Project Title

Smoke stimulated germination of Australian species for horticulture

Objectives

• Refine smoke stimulation of target species and devise methods for smoke stimulated germination of large seeded and other species which have not responded to current smoke procedures.
• Improve benefits of smoke for enhancing germination response of marginally germinable species.
• Determine optimal smoke concentration or smoke fumigation exposure times for eliciting germination responses.
• Refine smoke generation apparatus and methods for smoke application i.e. granulation, liquid application.
• Develop smoke application procedures for stimulation of germination in field and evaluate the best methods for subsequent establishment of plants.
• Develop a protocol for use of smoke germination technology in nursery propagation and possibly direct sowing of economically significant species.

Propagation of many commercially significant native species is limited to sporadic or erratic seed germination or costly in vitro procedures. For at least 200 species the only production methods for cutflower and foliage is collection from native stands. New methods developed by the applicant provides major new directions and stimulus for the development of large scale, seed-based propagation for native species once thought difficult or impossible to germinate. Smoke and smoke products have now been implicated as a key agent in the promotion of germination and in some instance growth of seedlings in over 400 species of previously highly recalcitrant, native Western Australian plants.

Research

A comprehensive range of 400 species were variously tested for ex situ (greenhouse) and in situ (field germination) response to smoke and the influence of smoke concentration on germination performance. Smoke was investigated in the aerosol form, as dissolved smoke in water and by direct application to seeds.

Outcomes

Over 400 native species of seeds respond to smoke treatment with a range of positive germination responses including improved rates of germination to absolute germination.

Research has found that smoke responsive native species occur throughout temperate southern and arid Australia. Species from habitats which are not obviously fire-prone (e.g. dunal communities) germinate well following application of smoke indicating that it is not possible to accurately predict the smoke responsiveness of species based on habitat requirements for fire. Whereas heat and ash are of limited value for breaking dormancy, in many species, smoke promotes:

• Germination of species which are difficult to germinate by conventional means.
• Enables more uniform germination.
• Promotes earlier germination.
• Often results in seedlings which are more robust.

Trees, shrubs, herbs and annuals respond to smoke-treatment. There is no clear distinction in the relationship between taxonomic groups and the requirements for smoke. Proteaceae, Myrtaceae and most other dominant Australian plant families contain smoke responsive species. Some experimentation is essential to determine if an untested species might be smoke responsive. Do not rely only on evidence from related species to predict if a species is smoke responsive.

For regions in southern Australia, smoke is best applied from autumn to early winter. For tropical or arid zones species, some experimentation may be required to determine the best time to apply smoke. As a general rule, sowing and smoking should be done when germination is most likely to occur in nature.

Smoke is highly water soluble and excessive watering of seed trays can leach the active agents from the soil before seed dormancy has been broken.

Liquid (smoke water) or aerosol smoke are the two most common methods for applying smoke to soil or seeds. Seeds can be smoked directly in a smoke tent or alternatively soaked in a dilute solution of smoke water (see below for method) for 6-24 hours. Treated seeds are then dried and sown when required. Alternatively, trays containing sown seeds can be smoked for 60 minutes and then carefully watered for the first 6-10 days to ensure adequate penetration of the smoke chemicals.

Broadcast seed which has been smoke treated is an effective way to germinate a wide variety of species. Smoke treated seeds used in broadcasting often germinate better including seeds of species which do not normally require smoke for germination under nursery conditions (eg. Eucalypts, Banksias).

If a seed bank is present in soil then good germination is possible following the addition of smoke either using aerosol smoke (area for treatment is limited using this method) or smoke water (using automated sprayers).

RIRDC Project No: KPW-1A

Researcher: Dr. Kingsley Dixon

Organisation: Kings Park & Botanic Garden, WEST PERTH WA 6005

Contacts: Phone: (08) 9480 3637  Fax: (08) 9480 3614

Development of fumigation techniques for postharvest disinfestation of Australian wildflowers for export

Objectives

• To develop effective postharvest fumigation techniques as alternatives to methyl bromide for disinfesting Australian wildflowers destined for export. To ensure that treatments control insects without damaging flowers.

