Microdochium

Microdochium is a genus of fungi that includes several plant pathogenic species. The most well-known and economically significant is Microdochium nivale, formerly known as Fusarium nivale, which causes snow mold in turfgrass, cereals, and other crops. This fungus is often found in cool, damp conditions and can overwinter under snow cover, leading to widespread damage in the spring.

Symptoms of Microdochium infection can vary depending on the host plant. In turfgrass, it typically manifests as circular patches of bleached or straw-colored dead grass, often with a pinkish or reddish hue at the margins. In cereals like wheat and barley, it can cause seedling blight, root rot, and a condition known as "pink snow mold," where affected plants exhibit a pinkish mycelial growth.

The life cycle of Microdochium involves the production of conidia, which are asexual spores, and sometimes ascospores, which are sexual spores. These spores are spread by wind, water, and contaminated equipment. Optimal conditions for infection and disease development are typically cool temperatures and high humidity.

Management of Microdochium diseases often involves cultural practices such as improving drainage, reducing thatch, and proper fertilization to promote healthy plant growth. In some cases, fungicides may be used to control outbreaks, particularly in high-value turf areas or commercial agricultural settings. Understanding the environmental factors that favor the fungus is key to preventing and managing infections.