Tag Archives Weed of the Week Archive — page 4

A look through provincial and U.S. state crop protection guides can yield many things. However, when searching for control methods for round-leaved mallow, the suggestions are fewer than for many broad-leaved weeds. Round-leaved mallow is generally an annual weed, but if allowed to grow for more than a few weeks, it can seem as though […] Read more

Redroot pigweed is tough to control in later seeded crops. Amaranthus retroflexus, as it is known to botanists, is an annual weed that has developed resistance to herbicides in Groups 2 and 5. More than 100,000 seeds per season gives the weed plenty of opportunity to select for genes that resist applications of everything but […] Read more

Of the Top 10 weeds on the Prairies, wild buckwheat is considered No. 3 on Agriculture Canada’s farmer surveys. In Alberta, it’s No. 1. Buyers will refuse crops such as canaryseed if the weed’s distinct, triangular seeds are found in shipments. Buckwheat can be tough to kill, even at spring burnoff, provided it gets a […] Read more

Reducing tillage has increased cash flow, boosted bottom lines and improved soil health. One of the downsides has been minor weeds becoming major problems. Some fall annual weeds have thrived where steel now fails to find them. Worse, pests like shepherd’s purse have managed to escape some of the handiest herbicides, such as Group 2 […] Read more

Canada fleabane is not considered a major weed in Western Canada. But in Ontario, it has developed into a herbicide tolerant pest. Fleabane is a winter or summer annual, with most of the seedlings making their appearance in a post-harvest environment from August to October. The pest forms a dark green rosette of hairy leaves […] Read more

  Dandelions are a serious pest for modern prairie farmers, but European pioneers considered them to be valuable plants. They were brought to the new world as a medicinal herb and were considered a resilient, perennial forage plant. It is known mostly as a problem weed on urban lawns, but it can also cause big […] Read more

It is a pig when it comes to using water, nutrients and land. Redroot pigweed, or amaranthus retroflexus, is a dicot weed in the amaranthaceae family. It was first discovered to have developed resistance to Group 2 herbicides in Western Canada in 2010. Group 2 herbicides are known as ALS inhibitors and are popular in […] Read more

Many of the top weed pests in Western Canada are showing resistance to herbicides, according to research led by Agriculture Canada. Hugh Beckie at Ag Canada’s Saskatoon Research Centre classifies wild oats as one of the 10 worst annual weeds in the temperate agricultural regions of the world. Research indicates that more than 10 million […] Read more

Wild buckwheat, or polygonum convolvulus becomes a problem when later season rain interferes with post emergent spraying or arrives after spraying. In those years, the weed can make seed and interfere with crops and harvestability. Its wiry stems rise up through the crop seeking sunlight. Unless treated with glyphosate or another preharvest herbicide, it can […] Read more

Most wheat crops used to have a yellow phase in late June or early July when wild mustard came through the crop. Before herbicide tolerant canola, the weed was a yield robber and a contamination threat to canola and rapeseed growers. The aggressive plant, formally known as Sinapis arvensis, can be found in most of […] Read more