Weeds of Concern – Planning, Management and Control

Weed infestations are a cause for increasing concern. These weeds are often perennial and hard to control plants. As a weed infestation increases in size and severity, the cost of control can increase exponentially. In forage stands, the loss of forage production from desirable plants results in less feed and forage for the livestock producer.

The Saskatchewan Weed Control Act lists weeds as Prohibited, Noxious and Nuisance. Weeds that are listed as prohibited are plants that are absent or rare in Saskatchewan but are aggressive in growth habit. Noxious weeds are weeds that are established in Saskatchewan beyond practical eradication but are still spreading into noninfested areas. Nuisance weeds are those plants that are widely established throughout the province and may also include native plant species.

Weeds such as foxtail barley, dandelion, and quack grass are designated as nuisance weeds. Weeds such as leafy spurge, absinthe wormwood, Canada thistle and common tansy are designated as noxious weeds.

When developing plans to deal with specific weed designations, the goals are very clear. If the weed is designated as prohibited, the goal is eradication through early detection and rapid response. If the weed is designated as noxious, the goal is containment and control to prevent further spread. When dealing with nuisance weeds, the goal should be to implement a change in land management that would improve the situation.

In all situations, the first step in management is proper identification. Consulting with an agrologist or local weed inspector for assistance in weed identification is recommended. The cause of the weed problem must also be identified. Long term weed management requires elimination or minimization of the cause to ensure success.

Correct identification of the weed is necessary to select the most effective control method. When dealing with a prohibited weed, eradication is the goal. Hand pulling may be the most effective control method. The goal of noxious weed control is containment and prevention. Controlling noxious weeds requires implementation of integrated control options, such as herbicide application, hand pulling, grazing and insects.

Monitoring the area for effective control following treatment is important. If adequate control has not been achieved, an alternative control measure should be undertaken. Reasons for a lack of effective control should be determined and corrected for future reference.

For more information on perennial weed control, contact the Regional Forage Specialist at 306-8675559 or the Agriculture Knowledge Centre at 1-866457-2377.