Weed control goes high-tech

Saskatchewan farmer Carl deConinck Smith is a dedicated early adopter who likes to keep on top of the latest innovations in digital agriculture technology.

No surprise then that he’s arranged to have some new precision ag tech put to use on his farm this summer. It’s a digital tool developed by Geco Engineering in Vancouver, B.C., one that not only predicts where weeds will emerge in fields but can also map areas where there’s herbicide resistance.

By season’s end, Geco CEO, Greg Stewart, aims to provide deConinck Smith with predictive spray maps he can use to dial in on weeds in either a post-harvest herbicide spray this fall or an early spring application next year.

“You can’t catch every single weed, but it certainly looks to me like you should be able to narrow it down to the really hot spots with this. Then you can determine how wide a net you want with your spray. You can cover a wider area or narrow area depending on what your tolerance is, basically,” says deConinck Smith.

“We can target more of the heavy, hard-to-kill weed areas rather than having to spray everything with a blanket application. It’s pretty darn expensive to blanket applicate. Most of these chemicals are $20 to $25 an acre, so to do that on a large area can get cost prohibitive.”

Strategic weed management

Stewart says a primary purpose of Geco’s tool is to enable farmers to be more strategic about controlling weeds.

“When farmers are looking at weed management, quite often the first thing on their minds is not saving money on herbicides. It is a cost, of course, and no one wants to waste money, but that’s not their primary goal,” he says. “What they really want is to be more strategic with the money they’re spending, so directing it to the right place.”

The predictive power of the Geco Engineering tool comes from data supplied by satellites, drones and farm equipment. Combined with artificial intelligence and machine learning techniques, this data is used to drive complex agronomic models on population dynamics that show how weeds grow and spread within fields.

“We’re taking data from wherever we can get it. It always includes satellite data, and then whenever possible we sharpen that up with data that we get from a drone or an optical spot sprayer, which tends to be much higher fidelity data,” says Stewart.

“If there is drone and optical sprayer data available, that’s great. Otherwise, we work from satellite imagery and do the prediction and then provide prescription spray maps back out to the farm.”

Later this season, deConinck Smith hopes to take information collected on his sprayer, which is equipped with a green-on-brown optical spot-spray system, and upload it to Geco to augment the satellite data.

DeConinck Smith says he believes the technology could be a valuable addition to the weed control tool box for producers, especially on larger farms.

“I know my fields and I could pretty much tell you where just about every weed is on our farm,” he says. “But for large operations where the managers aren’t in the sprayers, it provides a really good visual reference of what’s really going on.”

Potential cost savings

Stewart says in addition to early season herbicide applications, farmers he has talked to see post-harvest sprays as another key use for his weed detection technology. Some producers have also showed an interest in using it to augment spot-spraying devices or for performing spot spraying in situations where optical spot spraying is challenged — for example, in dusty conditions or when putting down soil-applied herbicides.

Stewart notes once predictive spray maps are ready, farmers are typically presented with several options based on different objectives for weed control and herbicide cost savings. He says it usually comes down to a trade-off around how much farmers are willing to spend and how much weed control they’re hoping to achieve.

“We’re working with the farmers on how they want to spray their fields,” says Stewart. “Some of the farmers that I’m talking to are saying, ‘OK, now that we know where the weeds are, what should we be doing? What is the optimal way of making sure that we keep these weeds under control not only for this season, but also so we don’t incur a resistance problem that bites us in a few years?’ ”

While the total chemical bill for farmers depends on how many weeds they have in their fields, Stewart estimates his tool can reduce herbicide use by 60 per cent or more and still achieve up to 85-90 per cent weed control depending on how farmers select their trade-off option.

Some may see Geco’s system as an affordable option for farmers who are seeking more precision in their weed control efforts but don’t want to invest in an optical spot sprayer. However, Stewart says he believes the best overall performance over a season will be achieved by combining both technologies.

“Spot sprayers can achieve an incredible weed-chemical trade-off on those spray events where weeds are visible,” says Stewart. “The combination permits you to be both comprehensive and focused, proactively beating down problematic areas before they are visible and targeting visible weeds after they have emerged.”

Herbicide resistance

Another important aspect of Geco’s technology is an app that can detect patches of herbicide-resistant weeds. It relies on similar data and agronomic modelling to produce maps crop scouts can use to zero in on and verify herbicide resistance within a field.

Geco has an early version of the app working and is starting to work directly with farms in Western Canada to test the technology. Stewart says farmers interested in trying it out are welcome to contact him at [email protected].

Stewart predicts the technology will generate a lot of interest since herbicide resistance is such a pressing issue for farmers in Canada and around the globe.

“Herbicide resistance is costing farmers anywhere between $10 and $150 an acre per year, depending on where they are in the world. If you look at any top five list of problems in agriculture, herbicide resistance is always there, sometimes at No. 1 or 2. So, I would say it’s definitely a very real problem for farmers,” he says.

“What we’re doing is providing a directed scouting tool. If you’ve got a 10,000-acre farm, it can be hard to make your way around to find every patch out there.”

Stewart says another main challenge with herbicide-resistant weeds is they’re usually well established in a field before anyone notices them. “If you’re able to catch that early on when it’s a small patch, there are a lot of things that you could do to prevent it from spreading.”

Stewart maintains early detection of herbicide resistance in weed populations, followed by localized management, could significantly postpone the selection for and spread of resistance, helping to prolong the effectiveness of herbicide products.

Localized management of resistant weeds could include measures like spot spraying with herbicides that still work, mowing patches before weeds can set seed, and other tactics to control the weed seed bank.

After founding Geco Engineering two years ago, Stewart started running pilot programs on farms in Western Canada, the United States and South America in 2022 to validate the technology. Field trials continue this year on 11 commercial farms across the Prairie provinces, including at deConinck Smith’s farm near the town of D’Arcy, Sask.

Geco’s technology is now in the early stages of commercialization. Stewart says while the focus up to now has been on developing a stand-alone product, he’s also been talking to potential industry partners about the possibility of incorporating the technology into existing software platforms.

For more information on Geco Engineering’s weed mapping technology, go to geco-ag.com.