Frost damage in small grains normally occurs when February and March are unusually warm and small grains initiate growth earlier than normal and/or from a unusually late severe frost event. Both were definitely the case this year. Freezing temperatures during sensitive growth stages can significantly impact grain yield because the developing seedhead is damaged.
If the level of damage to a small grain stand is severe enough to warrant termination of the grain crop, one option is to salvage the crop by utilizing it as forage. Frost damaged small grains can be mechanically harvested as hay or silage or grazed by cows and/or calves. Depending on the severity of the frost damage, plant growth may appear normal, but there may not be a viable seedhead in the stem. In more severe cases, main tillers may lodge and die, leaving secondary tillers to develop normally. In the most severe cases, both the primary and secondary tillers may lodge and die. Understanding the level of damage will help to determine how to manage the crop for forage.
~Chris Teutsch, Carrie Knott, and Roy Burris, full article available here.