Introduction

The Australian wildflower industry has the opportunity to expand its export markets by increasing the quality and variety of flowers marketed, according to a new research report.

And by diversifying its production base the industry will be able to extend its marketing season.

But to achieve these goals, the report says, the industry must develop methods for bringing new species into cultivation.

Bringing these new species into cultivation would also help the industry secure its access to these plants as many of them are bush-picked on Crown lands and access to these areas is increasingly being restricted.

Background

The Western Australian cutflower industry dominates the Australian industry, accounting for around 68 per cent of Australia’s total exports.

Western Australian exports have been growing at 10 per cent year between 1982 and 1996, reached $16.8 million in 1996.

This growth has been achieved mainly through bringing Waxflower, Banksia, and kangaroo paws into cultivation. Together, these species account for between 70 and 80 per cent of the industry’s exports.

However, to ensure the continued growth of the cutflower export industry, the industry must increase the variety and quality of cutflowers offered on export markets.

To address this issue the Rural Industries Research and Development Corporation commissioned the Western Australian Department of Agriculture to identify new native species which would be suitable for cultivation.

The research was conducted by Dr K A Seaton and Mr M G Webb from the Department’s Plant Research and Development Services’ division.

The aim of the research was to find new flowers which would provide a range of flowers that could be marketed over an extended period.

Following discussions with industry, more than 200 native species were identified as having export potential. Of this 200, five species were selected for study.

The five chosen species were:

• Native temp or flame bush (Adenanthos cuneatus)
• Blue smoke bush (Conospermum eatoniae)
• Swan River myrtle (Hypocalymma robustum)
• Qualup bell (Pimelea physodes) and
• emu bush (Podocarpus drouynianus)

The majority of these flowers are presently bush picked and, generally, stem production and flower quality is below optimum.

Given this and that access to crown land for picking wildflowers is being increasingly restricted there is an urgent need to develop methods to bring many of these species into cultivation, the report says.

The report also says that through cultivation, demand for some of these new crops will increase by being able to produce a more regular supply of high quality flowers or foliage.

The selection of other forms with variable flower and foliage colour, different harvest periods and increased stem length and yield should assist in increasing market share and potential demand.

Objectives

The research project’s key objective was to increase the diversity of cutflower exports and provide for the continued expansion of the native Australian cutflower industry by developing procedures for:

• maximising marketable stem production, and
• maintaining post-harvest stem quality.

Recommendations and findings

The research project found that Qualup bell and blue smoke bush have the potential to enter the cut flower market and to be used as filler or feature filler flower crops if the necessary cultural and management requirements are followed.

However, while it is possible to propagate Qualup bell and blue smoke bush, further work is required on these species to make this economic.

The authors concluded that emu bush would be unlikely to provide a positive return in the medium term from row crop cultivation.

The research found that to ensure the plants survived the hotter summer months, the flowers should be planted in early spring. This would allow them to develop an adequate root system ahead of the higher temperatures.

And to maximise establishment it was essential to ensure that the plants were not root bound when planted out. In line with this finding, the research found that holding plants until they were bigger or potting them on did not improve survival and tended to slow growth when planted in the field.

This was especially true for blue smoke bush, which the report says, should be planted out as soon as they are established in tubes and have been hardened off.

Mulching and drip irrigation were found to be critical in maintaining adequate soil moisture levels through summer under warm to hot conditions on sandy soils.

Leaf analysis showed that consistent plant growth was achieved for plants which had nutrient levels equal to or better than nutrient levels of bush grown plants.

Blue smoke bush was found to be a quick producer which responded to cultivation and although Qualup bell was slow to produce in the first year, it had vigorous growth in subsequent years.

The research also found that these plants did not appear to be great carriers of benign or damaging insects and that normal post-harvest disinfestation methods, such as dipping or aerosol treatment, were effective in dealing with insects.

Care was needed in the post-harvesting of both flowers to prevent crushing.

The study demonstrated that the successful cultivation of these new wildflowers depended on their response to the climatic and cultural conditions of the site selected.

The report also noted that there were advantages in growing wildflowers in several locations to spread flowering times. The research showed that the length of the picking season for Qualup bell could almost be doubled by growing plants at different latitudes.

Methodology

The research focused on determining which factors limited the commercial cultivation of the selected species. This involved:

• reviewing the state of knowledge for each species by surveying the literature and consulting widely with bush pickers, growers, exporters and nurserymen to determine uses and demand for each species;
• surveying natural populations to determine the habit and ecological characteristics of each species and identify superior selections;
• determining the best time and method for propagation, by investigating the type of propagule and hormone treatment, root striking media, the type and timing of taking cuttings and propagation environment;
• determining the appropriate time and method of plant establishment;
• determining the optimum fertiliser, irrigation and pruning requirements for maximising productivity and stem length;
• determining the correct post-harvest handling procedures to maximise vase life and ensure the delivery of high quality product onto export markets, and
• developing production and management protocols for each species and distributing this information to industry.

The research was conducted at the Medina Research Station, south of Perth, on two properties near Perth and at the Mr Barker Research Station, which is some 350 km south east of Perth. The post-harvest trials were conducted at Agriculture Western Australian and trial shipments were sent to Japan using commercial export facilities.

Conclusion:

The report concluded that the key factors affecting the successful introduction of new wildflowers and being able to maximise production were:

• establishing plants in disease and weed free sites;
• using mulch;
• protecting young plants by using windbreaks;
• planting young tube stock that has been hardened off early;
• planting in spring, and
• using drip irrigation and injecting fertilisers through the irrigation system.

The research also found that hard pruning was necessary in the first year to encourage good branch structure and stem production in the next year.