App for winemakers tests the water

In a vineyard operation, reducing water stress in vines is necessary to allow for adequate growth and development of the shoots, leaves and fruit. Uncontrolled water stress can potentially reduce the yield and quality of grapes, hence affecting the resulting wine.

To help winemakers address this issue, the South Australian Research and Development Institute (SARDI), in close collaboration with University of New South Wales (UNSW), has developed a smartphone app that measures vine water stress.

The project is funded by industry service and regulatory body, Wine Australia.

Growers will first use a thermal camera attached to their smartphones to take photos of the grapevine’s canopy. The app will then analyse the images and provide winemakers with instant feedback on the vine’s water stress levels, so they can optimise production and ultimately reduce water costs.

"Through many years of extensive research, methods have been developed to assess grapevine water status," says Wine Australia General Manager of Research, Development and Extension, Dr Liz Waters.

"This new app provides a portable solution to measure water status quickly and easily in the vineyard.

"It allows growers to make informed irrigation decisions that support the production of high-quality fruit grown to specification."

The app has been released for trial and fifteen vineyards across Australia are currently testing the app.

Initial trial results found the thermal camera easy to use and provided accurate information. However, feedback provided by growers suggests some modifications are required to ensure the app reaches its full potential.

Ian Macrae from grape growers co-op - CCW Co-operative Limited, trialled the app under varying degrees of moisture stress on hot days.

"The wet and dry reference discs were difficult to place in the area to be photographed, and had to be included in each photograph taken," he says to farmmachinerysales.

"We learnt that we had to be very careful to only photograph the vine in question, avoiding any background objects appearing in the photograph.

"I have no doubt this problem can be easily solved and we have made suggestions to the developers."

He adds he also found insufficient discrimination between the most and least stressed vines. However, he says he still sees great potential in the app, particularly in verifying data from soil moisture measurement equipment, testing the uniformity of irrigation systems and early identification of individual vines with root or trunk diseases.

He says he would like to see the problems he identified fixed in the next stage of the app’s development.

Other winemakers say they are yet to test the app, but are certainly interested in doing so.

"We currently use a combination of a 'Gopher' soil moisture probe & visual vine signs to monitor water stress," says Victoria’s Levantine Hill Winemaker, Paul Bridgeman.

"I’d be interested to give this app a crack."

Jansz Tasmania’s Technical Officer, James Aubrey, says the app could help support his current method of gauging vine moisture.

"We currently don’t measure vine stress directly, but we do measure soil moisture using capacitance probes," he says.

"There is a relation between soil moisture and vine stress and we have been able to estimate this point and irrigate accordingly.

"This is where the app could be useful, just to help confirm our estimates."

However, certain producers are not so keen on the technology.

"We are very small in the scheme of things and I prefer to manually irrigate based on experience and visiting the vineyard regularly myself during the growing season," says Ben Portet from Dominique Portet in Victoria’s Yarra Valley.

"So, having a camera in the vineyards would ultimately replace me. It’s not really something I feel would be great help to us."

UNSW is currently gathering feedback from the trials to help with further development of the app. The final version of the app is expected to be launched later this year.