Curtin University and Western Australian Department of Agriculture and Food have solid evidence that smoke can affect grapes with a resulting wine taint.
The WA Department of Environment and Conservation (DEC) – the body responsible for the management of forests and prescribed burning – is not ready to roll over yet, despite the fact that the taint has been recognised by 99pc of a tasting panel.
WA wine producers are seeking millions of dollars compensation after their crops were damaged by heavy smoke from burning near Margaret River and Pemberton, prescribed by DEC in 2004.
DEC policy and science director Drew Hassell is not prepared to accept without question, the results of the smoke taint research.
He says the material used to create the smoke in the experimental bunch smoking trials carried out by Curtin University researchers was very different from the fuel in forest fires.
"There is no doubt that the grapes in the trial were affected by smoke, but those trials used straw to produce the smoke," he said.
"Straw has different components fro those of eucalypt but was used because the trial could be replicated to confirm results.
It would be very difficult to set up repeatable trials that would mimic prescribed burns because of the variety of species and conditions."
DEC is also reluctant to accept responsibility for the smoke damage as the department's prescribed burns are not the only source of smoke in WA's south west.
"The link between smoke damage to grapes and prescribed burns is not clear cut," Mr Hassell said.
"There is a difference between the smoke from prescribed burns and the smoke from wildfires.
"The amount of compounds and particulates emitted by a wildfire burning at high intensity through big volumes of litter, dead timber and scrub fuel is significantly higher than from a controlled prescribed burn.
"Prescribed burns are managed to low intensity, consuming only the top few centimetres of litter, and are timed to have water vapour present.
"Water vapour in the vegetation and soil profile dampens the intensity of the fire," Mr Hassell said.
Smoke colour is an indication of compounds in the smoke. Wildfires are normally dark coloured smoke – the worst having an orange tinge to it.
The white smoke associated with prescribed burning is a lighter concentration of compounds and particulates.
Wildfire is the most damaging form of fire, and arson is the cause of almost half the cases.
• Lightning and accidents account for 35 per cent of fires
• 20pc is allocated to unknown causes and
• 2pc is escaped DEC burns.
The number of wildfires compared to prescribed burns varies from year to year.
"In fact, the more prescribed burns, the less the chance of wildfires becoming unmanageable," Mr Hassell said.
After consultation with the WA Wine Industry Association, the DEC's Autumn 2008 Prescribed Burn Program has been circulated to grapegrowers in affected regions.
The DEC burns about 100,000 hectares of land in the southern forests annually.
The department says it carefully considers the likely track and concentration of smoke that might occur near ground level, using state-of-the-art smoke modelling technology provided by the Bureau of Meteorology.
Details: The Department of Environment and Conservation www.dec.wa.gov.au