While you might measure how sweaty you are by the size of your pit stains, for avocado growers understanding how much water their trees are losing on a hot day can be a little harder to quantify.
But a trial of drone technology in Bundaberg, Queensland, is hoping to change that by mapping how much water orchards lose (or transpire, as it's known in plants). The ultimate aim is to be able to apply less water and produce better fruit.
Just like for people, the amount that trees transpire affects their overall hydration and health, which also affects fruit size, yield and quality.
Grower Clay Donovan became involved in the trial a year ago.
"What got us involved was interest in actually finding out if the irrigation that we're putting on is actually doing its job," he said.
"It's just making sure that we're not wasting too much water when we can and try to get the best bang for the buck."
By understanding what trees transpire more, Mr Donovan could change how he irrigated. In turn, he grows better fruit.
"Tree health is probably the main [thing] and trying to get less variation in the fruit size," he said of the trial.
Measuring sweat from the sky
The drone flying over Mr Donovan's orchards used thermal imaging to take the temperature of the trees and compared that to the ambient temperature, creating a map of "hot spots" where more irrigation might be needed.
Pilot Jamin Fleming partnered with South African agtech company Aerobotics, which developed the trial's mapping technology.
"We can identify where the problems are in the orchards with water issues, blockages … just by using the drones," he said.
"From a height it's looking at each individual tree, taking the data from that tree using different sorts of thermal imaging and multi-spec cameras to see how much water is in the tree."
"This mapping side of it is definitely taking off," he said.
"More and more growers are definitely bringing that data into their normal operations and getting a good result out of it," he said.
Mr Donovan said while it was still early in the trial for his farm, he was already changing aspects of his operation in response to the data.
"Even though a block can look very even just as you drive by we do find that there is some variability in there," he said.
"Especially at the tops of hills where the transpiration didn't look too bad, there's [a] massive difference [to] the trees about 30 metres away.
"We've just been trying to change sprinkler heads and change pressures just to try to tune it up a little bit more."
Data in the hot seat
The technology was also being tested in nearby macadamia nut trees.
Agronomist Rohan Orford first worked with Aerobotics in South Africa and said trials like the one funded by the Hinkler AgTech Initiative helped the technology continue to evolve.
"I've seen them add on new layers and refine certain facets of the platform and now it's become really quite powerful," he said.
"If used in the right way, in conjunction with good old hands-on farming like a shovel in the ground, it's been a very useful tool."
Mr Orford said there were still barriers for small operations to integrate the data into their farming businesses, but those that did could gain valuable insights.
"The farmers that are starting to understand it are saying, 'Okay, let me keep the fundamentals as they are, and adjust my approach with with these added insights,'" he said.
"You've got to engage in the whole data, AI technology, farming blend holistically and then the tools really work.
"But it's like with a lot of things in life — if you only pick one part and don't do the rest it's probably not going to give you what it can give you."
As part of the Hinkler AgTech Initiative, CQUniversity research officer Karli Groves helped connect farmers with technology companies wanting to use farms for product trials; there are about 50 running in the region right now.
She said it was valuable to have insights from real-world applications.
"You could do your search online and look at these different technologies, but you don't really know how they're going to work for you," Ms Groves said.
"Being able to link up growers who will try a tech before for them to get their honest opinions, it's just been really powerful for them.
"It leads to more adoption because they are a bit more confident going in and a bit more aware."
She said farmers had a natural caution when it came to investing in technology, but as word of the work spread, so had the interest.
"It's not like buying a new car or a new tractor. A lot of this stuff is just completely new to them," Ms Groves said.
"But once they do see it implemented successfully, they are more likely to look at other technologies as well.
"We are seeing adoption post trials as well, which is really great."
