In 2025 alone, over 244 million bushels were impacted by corn stalk rot diseases in the U.S.¹ Fungal or bacterial stalk rot of corn can be tricky to manage, so your first step should always be proper identification of the disease.
All stalk rots diminish a corn plant’s ability to transport water and take up nutrients. This weakens stalks and makes them more vulnerable to lodging in high winds.
Learn how to identify and compare stalk rot symptoms so you can address what’s going on with your crop.
Anthracnose stalk rot in corn
Anthracnose stalk rot is caused by the fungal pathogen Colletotrichum graminicola. It’s most prevalent in warm, humid regions and usually occurs after silking in warm, cloudy weather. It’s more common in fields with high residue and continuous corn.
Anthracnose stalk rot in corn infects plants through injuries caused by insects, hail or equipment.²
Anthracnose stalk rot symptoms
- Shiny black discoloration on the outer stalk near the nodes
- Shredded-looking pith inside the stalk
- Tan to reddish lesions on the rind
- Hollow and easily lodged stalks (in advanced stages)
- Top dieback or browning of the upper parts of the plant
- No tiny fruiting structures (pycnidia) appear on the exterior of the stalk (unlike other stalk rots such as Diplodia stalk rot, which often presents with pycnidia)
Gibberella crown rot and stalk rot in corn
Gibberella crown rot and stalk rot are caused by the fungus Gibberella zeae, the same pathogen that causes head scab in wheat and Gibberella ear rot in corn. That’s why Gibberella stalk rot in corn is more prevalent in wheat-corn rotations and continuous corn.
It prefers warm and wet conditions and will occur shortly after pollination. Infections can travel through roots via injuries on the stalk or on leaf scars.
Gibberella crown rot and stalk rot symptoms
- Pith will appear stringy and have a slight pink tint
- Stalk exterior will have tiny black or blue round fungal structures called pycnidia that can be scraped away with a fingernail
- Leaves can suddenly turn a dull green or gray
Fusarium stalk rot in corn
There are several species of Fusarium spp. that can cause Fusarium stalk rot in corn. The fungal mycelium, or the root-like part of a fungus, will overwinter in corn residue and can quickly spread via the wind and splashing in hot, dry years.³
Most symptoms appear near R5 when conditions are warm and dry and plants are stressed.⁴
Fusarium stalk rot symptoms
- The lower stalk will yellow, and the leaves will be dull green
- Stalk pith is deteriorated, appears hollow and shredded, and will have a pink or salmon color
- Plants might die before maturity, and roots are often rotted
- No tiny fruiting structures (pycnidia) appear on stalk exterior
Diplodia stalk rot in corn
Diplodia stalk rot is similar to other stalk rots and is caused by Stenocarpella maydis. If weather is dry before silking, then warm and wet after silking, there’s a good chance Diplodia stalk rot in corn will develop.⁵ Since this fungus will overwinter in corn residue, fields with continuous corn are most susceptible to infection.⁶
Diplodia stalk rot symptoms
- Symptoms can look like frost damage (wilted and grayish-green coloration)
- Pith inside the stalk is destroyed but lacks pink color
- Small black dots on the exterior of the stalk will develop and be embedded into the surface of the stalk, but they can’t be scraped off
- Stalk feels rough like sandpaper
- White mold can develop when fields are very wet
Get help assessing stalk rots in corn
Experts are available to help you diagnose stalk rots and make management decisions. 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
- Crop Protection Network. “Corn Disease Loss Estimates from the United States and Ontario, Canada — 2025.” Crop Protection Network, 6 Mar. 2026,https://cropprotectionnetwork.org/publications/corn-disease-loss-estimates-from-the-united-states-and-ontario-canada-2025. Accessed 22 June 2026.
- Esker, Paul D., Adriana Murillo-Williams, and Alyssa Collins. “Anthracnose Stalk Rot.” Cornell CALS Field Crops, Cornell University, https://cals.cornell.edu/field-crops/corn/diseases-corn/anthracnose-stalk-rot. Accessed 22 June 2026.
- “Fusarium Stalk Rot of Corn.” Crop Protection Network, 19 Mar. 2019, https://cropprotectionnetwork.org/encyclopedia/fusarium-stalk-rot-of-corn. Accessed 22 June 2026.
- Freije, Anna, Kiersten Wise, and Bob Nielsen. “Diseases of Corn Stalk Rot.” Purdue Extension, BP-89-W, Purdue University, 2020, https://www.extension.purdue.edu/extmedia/BP/BP-89-W.pdf. Accessed 22 June 2026.
- Freije, Wise, and Nielsen. “Diseases of Corn Stalk Rot.” Accessed 22 June 2026.
- “Diplodia Stalk Rot of Corn.” Crop Protection Network, 19 Mar. 2019, https://cropprotectionnetwork.org/encyclopedia/diplodia-stalk-rot-of-corn. Accessed 22 June 2026.
