As we prepare ourselves for harvest, there are still field symptoms to keep an eye out for. It is important to consider the end of season nutrient stress in your corn fields for current management decisions and for next season decisions.
Common areas of concern are going to be on the ear itself. Aborted kernels and ear abnormalities reflect nutrient, sugar and protein limitations to the kernels during grain fill. When kernel development is minimal at the tip of the ear, this could be due to poor pollination or kernel abortion. Multiple stress conditions may cause kernel abortion. Common stress conditions such as heat, moisture, hail, foliar, insects, disease or nitrogen deficiency are all things that could cause an ear to abort kernels. There is also the possibility that cloudy conditions occurring after pollination or plants being shaded from sunlight can also cause aborted kernels. If you have ears that are consistently filled to the tip, it is a strong indication that you could bump up your planting populations to maximize yield potential.
Stalks can also show you quite a bit about the plant’s health if you know what to look for. Nitrogen deficiency will cause stalks to weaken when the demand for carbohydrates to fill kernels cause the plant to remobilize nutrients from the stalk tissues. Potassium deficiency can also decrease the strength of stalks making them more prone to lodging. Not only can potassium help with stalk strength, lack of the nutrient can also lead to rotting of the stalk and difficulty for the plant to support photosynthesis.
Just remember that even though we are getting extremely close to harvest, it does not mean your fields don’t need to be checked. They always have something to tell you even if it will only be helpful for making decisions for next season