Mortierella root rot

Mortierella root rot is a plant disease caused by fungi belonging to the genus Mortierella. While these fungi are common soil inhabitants that typically live as saprotrophs on organic matter, they can behave as opportunistic pathogens under specific environmental conditions, attacking the root systems of agricultural crops and seedlings.

This pathology is categorized as a type of soil-borne root rot. The fungus invades the root tissues, causing necrosis and softening, which significantly impairs the plant's ability to absorb water and nutrients. In severe cases, the infection results in damping-off, where young seedlings collapse and perish, leading to significant stand losses in agricultural fields.

The host range includes a variety of crops, such as vegetables, cereals, and industrial plants. Susceptibility is highest during the early stages of plant development. Greenhouses and nurseries are particularly prone to outbreaks, as the controlled, humid environments often created for crop production favor the rapid colonization and spread of the Mortierella mycelium.

Symptoms of the disease manifest as stunted growth, wilting, chlorosis, and root discoloration. The roots often appear mushy and necrotic. A fine, web-like mycelium may sometimes be visible on the roots or surrounding soil in high-humidity conditions. The disease is most aggressive in cold, waterlogged soils where the root health is already compromised.

• Implement diverse crop rotations.
• Improve soil drainage to avoid waterlogging.
• Use high-quality fungicide-treated seeds.
• Promote healthy soil biology with beneficial microbes.
• Avoid overwatering in seedling production stages.

Effective management relies heavily on preventative agronomic practices. Since Mortierella is a common soil component, complete eradication is often impossible. Therefore, the focus remains on environmental management, such as maintaining optimal soil moisture levels, ensuring adequate aeration, and using biological control agents like Trichoderma to outcompete the pathogen and ensure plant vigor.