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​​​​​​​FAQ: Fusarium graminearum and Fusarium Head Blight (FHB)​

​​​​​​​​​​1.​ What is Fusarium graminearum? 

Fusarium graminearum is a fungal plant pathogen that causes a serious disease called Fusarium Head Blight (FHB)—also known as “scab”—in wheat and barley. It also causes Gibberella Ear Rot and Gibberella Stalk Rot in corn. This disease is one of the most economically damaging plant diseases in the U.S. and around the world. 

The fungus infects the flowering heads of cereal crops, leading to premature bleaching and reduced grain yield. But the most dangerous aspect of F. graminearum is that it produces m​ycotoxins, especially deoxynivalenol (DON), also known as vomitoxin. These toxins can contaminate grain and pose serious health risks to humans and animals, causing symptoms like nausea, vomiting, fever, headaches, and digestive issues.​

2. Why is Fusarium graminearum harmful? 

The diseases caused by Fusarium graminearum not only reduce crop yields but also contaminate grain with dangerous mycotoxins. The most concerning toxin produced by the pathogen is deoxynivalenol (DON), also called vomitoxin. DON can cause serious health problems in humans and animals, including nausea, vomiting, fever, and digestive issues. It’s especially toxic to pigs and other animals with single-chambered stomachs. Due to these risks, grain is routinely tested for DON before it can be used in food or animal feed. 

Beyond health concerns in humans and animals, F. graminearum has caused billions of dollars in crop losses in the U.S. and Canada since the 1990s. The disease is difficult to control and tends to flare up under wet and warm weather conditions, making it a persistent threat to food security and farm profitability. 

​Thanks to decades of research done by plant pathologists, the U.S. has developed effective tools to manage the disease—but continued support for the research and vigilance in monitoring the pathogen are essential. ​

3. What are the risks due to scab, the disease caused by the pathogen Fusarium graminearum in wheat and barley? 

Fusarium Head Blight (FHB or scab) poses serious risks to human and animal health, farmers’ livelihoods, and the global food supply. Scab is not just a plant disease: it’s a threat to public health, farm economies, and food systems. That’s why continued vigilance, research, and responsible management are essential. 

Key risks of scab include:

• Health Risks: The fungus Fusarium graminearum that causes scab produces mycotoxins, especially deoxynivalenol (DON or vomitoxin). DON can contaminate grain and cause nausea, vomiting, fever, and headaches in humans. It is especially harmful to non-ruminant animals like pigs, disrupting digestion and growth.
• Economic Risks: Since the 1990s, scab has caused over $3 billion in crop losses in the U.S. alone. Contaminated grain often cannot go to market or must be sold at a steep discount. The disease can make wheat and barley production unprofitable, especially in areas with frequent disease outbreaks.​
  
• Food Security Risks: Scab affects wheat, barley, and corn, the staple crops used in bread, pasta, beer, and animal feed. Severe outbreaks can reduce the availability of safe, high-quality grain, threatening the national food supply.
• Environmental and Management Challenges: The fungus F. graminearum is naturally widespread in the U.S. and thrives under certain weather conditions. Outbreaks are hard to predict without advanced forecasting tools. Managing the disease requires ongoing research, timely fungicide use, and resistant crop varieties—all of which depend on sustained funding and farmer education.

4. What are the risks of Fusarium graminearum in corn? 

Fusarium graminearum causes Gibberella Ear Rot (GER) and Gibberella Stalk Rot (GSR), two of the most damaging diseases to corn crops in the United States. 

Gibberella Ear Rot (GER) infects corn ears during the flowering stage (called "silking") in wet conditions. This causes an accumulation of the deoxynivalenol (DON) mycotoxin in the grain, which is dangerous to humans and livestock if it gets into food or animal feed. 

Gibberella Stalk Rot (GSR) starts when the fungus enters the plant from the soil through the corn roots, spreading into the stalk. It tends to happen when corn growth is stressed by factors such as drought and leads to DON mycotoxin contamination in both the grain and stalk. Contamination of corn stalks is a concern for livestock that are fed corn silage (made from all parts of the plant). Corn stalks with GSR left in the field after harvest allow the fungus to survive winter and produce spores that will spread the disease in the crop the following year. 

Similar to scab, integrated disease management is vital to combatting GER and GSR in corn. This includes planting partially resistant corn hybrids, rotation with nonsusceptible crops, and fungicide use as warranted.

​5. Why is disease management of Fusarium graminearum important? 

Managing Fusarium graminearum is critical because of its widespread presence, economic impact, and the health risks it poses through the production of harmful mycotoxins like deoxynivalenol (DON). 

Disease management of this pathogen, and pathogens like it, is important to: 

6. What can be done to combat ​Fusarium Head Blight (scab)​? 

Combating Fusarium Head Blight (FHB or scab), requires an integrated approach that combines smart farming practices and science-based forecasting tools—all backed by decades of federally funded USDA and university plant pathology research with national coordination. 

There’s no single solution to scab, but this multi-layered approach can help farmers significantly reduce the impact of this devastating disease. 

Steps to address scab include:

7. Why is regulation important for pathogens like Fusarium graminearum? 

Regulation is essential to protect U.S. agriculture, food safety, and public health from the risks posed by Fusarium Head Blight (scab), Gibberella ear rot, and their causal agent, Fusarium graminearum, as well from other plant pathogens and pests. Regulation isn’t about slowing down science—it’s about doing science safely and responsibly. Following the rules protects our crops, our economy, and our health. 

Additionally, regulation can: 

• Prevent the Spread of Dangerous Strains: F. graminearum is already widespread in the U.S., but strains from other countries may produce different or more potent toxins. Introducing new strains—intentionally or accidentally—could increase the severity of disease outbreaks or present new health risks.
• Ensure Safe Research Practices: Researchers often move plant pathogens across borders for research, but this must be done legally and safely. The USDA Animal and Plant Health Inspection Service (APHIS) ​requires a phytosanitary permit for importing pathogens like F. graminearum. These permits ensure that proper containment and safety protocols are followed.
• Support Responsible Science: Regulation helps maintain public trust in agricultural research. It ensures that scientists can study pathogens like F. graminearum without putting crops, ecosystems, or food systems at risk.​
  

8. Why is research and the work that plant pathologists do to combat pathogens like Fusarium graminearum important?

Plant pathologists are on the front lines—defending our crops, our health, and our economy. Their work is essential to protecting our food supply, economy, and public health. They work hand-in-hand with farmers to reduce disease and Fusarium-associated toxins through resistant crop varieties, fungicide strategies, and forecasting tools. These solutions are based on and validated by decades of scientific study and are constantly being improved to adapt to changing weather and farming practices. 

Pathogens like Fusarium graminearum thr​eaten staple crops of wheat, barley, and corn—the foundation of bread, pasta, beer, and animal feed. Without plant health research, we wouldn’t have the tools to detect, manage, or prevent devastating outbreaks of Fusarium Head Blight (FHB or scab). Over the past 30 years, scab has caused over $3 billion in crop losses in the U.S. alone. Research dedicated to scab has helped farmers protect their yields, maintain grain quality, and stay profitable, especially in regions where the disease is a recurring threat.