Exports of cut flowers and foliage from Australia are expanding, wildflowers comprise over 90% of the market, worth $A30.1 million in 1995/96. Detection of live insects in consignments of flowers in importing countries has resulted in considerable losses. Methyl bromide is used to control such problem pests but it reduces vase life of many flowers. Also it has been identified as a major ozone depleting chemical and its use is being restricted. Consequently alternative fumigant treatments need to be found.

Research

Wildflowers were screened for effect on flower quality and vase life against potential replacement fumigants carbon disulphide, carbonyl sulphide, cyanogen, ethyl formate, hydrogen cyanide, metham sodium and phosphine, with methyl bromide being used for comparison. Phosphine was the least damaging of these fumigants and was selected for testing in commercial fumigation chambers. Application of the cylinder gas formulation Phosfume® (phosphine and C0₂)to give a concentration of 1 am-3 of phosphine controlled several problem pests when applied for 16 hours at 15°C or above. Application of the aerosol Pestigas®. (pyrethrum and CO₂) followed 10 minutes later by Phosfume® improved control of insect eggs.

Outcomes

A new technique for fumigating cut flowers has been developed using the phosphine formulation Phosfume®. The manufacturer, BOC Gases, has applied to the National Registration Authority for extension of registration to include fumigation of cut flowers. A grower in Victoria has successfully used the new technique on export consignments of wildflowers to Japan.

Implications

The low phytotoxicity of Phosfume® and its effectiveness against pests makes it attractive as an alternative to methyl bromide for fumigation of cut flowers. It provides an alternative to use of insecticidal dips which can result in undesirable residues on flowers causing handling problems. Limitations are that the time required for fumigation is 1516 hours at 15°C or above.

Publications

Muhunthan M., Williams P. and Thorpe G. R. (1996). Phosphine-an alternative to methyl bromide for postharvest disinfestation of wildflowers. Agricultural Engineering Australia, 25: (3) 26.

Muhunthan M., Williams P. and Thorpe G. R. (1997). Phosphine-an alternative to methyl bromide for postharvest disinfestation of wildflowers in containers. Agricultural Engineering Australia, 26: (2) 29-33.

Weller G. L., van S. Graver J. E. and Damcevski K. A. (1996). Replacements for methyl bromide in quarantine treatments of cut flowers and ornamentals. Aust. P.harvest.Hort. Conf: Melb. 1995, 367-372.

Weller G. L. and van S. Graver J. E. (1997). Sorption of fumigants by cut flowers. Proceedings Controlled Atmosphere and Fumigation in Stored Products, Nicosia, Cyprus, April 1996, (in press).

Williams P. (1996). Alternatives to methyl bromide for fumigation of wildflowers. Aust. P.harvest.Hort. ConJ: Melb. 1995, 373-376. Williams P. and Muhunthan M. (1997). Fumigants for postharvest control of insect pests of cut flowers. Acta Hort., (in press).

Williams P. (1997). Postharvest disinfestation of western flower thrips. Under Control, 2: 17-18.

RIRDC Project No. DAV-90A

Researchers: P.Williams and M.Muhunthan,

Organisation: Institute for Horticultural Development,  Private Bag 15, SOUTH EASTERN MAIL CENTRE VIC. 3176.

Contacts: Phone: (03) 9210 9222. Fax (03) 9800 3521.  E-mail: williamsp@knoxy.agvic.gov.au

Evaluation and Selection of Chamelaucium species for Floriculture. Evaluation of Chamelaucium uncinatum for Floriculture.

Background

Geraldton wax forms the base of the Australian native flower industry, both here and overseas. This industry depends on a few cultivars which do not provide continuity of supply through the southern hemisphere production season. Our purpose was to discover the natural diversity, to record this for future industry needs and to identify any new clones which may fill gaps in the market. Furthermore we wished to establish a quality control system to ensure that any released material would meet minimum industry standards and requirements in productivity and postharvest performance.

