Be Cautious With Your Wheat Nitrogen Timing this Spring
Shawn Conley, WI State Extension Field Crops Plant Pathologist
With record high temperatures predicted this week if your winter wheat crop had not broken dormancy it soon will. I would like to caution growers and retailers to not get too anxious to apply N yet this spring. It is important to remember that the functional purpose of spring N is to 1. stimulate tillering and 2. provide crop nutrition. If ample tillering (> 70 tillers per square foot) has occurred growers can delay N applications up to pre-joint (Feekes 4-5; Zadoks 30). This practice will aid in minimizing early spring N loss. Applications of N made after this growth stage may lead to wheel track damage. If growers have < 70 tillers per square foot it is important to get across those fields as soon as possible to minimize yield loss due to low tiller/head counts. My concern related to an early application of N to a well tillered wheat crop is that we will stimulate crop growth and development which may increase the risk of yield damage if we get a sudden cold snap. I do not have a crystal ball but I would bet we have another heavy frost in our future. For more information related to freeze damage to winter wheat and to assess your risk for yield loss please read Know Your Wheat Growth Stage to Predict Wheat Freeze Injury.
For more information on assessing winter wheat stands please view Wheat Stand Assessment and Nitrogen Timing