ONTARIO GRAIN FARMER 20 AGRONOMY “Harvest weed seed control allows farmers to gain a foothold in weed management, but it’s meant to work as part of a larger solution,” says Thiessen. “Every field needs to find what fits, and a mix of crop management approaches is the best way forward.” Global pressure Herbicide resistance is not a regional problem — it is a global one, playing out in different ways depending on how long and how intensively growers have been dealing with it. While some countries and regions are still in the early stages of managing resistant weeds, others are further along the curve, where control has already become far more difficult. According to Thiessen, the adoption of more integrated or innovative management practices is often driven by necessity rather than choice. Australia, he notes, is a clear example of how quickly practices can shift once resistance reaches a critical threshold. There is a growing recognition across the global agricultural industry that lessons can be learned from the most severe resistance hotspots and used to inform more proactive management strategies. Thiessen points to South America as another region where resistance pressure is escalating. In countries such as Argentina, Brazil, and Chile, growers are increasingly facing limited chemical control options for several key weed species, including herbicide-resistant amaranth species. This is one reason Redekop has partnered with Bayer Crop Science to introduce HWSC technology as part of a broader integrated prevention and management approach in Chile. “We’re focused on sustainable crop management solutions, and that includes helping farmers make their herbicide products more effective by reducing weed populations,” says Thiessen. He adds that while weed challenges vary by country, demand for HWSC technology is growing across South America as resistance pressures continue to intensify. Looking ahead, both Thiessen and Flessner are keeping a close eye on the development of robotics, lasers, and precision spraying technologies. “There’s some promising technology on the horizon that could help farmers manage herbicide resistance while also delivering environmental and economic benefits,” says Flessner. “But any new spraying technology is only as good as the chemical being applied — if we lose effective herbicides, we lose the foundation everything depends on.” Thiessen agrees with Flessner and says that is why combining chemical and non-chemical tools to manage and slow the spread of resistance is more important than ever. He says Redekop is in the early stages of partnering with some technology providers to combine HWSC with field and weed mapping systems to maximize the effectiveness of targeted weed seed control. PREVENTION OVER REACTION “Canadian farmers understand the consequences of herbicide resistance, but the real opportunity is to learn from other countries before those problems escalate,” says Thiessen. “We need to shift our focus from reacting once resistance shows up to preventing it from becoming entrenched in the first place.” Flessner is quick to offer advice to Canadian growers, especially when it comes to preventing Palmer amaranth. “This is not a weed you want to mess with,” he warns. “Early detection and rapid response are key — if you find it, deal with it aggressively.” A recent case of Palmer amaranth with confirmed resistance to six different herbicide groups underscores how far the problem has already progressed in some regions of the U.S. Flessner urges growers to stay alert for any pigweed plants that look out of place or unusual, and, when in doubt, remove them by hand before the weed has a chance to go to seed and spread. “If you see a funny-looking weed from the seat of the combine and don’t stop, you may regret that decision three or four years later if it was Palmer amaranth,” he says. While herbicide resistance represents one of the most significant threats to growers from a production, management, and economic standpoint, not every weed control failure is caused by resistance. Flessner says farmers are often quick to assume resistance when a herbicide does not perform as expected, when, in reality, there can be several other explanations. Application issues, such as using the wrong surfactant, drought stress, weeds that are too large at the time of spraying, or rates that are too low, can all lead to poor results. “If there is a herbicide failure, it’s important to understand why and not jump to conclusions,” he says. A COMPLEX GLOBAL PROBLEM Herbicide resistance is widely recognized as one of the most significant threats to global crop production, but it is also one of the most complex. As Flessner puts it, “You can’t grow crops to feed the world if you can’t control the weeds.” That complexity is pushing growers, researchers, and industry leaders to look beyond borders for solutions. From Australia’s long-running battle with annual ryegrass to emerging pressure points in South America and North America, the message is consistent: reliance on a single tool is no longer enough. Instead, growers are seeing success in diversification — combining chemical, cultural, mechanical, and emerging technologies to manage resistance before it is too late. The strategies may differ by region, but the results are the same: prevention is becoming just as important as control. For Canadian farmers, the opportunity lies in learning from those experiences early, rather than after resistance has already been confirmed. Both Flessner and Thiessen agree the future of weed management will depend not on finding the next silver bullet, but on preserving the effectiveness of the tools that still work, and using them in smarter, more integrated ways. • continued from page 19
RkJQdWJsaXNoZXIy MTQzODE4