Grainswest - Winter 2026

Winter 2026 grainswest.com 41 A ROBUST AND RELIABLE WEED DATABASE At prairieweeds.com , farmers can access the latest weed survey results and resistance updates to help plan smarter weed control. Using a weed biovigilance strategy, a key component of which is weed monitoring, the Prairie Weed Monitoring Network (PWMN) equips farmers with the tools and knowledge to fight back against problem weeds and herbicide resistance. According to Charles Geddes, PWMN project co-lead, 70 per cent of fields surveyed between 2019 and 2023 held at least one herbicide-resistant weed biotype. He estimated the financial impact on Prairie farmers to be $658 million annually. “By looking at the big picture—surveying fields across the Prairies for weed resistance—we can help farmers deal with the weed populations they have and predict what’s coming next,” said Geddes. He noted PWMN resources such as factsheets and weed survey series reports are increasingly valuable tools that can inform weed management practices and reduce the occurrence of resistant weeds. The PWMN collects survey data from 4,000 fields and utilizes historical survey information that dates to the 1970s. By combining new information with past weed survey data, it can predict where resistant weeds are most likely to appear and how weed communities may change over time. To learn more, visit prairieweeds.com . allows him to input useful observations on the go. This information, plus input from an agronomist and input supplier, guides decision-making in-season and ahead of the coming year. “As farmers, we have to do what’s best to grow the healthiest crop we can,” said Mercer. “That requires thinking and planning for the long-term and preserving one of our most important tools—herbicides.” THE LAYERED LOOK Over the years, Standard area farmer Jay Schultz has refined his weed management strategy, but its key principle remains in place: use as many tools as possible in an integrated system. “No matter the approach, weeds eventually adapt and become problems,” said Schultz. Farmers need to protect their efficacy, he added. “It’s our job to adapt what we’re doing and layer in new approaches.” Shultz has enhanced the effectiveness of his own herbicide application strategies by studying how they work and assessing weed biology. He applies herbicides when weeds are most vulnerable, which requires diligent planning of application timing, strategic mapping of crop rotations and rotation of chemical groups. He also maintains a diligent scouting routine. Taking a four-year approach, he builds an overall goal that accounts for crop type, soil health, weed pressures and problems. Next, he layers in the weed control products required for each crop and determines how each active will be rotated and tank-mixed. Most importantly, said Schultz, he includes additional weed control tools and practices to ensure the actives remain effective. He then depends on scouting and monitoring to spot weed escapes. When escapes do occur, he investigates to determine their cause. He notes the environmental conditions at the time of herbicide application, tests weed samples for resistance and incorporates the results in his management strategy. Schultz has found wild oats a major challenge and dry conditions have accelerated the spread of kochia on his land, so he incorporates a wide range of tools. They include crop competition, crop and herbicide rotations, herbicide layering and variable fertilizer and seeding rates. He also relies on sprayer technology such as pulse width modulation, which includes turn compensation. Herbicide droplets are uniformly applied across the field on hills and corners and across environmental conditions. This technology provides a huge advantage over conventional sprayers, which enables him to manage weeds in tough-to-control field corners and reduce weed germination. “If you don’t control weeds, they end up controlling you,” he said. “I’m always trying a multi-tool approach to prevent and manage resistance. If there’s a practice that makes sense to integrate, that will protect active ingredients and allow us to use them for as long as possible, I’m open to trying it.” Green foxtail photo courtesy of Charles Geddes.