Where was your corn on September 1st?

Mike Rankin
Crops and Soils Agent
University of Wisconsin - Extension

       In most years we like to see corn dented by September 1st.  That's just not happening for most area fields in 2004.  Many charts have been developed based on Growing Degree Days (GDU's) to estimate time to crop maturity (black layer).  Although this method seems reasonable, there is also the complicating factor that the plant will speed physiological development simply because it "senses" the end is near.  With this in mind, I offer the following chart as my best guess as to how many days it will take corn to reach either 1/2 milk (silage stage) or physiological maturity (black layer) given the stage of development on September 1st.  Remember, be realistic in how you assess your crop.