2023 Corn Stage and GDD Report

By: Ben Hepler, Nutrient Management Community Educator

It is that time of year again! Forecasting silage harvest dates after tasseling using Growing Degree Days (GDD) is a great way to help plan your harvest and be successful.

It takes out half of the risk by forecasting silage harvest after the corn has tasseled. Through research done by Dr. Bill Cox at the Musgrave Research Farm, corn with a relative maturity (RM) of 96-99 need about 750GDD after tasseling to get it near silage maturity. Corn with a RM of 100-115 need about 800GDD. Both methods get the corn to about 32% dry matter (DM). Four to six days may pass before corn is ready to chop at the 35% or higher DM.  By using the Climate Smart Farming website, you can track GDD by field location and see what the forecasted harvest date might be. In the example below, we changed the planting date to the tassel date and enable targets to 800GDD. This will give a forecasted harvest window. Once corn starts to dry down, it averages .5% per day depending on weather. As corn silage harvest approaches CCE of Delaware County Ag team will be collecting corn samples to test their dry matters. This will help pin point the week to start harvesting and get the most from your corn crop.

Remember that all things depend on the weather and the Climate Smart Farming website is only a guide to work out when corn silage might be ready.

Early planted Corn started to tassel between July 23^rd and July 25^th. Using 800GDD as the target for reaching silage maturity and utilizing the Climate Smart Farming website, silage harvesting equipment should be ready around September 17^th with actual harvesting taking place a few days later.

For More information on using the Climate Smart Farming website, type www.climatesmartfarming.org or to learn more about the GDD tool, type http://climatesmartfarming.org/videos/csf-growing-degree-day-calculator-video-introduction-and-practical-usage/