Along with a growing number of others in Canada, Josh Lade would like his fellow farmers to consider mechanical harvest weed seed control to battle the growing number of herbicide-resistant weeds.
With his wife, Jeannie, Lade grows cereals, pulse crops and oilseeds on about 16,000 acres in Osler, Sask., in partnership with John, Janice, Rayden and Jenn Wiebe.
In Australia, where Lade is from, herbicide resistance forced growers many years ago to use various alternative herbicide control methods, such as directing chaff into narrow rows with inexpensive homemade or purchased implements.
“Many burn the chaff and no one wants that smoke or to lose nutrients that way, but they were forced to do it. Burning wouldn’t work here for a few reasons, even if it was allowed. We have to look at what we can use in concert with herbicide modes of action that still work,” he says.
“Every time a farmer sprays, they are forcing the level of resistance to grow. Every time. They need to ask themselves, ‘Do I have two modes of action in the tank, do I have a plan for in-season weed control and should I use mechanical weed control?’ We don’t want to cultivate young weeds because we lose too much moisture that way. Moisture is a limiting factor for many farms on the Prairies. We have to stop waiting for another herbicide and take action.”
In 2018, Lade and the Wiebes imported a Seed Terminator from Australia to see how it would work here. (Full disclosure: the owner and developer of the Seed Terminator is Lade’s cousin Nick Berry.) The results were positive and another Seed Terminator was purchased last year.
The Harrington Integrated Seed Destructor can also be imported from Australia. They are similar in effectiveness — above 95 per cent weed seed destruction — and in price, which is about C$100,000. However, Lade also points to the Canadian-made Redekop Seed Control Unit, which costs roughly the same and comes integrated with the firm’s MAV straw chopper. The unit is also currently being sold as an option through John Deere dealers. All of these weed seed smashers draw at least 70 horsepower and are intended for Class 7 and larger combines.
Two of the combines owned by Lade and the Wiebes are fitted with Seed Terminators, providing mechanical harvest weed seed control on 50 per cent of their fields in the most critical areas. “We talk to researchers about herbicide resistance often and we target mechanical control on the spray half-rate zones, the outside borders and around trees,” says Lade. “We also mark with FieldView where we might have a problem with wild oats or other weed escapes and treat those areas.”
Lade believes the perception that they’re no help with wild oats is a big factor holding back adoption of mechanical weed seed controllers. “All I can say is we’ve seen that they’re very effective in stopping (wild oat) spread,” he says. “If you don’t go into the patches and use a couple of modes of action and some sort of harvest mechanical weed seed control, some sort of chaff collection, you’re going to spread it and your problem is going to get many times worse.”
Lade says only about 50 per cent control of wild oats is achieved with the Seed Terminator, and that’s because, in his experience, the weed has poor seed retention and, therefore, the seeds don’t make it into the combine. Even a residual herbicide has an efficacy of 50 to 70 per cent on wild oats, and an in-season pass to kill survivors is required.
With respect to the control of volunteer barley last year, Lade explains they had to rush the harvest due to impending rain, and at the speed they needed to go throw-over was substantial.
“The field was green late fall except for where we used the Seed Terminator,” he says. “Where we didn’t use the Terminator, it was at the three-, four-, five-leaf stage before we got a fall spray done, not to mention how much bigger the volunteers could have got before freeze-up. That weed growth used up soil moisture, which is really important to preserve in some fields in the fall as well as in the spring. The moisture lost would have maybe made a difference of up to $10 an acre this year for canola.”
Cost per acre
Cost is another issue that may be holding growers back. Let’s crunch the numbers.
Each unit costs about $100,000, and over four years of payments that’s added up to more than $120,000 with interest for Lade and the Wiebes. “That’s about $30,000 a year, and then, for 4,000 acres per combine, add an extra dollar per acre for fuel and another dollar for maintenance, that adds another $10,000 a year — about $40,000,” says Lade. “Overall, it’s about $10 per acre for us, similar to an in-crop herbicide pass.”
Lade and the Wiebes plan to add more weed seed smashers as they upgrade their combines in the future.