Just forty or fifty years ago, weed control strategies and options differed greatly from what farmers have to deliberate between today. With a heavy reliance on tillage, physically destroying weeds took a heavy toll on soil moisture reserves and soil structure, leading to issues with salinity and erosion. Today’s western Canadian farmers have moved en masse to reduced and even zero tillage, made possible in part due to access to effective herbicide options.
But even that evolution in weed control had its limits, says retired Agriculture and Agri-Food Canada weed scientist Dr. Robert Blackshaw. Blackshaw was recently honoured with the Orville Yanke Award at the Farming Smarter conference, and RealAg Radio host, Shaun Haney met with him after the award ceremony to talk about the changes in weed management he witnessed over his career. The limit, of course, is that resistance to herbicides evolved — and evolved quickly.
Blackshaw admits even scientists were surprised by the rate of resistance, and denial early on of it even being a problem likely didn’t help to get ahead of the problem. Just like when tillage proved to be problematic, farmers moved to cultural controls to increase crop competitiveness, Blackshaw says the same holds true when facing the resistance issue going forward. Increased seeding rates, more competitive cultivars, early seeding, robust fertility — all of these are a continuation of those cultural controls to suppress weeds, he says.
Over the course of his career, adoption of reduced tillage and the advent of effective herbicides moved 30 million acres of Western Canada out of fallow and chem fallow and into food production, including growing pulses and oilseeds. And that, says Blackshaw, is likely what he’s most proud of — to have been a part of helping farmers navigate a rapidly changing production system.