Each week we will be offering the air Growing Degree Days (GDDs) for corn that have accumulated to date from 13 locations across the team 8 county area.  A thank you to our intern Peter Burritt for pulling this information together.

Four planting dates will be listed and included will be:

GDDs Season To Date
15 Year Average GDDs
30 Year "Normal" GDD
Period of Record - Max and min recorded GDDs for that time period

See Growing Degree Day Calculator

Growing Degree Days for corn are Base 86/50 degree F and calculated by taking the average daily temperature, ((Daily Max Temp - Daily Min Temp)/2) - 50.  But the maximum temperature cannot be more than  86 degree F and the minimum less than 50 degree F.

With the exception of the May 1 planting date GDDs are at or above the 15 year average and definitely above the 30 year "normal" for the date.

Corn will reach the V12 stage by around 815 GDDs which we have achieved at many locations with the exception of higher elevations.  Earlier planted corn at lower elevations may approach tasseling/silking (1200-1300GDDs) in the next week if high temperatures continue.

The potential number of kernels per row is developed coming into the V12 stage so yield can begin to be limited by drought and or nutrient deficiencies at that time.  Drought stress becomes even more critical as corn approaches silking as the greatest yield losses can occur at that time.  As of July 7, all eight of our counties were listed in the abnormally dry category at the United States Drought Monitor site and much of Saratoga County indicated as moderate drought:
NY State Drought Monitor Map

See the attached table for more of the July 10, 2020 results.
See the attached pdf for a good guide on corn development and our reference for growth stages.