Have You Been Accurately Staging Your Corn Plants in Later Vegetative Growth Stages?

There are various ways to count growth stages of corn plants throughout the season. We use methods such as leaf over and corn height to decide when to come into fields and apply post emergence herbicides. Though what is the best method to assess corn growth in later vegetative stages? This becomes challenging when lower leaf senescence occurs and you can start to lose earlier developed leaves. 

 

 

One of the most commonly used ways to consistently determine corn staging throughout the growing season is done by the leaf collar, or “V” method. When using the leaf collar method it is important to count all visible leaf collars starting from the first, rounded tip leaf to the uppermost visible leaf collar. As pictured in Figure 1, leaf collars can be distinguished as light yellow in appearance with a shirt-like collar at the base where the leaf blade meets the leaf sheath (True-Collar). Leaves still wrapped in the whorl that are not disclosed, do not count as a growth stage until the true collar becomes fully visible. Every true leaf collar is assigned a vegetative growth number. Therefore, since Figure 1 has eight visible true leaf collars, the plant is in V8 growth stage.