Corn emergence

By Stephanie Karhoff

Emergence issues can cause reduced stand and uneven plant development, lowering yield potential. As corn planting progresses throughout Ohio, revisiting the emergence process and how environmental and management factors influence it is important.

Corn requires between 100 and 120 growing degree days (GDDs) to emerge (based on air temperature). Daily GDD accumulation is determined by calculating the average daily temperature and subtracting the base temperature of 50 degrees F. Actual daily low and high temperatures are used if they fall between 50 and 86 degrees. If the temperatures are below 50 degrees or above 86 degrees, then 50 degrees or 86 degrees are used in the formula. This adjustment is made because corn growth rates do not increase above 86 degrees, and at 50 degrees, growth is already near zero.

After germination, the mesocotyl will elongate and push the coleoptile up until it breaks through the soil surface.… Continue reading