As a member of the Latham Corn Product Team, it’s my job to walk research plots throughout the growing season and take notes. It’s hard to put into words just how exciting these crop tours have been this fall! The performance of Latham® corn products has been outstanding, so I’m having fun making recommendations for promising new products that could complement our current lineup.
We not only take these plots to yield, but we also note disease pressure. This year we noticed more hybrids than normal with some degree of stalk rot or stalk cannibalization. When cutting damaged stalks lengthwise, I usually found the internal pith tissue was still white and not compromised by disease. They may be shrunken, cracked, or otherwise weakened, yet the stalk rot didn’t invade the plant.
In high-yield environments, a shortage of nutrients or other weather-related stress weakened the plant by mobilizing sugars or nutrients that were stored in the stalk, and moved them to the ear to help fill kernels. Usually any factor that stresses corn allows pathogens to enter the plant: wet soils, daytime temperatures that are either too hot or too cold, nighttime temperatures that are too warm, flooding, moisture stress, hail, or leaf diseases.
There are very few (if any) years with ideal growing conditions, so it’s important to scout and manage fields for disease before harvest every year. Stalk rots don’t show up until later in the growing season, so I start scouting for them in August at the same time I am looking for leaf diseases. Early symptoms include dying lower leaves and the plant color appears pale green to gray.
While there is no one way to eliminate stalk rots and disease, the best management practice is to manage stress on the corn plants including proper soil drainage, proper fertility, plant selection and populations, foliar fungicide, and crop rotations.