New technology to track grape development for better harvest

• New Android mobile phone app to help track the development of the size and colour of grapes.
• The app will rapidly collect data to help growers make harvest and vineyard management decisions.
• The research was carried out by the NWGIC and funded by Wine Australia.

Measuring and tracking the development of grapes in the vineyard is now easier – thanks to a mobile phone app developed by the National Wine and Grape Industry Centre (NWGIC) and funded by Wine Australia.

The WineOz Smart Grape Android app was developed by Charles Sturt University (CSU) researchers and is available for growers and vineyard managers to use this coming harvest.

Lead researcher and NWGIC Director, Professor Leigh Schmidtke, said, “This smartphone app allows growers to quickly measure and then chart the colour and size of the berries.

“A probe around the size of a single grape is inserted into the cluster to act as a reference point for size in the app.

“You then take a picture of the grape cluster. The algorithms in the computer program calibrate the distance from the camera to the berries. The software will also take the probe measurement in pixels then relate it to the size of the surrounding grapes.

“As grapes mature they change colour, for instance, white varieties go from pea green to yellow gold as they develop. Each particular shade in that colour change relates to changes in the sensory style of wine.

“Being able to measure and chart colour change is very valuable and allows winemakers to predict when they should be harvesting the grapes to end up with the style of wine they want to produce.

“What’s more, the colour and berry size data can be used to monitor negative developments in the crop. For example, if you start to see a reduction in the size of the berries that you wouldn’t expect as they normally mature, you know that they are losing water and can take remedial action.”

Wine Australia General Manager Research, Development and Extension, Dr Liz Waters, said the app has translated Australian-based research on sequential harvesting into a simple tool that growers can use in the coming vintage.

“The app will make it easier for grapegrowers and winemakers to use objective measures – proven for Australian conditions – to determine the optimum fruit picking ‘window’ to suit desired wine styles by tracking the evolution of fruit colour (white varieties) or volume (for red and white varieties)”, Dr Waters said.

“By measuring berry volume, the app will also allow grapegrowers to make improvements to irrigation scheduling to control vine water status, which will assist in avoiding berry water loss and shrivel, enhance fruit quality, and improve bunch consistency.”

The Android app is available through Google Play and is supported by other resources on the NWGIC website.

The research was carried out by a multidisciplinary team including Professor Schmidtke from the CSU School of Agricultural and Wine Sciences, Dr Ken Ang and Dr Jasmine Seng from the CSU School of Computing and Mathematics, and Mr Alex Oczkowski from the NWGIC.