Pulse crop growers face unique challenges in terms of managing weed populations in their crop. Not only are pulse crops less competitive, there are limited choices for pre-seed and in-crop herbicide applications, compared to canola and corn. Plan ahead to manage weed populations and resistance using the tools available.
There are many choices for grassy weed control in pulses, but few options for broadleaf control. Pulses are a broadleaf plant, and it is difficult to control a broadleaf weed in a broadleaf plant without damage or loss, and there is less investment in developing chemistry.
There are a few approaches growers can take to control weeds in pulse crops:
- Strategic tillage: Limited tillage where necessary, can be used as a way to help control weed populations.
- Plan ahead: Plan in-crop or pre-seed herbicide treatments on fields one or two years before the pulse crop year, specifically for aid in controlling perennial or biennial weeds where control options don’t exist in pulses.
- Pre-emergence: Incorporate pre-emergence herbicide technology from Groups 3, 8, 13 and 14 on parts of your fields that traditionally have weed problems.
- Multiple groups: Avoid relying on just one herbicide group to control weeds in pulse crops.
- Herbicide layering: Use two, three, or four different herbicide groups in a cropping system or use them sequentially for pre-emergence, pre-seed, and in-crop applications.
- Cultural weed control: Use cultural weed control techniques that return as few as possible weed seeds to the land. This may include technology such as the Harrington Seed Destructor to destroy weed seeds to manage herbicide resistance.
When choosing a pre-seed herbicide, consider both existing weed problems and anticipate potential issues in terms of weeds and resistance. Crop tolerance, efficacy and diversification need to be considered when choosing a herbicide.
There are several newer groups and choices available in Western Canada that growers can use to manage resistance. However, there is no silver bullet solution, and growers need to balance weed control with herbicide diversification.
Doug Fehr, PAg, is a technical sales agronomist with DuPont Crop Protection.