This may look like a “just harvested” corn field and it is, but with a very important difference. This field is suffering from a severe case of stalk rot!
What is stalk rot? It is a disease of the stalk that really shows up or let’s say, gets worse as the stalk is maturing or just before grain harvest. This disease can be the result of either a fungus or a bacteria infecting the plant, but getting worse as the plant goes through some sort of stress. That said, every year in almost every field of corn, there is stalk rot in some parts of the field. The disease is not hardly noticeable most years, but sometimes in some fields like this one, it can be almost 100% of the field.
According to a great publication (linked to at the bottom), “Stalk rot diseases tend to be more common in higher yielding hybrids that produce large, heavy ears. During times of stress, such as when foliar disease cause substantial loss of leaf area, these large ears may cannibalize carbohydrates from the stalk and weaken it.” Of course, a plant that is weakened but with heavy ears will lodge or fall over making harvest difficult or impossible.
If you look closely at the picture you can see that most of these plants and ears did not make it through the combine because they were already on the ground. One practice, to prevent as much loss, is to be scouting fields early, checking to see if stalks are weak or prone to break over. If there is significant damage starting to show up then harvest as soon as possible.
Unfortunately, or fortunately, this was a great corn year with great yields. This great year may have set up the plants for stress which allowed the fungi (probably fusarium) to invade plant stalks causing stalk rot. To read the publication from Nebraska Extension just click the box below.
Texas A&M AgriLife Organic 