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SHAPING THE FUTURE
FOR THE TEA TREE INDUSTRY
A research update on the tea tree industry from RIRDC distributed to researchers, industry, government, farmers, libraries and consultants. Contributions are welcome. Contact Roslyn Prinsley, RIRDC General Manager Research on Phone 026272 4033, Email: roslynp@rirdc.gov.au
In this issue:
Tea tree growers will benefit from the release of new improved tea tree seed this year that could increase the yield of oil by 30% on varieties grown in the early nineties.
This will be the fourth release of seed from the Tea Tree Breeding Project with 7kg of seed already released over the past three years, enough to plant over 1000 hectares of tea tree.
NSWAgriculture plant breeder Gary Baker says that the aim of the project is to produce improved seed lines with yields up to 17% higher than the existing industry selections by 1997, 30% higher by 1999 and 60% higher by 2003.
Low cineole clonal seed orchard
"Based on work in our seed orchard, we are well on the way to achieving the 60% improvement in yield by 2003 and this 2000 release should produce plants with a 30% higher yield than those plants we began with."
"Seed available this year will again be from the best provenance as well as the improved seed from our seedling seed orchard."
Tea tree clones
A study on the use of cloning (mass vegetative propagation) for tea tree production has shown that it is a very effective way of maximising "Based on work in our seed orchard, we are well on the way to achieving the 60% improvement in yield by 2003 and this 2000 release should produce plants with a 30% higher yield than those plants we began with."
"Seed available this year will again be from the best provenance as well as the improved seed from our seedling seed orchard."
Tea tree clones
A study on the use of cloning (mass vegetative propagation) for tea tree production has shown that it is a very effective way of maximising the capture of genetic gain made through traditional breeding methods.
The CSIRO’s John Doran says cloning is a quick way to access and maintain genetic gain and has been long practiced in horticulture and more recently for a few forest trees.
The main stumbling block to wider use of clones in the tea tree industry is cost. There are also some concerns about the development of a stable root system by the cloned seedlings.
A CSIRO study (Short Report No. 73) showed that cloning could result in a 100% to 200% increase in tea tree oil yields.
An economic analysis showed that if the tea tree oil price drops below $25 then the large gains in yield, which could be delivered by clonal plantations, would be needed for profitable production.
"If nurseries can produce rooted cuttings of M. alternifolia at 37 cents each, as done in northern Queensland, then growers would be well advised to consider the clonal option carefully," says John Doran.
Contact: Gary Baker,
Wollongbar Agricultural
Institute,
Ph (02) 6626 1224,
Email gary.baker@agric.nsw.gov.au
Hopeful results for control of ‘golden staph’ infections
Research underway on the potential for using tea tree oil to reduce the risk of ‘golden staph’ infections has come up with some promising results.
Researcher Meredith Caelli has just recruited the 90th person to be part of a trial testing tea tree oil to treat carriers of multi-drug resistant Staphylococcus aureas (MRSA or ‘golden staph’) at Westmead Hospital in Sydney and so reduce the risk of potentially serious infection.
‘Golden staph’ is a major infection control problem in Australian hospitals. There are a limited number of antibiotics effective against this potentially fatal organism. Infected patients require large doses of expensive high-class antibiotics which have significant side effects. Their length of stay is extended and they often carry the organism for life.
Natural alternative
The application of a topical antimi-crobial body wash solution is currently recommended for golden staph carriers, however there are varied success rates and increasing resistance to topical therapies.
Therapies using tea tree oil are seen as a possible safe natural alternative for treatment of golden staph.
Half of the patients in the Westmead study are being treated with tea tree oil nasal ointment and body wash and the other half routinely with triclosan body wash and Bactoban nasal ointment.
Faster clearing
Meredith reports that a preliminary analysis of the outcomes for the first 77 participants showed that fewer of the patients treated with tea tree oil remained colonised with MRSA (36%) compared to those who were given the routine treatment (47%).
"The other positive thing to report is the tea tree products that have been specially designed for the study have to date caused no adverse effects either topically or nasally to the patients."
This research is being generously supported by Australian Bodycare Pty Ltd.
Contact: Professor Tom
Riley,
University of Western
Australia
Department of Microbiology,
Ph (08) 9346 1896
Email triley@cyllene.uwa.edu.au
Apilot study on the use of tea tree oil to treat cold sores caused by the herpes simplex virus 1 has come up with some promising results.
The small study showed that people who used a gel containing 6% tea tree oil up to 5 times a day had faster crusting (3.7 versus 4.6 days), and healing (10 versus 12 days) of the sores.
