Field cap

Field cap (Agrocybe dura) is a basidiomycete fungus commonly found in agricultural landscapes. While it is primarily a saprotroph that decomposes organic matter, it plays a complex role in agro-ecology. In agricultural settings, it can compete with crops for soil nutrients, potentially acting as a problematic organism in high-organic-matter cultivation systems.

The biology of Agrocybe dura involves the secretion of powerful extracellular enzymes designed to break down cellulose and hemicellulose in plant residues. This biological activity often results in the immobilization of mineral nitrogen in the soil, which creates a competitive environment for young crops. Consequently, seedlings may exhibit symptoms of nutrient deficiency and stunted development during the peak growth of the fungal mycelium.

This fungus typically thrives in environments enriched with organic mulches, compost, or crop residues left on the soil surface. It is frequently identified in commercial greenhouses and open fields where vegetable crops are grown under intense fertilization programs. The presence of the fungus is often overlooked until the appearance of its characteristic yellowish-brown mushrooms on the ground.

Symptoms of its influence on plants include reduced vigor, leaf chlorosis, and poor root development. Unlike direct fungal pathogens like Fusarium or Rhizoctonia, Agrocybe dura does not invade the plant's vascular system. Instead, its negative impact is indirect, stemming from the degradation of the local soil structure and the alteration of the rhizosphere chemistry.

• Implement deep plowing to bury crop residues early in the season.
• Improve soil aeration to hinder mycelium growth.
• Regulate nitrogen fertilization to compensate for potential immobilization.
• Monitor greenhouse humidity levels to prevent fungal fruiting.
• Remove and destroy fungal sporocarps before they release spores.