The images, taken by three cameras fitted to a fixed-wing Cessna aircraft 300m above the vineyards, will help viticulturists rapidly identify canopy temperature, vine water stress and nutrient status issues.
Meanwhile, researchers from the University of Adelaide have been collecting data on the ground from vines across the 22 vineyard blocks involved in the project.
This data has been used to measure chlorophyll levels, vine canopy temperatures and growth and converted into maps on a block-by-block basis.
Project leader and Wynns Coonawarra Estate viticulturist Cath Kidman said the three cameras captured thermal, NDVI (Normal Differential Vegetation Index) and Chlorophyll Index images.
She said data from a network of weather stations in the area and the full suite of data would be used to model irrigation schedules.
“We’re gaining ‘real-time’ information that can be accessed within 3-4 days of an initial fly-over, which in turn means that growers can potentially make strategic irrigation decisions a whole lot earlier than was previously possible,” Dr Kidman said.
“While we are still in the early stages of data analysis, the imagery is definitely showing a lot of promise because you can see instantly the variations in a vineyard block.”
Dr Kidman said while the data analysis could expose nitrogen and fertiliser issues, possible soil structure problems and irrigation inefficiencies, it also offered a raft of opportunities for further vineyard trials.
“The aim is to see whether remote sensing is a viable technology to use for irrigation scheduling in viticulture but potentially it could have flow-on effects to other horticulture and agriculture industries,” she said.
“We’re undertaking this project with a commercial hat on, not a research hat. This is all about working as a community to innovate and enhance grape and wine quality, whilst conserving Coonawarra’s precious groundwater.”
Aerial sensing in the trial has covered around 1,000 hectares, while the ground crews assessed 150 hectares within the aerial zone.
Dr Kidman said the cost of the sensing flights and ground measurements would need to be measured against efficiency savings and crop improvement before a decision could be made on the long-term viability of the methods.
The project, part-funded by the South Australia government, will ultimately review vine water status in relation to fruit quality across YAN, Ph, TA, colour, tannin and Brix.
“We’ve been really heartened. It’s proving to be a really good surrogate for irrigation scheduling and for giving us an idea of crop water stress and we’ve got some really useful case studies coming out,” Dr Kidman said.
South Australia is consistently responsible for almost 50 per cent of Australia’s annual production. The Coonawarra is among 18 wine regions in the state and is famous for its full-bodied cabernet sauvignon.
Katnook Estate vineyard manager Chris Brodie said data from the first flyover of his vines highlighted some areas that were clearly under stress, prompting the replacement of 50 irrigation lines within a month. He said data generated by a second flight a month later showed that the vines in the affected area were recovering and experiencing less stress.
“Accessing actual vine water stress information in a timely and relevant way means that our company can use water more efficiently … and potentially, improve the quality of our wine,” Brodie said.
A final report on the results of the trial flights and data gathering is due later this month.