The cold temperatures in Texas in February’s cold snap range from as low as -12° F in the Panhandle to mid-single digits as far south as the Austin region. A few locations in Texas set all-time low records (Tyler, TX for one). Lubbock recorded -6° F, only the third time below 0° F since 1980, and the coldest since 1963.
Furthermore, the temperature was below freezing for a full seven days at Lubbock (and much of that below 10° F, allowing temperatures to potentially penetrate any canopy and into the ground.
Below are key points about this pronounced freeze on Texas wheat and other small grains. Our key points about the effects on the recent freeze on growth and development in wheat are taken from Texas A&M AgriLife’s “Wheat Freeze Injury in Texas” document here. This document comments on the conditions and effects of prolonged freeze on wheat in the tillering stage and at other stages of growth.
The Texas wheat crop in South Texas and possibly into Central Texas (especially for early maturity varieties) was possibly at some stage of growth of jointing. We believe this wheat was the most susceptible to injury as the growing point would be at or above the soil surface. You can best tell by looking for hollow stems. If you find a hollow stem, then the growing point is above the hollow area.
Other small grains in Texas are also susceptible to the freezing conditions. Rye and triticale, however, are generally more cold tolerant than wheat, but oats and barley less so.
- Temperatures were below freezing over much of Texas wheat for 6-7 days.
- We know of no wheat in the Texas High Plains that was close to jointing at the onset of the freeze. Probably not in the Rolling Plains either. So, this lessens injury potential. South, Central, and possibly Northeast Texas might have some wheat that was beyond the tillering stage (jointing, or further development).
- Essentially all wheat varieties in the Texas High Plains and Texas Rolling Plains are grown several hundred miles to the north, so they do have cold tolerance.
- The fact that it had been so warm might make wheat more susceptible to freeze. For example, it was tied a record high of 80° F in Lubbock on Super Bowl Sunday (Feb. 7).
- If you received some snow in the early part of the freeze, if it is not blown off the field then that can help protect the wheat. This is common cold protection for winter wheat in the Central Great Plains. This protection is good, and there is moisture for the wheat crop when it warms up.
Additional comments from “Wheat Freeze Injury in Texas” on the conditions and effects of prolonged freeze on wheat in the tillering stage. These include:
- The document suggests temperatures below 12° F for at least two hours could cause some damage (leaf yellowing, leaf tip and leaf tip burn, silage odor, bluish color). These symptoms have only slight to moderate impact on yield. We do not think 12° F is that important as much winter wheat in the Texas High Plains is well below this temperature in different years.
- Low temperature and its duration, soil moisture, and wind can influence injury potential. Soils that are very dry enable the cold to penetrate further into the soil to the crown. This is more likely in the droughted areas of Texas, especially in the High Plains region where the Drought Monitor shows some extreme and exceptional drought. If soil moisture is high then the foliage likely has a high moisture content and is more susceptible to freeze damage. So, for Texas, which factor in the recent freeze was more important. For North Texas, the Rolling Plains, the High Plains, and possibly the Concho Valley, the importance of the growing point—still below the soil surface—is much more important than possible loss of leaves due to freeze and burn.
- Leaf burn usually does not have a great impact on yield potential at the current stage of growth for most Texas wheat. The plants will develop new leaves. This may be less so for wheat in South Texas. But even there, if much of the foliage is lost, and even a few growing points, the wheat can compensate with new tillers. Inspect the base of the wheat plant (crown) below the soil line. If it is turgid and green, there is no reason for concern.
An aspect of major concern in the northern and High Plains part of the state is drought-stressed wheat that is being grazed. Grubbing the wheat down too much will curtail its ability to recover if moisture becomes available. This is a case of “less is more.” Less grazing—hopefully, cattle can be moved off the wheat for a couple of weeks (do you have a place to go with them?), then return after moisture and jointing to catch the burst of early spring growth.