Early green up increases potential of freezing injury in winter wheat

 

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Good residue and sufficient soil moisture help reduce risk of freezing injury in winter wheat

 

Winter wheat is currently in pretty good condition mostly due to good moisture at planting and favorable temperatures for plants to winter harden (vernalize) before cold temperature set last fall. Yet, many farmers have been concerned about higher then normal temperatures during February and wondering how this might affect winter kill in wheat.

Wheat does loose winter hardiness every time warm temperatures break its dormancy, and so it is important to become familiar with wheat sensitivity to cold temperatures at different growth stages.

During tillering stage, growing point of wheat is near the soil surface and well protected from frizzing injury. Plants might show damage in form of leaf twisting and discoloration, or even loosing tillers, but plant will be able to come back from the secondary tillers and produce good yield.

This years’ sufficient soil moisture helps reducing potential freezing injuries on crown and roots that might come from temperature fluctuations, as moist soil warms up and cools down about six times slower then dry soils.

In the jointing stage, when wheat starts to move the head up the stem, growing point is above the soil surface and more susceptible to injuries that might come from freezing or hail injury. According to K-state research, wheat will still be able to tolerate temperatures in the mid to upper 20’s without causing significant yield losses.

Farmers in this region frequently tell me: “Wheat dies 9 times before you get any grain out of it.” Therefore, fallow these wise words and if you suspect winterkill try not to make any quick decisions. Wait for several days of warm temperatures, give plants an opportunity to recover, and conduct careful assessment crop condition and its yield potential before you decide to tear out a field.