Humaria hemisphaerica

Humaria hemisphaerica is a soil-dwelling fungus belonging to the Pyronemataceae family. While primarily a saprotroph that thrives on decaying organic matter, it is often documented in agricultural settings such as greenhouses, where it can colonize moist substrates and impact young plant development.

The fungus is characterized by its distinct, cup-shaped fruiting bodies (apothecia) that are typically covered in stiff, dark hairs. As an Ascomycete, it reproduces via spores that spread easily through water droplets and contaminated soil, making it a common visitor in poorly ventilated glasshouses.

Crops most susceptible to its presence are seedlings and small ornamental plants. In nurseries, it can colonize potting mixes rich in non-decomposed peat or manure. Although it does not usually kill healthy plants directly, its presence often indicates an imbalance in the substrate that can hinder plant growth.

Symptoms in the nursery include the appearance of small, hairy cup-like structures on the soil surface. Affected plants may show stunted growth, yellowing foliage, and compromised root health due to the competition for soil nutrients and oxygen saturation, especially in waterlogged conditions.

Prevention is the primary method of management. This includes sterilizing growing media to ensure organic material is fully broken down, maintaining appropriate drainage to prevent water stagnation, and regulating humidity levels. If the fungus appears, removing the fruiting bodies and applying fungicides can prevent further spore dispersal.