Outcomes

As a result of these projects, 63 populations were located and sampled both using a random sampling method and a visual sampling based on visual, horticultural attributes. Three hundred and fifty (350) clones from forty five (45) populations were established in cultivation in replicated plots and evaluated for early productivity, stem characteristics and postharvest life. Forty five (45) of these were selected for further testing at twelve (12) sites in Australia and three sites overseas (one in Israel, and two in California). One clone has been released to industry (Jurien Brook) and another two are under consideration for early release in Australia and overseas. Considerable variation was observed in habit, habitat, vigour and postharvest life (varied from a few days to greater than 30 days). These clones are now serving as the basis of a deliberate breeding program. The results of these projects have been widely publicised in industry through field days, workshops, seminars and industry publications

RIRDC Project No: UWA-20A

Researcher: Professor John Considine

Organisation: Faculty of Agriculture, The University of Western Australia, NEDLANDS WA 6907

Contacts: Phone: (08) 9380 1783  Fax: (08) 9380 1108  E-mail: consid@cyllene.uwa.edu.au

The propagation and horticultural development of Caustis blakei for the export market.

Objectives

• To study the field factors limiting fruit set and hence propagation;
• To develop methods of mass propagation of C. blakei;
• To establish a protocol for the commercial production of rooted plants of C. blakei;
• To examine the growth and development of nursery-grown plants of C. blakei;
• To identify and multiply superior genotypes of C. blakei;
• To provide information to the industry on agronomic and post-harvest requirements of C. blakei.

Caustis blakei is an attractive perennial sedge which is used as cut foliage in the floricultural industry. At present, all material sold is harvested from natural populations which does not guarantee quality and continuity of supply to the market. The export demand for this product is high but development of the industry is limited by our inability to produce C. blakei commercially. The commercial production of this species would provide more high quality product for the export market, provide new crops for nurseries and growers and protect natural stands, some of which are threatened.

Research

Three areas were investigated in this study:

1. Fruit development in the field;
2. In vitro propagation, multiplication and root initiation; and
3. Growth of in vitro-propagated plants in a containerised system.

The fruit/flower ration of C. blakei is very low and studies indicate that this may be related to limitation of resources, particularly rainfall and possibly soil nutrients.

Explants of C. blakei were successfully introduced into aseptic culture and a mean maximum multiplication rate of approximately four times was achieved every four weeks on media with a range of cytokinin concentrations. Roots were initiated on health plantlets on a medium free of plant growth regulators. Superior genotypes were selected and were found to differ in their multiplication response with rapid-response and slow-response types identified. These types appear to be morphologically different.

Rooted plants were transferred to the nursery with a success rate of approximately 95%. Growth and development of C. blakei in containers supplied with nutrients and water indicate that plants may be harvested after 18 months compared to eight to ten years for plants growing in natural stands. Further research is required to identify the role of mycorrhizal associations in nursery-grown plants of C. blakei.

Implications

The foliage sector of the export floriculture market is large with a current projected value of AUD 200 million. Caustis blakei is a versatile cut foliage with a long vase life but export of stems if limited because this species has been difficult to propagate. This study has established the protocol for commercial production of C. blakei. The selection process had identified 15 superior genotypes, some of which are suitable for the cut foliage market and others for the potted plant market. Subject to further testing this will provide the industry with new floricultural and nursery crops.

RIRDC Project No: UQ-29A

Researcher: Dr. Margaret E. Johnston

Organisation: Horticulture Section, School of Land and Food,  The University of Queensland Gatton College, Gatton College, LAWES QLD 4345

Contacts: Phone: (07) 5460 1240  Fax: (07) 5460 1455

Flannel flower (actinotus helianthi) as a cut flower crop

Objectives

• To establish the flannel flower as a horticultural species, particularly for cut flower production and export by assessing the propagation and cultivation requirements.

Flannel flowers (Actinotus helianthi) were recognised and used as a cut flower for many years although all stems had been bush harvested until about 1995. They can be utilised as focal fillers and complement, in arrangements, other Australian species such as the feature cut flowers waratahs and banksias. There has been considerable interest in this species overseas, particularly from Asia. The limiting factor in establishing flannel flowers as an export crop has been the lack of planting material available commercially. Propagators have attempted to grow flannel flowers with limited success and therefore the development of propagation techniques was the most important objective in the research program.

Research

Propagation by seed, cuttings and tissue culture has been investigated and suitable methods have been established. Other aspects of flannel flower cropping investigated, include plant spacing, early pruning and nutritional requirements. Concurrently, extensive collection of flannel flowers throughout the area of natural distribution has resulted in the selection and development of long stemmed varieties suitable for the cut flower market.

Outcomes

Flannel flowers are being cultivated and exported in limited numbers by an increasing number of growers. Selected flannel flower varieties will be tested on a national scale during 1998-1999 with the aim of releasing selections for commercial use during 2000.

