Tomentella root rot

Tomentella root rot is a soil-borne fungal disease caused by various species of the Tomentella genus. While often characterized as mycorrhizal fungi in forest ecosystems, in agricultural settings, these pathogens can become opportunistic parasites, targeting the root systems and crowns of various crops.

The disease primarily impacts potatoes, vegetables, and ornamental nursery stock. The fungus colonizes the root cortex and stolons, manifesting as a thin, felt-like mat on the surface of the infected tissues, which can be easily identified under moist soil conditions.

Symptoms are often non-specific, resembling other root rots: stunted vegetative growth, chlorosis, and general wilting during midday. Upon closer inspection, the presence of brown or greyish fungal mycelium around the base of the stem confirms the infection, which often restricts nutrient uptake and leads to significant yield losses.

Optimal development for Tomentella occurs in poorly drained, acidic soils with high moisture content. The fungus survives in the soil and on crop debris, making it a persistent threat in fields with low biodiversity and repetitive cultivation of host crops without proper sanitation.

Effective management requires a multi-faceted approach:

• Implementing long-term crop rotation to break the pathogen's life cycle.
• Improving soil drainage and structure to prevent favorable humidity for fungal growth.
• Applying fungicides specifically labeled for soil-borne pathogens during planting if the field has a history of the disease.
• Using biocontrol agents like beneficial fungi to suppress the development of pathogenic Tomentella in the rhizosphere.