Epichloe mollis

Epichloe mollis is a fungal disease that primarily affects wild and forage grasses. The pathogen is an ascomycete fungus that belongs to the group of endophytic micromycetes, which maintain a close, integrated relationship with the host plant tissues throughout their entire life cycle.

Unlike other species within this genus, this disease is characterized by the formation of a stroma around the grass stems. This leads to the development of the condition known as "choke disease," where the fungus restricts the development of the inflorescence, preventing it from emerging properly or producing viable seeds.

The primary hosts of this pathogen are species of fescue (Festuca) and several other perennial grasses. The fungus spreads both vertically, through infected seeds, and horizontally, via ascospores dispersed by wind or insects, making the infection difficult to manage in natural meadows and pastures.

The development of Epichloe mollis is favored by moderately warm and humid weather during the active growing season. High relative humidity is a critical factor for spore germination on young plant tissues, facilitating rapid spread across new areas of the field or lawn.

The economic impact of the disease involves a significant reduction in the seed yield of forage grasses. Because the pathogen suppresses the reproductive organs of the plants, farmers and seed producers suffer heavy losses. Additionally, infected plants may show reduced overall vitality and resilience to environmental stressors.

To effectively manage and prevent the spread of the disease, consider the following practices:

• Using certified disease-free seeds for planting.
• Mowing the grass canopy early to prevent the maturation of fungal sporocarps.
• Implementing crop rotation and maintaining spatial isolation from wild grass reservoirs.
• Monitoring fields closely during the early heading stages of growth.