Great Bend Tribune
Published February 20, 2022
As of February 15, moderate drought and a large area of severe drought envelope our area, especially Barton and Stafford Counties. The drought level increase as you head towards the northwest and southwest corners of the state, especially the southwest corner. We are starting to see wheat try to green up and break dormancy, so this is definitely not what we need. The six to ten-day outlook (February 23 to 27) indicates we can expect an 80 to 90% chance of below-normal temperatures and a leaning towards a 33 to 40% of above-normal precipitation (which still isn’t much). The eight to fourteen-day outlook (February 25 to March 3) indicates a 50% to 60% chance of below-normal temperatures and a 33 to 40% chance of below-normal precipitation. Not the outlook wheat farmers need to hear, but at least temperatures won’t be excessively high.
There have been a few blurbs about potential winterkill in wheat and for certain parts of the state winter canola. So today, what is winterkill, and how plants adapt to surviving winter conditions.
- Winterkill is the natural death of the plant. Plants like winter wheat and canola can experience the loss of leaves produced in the fall prior to dormancy over the winter, and that is normal. The key for these plants is to keep the growing point alive. As long as the growing point survives, the plant will experience new growth as the day length increases and temperatures improve. If the growing point is killed over the winter, the plant is dead. True winterkill isn’t very common in winter wheat. More common is freeze damage after dormancy and the plant experiences prolonged freezing temperatures after regrowth starts. Canola is more susceptible to true winterkill, and let’s now explore the difference.
- Winter wheat is a grass, a monocot, which means the growing point (where new growth originates) is below the ground until normally sometime in March. Here the new growth is above the growing point. Canola is a dicot, so when the seedling emerges, the growing point is at the soil surface and exposed to the atmosphere. Wheat’s growing point is protected by the soil from temperature extremes. Soil temperatures change more slowly than air temperature, especially with good soil moisture. Dry soils cool more easily. This is why winterkill is more likely with dry soil conditions. That and the growing point and root system are more vulnerable when moisture stressed. How do plants become winter hardy?
- Both canola and wheat “harden off” to survive winter. As day length decreases and temperatures start to decline, these plants change the cell contents and essentially create “antifreeze” to lower the freezing point of cells. They also grow prostate and opposed to erect, and being close to the ground helps ameliorate temperatures. The wheat-growing point is protected as it’s under the soil surface and the canola growing point by adequate leaf growth prior to winter in the form of a rosette that protects the growing point in the center. Both these plants are well-able to survive winter temperatures in Kansas fairly easily with adequate soil moisture even with the extended cold. What’s even better for both is a nice layer of insulating snow, especially for the canola.