World-first solution to combat spray drift saves growers time, money

Darling Downs and northern NSW cotton growers were left devastated after suspected 2,4-D spray drift settled on hundreds of thousands of hectares of crop in December 2022.

At the times agronomist Matthew Holding said it was likely the worst worst spray drift he had ever seen on the eastern Darling Downs.

"We're not talking about a few thousand dollars here, we're talking about tens of millions if not hundreds of millions," he told Queensland Country Life in December 2022.

A survey conducted by the Cotton Research and Development Corporation with growers in 2023 found that 48 per cent of growers were affected by spray drift between 2022 and 2023.

On average, 48 per cent of their crops were affected and the average cost to each grower was $254,000.

CRDC senior research and development manager Susan Maas said it wasn't just an issue for cotton either, and that it was an issue shared by all primary producers in the industry.

"This isn't a cotton versus grains, it's a whole of ag issue - all pesticides have the potential to drift," she said.

Ms Maas was concerned about the impact of cost of living pressures and labour shortages on growers this season.

"Not having enough people, enough ground rigs or access to contractors, may mean people are pushing into spray windows where they shouldn't be spraying," she said.

"So far, we've seen it in New South Wales, but I haven't heard big reports in Queensland.

"I'm hoping I'm wrong but my suspicion is, we could be having more discussion in the new year around spray drift damage."

In what could be a lifeline for growers, Australian researchers have developed a world-first weather data system to help minimise spray drift.

It has already been taken up for more than 2400 grain and cotton growers and spray contractors across QLD and NSW.

The Weather and Networked Data system is a result of six years of collaborative research by the CRDC and Grains Research and Development Corporation - with the support of commercial partner, Goanna Ag.

To date there are 101 towers throughout QLD and NSW that report on spray drift conditions in real-time and for the next two hours. The current model is free to access, only requiring an email to sign in.

From growers who had signed up, 60 per cent reported they had already made a change in their spray application.

"In the absence of evidence of when a hazardous inversion exists, the rule of thumb has been to not spray during the period from two hours before sunset, until two hours after sunrise," Ms Maas said.

"WAND replaces that assumption with real-time data on specifically when a hazardous inversion is present, allowing spraying to continue during periods when hazardous inversions are shown to be absent."

In addition to the two-hour nowcast which will continue to be available to all users, WAND will be releasing a subscription model starting at $100 per year which will offer a 24-hour forecasting service.

"From January we are introducing a new 24-hour forecasting feature, this will provide users with significant benefits in terms of spray job planning, staffing and logistical support," CEO of Goanna Ag, Jay Jalota said.

"They can log in to WAND the day before, check if conditions will be suitable, and then make decisions about whether to send out workers or not. It will save them time, and money.

A second new paid feature will be the ability to see all historical data, graphically represented back as far as two years, rather than the current limitation of only 48 hours.

Ms Maas said this was an important step to transition the service from a research and development model of funding to "self-sustaining" model, which would help with maintenance and repair of the towers.

She said while the sustainability had to be proved before expansion of network of towers could be considered, there were commercially available options for groups of growers to have additional towers added to the network.