An advanced mobile automated sampling unit under development could revolutionise the detection and management of pests and diseases in a range of crops.
The first season of trials in cotton using sentinel prototypes, developed as part of the iMapPESTS project, highlighted the presence of thrips in large numbers early in the season at Whitton, in the NSW Riverina.
Thrip numbers peaked at 10,000 a day in one of the sentinel's suction traps, but continued monitoring found numbers were naturally decreasing.
iMapPESTS project coordinator Shakira Johnson said this information, and data about the presence of beneficial insects, allowed them to encourage growers in the area not to apply unnecessary extra sprays.
"You can't go out there and convince people to spray or not," she said.
"All you can do is provide them with evidence and reasons why they should change the way they do things."
As well as early thrips, insect monitoring focused on green mirids at flowering and silverleaf whitefly in the late season.
Ms Johnson said silverleaf whitefly was difficult to identify in the field and easily confused with whitefly.
"You need molecular tests to be able to identify it," she said.
"So people will just throw sprays at it, thinking it's silverleaf whitefly, when it's not.
"With only one really good effective spray for the season and the risk of insecticide resistance, it's a really big issue.
"The whole aim of iMapPESTS is about having accurate information to make better decisions around crop management.
"Spray when you need to, not because that's what you routinely do."
The Sentinel units are solar powered, have a weather station and can be monitored and controlled remotely.
The two used in the cotton trial have insect suction traps at 6m and 2m and a separate sampler for airborne fungal spores.
CottonInfo Southern NSW regional extension officer Kieran O'Keeffe, who is based at Griffith, collected the samples each week from November to April.
Samples from the 6m insect trap were sent to a South Australian Research and Development Institute laboratory for analysis using traditional techniques.
The samples taken at 2m were sent to Agriculture Victoria Research for metabarcoding, a new method of non-destructive DNA extraction.
"Unfortunately, for us, but fortunately for cotton, it was a low insect pressure year," Ms Johnson said.
"Even though we saw those really high thrip numbers in the early season, by the time January came, and everyone was worried about mirids, it wasn't actually a big problem."
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Researchers are now sifting through the large volume of data generated by the metabarcoding process, with the aim of finding targets, patterns and "trying to understand what it all means".
Ms Johnson said they hoped to be able to produce a guide to insect biodiversity across the season that could be used to educate growers about how to protect biodiversity and use natural integrated pest management to support their traditional spray programs.
Pathogen samples are also being reviewed for the presence of an emerging fungal disease of cotton, recurring wilt, caused by a novel species of eutypella.
Even though the iMapPESTS project is wrapping up after six years, Ms Johnson said planning for future R&D was already underway.
"We need to understand the relevance of these single data points, one Sentinel at one cotton farm, and what that means for the region," she said.
"We're also exploring ways to speed up the diagnostics pipeline, so we get the data back to growers quicker."
But growers keen to get their hands on a sentinel of their own will have to be patient.
"There has been a lot of interest from the growers in that region where we had the sentinel deployed in cotton," she said.
"They asked really great questions like, 'Is the idea that my agronomist would go out and identify what's in these pots?' Maybe, but we'll need to think about building that capacity within those agronomist networks to be able to do that identification.
"And in the case where you need a molecular test, maybe we should be thinking about in-field diagnostics, turning these sentinels into mobile in-field laboratories."
Current research includes spatial analysis between sentinels deployed this year in southern broadacre cropping regions and there will be an assessment of the feasibility of commercialising the units.
"One of the greatest things with this project is not only the collaboration between the different research groups that are part of the iMapPESTS project, but also the collaboration with people outside of the project," Ms Johnson said.
"It's been nice to see just how much potential the technology actually has to suit a whole bunch of different needs."
iMapPESTS is a cross-industry project involving the sugar, forestry, cotton, grains, horticulture and viticulture industries.
It is led by Hort Innovation, through funding from the Australian Government Department of Agriculture, Water and the Environment as part of its Rural R&D for Profit program.
Data from current and previous trials is publicly accessible through a dashboard on the imappests.com.au website.