Peziza repanda

Peziza repanda is a common species of cup fungus belonging to the Pezizaceae family. It is essential to clarify that it is not a plant disease in the phytopathological sense. It is a saprotroph, meaning it feeds exclusively on decomposing organic matter and does not cause infections in healthy, living plants.

The fungus thrives in environments with high moisture and an abundance of cellulose-rich materials, such as decaying wood, garden mulch, or immature compost. In agricultural settings, its presence is often a biological indicator of excessive moisture and poor air circulation within greenhouses or garden beds.

While Peziza repanda does not parasitize crops, its proliferation can be a concern for farmers if it appears on structural wood or directly inside potting mixes. It can outcompete desirable microbes or create an excessively acidic microenvironment if the organic matter decomposition becomes too intense.

The primary symptom of its presence is the appearance of brownish, cup-shaped fruiting bodies, sometimes reaching several centimeters in diameter. These bodies emerge from the soil or rotting timber during damp conditions. Unlike pathogens, it does not cause visible lesions, necrosis, or chlorosis on leaves and stems.

Preventative measures are purely cultural and aimed at adjusting the growing environment. To minimize the presence of this fungus, focus on the following:

• Ensure proper drainage and avoid waterlogging.
• Improve ventilation to reduce atmospheric and substrate humidity.
• Replace rotting wooden greenhouse structures with non-organic alternatives.
• Avoid over-mulching with undecomposed organic materials near stems.