This year’s warm, open fall has prevented much of the nation’s winter wheat crop from going dormant, which could pose a risk to the crop if temperatures drop suddenly.
“The biggest concern with the higher-than-normal temperatures is how quickly we go into cold,” said Mary Knapp, climatologist at Kansas State University. “The wheat needs to go into dormancy before temperatures get too cold.”
Much of the Great Plains region has experienced an exceptionally warm fall. In Kansas, the nation’s largest producer of winter wheat with nearly one-fifth of production, temperatures have been well above average. As of Dec. 8, the average temperature in Kansas was 4°F above the 30-year average for the season at 59.8° F, said Knapp.
“Cattle are grazing on the winter wheat, which we haven’t seen in a good number of years,” Knapp said. “The biggest risk for the crop would be an abrupt temperature change, but wet soils would temper that.”
So far the winter wheat belt is nearly snow free after a brief period of snow cover.
“Snow cover offers protection from extreme cold temperatures,” Knapp said. “The ground in Kansas has not frozen and the recent snow cover has vanished.”
Moisture Also a Concern
Not only would a sudden cold snap be detrimental to the winter wheat crop, but the wheat is continuing to grow, which means the plants are drawing more moisture out of the soils. So far, however, moisture has been adequate in much of the wheat belt, but dryness is starting to spread, according to the U.S. Drought Monitor Index.
“There are good things and bad things about an open fall,” said Jim Shoyer, professor emeritus and wheat specialist at Kansas State University. “On the positive side, wheat plants are able to root and get well established, and there is a fair amount of top growth.”
On the negative side, Shoyer said that with the excessive late-season growth, the plants use more water. In years past when that has occurred, the soils have become excessively dry, predisposing the wheat to winterkill.
“With good moisture going into winter, it’s not an issue,” Shoyer noted.
Moisture Outlook Promising
The three-month outlook, December through February, for the winter wheat belt is fairly positive, stated Knapp. Cooler-than-normal temperatures are expected for Texas, while warmer-than-normal temperatures are anticipated north of the Red River of the South to the Canadian border.
“The moisture outlook is even more promising, with a wetter-than-average outlook for the three-month period,” said Knapp.
While a lot of the winter wheat has received adequate moisture, the longer dormancy is delayed, the more water the crop will use, according to Shoyer.
“The other thing that is equally or more important is that the longer we have an open fall, the longer aphids are able to move,” Shoyer said. “When we have an open fall, I worry about the level of disease we will have next spring.”
Diseases spread to winter wheat by aphids are wheat streak mosaic virus (WSMV) and barley yellow dwarf virus (BYDV).
How is your winter wheat crop doing? Let us know in the comments.