I have gotten a couple calls this morning on evaluating wheat and maybe other small grains that were emerging with the frost damage last night. Although we were very cold last night, I want everyone to use caution in making quick assessments as to how damaged small grains were. Here are some thoughts:
- Wheat is more tolerant of cold temperatures than barley or oats.
- Wheat and all small grains do not bring the growing point above the ground until all around the V5 growth stage, which is very similar to corn.
- If the small plants were frozen all the way down to the seed, then obviously we will see some severe damage. However if only the tops were nipped, we really need to wait for a few warm days to assess whether the plants have the ability to push a new leaf through the damaged tissue above. Assessing this type of damage is difficult immediately after the frost event. Fields can look pretty ugly with the water soaked then later white tops, but still be okay at the base of the plants.
- The drier conditions we have do not help us here, as plants are a little less vigorous then if we had a little better moisture. That said, we have had enough to get plants going, just not a lot of support for future growth.
- My biggest concern would be for grain that is just emerging and the coleoptile (the sheath around the emerging leaves) gets twisted before any actual leaves emerge.
- My bottom line is for now, we need to be in a wait and see mode. We simply have to let these plants have the opportunity to show us their hand. Wait until Friday or Saturday at the earliest to pull any plants and evaluate the below ground portions. Really next Monday is probably a better time, as the plants would be able to show evidence of a new shoot by then.
We are still relatively early in the planting season. Let's not be in a rush. Small grains are pretty darn tough, and likely will come through this without a lot of real severe damage.
Evaluate alfalfa carefully as well. Young tops on the plants may have gotten nipped pretty hard depending on additional coverage available in the fields. Also watch corn fields in the next couple weeks for any imbibitional chilling damage for corn that was planted early.
Think warm and be safe!