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Multiple Freezes Threaten Winter Wheat in Southern Great Plains

Emily Unglesbee
By  Emily Unglesbee , DTN Staff Reporter
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The ice John Schlessiger is finding in wheat stems after several consecutive nights of freezing temperatures is causing concerns for the winter wheat crop near Claflin, Kansas. (Photo courtesy of John Schlessiger)

ROCKVILLE, Md. (DTN) -- The crunch John Schlessiger heard when he stepped into his wheat field early this week sent a chilling signal. For three nights in a row, temperatures have dropped well below freezing where he farms in central Kansas, near Claflin.

Early in the morning hours of April 15, temperatures dropped to 23 degrees Fahrenheit on his farm, after a low of 21 degrees on April 14 and a plunge to 19 degrees the previous day.

"They say we have to kill the wheat crop three times before we harvest it," Schlessiger said. "I'd say we've made a fair start on it."

Those chilly nights have been widespread across the Southern Great Plains, noted DTN Senior Ag Meteorologist Bryce Anderson. "Central Kansas temperatures got down to the 19 to 22 degrees early this week," he noted. "This is typically the highest-producing wheat area in Kansas -- the breadbasket of the breadbasket."

Overall, most of the state's winter wheat acres have been exposed to potentially damaging low temperatures, concluded Romulo Lollato, Kansas State University wheat and forages specialist. "It really seems like the entire state could have some level of freeze damage," he said.

Lollato estimates that fields in the state's wheat-heavy central and south-central counties were either jointing or approaching flag leaf.

Schlessiger's fields were among them, with most wheat plants in the first or second jointing stage. That means that young wheat heads were pushing their way up toward the top of the growing wheat plant, still coiled inside the stem but far from the protective cover of the soil.

At these stages, just two hours below 24 degrees can result in moderate to severe yield loss from freeze injury, Lollato noted. (See a chart on freeze injury potential by growth stage here: https://bookstore.ksre.ksu.edu/…)

Some of Oklahoma's wheat crop, which is further along, is also at risk from freeze damage, after temperatures in the state dipped to freezing and below this week, a dangerous temperature for the 2% of the state's crop in the heading stages, (as estimated by USDA NASS on Monday). See more from Oklahoma State University here: https://osuwheat.com/….

Both Kansas and Oklahoma experienced additional cold snaps last week, on the night of April 3 into April 4. Although Lollato suspects most Kansas wheat probably came through those chilly hours OK, Oklahoma Small Grains Extension Specialist Amanda de Oliveira Silva reported that some level of injury was possible for some northern Oklahoma growers. (See more here: https://osuwheat.com/….)

The April freezes are a painful example of the danger of "false springs," a phenomenon where warmer-than-average temperatures early in the year lure crops into rapid springtime growth, Anderson noted.

"March temperatures were above or much above normal east of the Rockies and encouraged plants to move into their spring phases," he noted.

Schlessiger believes the second and third night of subfreezing temperatures in Kansas this week pushed the cold air deeper into the canopy of wheat fields, further increasing the risk of serious freeze damage. "We've seen freezes like this, but not consecutive one after the other," he said.

"Wheat had an actual frosted look on the leaves that it didn't have on Monday," he continued. "On Monday, it still had some elasticity to it, and on Tuesday, you could actually hear it crunch under your feet."

These freezes came amid dry weather, which means wheat fields had no insulating effects from snow, Schlessiger added.

More cold weather is expected for this region for the remainder of the week, said DTN's Anderson. "The rest of this week in the Southern Great Plains will still be chilly -- lows in the upper 20s to low 30s in central Kansas," he said.

After the mercury finally creeps back up, the hardest part will begin for farmers, Lollato said.

"We need to wait about a week to 10 days to see the extent of the damage," he estimated. "It will be a long, anxious time."

The color of any new wheat leaves will be farmers' first clue to the wheat plant's fate, Lollato said. Green, growing leaves are a good sign; yellow leaves mean the leaves are dying or dead.

A pocketknife can deliver the final verdict on each tiller.

"Split the stem open lengthwise and look for the developing heads," Lollato said. "If it is nice and light and green, that is a good sign. If that head is whitish, yellow, brown or mushy, then that tiller is gone."

Don't forget to check a plant's smaller additional tillers, too, he added. The plant's primary tillers are usually furthest along in development, so secondary and tertiary tillers can often be less mature and may have escaped damage.

"That small difference in development can make a huge difference in whether they survive or not," he said. "Even if some primary tillers die, there is a good chance a wheat plant will have enough additional tillers to make up some yields."

That possibility will depend heavily on the weather, however.

"We are actually dry right here, and we've missed our last few chances at moisture," Schlessiger said. "That's what has me more concerned is about the plant's ability to recover. If we don't get a rain, it's going to be challenging for us."

Lollato agreed, noting that cool conditions with good moisture would be ideal for wheat plants to recover and even rebound from injury.

Those conditions may only materialize for some, with light and scattered rain and snow showers expected for Kansas and Oklahoma, with the exception of the Oklahoma Panhandle, the rest of this week, Anderson said.

Schlessiger does have the option of chopping silage if wheat doesn't recover.

"It just so happens that all of our silos where we can store silage long term are empty, and we were joking right before this freeze hit about it," he recalled.

But for now, he plans to go ahead and let the wheat grow and see what it looks like.

"We're not going to kill it before it's dead, but we will chop some of it if that turns out to be an option," he said. "We have our own chopper and trucks and can do it ourselves."

See more on how to evaluate freeze injury in wheat from Kansas State here: https://bookstore.ksre.ksu.edu/….

See a Kansas State University article on the April 3 freeze event here: https://webapp.agron.ksu.edu/….

Watch Kansas State's agronomy page for updates on this week's cold temperatures and their effects on wheat here: https://webapp.agron.ksu.edu/….

Emily Unglesbee can be reached at Emily.unglesbee@dtn.com

Follow her on Twitter @Emily_Unglesbee

(PS/AG)

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