Check Wheat for Winterkill and Pests

17:53PM Mar 04, 2019
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As winter winds tear through wheat growing states it’s important to keep weather conditions in mind as spring comes to call. Temperatures and precipitation have been a mixed bag across the Great Plains, but overall experts are optimistic for the crop.

In February and March, during spring green-up, scout wheat fields to check stands and set expectations for the season. A disappointing stand could mean you need to look at alternate crop options, while stellar stands might mean it’s time for nutrients.

“Our winterkill risk has been lowered,” explains Ron Meyer, Colorado State University Extension agronomist, who covers Colorado and parts of Kansas. “Moisture helps everything, and it [the fall moisture] made the wheat more winter hardy.”

Winter wheat loss, desiccation, is common when roots are in dry ground and the plant can’t protect them from extreme cold. Moist soil offers insulation for the dormant plant’s roots.

“If we get really cold, below zero, that could damage the crop before it hardens off,” Meyer says. While areas in Colorado are looking optimistic, wet fall weather meant farmers in Texas didn’t get some wheat acres planted until late—if at all.

“You want to see wheat planted on time to allow sufficient time for tiller development in the fall, which tend to be your most productive tillers,” says Clark Neely, Texas A&M Agrilife Extension state small grains and cool season oilseed specialist. “Late planting means you also need to watch for harvest to get pushed back, which tends to hurt yields because there tends to be more heat stress when the crop is flowering and filling grain.”

Have a scouting plan handy before it’s necessary. Come spring, you’ll need to consider not only the stand, but weeds, insects and other yield-limiting factors.

“The first thing we look for in early spring is weed infestations,” Meyer explains. “Kochia comes on early in the year and so do grasses such as downy brome.”

If you’re seeing an influx of weeds it might be time for a herbicide application. During application, keep an eye out for insect feeding too.

“Look for cutworms, armyworm or pale western cutworm, some of which you might have to dig in the soil to find,” Meyers adds. “As it warms up, look for brown wheat mite, which feeds on leaves. You might need to treat if you see more than 75 per plant or if populations quickly multiply.”

While you check for weeds and insects, pull a few wheat plants.

“If you have freeze damage it might be difficult to know if the plant is alive or not,” Neely explains. “Symptoms can take days to weeks to develop.”

A brown, mushy, withered or desiccated crown means it’s likely you have some winterkill. Check several spots throughout fields to discover just how widespread the damage is before making any decisions.

“We like to have 10 to 25 plants per square foot in dryland production and 25 or more per square foot in high rainfall or irrigated conditions,” Neely says. But he also says to keep conditions in mind—if weather is favorable the crop could somewhat compensate low populations with tillering.