Vernalization requirements for winter wheat

by | Mar 1, 2020 | Ohio Country Journal

By? Laura Lindsey, Will Hamman, Ohio State University Extension

In the southern portion of the state, above-average temperatures have resulted in winter wheat remaining green (see picture). Will the vernalization requirement be met?

Winter wheat has molecular regulation preventing the transition to reproductive growth until a certain threshold of cold days has been reached. This regulation is called “vernalization.?? In winter wheat, the vernalization period protects plants from breaking dormancy too early.

The vernalization requirement varies among cultivars and is temperature (and day length) dependent. In a study conducted on one winter wheat cultivar, it took 40 days for plants to achieve vernalization at 52°F while it took 70 days for plants to achieve vernalization at 34°F. Temperatures above 64°F were ineffective for vernalization. Although winter wheat is green and the winter temperatures have been fairly mild, winter wheat should meet the vernalization requirement.

Once the vernalization requirement has been met, growth is driven by growing degree units.? Continue reading