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Protecting Your Midwestern Corn Fields from 4 Common Soil Diseases

Protecting Your Midwestern Corn Fields from 4 Common Soil Diseases

Corn cultivation faces challenges with diseases that threaten crop health and productivity. For farmers in the Midwest, where most of the nation's corn is produced, recognizing and combating the following diseases is essential to effective agronomic management. 

Every year, the United States dedicates approximately 90 million acres to corn farming, with Iowa and Illinois leading the charge. These states alone account for roughly one-third of the country's corn output. This blog post aims to share the knowledge and tools available to protect your corn fields from some of the most common and notable soilborne diseases.


Common Corn Soil-borne Diseases Corn in US


Four Common Corn Soil-borne Diseases

  1. Red Root Rot: Caused by the fungus Phoma terrestris., this disease affects corn roots, leading to rot and reduced nutrient uptake.

  2. Gray Leaf Spot: Caused by Cercospora zeae-maydis, this disease results in grayish lesions on corn leaves, potentially affecting photosynthesis.

  3. Diplodia Rot: Caused by Stenocarpella maydis, this disease affects corn ears, leading to rot and reduced grain quality.

  4. Nigrospora Rot: This fungal pathogen affects corn ears, causing mold growth and reducing grain quality.

Controlling Bacterial and Fungal Diseases in Corn

Preventing and treating common corn diseases is essential for maximizing crop productivity. Here are suggested preventions and treatments for the four most common diseases found in corn:

Red Root Rot

Red root rot in corn crops can be challenging to control due to the lack of disease resistant seed varieties available. This disease is often associated with high density corn populations, high fertility, and irrigation, so avoiding overly dense seed rates, overfertilization, and overirrigation can help mitigate outbreaks. Rotating to non host crops like soybeans helps break the disease cycle by disrupting the pathogen's survival and spread. 

Gray Leaf Spot

Controlling gray leaf spots in corn involves several key practices. Like many other fungal pathogens, this disease tends to prefer high moisture environments, and it can also be problematic in no-till and minimum tillage scenarios. Effective management of gray leaf spot in corn entails employing various strategies such as crop rotation, planting resistant hybrids, and tillage, where appropriate.

Diplodia Rot

Diplodia rot can be challenging to manage in corn due to the fact that fungicides do not demonstrate consistent efficacy in the field. Cultural practices like diversified rotations can prove beneficial for mitigating outbreaks, however, because this disease can overwinter in crop residues, at least a 2-year rotation away from corn may be necessary. Certain corn varieties demonstrate some degree of resistance to Diplodia rot, although no varieties are considered to be entirely resistant.     


Controlling Nigrospora in corn crops requires a comprehensive approach. Select a hybrid with resistance to Nigrospora rot, refrain from consecutive corn planting, particularly under conservation tillage practices, and minimize plant stress through proper fertilization and effective insect pest control.

BeCrop Biological Soil Analysis For Disease Treatment and Prevention

BeCrop® biological soil analysis offers a valuable tool for identifying and addressing various diseases affecting corn crops. By utilizing BeCrop® biological soil analysis, farmers can promptly detect diseases like Red Root Rot, Gray Leaf Spot, Diplodia Rot, and Nigrospora in corn fields. This technology enables targeted treatments and preventive measures to mitigate the impact of these diseases on crop health. The analysis is done by sampling soil and assessing the extent of the presence of various microbes, which also presents insights into the best way forward for disease prevention and treatment. 

See below a sample report where several diseases above were detected early from a single soil sample.


BeCrop Report

Protecting corn crops from diseases is essential for ensuring a successful harvest. By understanding common corn diseases, implementing preventive measures, utilizing BeCrop® biological soil analysis and maintaining a healthy microbial community in the soil, farmers can effectively safeguard the health and productivity of their corn crops.

Top Soil Diseases by Crop in US

Note: Biome Makers agronomists have identified some of the top soilborne bacterial and fungal diseases affecting crops in the US. These diseases are found in the soil. While not all soilborne diseases are included, the selected ones are among some of the most impactful, with variability by region. It's important to note that the diseases are not listed in order of impact, and they do not include viruses. The detection of these diseases is made possible by BeCrop technology and soil database, offering valuable insights for crop management and disease prevention.