Extension Logo
Extension Logo
University of Minnesota Extension

Heat canker in wheat, barley and oats

In the spring, dry sunny weather with high winds helps dry off fields and make strides with planting the crop. Unfortunately, this can also stress the young, small grain seedlings.


The daytime heat at the soil surface can cause heat canker. This basically cooks the tender young tissue at the soil surface, which appears as a yellow, slightly constricted band (Photos 1 and 2).

As the leaf continues growing, this yellow band (1/8 to 1/4 inches) moves upward and away from the soil surface. If the hot and dry weather lasts for several days, repeated bands can become visible.


Because of the high winds, the tips of leaves may break off at the yellow band, as with freeze injury, and give a field a very ragged appearance. Damage from heat canker is temporary and shouldn’t affect further growth and development.

heat canker
Photo 1: Wheat seedlings with the yellow, constricted appearance that’s a symptom of heat canker. Photo credit: Luke Steinberger.
Heat canker on just-emerged wheat.
Photo 2: Heat canker on just-emerged wheat.

Jochum Wiersma, Extension agronomist

Reviewed in 2021

Share this page:
Page survey

© 2022 Regents of the University of Minnesota. All rights reserved. The University of Minnesota is an equal opportunity educator and employer.