Heatwave burning issue for vineyards

Increasing hot weather patterns in the South West are causing sun damage to grapes and vines in some popular wine growing regions.

AHA Viticulture managing director Jim Campbell Clause said the higher temperatures were affecting many grape growers.

He said a majority of the South West producers suffered sunburn on their grapes during the recent heatwave.

"Most grape varieties in the Margaret River region are reaching veraison, which means the onset of ripening," he said.

"The heat is causing sunburn damage to the berries and foliage, especially on the younger vines.

"The more exposed fruit are most susceptible to damage," he said.

Mr Campbell Clause said the alcohol content increased in the wine because of higher sugar content.

"The warmer temperatures increase the sugar content of the grapes, giving them higher alcohol content," he said.

"There is market pressure for lower alcohol wines driven from a health perspective."

Bureau of Meteorology spokesman Neil Bennett said the South West climate this summer was the fourth hottest year on record.

"2010 was the warmest and 2012 was the second warmest year we've ever had," he said. "We are seeing warmer temperatures across the whole year, but especially throughout the growing season."