Drought is one of a number of potential causes of stalk rot, which takes place when photosynthesis is slowed. And, now is the time to start scouting to see what kind of trouble you might face because of stalk rot once you begin harvest," says University of Illinois Extension educator Angie Peltier.
"Stalk rots increase lodging potential, which can decrease harvestable yield and leave much of it on the ground. Corn plants are top-heavy, and stalk rots increase the chances that plants will fall over, or lodge, due to gravity or wind and weather events," she says.
If you know you have stalk rot in your fields right now, you're out of luck for this year. There's no way to get rid of it at this point in the year. But, reaching that diagnosis can only come in scouting your fields now. Peltier recommends checking stalks for discoloration around the outer margin of lower nodes.
"External symptoms do not indicate what is happening inside the plant. Plants with rind symptoms do not necessarily have internal symptoms, and some plants without any external symptoms can be severely diseased inside," according to a University of Illinois Extension report. "Internal symptoms include blackened and discolored tissue that can be easily crushed."
If you scout and you do find it, it's not the end of the world. Timing gets more important, though, both for scouting and harvest. Make sure you don't wait too long to scout, and if that scouting does ultimately reveal stalk rot, consider rearranging your harvest plans.
"Begin scouting just before physiological maturity, when grain moisture is between 30% and 40%. Scout each field either by pinching or pushing plants. Walk each field in a zig-zag pattern, checking 20 random plants from 5 spots in the field," according to a university report. "Lodging potential is significant if 10% to 15% of the plants fail. Harvest the fields with the greatest lodging potential first. When harvesting lodged corn, drive slowly, and harvest against the grain."
If you're worried about stalk rot down the road, there are ways to minimize your chances if seeing it again next year. First, look for seed that has a good standability rating. And, consider crop rotation and management practices that can help foster better moisture and nutrient balance in the plants and soil, "such as balancing soil fertility, planting recommended populations and scouting and treating for insects and diseases that have reached economic thresholds," Peltier says.
