The following is from Jeff Burbrink, Elkhart County Extension educator.
As you drive the county roads today, you can't help but see that much of the corn is light green or yellow in color, especially near the base of the plant. While it is not fair to judge an entire field by the rows closest to the road, there is a clear indication that much of our color has nitrogen deficiency this year.
Much of that N deficiency, of course, is related to the tremendous amount of rain we had in May, June and July. Nitrate is a nutrient that can dissolve in water, and if not tied up in soil organic matter or used by the plant, it can, and did, wash away.
At the recent Pinney Purdue Field Day Bob Nielsen, Purdue Extension's corn specialist, explained that when a corn plant is short on nitrogen (N), it has the ability to move N from the lower part of the plant to the upper leaves, where it is used to more effectively fill the ear.
Unfortunately, the movement of N and other nutrients from the lower stalk into the ear of corn also sets up the plant for stalk rots. Nielsen warned that this fall could be very challenging in those fields showing signs of N deficiency due to those stalk rot concerns, and he urged farmers to check fields for stalk rots and ear rots. Those fields showing signs of early stalk rot are vulnerable to lodging, which, of course, leads to yield losses.
Fields that have had stalk rots before are often the fields that will have stalk rots again. Consider taking a look that those fields, and those exhibiting signs of (N) deficiency early in September. Those fields with higher levels of stalk rots should be harvested early if possible.
Kirsten Wise, Purdue Extension's crop disease specialist, suggested you look closely at corn ears also. There is a high probability that ear rots will be an issue this year also. As you examine ears, she suggested looking at the base of the ear, not just the tip. Many of the ear rots will start where the ear attaches to the stalk. Harvesting early to prevent further loss, and drying the grain to below 15 percent are the two primarily management strategies in fields with ear rots.
Depending upon the ear rot, there may also be risks of toxins being produced that can affect the nutritional value of the feed. As we move closer to harvest, I will try to keep you aware of what we are seeing in area fields. For now, I would encourage growers to be checking fields.