Executive Summary
The total area of cut flowers in Australia exceeds 100,000 ha, with Australian exports of native fresh flowers valued at over $20 million. Australia has 8% of the Japanese market share. This project has the potential to increase production of Australian eucalypt bud and flower cut stems ten fold. At present, most native flower cultivation is confined to coastal areas with good soils. Eucalypts will grow in a wide range of soil types and water qualities, and the development and proving of novel lines, along with the propagation, production and postharvest information for optimum quality, will expand current production into new areas.

This project addressed the development of new eucalypt cultivars for cut stem production, a step that is essential for the future competitiveness of this Australian export industry. As relatively little work had been conducted in this area previously, the approach was wide-ranging. Research addressed the development of interspecific hybrids, evaluation of these hybrids for superior characteristics, investigation of their postharvest vase life, investigation of vegetative propagation, and investigation of pruning treatments.

An interspecific hybridisation approach was adopted as most current horticultural cultivars have complex pedigree. Parents with desirable characteristics were selected, and twelve superior selections have been produced for further evaluation. Postharvest vase life is important for any cut stem commodity, but particularly in product for export. The research has shown that clean water is the best postharvest treatment. Vegetative propagation of superior selections is essential to capture the advantages of genetic gain via breeding, as eucalypts are outcrossing so characters are not fixed via seed propagation. The research has shown that vegetative propagation is possible via cuttings, grafting and tissue culture. Cost-effective production depends upon pruning methods that stimulate the long stem length required on discerning export markets. The research has shown that pruning back to 1 m in spring is essential to stimulate required stem length.

The next stage of the project is registration of these selections for Plant Breeders Rights. Subsequent release to the industry will furnish Australian cut stem growers with a strong competitive advantage.