Faster healing
Researcher Christine Carson says the improved rate of healing with tea tree oil is comparable to that achieved by Acyclovir, another product widely used for the treatment of cold sores.
Analysis of the virus carried by the patients in the pilot study is now underway to determine the effect of the tea tree oil on the viral infection.
Further studies in the lab have shown that concentrations of tea tree oil in the range of 1–2% have been shown to inactivate herpes simplex viruses rendering them incapable of infecting host cells.
A larger study, funded by RIRDC is now underway to verify the results of the laboratory studies.
It is planned that over 100 partici-pants will be involved in this study.
Treatment with tea tree oil will be compared to the standard topical treatment acyclovir.
Natural alternative
There is a concern about resistance to this commonly used product, and it has in fact not been licensed as an over the counter treatment in some parts of the world for cold sores because of this concern. It is also a very expensive treatment.
Contact: Christine Carson
or
A/Professor Tom Riley,
University of Western
Australia
Department of Microbiology,
Ph (08) 9346 1896, Email:
ccarson@cyllene.uwa.edu.au or triley@cyllene.uwa.edu.au
Tea tree oil effective against fungal infections
Laboratory tests have shown tea tree oil to be a very effective way of controlling and killing some types of fungi.
Researcher Kate Hammer of the University of Western Australia reports that the growth of fungi including Candida (cause oral and vaginal thrush), Cryptococcus, Rhodotorula, Saccharomyces and Trichospron were all inhibited by tea tree oil in the range of 0.06% to 0.5%, and were killed at concentrations of 0.06% to 1.0%.
Similarly, results for the dermatophytes (that cause fungal infections such as tinea, athletes foot, ringworm and nail infection), including the genera Epidermophyton, Microsporum and Trichophyton were inhibited in the range of 0.004% to 0.06% and killed in the range of <0.03% to 1.0% tea tree oil.
Limited treatments
Kate says the next step is to carry out good, randomised successful trials on humans to further test these results.
"The main reason for doing this research is that there are a very limited number of antifungal treatments available and there is a concern about resistance devel-opment in these products."
Contact: Kate Hammer or
A/Professor Tom Riley,
University of Western
Australia
Department of Miocrobiology,
Ph (08) 9346 1896, Email
khammer@cyllene.uwa.edu.au
or
triley@cyllene.uwa.edu.au
The presence of tea tree
oil in the agar slowed or stopped the growth of the fungi belonging to
a group of organisms called the Dermatophytes that cause skin infections
such as ringworm and tinea. Growth of dermatophytes on Saboraud’s dextrose
agar containing tea tree oil (% v/v) (left to right; 0% control, 0.03%,
0.06%, 0.12%), after incubation for 14d at 30°C.
| Epidermo-phyton Floccosum |  |
| Microsporum canis |  |
| Microsporum gypseum |  |
| Trichophyton
mentagro-phytes
var interdigitale |
 |
| Trichophyton rubrum |  |
More information regarding
the tea tree work conducted at the University of Western Australia can
be seen at
http://server.microbiol.uwa.e
du.au/~Tea_Tree/home.htm
For information on The Tea Tree Oil Program and to review RIRDC Tea Tree publications see http://www.rirdc.gov.au
Anti-inflammatory effects of tea tree oil looks promising
"The water soluble components of tea tree oil reduced the production of inflammatory mediators," said Dr Hart. "We found evidence that terpinen-4-ol, which constitutes approximately 40% of tea tree oil, was responsible in large part for these regulatory effects."
This study supports the selection of superior trees for propagation after identification of productive clones which produce tea tree oil high in terpinen-4-ol. Alternatively, an aqueous extract of tea tree oil which produces a fraction very high in terpinen-4-ol, may be used as an anti-inflammatory agent.
Skin deep
"There was also some evidence that tea tree oil may potentially control inflammatory responses to foreign antigens in the skin. With application of tea tree oil to skin,
Testing of the anti-inflam-matory effects of tea tree oil on humans and mice will soon be underway to further inves-tigate the potential of tea tree oil as a safe, topical anti-inflammatory therapeutic agent.
Researchers Professor John Finlay-Jones and Dr Prue Hart of Flinders University SA have already had some very promising results with the application of tea tree oil on various human cells in laboratory experiments.
The research is being sponsored by Thursday Plantations.
Inflammatory responses to bacteria, insect bites and allergens such as pollen involve the release of a range of chemicals known as mediators.
This research looked at the effects of tea tree oil on the production of mediators of inflammation by human white blood cells. toxicity would be limited and the anti-inflammatory water-soluble components may penetrate into the vascularised dermis (skin) and regulate inflammatory processes.
"We are uncertain of the concentrations of terpinen-4-ol that may penetrate beyond the stratum corneum layer of skin. So the potential of tea tree oil as a topical anti-inflammatory agent will only be confirmed by documentation of a reduction of inflammatory cells and mediators in skin after application of tea tree oil," she said.
Preliminary work to establish mice and human trials of tea tree oil as an anti-inflammatory agent is now underway.
Contact: Dr Prue
Hart, Flinders
University of South Australia,
Ph (08) 8204 5404,
Email Prue.Hart@flinders.edu.au
Fertiliser study gives surprising results
Asurvey of fertiliser use and tea tree oil yields has surprisingly found little or no correlation between fertiliser inputs, soil fertility rating and oil yield.
Researcher James Drinnan says this was unexpected given the large amount of nutrients that are removed at each harvest.
"Possibly, in the early years of a plantation the trees can obtain sufficient nutrients from soil reserves. However, it is important that the plant and soil nutrient status and yield trends be closely monitored to detect when soil reserves are running down."
The survey of 60 growers from northern NSW and North Queensland gathered information on fertiliser practices, leaf and soil nutrient levels, biomass production, oil concentrations and yields, soil type and fertility, leaf drop, irrigation levels and plant size at harvest.
A well fertilised block of tea tree
Inadequate nutrients
James says growers are generally providing inadequate nutrients to replace those lost through harvesting which could lead to a gradual loss of soil nutrients.
"I believe a conservative approach and one that would apply in the long term and be sustainable would be to replace those lost through harvesting which could lead to a gradual loss of soil nutrients.
"I believe a conservative approach and one that would apply in the long term and be sustainable would be to use sufficient fertiliser to replace the nutrients removed at harvest.
"In Queensland this would be around 180 kg N, 20 kg P and 220 kg K/ha/year and in NSW 130 kg N, 15 kg P and 158 kg K/ha/year. The fertiliser should be applied regularly in small amounts throughout the growing season in approximately the following proportions.
Table 1. Distribution
of fertiliser applications during the growing season
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Contact: James
Drinnan,
Queensland Department
of Primary
Industries Mareeba,
Ph (07) 4092 8555,
Email drinnanje@dpi.qld.gov.au
Looking ahead
The ATTIA / RIRDC Tea Tree Oil program is currently finalising negotiations with A/Professor Tom Riley and his team at the University of Western Australia to contract four new projects for the financial period 2000 / 2001.
These will be supported by a substantial financial contribution to the program from Australian Bodycare Pty Ltd. The program will match most of the funds provided by Australian Bodycare. Steen Jorsal of Australian Bodycare has been very generous to the industry in providing funds for research to be conducted in the public domain at a time when the industry is struggling to provide a voluntary levy. The four projects include:
Antimicrobial activity of tea tree oil against oral microorganisms, a project which aims to increase the acceptability of tea tree oil as a naturally occurring anti-microbial both nationally and internationally by publishing scientific data. The data will demonstrate the susceptibility of a wide range of oral microor-ganisms to tea tree oil. This will assist in determining the suitability and placement of tea tree oil in oral health care markets.
Clinical efficacy of tea tree oil for treating cold sores, a project which aims to increase national and international acceptance of tea tree oil as an anti-viral therapy for the treatment of cold sores. This project will build on cold sore study reported earlier in this research update.
The antifungal activity of tea tree oil in vitro, This project will generate in vitro susceptibility data for a wide range of yeasts and dermatophytes, building on the findings of previous antifungal studies as reported earlier in the research update. It will also investigate the mechanism of action of tea tree oil against fungi.
Multi-centre randomised clinical trials of tea tree oil products for vaginal infections Vaginitis is the most common gynaecological problem encoun-tered by physicians providing primary care to women, being responsible for 10 million GP visits in the US each year.
If tea tree oil products are demonstrated to be an effective OTC cure then a large new market will be opened up to the industry. This project aims to demonstrate that tea tree oil products are safe and efficacious for the treatment of two vaginal infections (candida vaginitis and bacterial vaginosis) using randomised clinical trials, following a pilot study, to show efficacy.
This project consists of two multi-centre randomised clinical trials, one for bacterial vaginosis and one for candidiasis. The studies will be carried out in Perth (WA), Stockholm (Sweden) and Swansea (Wales). In both studies tea tree oil will be compared to other recommended therapies.
A new project, The anti-inflam-matory and anti-itch properties of tea tree oil is also currently being negotiated with Professor John Finlay-Jones from Flinders University in South Australia. This project is a continuation of existing research described elsewhere in this newsletter which has been jointly supported by Thursday Plantation and the RIRDC / ATTIA program. RIRDC is currently negotiating a new project with Thursday Plantation for the 2000 / 2001 financial year. Thursday Plantation has been very generous to the industry in providing funds for research to be conducted in the public domain at a time when the industry is struggling to provide a voluntary levy.
The new project will continue to assess the anti-inflammatory activity of tea tree oil and its components. The effect of tea tree oil on selected inflammatory responses in skin will be evaluated. This will be coupled with a study of the ability of tea tree oil to affect the responses of mast cells, which are central to the initiation of immediate hypersensitivity’s and itch.
Contact: Roslyn
Prinsley,
Research Manager,
Tea Tree Oil Program
Ph (02) 6272 4033,
Email roslyn.p@rirdc.gov.au
Uing Clones to Establish
Tea Tree Plantations
Cloning is the quick way
to access and maintain genetic gain. However, biological constraints, such
as the plant materials ability to give high multiplication rates, and additional
costs associated with vegetative propagation compared to seedling stock
have limited the usefulness of cloning for most forest trees.
2000. Short Report 73, free
Skin Sensitivity Testing
for Tea Tree Oil
by J.E. Greig
Provides safety information
on the use of tea tree oil and adds strength to the argument for registration
of the oil with national regulatory bodies. Describes work that deter-mines
the prevalence of immediate and delayed sensitivity to tea tree oil, including
both irritant and allergic skin reactions following extended exposure.
1999. 54pp, Pub. No.
99/76, $15
Antimicrobial Activity
of Tea Tree Oil
by C. Carson & T.
Riley
Describes work which confirms
and characterises the antimicrobial activity of the oil, and therefore
may assist in the accessing of inter-national markets and the regis-tration
of the oil with national regulatory bodies 1998. 63pp, Pub. No. 99/070,
$10
Development of the North
Queensland Tea Tree Industry
by J. Drinnan
Demonstrates how the tea
tree oil industry can be further developed in North Queensland, and shows
the potential of production in other areas of Australia. Also outlines
Australian Tea Tree Oil
– Plant Nutritional Survey
by J. Drinnan
This report looks at the
current nutritional status and corresponding yields and fertiliser practices
of tea tree grown in Australia (North Queensland and New South Wales).
Some ballpark optimum fertiliser recommendations and leaf nutrient levels
for tea tree are made based on nutrient removal work. 2000, 36pp, Pub.
No. 00/107, $10
Tea Tree Oil Completed
Projects and Research in Progress to June 2000
The following report is
a hardcopy extract covering Sub-program 2.7. It contains all entries from
continuing and completed Tea Tree Oil research projects funded by RIRDC.
This program aims to support the continued development of a profitable
Australian tea tree oil industry in Australia. 2000, 25pp, Pub. No.
00/86, Free guidelines for scheduling irrigation to maximise oil yield
and quality. 1998. 40pp, Pub. No. 98/006, $10
Towards Non-Chemical Control
of Weeds in Tea Trees
by B. Sutton, J. Virtue
& G. Murtagh
Examines a range of weed
control strategies to minimise weed compe-tition. 1997. 98pp, Pub. No.
97/063, $15
Controlling Insect Pests
in Tea Tree
by A. Campbell &
C. Maddo
Outlines an effective and
sustainable pest management strategy to guard against severe outbreaks
of the pyrgo beetle. 1997. 64pp, Pub. No. 97/062, $10
Why Cineole is Not Detrimental
to Tea Tree Oil
by I. Southwell, J. Markham
& C. Mann
Describes the degree of
skin irritancy caused by tea tree oil with different concentrations of
cineole.
1997. 128pp, Pub. No. 97/054, $15
Improving Tea Tree Yield
& Quality Through Breeding & Selection
by J. Doran, et al.
Describes the successful
devel-opment of a breeding strategy for high yielding varieties of Melaleuca
alternifolia.
1997. 52pp, Pub. No.
97/053, $10
R&D Plan for the Tea
Tree Oil Program 1998-2003
by RIRDC
free
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Last updated: 16 August 200
Copyright © RIRDC
http://www.rirdc.gov.au/pub/newsletters/tea-tree-oil/august00.html
