Wine Worries: Grape Growers harvesting Earlier each Year


Australian-Wine-Research-HarvestResearchers from the Australian Wine Research Institute are warning grape growers they must adapt to warmer and drier conditions leading to earlier harvests.

The institute reported wine grape harvests had on average become eight days earlier every decade since the 1980s due to warmer weather.

Viticulture scientist Dr Paul Petrie said there were things growers could do now to delay harvest and make sure grapes were not being picked in hot weather.

He said changing vine orientation, moving from north to south facing east to west, early pruning, using grape sunscreens or changing irrigation levels before heatwaves could help farmers.

Our ability to forecast those heatwaves has improved dramatically over the last decade,” he said.

“The wine industry is very aware of the potential impact of warmer temperatures because we’re so attuned to the impact of environment on our grape quality and on our wine quality.

“The good news is there is still a lot of capacity for our growers to adapt and those innovations are going to continue to occur… there’s no reason to expect we won’t be able to keep growing grapes in these regions in the future.”

Dr Paul Petrie said some technologies have had mixed results but in some places simple methods like early pruning had been successful.

“There are a couple of different products that are available as sunscreens… they effectively work like a whitewash so a white paint that you would put over the canopy that would reflect the sun,” he said.

“The mechanism of their effectiveness has been quiet well demonstrated and they’ve been used on things like apples overseas to prevent sunburn, so there’s potential for them to work in vineyards.

“Another method would be to try and delay the maturity of your fruit until a slightly cooler part of the season, this method hasn’t been trialled in some of the warmer irrigation regions.

“But certainly in the Barossa delaying pruning until the shoots on the developing vines are four to five centimetres long can delay harvest by up to two weeks.”