Calculating Growing Degree Day Units for Plot

Thru yesterday, June 2nd, the plot accumulated 470 GDD units, slightly behind short-term average accumulation and right in the middle of the long-term average range of 365 GDD’s to 682 GDD’s. At 470 GDD’s the plot averages V-4 (vegetative growth stage), and once the plot accumulates 583 GDD’s, the plot will be at V-6 stage. Since our last post on May 17th, the plot has benefited from 4 inches of timely rainfall, and now the plot needs some heat units. The 3-5 day forecast for Pike County, Illinois includes temperature ranges of 82-88 degrees and sunny conditions, perfect for adding GDD”s and helping the plot hit the nitrogen and put on vegetative growth.

The bottom chart, courtesy of the Midwest Regional Climate Center, shows the GDD accumulation along with the long-term average range thru June 2nd. According to the chart, the plot is currently projected to hit silk stage around July 15th.

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