Weed control is often focused first on out-competing the pest. Some escape, of course, so “control” shifts to decreasing the weed seed bank. There are limited ways to eliminate those weeds with mature seeds at harvest, but recent work in Australia and here in Canada is focused on destroying weeds at the combine.
According to Breanne Tidemann, weed scientist with Agriculture and Agri-Food Canada, there are about seven different harvest weed seed control options farmers can use, but many of them involve fire, which make them less than a great fit for dry falls in Western Canada. But three pieces of equipment do offer decent options.
“Of what actually goes into the mill from the combine, you’re getting probably greater than 95 per cent control, from what we’ve seen across all three mill types,” says Tidemann. “Of the field population…typically what they’re seeing in Australia…[is] 60 to 70 per cent population control, variable from year to year, of course.”
Weed seed control mills are now developed to integrate into the back of combines. Those available include:
- IHSD, or the Integrated Harrington Seed Destructor;
- Seed Terminator from Australia; and
- Redekop Seed Control Unit, from Saskatoon, Sask.
When it comes to what’s holding Canadian farmers back from adopting the technology, Tidemann says there are a few factors including their cost: a sense that we don’t need to use them yet, and a desire for proof that they work here in Canada.
Tidemann says it will take the results of ongoing research, and testimonials from early adopters, to encourage uptake. But, she reminds farmers, weed seed control at harvest isn’t limited to mills, or herbicides.