After raining almost every day last week, I saw field corn that was yellowing. All plants had same symptoms and ranged from V2 to V5 growth stage. Some lower leaves were solid yellow indicating N deficiency and certainly nutrients have leached with rains. The stripes in leaves pictured below resemble Magnesium deficiency. For Mg, UGA Extension Fertility Specialist, Dr. Glenn Harris, says you can spread Kmag, spray Epsom salts, or put Epsom salts through the pivot.
Seminole Ag Agent, Rome Ethredge, discovered field corn with Sulfur deficiency and nematodes. With corn yellow, he discussed 4 primary reasons we are seeing this now:
- Leaching rains have depleted nutrients such as Nitrogen and possibly Sulfur, and it’s time to add more but it’s too wet to run the spreaders or liquid rigs to put it out.
- Another reason is the erratic cool weather, with some very cool nights.
- Wet soil. The soil is staying so wet that we are loosing soil oxygen and that is bad for roots.
- Nematodes – which goes along with poor growing conditions. Nematodes affect the roots and therefore plant growth and health.
A last reason that we is not counted is that where over the top herbicide applications have been made, that many times further yellows corn for a few days as well.