Date of this Version



© 1977, The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved.


Herbicides recommended for postemergence application in corn, sorghum, and small grains are discussed in this NebGuide. Proper timing of postemergence herbicides is essential to achieve maximum weed control and minimum crop injury. As field crops grow and mature, their tolerance to herbicides changes. As a general rule, annual and biennial weeds are more susceptible to postemergence herbicides when they are in the seedling stage. As they mature they become increasingly difficult to control, facing the grower with the problem of when to apply the herbicide to achieve the least crop injury and the most satisfactory weed control. Field crops differ in their growth stages and, consequently, in the periods when postemergence herbicides safely can be applied. Each crop must be considered separately to identify the correct crop growth stage for the application of a specific herbicide.