Fusarium ear rot

The fungus Fusarium verticillioides is the primary pathogen responsible for Fusarium ear rot in maize. It is a cosmopolitan fungus that survives in crop debris and soil, acting both as a saprophyte and a parasitic agent capable of causing systemic infection throughout the corn plant.

While corn is the primary host for Fusarium verticillioides, the pathogen can also infect a variety of other crops, including sorghum and rice. The fungus initiates infection primarily through silk channels during pollination or through wounds caused by insects feeding on the ears, although seed-borne infection is also a common route.

Field identification is marked by the presence of a white to salmon-pink mycelial growth on the ear kernels. In many cases, this rot is localized around insect damage, but severe infestations can lead to a scattered pattern of individual infected kernels across the ear or entire ear rot if weather conditions remain favorable.

Development and spread are strongly correlated with environmental conditions, specifically warm temperatures and high humidity during the reproductive stages of corn development. Insects such as the European corn borer play a critical role as vectors and facilitators, opening infection courts for the fungus to enter the ear.

Beyond yield losses, the economic and health impact is driven by the production of fumonisins. These mycotoxins represent a significant food safety concern, as they are toxic to livestock and humans. Regulatory limits for fumonisins in corn grain often lead to market rejection of heavily infected harvests.

• Planting hybrids with good husk coverage to limit insect access.
• Utilizing fungicide seed treatments to minimize seedling blight.
• Implementing integrated pest management (IPM) to reduce insect damage.
• Rotating crops to break the pathogen's life cycle in the field.
• Ensuring proper grain drying and storage to prevent further mold growth.