Becky Zimmer
With sustainability and precision agriculture becoming a hot topic in the last few decades, more and more machinery companies are taking on the task of developing their own answers to precision spraying.
While it’s nothing new to North American agriculture, industry professionals and developers are excited for what the future holds for spot spraying technology, where sprayers or mountable systems use sensors or cameras to detect and spray only the weeds that need to be treated with herbicide.
Spot spraying has been around for decades. The Concord DetectSpray, which was later called the Trimble WeedSeeker, came out in 1992 using Normalized Difference Vegetation Index (NDVI) technology to detect and spray weeds using RGB (red-green-blue) wavelengths.
Tom Wolf doesn’t know anyone who actually bought or used a Concord in Western Canada back in the ‘90s, but after working in the industry for the past 36 years, spot spraying has been one of the most exciting developments of his career. Even if adoption has been slow going, Wolf notes several options currently available for western canadian farmers, including WEED-IT and the John Deere See & Spray™ Select.
Jason Wiens, Precision ag lead in southern Alberta for Brandt, says this is the first year the John Deere See & Spray sprayers have been readily available to farmers, and they are doing their best to get the word out. Using green-on-brown spraying, RGB cameras sense the green colour against brown soil. During pre-seed burn-off, these are nothing other than unwanted weeds.
Even at this early-adopter stage, Wiens is starting to see sales pick up with five systems sold in their trade region. While they are getting the market excited for the technology, it is a tricky time since they are still working on product development. As well as being sold as a brand-new sprayer, John Deere is already working on a retrofitted system that could be available as early as June.
With the RGB camera system, Wiens notes they are seeing anywhere from 70 to 85 per cent reduction in chemical usage, and farmers have been extremely happy with the See & Spray performance.
“It’ll spray a plant the size of a dime at anywhere from 12 to 15 miles/hour and we haven’t heard of any misses or anything like that,” he says. “Guys are pretty happy with the coverage that they’re getting so far.”
Researchers at Iowa State University used the See & SprayTM Ultimate for field trials back in 2024 and saw an average of 76 per cent product savings and an economic savings of nearly $6,500 USD ($15.7USD/ac) between five test plots, according research results published by Doug Houser, Matt Darr and Ryan Huffman.
WEED-IT originated in the Netherlands, but has been in Canada since 1999.
“During the pre-seed burn-off, their line scanner detects the chlorophyll of actively growing plants and gives them a hit of herbicide,” says Dieter Schwarz, general manager of WEED-IT Canada, based in Winnipeg. “This is especially advantageous for plants like koshia that have a purple colour in the early stages and broadens those optimal spraying conditions.”
Schwarz continues, “It (kochia) still gives off chlorophyll to the scanner, so the scanner will still pick it up. It’s not beholden to that plant being a certain shape or colour. We (the system) are not beholden to light conditions or dust conditions. Our scanner works at night. It’s a very good system for the conditions that we encounter on the Prairies.”
During Joy Agnew’s 2021-22 field trials, she and her team studied WEED-IT precision spray technology under three treatments: full spray, spot spray and bias spray, along with spot spray plus a reduced full spray, including a control with no herbicide application during pre-seeding burn-off.
Agnew’s paper, “Performance and cost benefit of optical spot spraying technologies in conventional, dryland farming in Western Canada,” looked at spot spraying technology performance and its impact on chemical use and crop yields. It was funded and published by Sask Wheat in partnership with Alberta Innovates and Western Grains Research Foundation.
Looking at the spot spraying treatment, upwards of 97 per cent less herbicide was applied in 2021 to a herbicide-tolerant canola variety and 98 per cent less herbicide was applied in 2022 to a herbicide-tolerant barley variety. The decrease in weed density was between 55 and 81 per cent in 2021 and between 83 to 88 per cent in 2022.
Agnew also noted that crop yields were not improved using pre-seeding burn-off. However, if weed management is deemed essential, spot spraying significantly reduces input application.
“Herbicide bills could be upwards of $50/acre,” says Wolf, “so any way farmers could cut input costs without losing efficiency is a very desirable outcome. Think of it this way. You have a 10,000-acre farm and you have a $50-per-acre bill, that’s $500,000 you can cut in half. That’s big money.”
Especially with dual tank systems and bias spray, Wolf says there is an option for farmers to broadcast spray at a lesser concentration as well as spot spray for some added coverage, but that will limit the herbicide reduction some farmers might be seeking.
Should cost savings be the only reason to adopt this technology?
“Spot spraying could also slow down the ever-growing problem of herbicide resistance,” says Wolf, “which is another important reason for farmers to cut back their input usage.”
This could be an important investment for farmers in more ways than just cost.
“We are in a stage in herbicide use worldwide where resistance has become too big to ignore. We’re simply losing herbicides to some weeds. Once those herbicides are no longer useful, we might end up with a weed that we just simply can’t control with our herbicide portfolio. That is in our future.”
Pre-seed burn-off is a common practice in Western Canada, but the conventional use of broad application to entire fields poses “a number of negative impacts on the environment,” including “soil health; water quality, following runoff of chemicals into surface water bodies like creeks; infiltration into groundwater sources and air quality, with the possibility of subsequent ecological damage to trees or other vegetation from spray drift,” wrote Agnew.
“However,” notes Wolf, “given the ecological and economic advantages, there are still challenges ahead for spot spray adoption. For those mid-season applications, a green-on-green system, spraying green weeds among green crops, would be beneficial to western Canadian farmers. It is most commonly restricted to spraying crop rows instead of the entire field, an especially useful practice for cotton, corn and soybean crops. United States farmers have adopted this practice for these are big markets. Agrifac’s AiCPlus uses the Intelligent Spot Spraying System from Bilberry to distinguish grasses from the cereal canopy, but is yet to recognize broadleaf weeds.”
Other companies that Wolf is keeping his eye on for their green-on-green products is Greeneye Technology™, which is gaining traction in the United States; ONE SMART SPRAY, a partnership between Bosch and BASF; and Carbon Bee, a French company popular in South Africa and Australia that is expected to enter the Canadian marketplace in 2026.
“Improvements to green-on-green technology are on the way,” confirms Wolf. “It’s been a little bit slower to see green-on-green in our small seeded grains and oilseeds, but we’re hoping for them to arrive.”
Farmers are also questioning the system’s efficiency.
“With green-on-brown, there isn’t much the camera doesn’t pick up,” says Wolf, “but companies are looking to expand spot spray usage to other avenues, like desiccation and fungicide application. This makes the accuracy of the spray more of a challenge since the camera will have to spray through the canopy in some instances.
“In ideal conditions, there is one sensor for every four nozzles in a common one metre row spacing. Pointing the camera ahead one metre gives the whole system maybe 100-200 milliseconds in which to make a decision, and that seems to be enough time. When cameras have to take a deeper look into the canopy, that camera angle will be even more important.
“Current price points of brand-new spot sprayers have been a concern,” he concludes, “which means larger farms will be seeing the benefits before smaller operations.”
However, those savings can nonetheless become investments for farmers as they save money on inputs.