In the flurry of activities on a farm or ranch, it is easy to forgo the critical task of weed scouting or surveying. In the meantime, weeds can be busy invading a forage stand while killing yield potential. A University of Alberta study on yield loss associated with Canada thistle showed a two-to-one impact on forage stands. This means that every pound of thistle material created a two-pound forage yield loss. Weeds have a lasting negative impact on forage production and being on guard against weeds makes good economic sense.
Win the weed war through early detection. Eradicating a few isolated plants is much less time and money consuming then trying to work with a weed that has managed to spread across entire fields or quarter sections. Weeds can travel on equipment, in bought hay, or blow in across a fence line. Weed seeds may also hitch a ride in livestock. For example, if cattle are grazing in a field with leafy spurge plants, they may well consume the occasional plant. Leafy spurge seeds remain viable even after digestion. If the animals are moved to a new pasture, seeds can be spread through the manure. Even a handful of leafy spurge plants can start a lifelong battle against the weed.
Know the enemy. Weed books, weed apps or a local agrologist can help with the identification of plants that you are unfamiliar with. Find out what weeds you currently have and observe which weeds are present in surrounding fields. Weeds do not stop at a fence line or RM boundary. It also pays to know the classification of each weed. The Weed Control Act dictates that noxious weeds like leafy spurge, absinthe and common tansy, need to be controlled, while prohibited weeds like salt cedar or knapweeds must be eradicated.
Focus on weeds that matter the most. Not all weeds are created equal in terms of the negative impact they can generate. For example, even though dandelions are a nuisance weed, they can still provide some nutrition to grazing cattle. Absinthe and common tansy on the other hand, are not generally consumable by livestock and will steadily increase in abundance unless control measures are taken.
Know which weapon to use at what time. Depending on the weed, the size of the infestation, the physical properties of the field, different approaches will be called for. An integrated weed control approach, that combines cultural, biological and chemical control options, usually promises the most success. Also consider that some weeds may be unpalatable to one type of livestock but would provide good quality forage to another. In forage stands, grazing and cutting management is also part of weed management. Strong and healthy forage plants leave less room for weeds to take a stand.
