By August, many growers have a clearer picture of what their corn crop can deliver. Kernels are starting to fill, stand density is easier to evaluate and harvest is beginning to come into view.
But late-season risks can still threaten yield potential before the combine enters the field.
One of those risks is corn stalk rot. What looks like healthy stalks of corn from the road may already be vulnerable to disease, weakness and lodging. When stalks break down before harvest, lodged corn can slow harvest, increase ear loss and reduce returns.
August may be the time to finish strong, but it’s not the time to let your guard down when it comes to protecting stalk integrity, lodging in corn and your bottom line.
What causes stalks of corn to lodge late in the season?
Corn lodging can result from a variety of factors, including drought stress, nutrient deficiencies, late-season weather and diseases such as corn stalk rots.¹
While symptoms can vary by stalk rot species, many of them weaken the lower stalk by breaking down or damaging internal stalk tissue. As the pith deteriorates, the stalk loses some of the structural support it needs to hold the ear upright through grain fill and into harvest. That weakened stalk is more likely to collapse, especially when late-season winds, heavy ears or prior drought and nutrient stress have already put the plant under pressure.
How stress and foliar disease affect corn stalk strength
Late in the season, the ear becomes the corn plant’s top priority. Much of the sugar produced through photosynthesis is directed toward grain fill, helping the plant finish kernel development before harvest.
When drought, nutrient stress or corn stalk diseases limit photosynthesis, the plant may not produce enough carbohydrates to support the developing ear. In response, it can begin pulling stored sugars from the stalk to help finish grain fill. This ultimately weakens the lower stalk and makes it susceptible to breaking and lodging from heavy rains or wind.²
Foliar disease can intensify that risk by reducing healthy green leaf area, limiting photosynthesis and increasing the pressure on the stalk. Protecting the plant late in the season can help preserve the green leaf tissue needed to support grain fill, maintain stalk integrity and reduce the risk of lodged corn before harvest.
A late-season fungicide application, like Veltyma™, can help protect green leaf tissue during grain fill, supporting the plant’s ability to maintain photosynthesis and reduce stress on the stalk. By helping preserve plant health, Veltyma can play a role in maintaining stalk integrity, improving harvest efficiency and protecting yield potential.³
By August, the focus shifts from building yield potential to protecting what’s already been earned. Managing foliar disease including corn stalk rot, monitoring stalk strength and supporting late-season plant health can help reduce the risk of lodged corn and keep harvest moving more efficiently.
Experts are available to help you mitigate the risk of corn stalk rot. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.
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Endnotes
- Telenko, Darcy, and Dan Quinn. “Stalk and Ear Rots: The Importance of Identifying Them Now to Help with Harvest Decisions.” The Kernel, Purdue University College of Agriculture, 21 Sept. 2023, ag.purdue.edu/news/department/agry/kernel-news/2023/09/2023-corn-stalkrot-earrot.html.
- Robertson, Alison, Meaghan Anderson, and Rebecca Vittetoe. “Crop Standability an Issue This Fall.” Integrated Crop Management, Iowa State University Extension and Outreach, 12 Sept. 2023, crops.extension.iastate.edu/post/crop-standability-issue-fall.
- Jackson-Ziems, Tamra A., Jennifer M. Rees, and Robert M. Harveson. “Common Stalk Rot Diseases of Corn.” Nebraska Extension Publications, University of Nebraska–Lincoln, 23 Sept. 2009. Revised 12 Nov. 2014, extensionpubs.unl.edu/publication/ec1898/common-stalk-rot-diseases-of-corn.
