pulsing to extend vase life, or to improve vase life following dry storage, except for the hybrid <jats:italic>E. spathulata E. platypus</jats:italic>. Chemical name used: 8-hydroxyquinoline citrate (8-HQC).</jats:p>