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Rural Industries Research & Development Corporation |
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Rural Industries Research & Development Corporation |
THE FULL REPORT
This short report is a summary of RIRDC project no. DAQ-127A by Peter Beal, Lois Turnbull and Lief Forsberg. Mr Beal can be contacted at Redlands Research Station, Cleveland, QLD. Phone: (07) 3286 1488, fax: (07) 3286 3094.
There is considerable demand for rice flower as a cut flower crop both within Australia and internationally in fresh and dried form.
The emerging rice flower industry can look forward to a 12 to 16 week harvest season if further genetic improvements are realised. Also, the industry will have an enhanced potential if suitable control practices are followed and appropriate postharvest measures used, according to recent research.
Rice flower (Ozothamnus diosmifolius syn. Helichrysum diosmifolium) is a common shrubby species which grows from central Queensland to south eastern New South Wales. There are pink and white flowered types.
Until the late 1980s rice flower was cut extensively from natural stands and marketed fresh as a filler in mixed bunches or sold dried. In the early 1990s the rice flower growing industry had only a limited few weeks harvest season for commercial production.
For rice flower to develop successfully as a cultivated crop requires access to adapted varieties, efficient propagation techniques, identifying suitable cultivation practices, identifying causes of disease and their control and developing appropriate methods of post-harvest control.
Genotypes with suitable flower colours, flower form and seasons of flowering and adaptation to cultivation are needed.
The Rural Industries Research and Development Corporation commissioned the Queensland Department of Primary Industries to carry out a three-year research project to meet these objectives.
The researchers examined three clones: Cook's Tail, Redlands Sandra and Cook's Snow white. The study found that these together can provide a three to six week harvest season.
The report says that the commercial and experimental clones of rice flower held by growers and researchers have the potential, when they become available, to provide a probable 10-week harvest season in South East Queensland.
Further substantial extension of the harvest season may be possible depending on location. The report says this may particularly apply in colder climates.
In the longer term, a 12 to 16 week harvest season seems possible if further genetic improvement is realised.
Trials with Redlands Sandra conducted at Redlands Research Station, Cleveland, Queensland, resulted in yields of 30 to 43 marketable stems per plant in the first year of growth and 85 to 109 stems in the second year. The plants were grown in well drained fertile krasnozem soil with adequate irrigation and planted at intra row spacings of 0.5 to 0.75 metres.
The report says that at planting densities of 3,333 to 5,000 plants per hectare, this cultivar has the potential to yield within the vicinity of 150,000 stems in the first year and 400,000 in the second year.
It says disease control is a major issue for the industry as severe continuing losses can reduce the economic life of a crop to three years or less. Diseases and disorders affecting rice flower were identified and tentative measures for control recommended.
Improved harvesting and post-harvest handling practices also have the potential to extend the harvest season and maintain stem quality. Flowering stems in some clones can be harvested at an earlier maturity (20 to 40 per cent of capitula of full size) than presently specified. This has the potential to extend the commercial harvest of such clones by up to 10 days, much longer than the present two to five day harvest periods of some clones.
The research also found that rice flower had a vase life of at least 10 days when held in a solution of 0 per cent or 2 per cent sucrose with 50 ppm chlorine.
Laboratory trials showed that removing field heat from flower stems immediately after harvesting and holding the stems at around 2 degrees Celsius prevented foliage blackening.
The objectives of this project were to:
