Making news
GrapeGrowers & Vignerons, August 2012 11
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Woodshield posts are made of pine and coated with a 6 millimetre layer of plastic.
CCA restrictions encouragevineyard trellis post rethinkBy FRANK SMITH
THE trellis posts mostcommonly used in Australianvineyards are made of pine
treated with the chemicalpreservatives creosote or copper-chromium-arsenate to protect thetimber against termites and woodrot.
New restrictions on the use ofcopper chrome arsenate fortreating timber came into effect inJuly this year.
The Australian Pesticides andVeterinary Medicines Authorityreviewed CCA timber treatmentsbecause arsenic could be absorbedthrough the skin, swallowed orinhaled if the treated timber wasburnt.
“Following this review, CCA hasnow been declared a restrictedchemical product from 1 July”,APVMA Pesticides ProgramManager Raj Bhula said.
“This means CCA products canonly be supplied to, and used by,suitably trained personsauthorised under a relevant stateor territory law from that date.
“The APVMA does not haveregulatory powers to control theuse of CCA-treated end-products –our powers extend only to thepoint of sale of the chemical itself –and this step tightens up therequirements for industry andretailers to ensure users of such
products are well-informed of therisks and permitted uses.”
CCA can continue to be usedon timber intended for vineyardtrellises but it cannot be used onhigh-contact timber structures.This includes garden furniture,picnic tables, exterior seating,children’s play equipment, patioand domestic decking, andhandrails.
The major concern is the lackof a safe disposal method. CCAtreated posts cannot be burnt andmust be disposed off by burialwith possible contamination ofthe soil.
According to the VictorianDepartment of PrimaryIndustries, organic standardsregarding CCA treated posts vary.Under most standards, existingposts do not have to be replacedwhen a vineyard converts toorganic, but new posts must notbe treated with CCA. Creosote isacceptable to some codes butgenerally discouraged.
Alternatives are posts treatedwith Alkaline Copper Quaternary,steel or plastic options and posts
made from termite tolerant nativetimbers.
ACQ is a copper-basedpreservative treatment, whichunlike CCA does not containchromium or arsenic. It has beenapproved under at least oneAustralian organic standard.However, ACQ-treated radiatapine posts are not as strong asthose treated with CCA.
Steel and concrete posts candamage mechanical harvesters.Galvanised posts corrode quicklyin coastal districts or areas withsaline soils, although some steelposts now on the market haveimproved construction patternsand protective coatings
Plastic posts made fromrecycled plastic are termite, rotand corrosion-proof, but havelimited load-bearing capacity.Recycled plastic posts haveperformed adequately in a coolclimate vineyard, but failed in ahot inland vineyard. Themanufacturers claim a service lifeof more than 50 years.
Use of these posts would havethe side benefit of reducing theamount of plastic waste going tolandfill, and the posts themselvesare recyclable.
Some native hardwood timbersare suitable, although likely to beexpensive. In some cases thesemay be harvested from wood lotson the property.
A more recent development isplastic coated pine. These aremarketed as Woodshield posts.They are made by machining apine post and coating it with a 6millimetre layer of plastic.
“The recycled plastic is wastefrom the agricultural industries,”Woodshield sales manager AshleyDavidson said. “We take the oldused dripper tube or irrigationpipe off the vineyards or farms,recycle it and put it back out on apost.
“Then in 50-plus years, thetested life span of the plastic, youcan strip it, chop it up and recyclethe plastic again. The wood canbe mulched, chipped or turnedinto firewood. Because it is non-treated there are no chemicals toworry about.”
The manufacturers claim a 40per cent to 50pc greater strengththan CCA treated timber postsand greater ability to bend beforebreaking.
Each end has a hard capencapsulated inside and therecycled plastic is extruded overboth the cap and the timber post,completely sealing it.
These options are worthconsidering for a new trellissystem, but there is no need toreplace existing CCA treatedposts.Details: Ashley [email protected]
■ CCA regulations tightened
■ Confusion about organic use
■ Vineyard use permitted for now
➠ AT A GLANCE
China chasingCanberra wineBy JOHN THISTLETON
CHINA cannot get enough of Australia’spremium wines, according to a specialistexporter.
Inland Trading Company principal Greg Corra,who is about to send his biggest wineconsignment worth $US500,000 ($A487,000) toa supermarket chain in China, says although theindustry is facing a difficult market, the hurdleswere not insurmountable.
He said if it were not committed to othermarkets, he could sell every drop of Canberra’sClonakilla premium wines to China.
An award-winning entrepreneur of Wamboinin New South Wales, Mr Corra was commentingon the latest industry analysis which saysimport tariffs are holding back the potential ofwine exports to China.
Australian Bureau of Agricultural and ResourceEconomics and Sciences executive director KimRitman said economic analysis showed removalof China’s import tariff could lead to a fall in theChinese retail price for Australian wine by about12 per cent for bottled wine and 17pc for bulkwine.
Mr Corra said getting supplies was asimportant as the tariff hurdle.
“If we could source more premium wine wecould sell it. We have allocations fromproducers which need to be spread acrossmarkets,” he said.
Mr Corra said many Australians believed therewas a glut of wine, and often referred to a winelake hanging over the domestic market.
A disastrous 2011 vintage meant someproducers did not make any premium wine, andthis year many producers were likely to be 30per cent down on production at the premiumend of the market.
“There is absolutely no wine lake at themoment,” he said. The telling factor is the waybulk wine prices are going up in this country,beyond what you would ever expect.”
He said a Canadian winery had sought winefrom him three years ago to blend with otherwine, which cost $250 a litre.
“I could not find a similar wine at $450 [thesedays]. Yes, a lot is related to vintage, but a lot ofit is also related to the fact Australia no longerhas a wine lake as everyone would like tobelieve,” he said.Details: clonakilla.com.au
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