Fickle winter weather favors shifting weeds
Mother Nature is keeping winter wheat farmers on the edge of their seats as they watch the weather and plan spring weed management programs. A remarkably warm early winter gave growers high hopes for crop yields, coupled with concerns about weeds benefitting from the same good fortune. Weed competition is often a top issue for wheat growers, as it robs plants of precious water, nutrients and sunlight; however, it can be especially devastating during drought years, when dry conditions have already taken a toll on crop yield and quality. To complicate weed predictions further, the temperature freezes that took hold in the middle months of winter, along with the lack of consistent insulating snow cover, may already be giving spring weeds an advantage.
North Dakota State University associate professor Kirk Howatt explains, “Due to the open snow cover we’ve been seeing this winter, weeds may get started earlier this year. When the ground is showing, we sometimes get a flush of weeds that come up and become established.” Howatt says that this winter the Northern Plains seems to be in a weather cycle fluctuating from cold to exceptionally cold temperatures. While the weather trend has been steady for a few weeks, he adds, “There have also been years when February was warm enough for early emerging spring annuals, or later emerging winter annuals to become established, even when the ground was still fairly frost-bound. Scouting over the next few weeks will help us determine if that was the case this year, too.”
Syngenta recommends diversity, integrated management to combat weed competition
Jill Herold, a Syngenta agronomic service representative in Montana, advises growers to use an integrated approach for spring weed management. “Utilizing chemical products alongside tried and true cultural practices has become the key to managing weed competition.” In regard to weed resistance, Montana is in a similar situation to the Pacific Northwest (PNW) region. According to Herold, this year the main weed threats to western winter wheat in the Northern Plains are kochia, foxtails, barnyardgrass, wild oat, brome grasses, and most recently, hawksbeard.
“Hawksbeard acts like a winter annual,” she explains, “so it’s going to be one of those early weeds and we’ll have to watch for its emergence. It can be easily mistaken for prickly lettuce or several other broadleaf weeds, so we’ll have to keep an eye out for it.”
Herold recommends applying Axial XL herbicide to protect against foxtails, wild oat and barnyardgrass, while using Axial Star cross-spectrum herbicide for its unique strength against kochia. For difficult grasses in the brome family, Herold suggests that using Sierra can help, adding that it is also very effective on wild oat and foxtails.