Submitted to: Forage Focus
Publication Type: Trade Journal
Publication Acceptance Date: 11/22/2016
Publication Date: 12/1/2016
Citation: Samac, D.A. 2016. Why is my alfalfa yellow?. Forage Focus. December 2016 p. 18-19.
Technical Abstract: In 2016, many parts of the Midwest experienced far wetter than normal summer weather and by August or September, many growers were asking, “Why is my alfalfa yellow?” When all or part of an alfalfa field is yellow, it is a certain sign that something has gone wrong. In this case the problem in most areas was due to the wet soil conditions that resulted in nitrogen deficiency and root rot. Fields where this occurred should be monitored closely in spring to determine the amount of winter injury and winterkill. Plants under nutrient stress are more likely to succumb to crown rot and root rot diseases, especially those that are active in cold soil, such as brown root rot of alfalfa. This article discusses the different causes of yellowing in alfalfa and with a little detective work, you can identify the most likely cause of yellowing in your alfalfa stand and take corrective action.