The NSW Department of Primary Industries (DPI), Wine Australia and Riverina Wine Grapes Marketing Board project is exploring the potential of new technology to inform irrigation decisions which could help better manage grapevines in the heat.

NSW DPI viticultural development officer, Adrian Englefield, said new sap flow meters and dendrometers have been installed at two Riverina vineyards, in partnership with Edaphic Scientific.

“We are monitoring vine stress in Shiraz, Cabernet Sauvignon, Merlot and Chardonnay varieties at temperatures of 40 degrees Celsius and higher,” Mr Englefield said.

“This project aims to identify the point where vines could benefit from better informed management decisions.

“Generally sap flow is highest during the day when plants are actively transpiring and minimal at night when little or no transpiration occurs.

“We are measuring sap flow trends and comparing them during the growing season.

“Any reductions in sap flow during extreme weather events, compared with baseline measurements, can indicate vine stress.

“Dendrometers measure tiny changes in trunk diameter - a healthy vine has a smooth dendrometer cycle where trunks expand during the day and shrink at night when transpiration has ceased.”

Coupled with soil moisture information, canopy temperature and humidity sensors, the pilot project aims to monitor vine stress under different irrigation schedules during the hot summer months.

As part of Wine Australia’s Regional Program in the Riverina, NSW DPI has run grower workshops exploring management options and technologies which are available to mitigate extreme heatwave events

Live data from the heatwave management project and information about vineyard management is available online.