Implications

The outcomes of this work are already impacting on the commercial cut flower industry as well as plant propagators and nurseries. We estimate that the number of flannel flowers in cultivation has at least quadrupled during the last three years and that this number is increasing rapidly. As cultivars and seed lines are identified, the associated agronomic optimisation and export marketing should be developed and adopted. It is then likely that the flannel flower will become a staple cut flower crop providing reliable export earnings. Throughout 1996-1997 a commercial micropropagation laboratory was involved in some trials to assess the suitability of flannel flowers in tissue culture. This proved very successful and steps are under way to establish a partnership for the commercial release of the other varieties.

Publications

Bullock, S., Summerell, B.A. & von Richter, L. 1998. Vascular wilt of flannel flower caused by Fusarium oxysporum. Australasian Plant Pathology (in press).

Offord C.A. & Tyler J.L. 1996 Actinolus helianthi (flannel flower) Family Apiaceae (Umbelliferae). In: Native Australian plants horticulture and uses. Eds K. A. Johnson and M. Burchett UNSW Press pp. 212- 217.

von Richter L. & Offord C. 1996 Flannel flowers as cut flowers. IV National Workshop for Australian Native Flowers University of Western Australia, Perth 28-30 September 1996 pp. 253-258.

von Richter L. & Offord C. 1997a. Propagation of flannel flowers (Actinotus helianthi). Combined Proceedings International Plant Propagators’ Society 47: 28-30 (in press).

von Richter L. & Offord C. 1997b. Flannel flowers put to the test. Australian Horticulture 95 (8): 35-37.

von Richter L. & Offord. 1997c. Flannel flowers. In: Rural Industries Research and Development Corporation Compendium Handbook for farmers and investors. Pp. 505-511 (in press).

von Richter L. & Offord C. 1997d. Flannel flowers go national. Flower Link 15 (169): 24-27.

RIRDC Project No: RBG-1A

Researcher: Lotte von Richter and Catherine Offord

Organisation: Mount Annan Botanic Garden, Mount Annan Drive,

Contacts: Phone: (02) 4648 2477    Fax: (02) 4648 2465

E-mail: Lotta_von_Richter@rbgsyd.gov.au     Cathy_Offord@rbgsyd.gov.au

Acacia cut flower and foliage production manual

Objectives

• Our aim is to provide practical information on markets, production, handling and economics.

The manual was produced as part of RIRDC project No. DAV-91A "Developing native Acacia species as an export cut flower crop". Acacia is a significant spring flower crop in Europe, where it's sold as Mimosa, and it's also grown and sold in USA and Japan. Australia is home to hundreds of Acacia species yet it is hardly used on the local market or for export.

Outcomes

Our market research indicates markets for our Acacia during Japanese autumn, winter and spring and there may also be markets in other northern countries in their autumn and winter. The main contents of the manual are:

• Background information on Acacias, their flowers and the control of flowering.
• Market research, particularly for Japan.
• Selecting species to grow and details of promising species.
• Propagation and cultivation, including information from the French industry.
• Postharvest treatments which are critical to quality and life.
• Export issues, procedures and documentation.
• Economics of Acacia and similar crops.

Implications

We suggest growers explore their likely markets and then plant several species to determine what grows well on a property and what sells well. It is important that good forms of Acacia species, particularly those with long vase lives after transport, are selected and propagated. Future research should also investigate the effects of growing conditions on vase life.

RIRDC Project No: DAV-91A
 
 

Researchers: Organisation:             Contacts:  Phone: Fax:     Email:

Francha Horlock and John Faragher Institute for Horticultural Development Knoxfield, Agriculture Victoria, Private Bag 15, SOUTH EASTERN MAIL CENTRE, Vic, 3176.   03 9210 9222 03 9800 3521 horlockf@knoxy.agvic.gov.au faragherj@knoxy.agvic.gov.au

Dr. Rod Jones National Flower Centre, Box 1, 542 Footscray Rd FOOTSCRAY, Vic, 3011       03 9258 6100 03 9687 7714 jonesr@netspace.net.au

 

       Last updated: 25 August 1998 Copyright © RIRDC http://www.rirdc.gov.au/comp98/wnf1.htm