Published on Friday, August 5, 2022
The Corn Grower Degree Day (GDD) Decision support tool can help farmers identify the likelihood of early and late frost or freezes, estimated hybrid physiological maturity requirements and GDD projections, and historical and projected GDD when considering forward pricing and crop insurance purchases.
It's important to remember when utilizing the GDU calculator that it does not account for the fact that later planted hybrids require fewer GDUs to reach black layer. Research (Nielsen et al., 2002) indicates that on average, for every day of planting delay past May 1, plants require approximately seven fewer GDUs to reach black layer. For instance, if a hybrid is planted on May 31, that 30-day delay means the hybrid would require 210 fewer GDUs to reach black layer (Day Delay X 7 = fewer GDUs required to reach black layer). So, if a hybrid normally requires 2,610 GDUs to reach black layer, it would only require about 2,400 planted on May 31.
Author: Jim Schwartz
Categories: Agronomy, Agronomy Talk
Tags: corn, Replant, gdu, corn stand, termination