The May 30th frost impacted spring cereal crops across Manitoba. Fortunately, majority of spring wheat, oats and barley were at the tillering stages of development where the growing point is still below ground and therefore protected from the cool air temperatures (the growing point moves above ground at jointing or stem elongation).
However, this doesn’t mean cereal crops escaped without some symptoms of injury. In MAFRD’s June 3 webinar (available on YouTube at http://youtu.be/UDa3uWMmZzg), I covered some of the basics of frost injury symptoms in cereal crops and what to look for in terms of recovery. (And for those interested in canola and flax, my colleague Anastasia Kubinec of MAFRD covered some excellent material for those crop types in the same webinar).
For cereals, you want to look for new leaf growth (normal green color) from the growing point that should follow within 2 to 3 days after the frost event. It can go upwards of 5 days if growing conditions are cool. Below is a great photo by Lionel Kaskiw with MAFRD which shows barley impacted by frost recovering. You’ll also notice the water-soaked appearance of some of the older leaves, a classic symptom of frost injury.
Fortunately, the loss of leaf tissue at this early stage should have little impact on yield. But be cautious when applying herbicides in the coming days. Generally, you want to wait for at least 48 hours after the frost event, as well as seeing the crop resuming growth. However, please check with your local chemical representative in terms of when it should be safe to apply herbicides after a frost event as it can be product-specific.
More additional information on frost damage, refer to MAFRD’s Spring Frost Damage Bulletin.
Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD