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Adding some IQ to smart spraying

Weeds are in for some one-on-one attention with the latest spot-spraying tech coming down the pipe

It looks like something out of science fiction.

Above a Saskatchewan field, a line of drones rises in formation, sensors primed to pick out enemy targets below.

But this isn’t the latest Terminator movie.

This is Daniel McCann’s brainchild for green-on-green spot spraying, an offshoot of precision spraying that promises to identify and take out weeds in a growing crop.

Why it matters: Smart spot spraying is being pushed as a “best of all worlds” solution to decrease input use, save farmers money, get better agronomic outcomes and pacify a public worried about pesticides in the field.

McCann’s company, Precision.ai, has developed drones with artificial intelligence to achieve that goal. Twenty drones can fly at a time. Sensors identify over 48,000 plant types as they fly over and deliver a micro-dose of herbicide to weeds, leaving surrounding plants untouched.

Daniel McCann of Precision.AI says his drones are smart enough to spray the weeds, and only the weeds, in a crop, potentially letting farmers save up to 95 per cent of their chemical cost or even use a non-selective herbicide.
photo: Alexis Stockford

It promises to save farmers “a huge amount on chemical cost,” according to McCann. It will also address public concerns with pesticides and reducing the environmental impact of farming, since the drones themselves use no gasoline or chemical fuel.

The Precision.ai website estimates drones can reduce spray use by almost 95 per cent.

“Because of the chemical that we’re going to be saving, we actually forecast that we could potentially do a custom spray for the entire field for less than the cost of just the chemical that the farmer is using today,” McCann said.

The drone’s 20-litre tank gives roughly the same coverage as a 600-litre tank in a traditional sprayer, depending on how clean a field is, he added, although a farmer may need an additional pass if they have a weed with a very specific herbicide requirement.

Precision.ai is one in a growing list of agribusinesses trying to make spot spraying smarter. It’s a trend seemingly driven on all sides, as farmers look to cut input costs, agronomists watch weed resistance with a wary eye and public pressure against pesticide use mounts.

BASF’s digital agriculture arm, Xarvio, is in the process of merging their scouting app, which identifies weeds and diseases through a picture, with precision spraying.

“After the pictures are taken, the smart sprayer concept actually sends that result to the controller of the sprayer to decide what product to use and then it puts that product in the boom line,” Warren Bills, Xarvio’s Canadian commercial operations lead, told Glacier FarmMedia this July at the Ag In Motion show near Saskatoon.

Xarvio’s smart sprayer earned an innovation award during its Canadian debut at that event.

Green-on-brown vs green-on-green

For Tom Wolf of Agrimetrix, smart spot spraying is a matter of industry survival.

Wolf is one of the premier spraying experts on the Prairies, both through his own Saskatchewan-based company, and as a founder of Sprayers 101, a free online resource outlining best spraying practices that he runs with Jason Deveau.

Until now though, Wolf has been steadfastly neutral when it comes to company endorsements. He broke that trend for the WEEDit spot sprayer and its Dutch manufacturer, Rometron. Wolf has been tapped to market the sprayer, already established in Australia and South America, as the company makes a bid to bring it on the Prairies.

The WEEDit green-on-brown system detects chlorophyll by how it converts blue light into a different wavelength, triggering the nozzle to spray.
photo: Alexis Stockford

Unlike Xarvio and Precision.ai, WEEDit is green-on-brown, not green-on-green technology. Blue light is projected down, and sensors mounted on the boom detect the specific wavelengths converted presence of chlorophyll, thus triggering the nozzle to spray. Producers using the system have reported up to 75 per cent herbicide cost savings, the company says.

The technology is largely used for pre-season or post-harvest burn-off, as it cannot differentiate between weeds and a growing crop, although Wolf suggests that it might also find a pre-harvest use when crops are fully mature.

It is, however, the smart spraying technology already on the market, while green-on-green systems are still being developed.

Precision.ai hopes to launch their services next year, while Xarvio estimates that their technology will hit the fields within three years.

Self-preservation

Wolf argues that precision spot spraying will be key to addressing the agronomic and market hurdles ahead.

“Let’s look at two current important issues,” he said. “We all know that glyphosate in particular is under a magnifying glass by the non-farming public right now, and one of the uses of glyphosate, pre-harvest, has come under extreme scrutiny.”

Manitoba producers get a look at the WEEDit system in action at Carberry’s Cropsapalooza event this July.
photo: Alexis Stockford

The pesticide has had a long string of bad press. In September 2018, advocacy group Environmental Defence Canada published results after testing 18 foods, most of which were positive for glyphosate, although all levels fell well within Health Canada guidelines. Despite that, the results gained traction and sparked public worry.

A number of experts, including Wolf, are now calling on producers to curb use of glyphosate as a desiccant and refocus on pre-harvest weed control.

“This is where, I think, some farmers have issues because you have a fairly high rate of glyphosate and you have a fairly low density of weeds, perennial weeds, in the field, so your potential expenditure is so huge for very little gain,” Wolf said. “Spot spraying is the answer to that. It now makes pre-harvest glyphosate very economical — so that has tremendous value — and maintains the acceptability of the MRL (maximum residue limit) scrutiny of the practice. This is the technology that will keep us spraying pre-harvest glyphosate.”

Wolf’s other reason, he said, is the “slowly rising tide of herbicide resistance” across the Prairies.

A 2016 Manitoba Agriculture survey found that herbicide resistant weeds were present of 5.4 million acres in the province, up by an additional 1.4 million acres since 2008. In the ensuing two years, that number has likely continued to climb. Glyphosate-resistant kochia has been a repeat offender in the headlines, while five municipalities now report tall waterhemp, a weed infamous for both its seed production and glyphosate resistance in the U.S.

“We can’t totally prevent it, but we can delay the onset of resistance with multiple effective modes of action,” Wolf said.

“Multiple modes of action” is a familiar phrase to anyone attending an herbicide seminar in recent years, but Wolf says the expense of such mixes has kept farmers from embracing them.

The balance sheet looks more attractive, however, if the farmer is suddenly able to put down a fraction of that mix and get better results than blanket-spraying a cheap blend, he added.

The industry will have to adjust to a plant-by-plant, rather than field-by-field basis when they think about pesticide, Bills argued, while McCann says the technology will rewrite how farmers think about chemical mixes in-crop.

“If you’re able to surgically target a weed within a six-inch area, you could potentially use a non-selective in crop, which you can’t do right now,” McCann noted.

Wolf, meanwhile, is excited about the incoming advances for smart spraying, even if they are not the product that he is championing. In fact, he fully expects that those technologies will one day replace green-on-brown systems.

“I’m not picking sides here at all,” he said. “I’m looking forward to green-on-green technology. It’s the next step in this change.”

About the author

Reporter

Alexis Stockford is a journalist and photographer with the Manitoba Co-operator. She previously reported with the Morden Times and was news editor of  campus newspaper, The Omega, at Thompson Rivers University in Kamloops, BC. She grew up on a mixed farm near Miami, Man.

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