Volunteer canola can be a very difficult weed to control in any situation, let alone when millions of seeds are left on the ground at harvest.
Dubbed the $1-billion wind by some, strong gusts up to 100 km/h were responsible for standing crop losses as well as rolling swaths last fall that shattered canola and led to significant seed loss. According to the University of Saskatchewan, an estimated 70 million bushels of canola seed were left behind, accounting for up to $1 billion in yield losses.
“Those winds were strong enough to scatter seed to neighbouring fields, so volunteer canola will be a major concern this spring,” says Robert Hornford, a technical specialist at BASF Canada “Volunteer canola will also have different growth stages than the seeded canola crop, causing management issues for herbicides and fungicide timing.”
Volunteer canola can be difficult to control. Weed seed can survive in the top few inches of soil for up to three years, making volunteer canola a threat for follow crops where it can compete with nutrients in the soil to rob yield.
Hornford recommends growers consider several steps to mitigate yield loss due to volunteer canola in any crop this spring:
• Manage early weeds - Scout fields in early spring to evaluate a herbicide application that can eliminate volunteer canola early. Adding Heat herbicide from BASF Canada to an early glyphosate application before cereals and pulses has been shown to help manage volunteer canola.
• Rotate systems – If growing canola this spring, you may want to consider a different system. As part of the Clearfield Production System for canola, growers gain access to such herbicide innovations as Ares — it controls tough grassy and broadleaf weeds, including non-Clearfield volunteer canola.
• Apply a fungicide - For canola, diseases such as blackleg can overwinter on volunteer canola to affect future canola crops. Applying a broad-spectrum fungicide such as Headline at herbicide timing can protect against such diseases when used preventatively.
“Volunteer canola from shatter can cause significant problems in future crops, and farmers are going to need to manage that risk this spring,” says Hornford.
“Growers should look for products and systems that offer new modes of action to gain flushing control of volunteer canola — it is the most effective way to manage the threat.”
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