Plant Disease · Plant disease

Fusarium Head Blight

Fusarium graminearum (teleomorph Gibberella zeae) and related Fusarium species

Also known as: FHB, Head scab, Ear blight, Scab

Fusarium head blight is a fungal disease of cereal heads caused chiefly by Fusarium graminearum. It bleaches infected spikelets, shrivels grain, and can lead to mycotoxin contamination, making it a serious food-safety as well as yield concern.

Dated referenceLast reviewed: 2026-07-13Updated: 2026-07-13

Illustrative diagram · AgricultureID (original)

Fusarium head blight, often called head scab, is caused by a complex of Fusarium fungi, with Fusarium graminearum the most common species in many regions. It infects the flowering heads of wheat, barley, and other small grains, as well as maize ears, bleaching florets and preventing normal grain development.

Beyond direct yield loss, the disease is important because some Fusarium species produce mycotoxins that can accumulate in grain and affect its safety for food and feed. This dual impact on both quantity and quality makes head blight one of the most closely managed cereal diseases, with strong emphasis on prevention around flowering.

Symptoms and identification

In wheat, infected spikelets lose their green colour and turn straw-coloured or bleached while the rest of the head is still green, so partly bleached heads are a classic sign. Under humid conditions, pink-to-orange fungal growth may appear at the base of infected spikelets. Affected grain is often shrivelled, chalky, and lightweight, sometimes with a pink tinge. In maize, related Fusarium species cause ear rots with pink to white mould on kernels.

Pathogen and disease cycle

Fusarium fungi survive on infected cereal and maize residue, where they produce spores that are splashed and wind-dispersed onto cereal heads. Infection is concentrated around flowering, when open florets are most susceptible. Warm, wet conditions during this narrow window strongly favour infection and later mycotoxin accumulation.

Infected cereal and maize residue is the main source of inoculum
Spores reach heads by wind and rain splash during flowering
The flowering period is the critical window for infection
Warm, humid weather at flowering increases both infection and toxin risk

Hosts and favourable conditions

Wheat and barley are the most economically affected cereals, with oats, triticale, and rye also susceptible, and maize hosting related Fusarium ear rots. Cropping sequences that place cereals after maize or after cereals, combined with retained residue and wet weather at flowering, create the highest risk.

Warm, wet, humid weather coinciding with crop flowering
Cereals grown after maize or after cereals with residue retained
Reduced tillage that keeps infected residue at the surface
Susceptible varieties and uneven flowering across a field

Management principles

Because infection is tied to flowering, management combines longer-term measures that lower inoculum with in-season attention to the flowering window. Resistance is only partial in most cereals, so an integrated programme is essential.

Grow varieties with the best available head-blight resistance ratings
Rotate away from maize and cereals and manage residue to reduce inoculum
Use head-blight risk tools and weather information around flowering
Aim for even crop stands so flowering is more uniform and easier to protect
Follow grain-safety testing and segregation guidance where toxins are a risk

Relationships

Evidence-backed connections in the knowledge graph.

Affects

Risk increases under

Scope & limitations

Geographic scope: Global; occurs across cereal- and maize-growing regions, with severe outbreaks and mycotoxin risk concentrated where warm, wet weather coincides with flowering.

Climate context: Favoured by warm, wet, humid weather during the flowering window; the same conditions that drive infection also increase the risk of mycotoxin accumulation in grain.

This is a general overview and does not replace field diagnosis or region-specific extension guidance.
The Fusarium species present and their mycotoxin profiles vary by region and season; grain-safety thresholds are set by local authorities.
Control-product recommendations are jurisdiction-specific and are deliberately not provided here.

Sources

This article draws on the following authoritative sources. See our sources & methodology for how they are selected.

[1]CABI Digital Library — Crop Protection Compendium (opens in a new tab)
CABI (Centre for Agriculture and Bioscience International)
High
Cited for: Pathogen complex, disease cycle, and host range
Type:
Reference database
Jurisdiction:
Global
Accessed:
2026-07-12
[2]EPPO Global Database (opens in a new tab)
European and Mediterranean Plant Protection Organization (EPPO)
Authoritative
Cited for: Pathogen nomenclature and distribution
Type:
Reference database
Jurisdiction:
Global
Accessed:
2026-07-12
[3]CIMMYT — International Maize and Wheat Improvement Center (opens in a new tab)
International Maize and Wheat Improvement Center (CIMMYT)
High
Cited for: Cereal head-blight resistance and integrated management context
Type:
Research institute
Jurisdiction:
Global
Accessed:
2026-07-12
[4]University of Minnesota Extension — Crop and pest resources (opens in a new tab)
University of Minnesota Extension
High
Cited for: Identification, flowering-window risk, and management principles
Type:
University extension service
Jurisdiction:
United States (Minnesota)
Accessed:
2026-07-12