Chad Lee, Extension Agronomist, University of Kentucky
Corn was planted late and the cool and cloudy days are slowing development. Most corn hybrids in Kentucky need about 2,700 to about 3,300 GDD’s or heat units to reach black layer (physiological maturity). Looking at the GDD calculator on the UK Ag Weather Center, corn planted April 15, 2013 in Mayfield, Kentucky won’t get to 3,000 GDD’s until Sept. 1. Corn planted April 15 in Henderson will get to 3,000 on Sept. 3. Corn planted May 15 in Lexington will get to 3,000 GDD’s about Sept. 27.
