The title of this article might have some questioning their connection, but it is an issue that needs to be considered. We are getting reports around the state that due to the extreme winter conditions the past several weeks, some wheat has experienced frost heaving (and I wouldn't be surprised if the same thing happened in other small grains and alfalfa fields, too).

And with the changing of the seasons, farmers and applicators are getting anxious to get some field work done. However, it might be best to wait if the crop has been injured by winter weather.

Since frost heaving causes the roots to be dislodged from the soil, the crop is in a compromised situation. Some plants may be pushed significantly upwards with only a single root holding it, while others might still be somewhat anchored, but their secondary and tertiary roots have been detached or injured. Either way, the crop is stressed and not actively growing.

Applying a herbicide at this point would only exacerbate the problem. Many herbicide labels warn not to apply herbicides to crops that are stressed by severe weather conditions (including winter stress), drought, low fertility, flooded soils, disease, or insect damage. For wheat and other winter small grains, the risk of injury is usually greatest when the crop is in the 2- to 5-leaf stage of growth, but injury can occur at later stages as well, especially if plants are stressed.

Before spraying, it is necessary to first conduct a stand evaluation of the field to determine the severity of the winter injury. If the crop is still salvageable, it is best to wait until it has had time to recover by developing a strong root system that is actively growing.

Once this occurs, the crop can metabolize the herbicide much better, reducing the potential for further crop injury.

As always, after a cold spell, wait until a few days of warm, sunny weather have occurred before applying herbicides. It's best to wait until daytime temperatures are in the 50s and nights in the 40s so both the crop and weeds are actively growing.