By Sarah Sommerfeld PAg, Agri-Environmental Specialist, Outlook
A weed can be any plant growing in the wrong place at the wrong time. A weed can also be described as any non-native plant that has been introduced outside of its natural habitat. Based on this description, a weed is often referred to as an invasive plant, or invasive species. Invasive plants can thrive in introduced habitats. The new habitat is free of natural enemies that would normally hinder or keep the plant’s growth in-check. Invasive plants have characteristics that allow them to take advantage of growing conditions to out-compete native plants and agricultural crops. These characteristics allow the plants to adapt to one or several habitats very quickly and thrive. As an invasive plant infestation grows in size and severity, the negative impacts to production, profitability and biodiversity increase. Invasive species have been recognized as the second greatest threat to biodiversity, second only to fragmentation.
Implementing practices to help manage and control the spread of invasive plants is necessary to limit or minimize potential negative impacts. Actions to prevent the introduction of invasive plants is the best defense, and the most cost-effective management tool.
If an infestation is limited to a small area, actions that work towards elimination of invasive plants can be implemented. Early identification of an invasive plant improves the likelihood of eradication and if followed by timely control actions, can result in significant cost savings over the long term.
Once an infestation is established, actions to contain the infestation and to minimize the spread to non-affected areas are the best choice. Implementing an integrated management plan is recommended, and requires using multiple methods of control. Control methods can be biological, chemical or physical and in some situations the use of grazing livestock to control invasive plants may be used. When considering a control method, be aware of the environment surrounding the weed infestation. Chemical application is often considered the primary option for invasive plant control, as it is perceived as easy and relatively effective. However, consideration of location accessibility, site topography, weed infestation size, proximity to water and soil texture are all valid justification to use alternative methods of control.
For more information on problem weeds and weed management options, contact the Agriculture Knowledge Centre at 1-866-457-2377.