Ivory funnel

The ivory funnel (Clitocybe dealbata) is a toxic saprotrophic fungus that, while primarily known as a forest or grassland inhabitant, can become a significant nuisance in agricultural and horticultural settings, particularly on lawns and managed pastures. It is recognized for its ability to modify the soil environment in ways that negatively impact the health and vitality of surrounding vegetation.

This fungus typically targets turfgrasses and pasture vegetation. By establishing an extensive mycelial network in the root zone, it disrupts the ability of grass plants to uptake water and essential nutrients. This competitive interaction leads to poor growth, thinning stands, and the appearance of unsightly patches in otherwise healthy turf.

The most distinctive symptom of an infestation is the development of «fairy rings». These are circular or semi-circular patterns of grass that show stress symptoms such as yellowing, browning, or stunting. In the later stages of development, the fungus produces small, pale, funnel-shaped fruiting bodies along the edges of these rings during cool and wet weather conditions.

Environmental conditions that favor the spread of Clitocybe dealbata include high soil moisture, poor drainage, and the accumulation of thatch or decaying organic matter. The mycelium thrives in compacted soils, making golf courses and frequently mowed lawns particularly susceptible to colonization if aeration is neglected.

The economic impact involves the high cost of restoring degraded turf and potential health risks to livestock grazing on infested pastures. Protection strategies include regular aeration to improve soil drainage, dethatching to reduce food sources for the fungus, and targeted application of fungicides. Preventive measures should focus on maintaining optimal soil pH and balancing fertility to promote strong, competitive turf growth.