Debilitated animals should be moved quietly to a dark, quiet barn corner and supplied with endophyte-free feed and water until the toxins have been cleared from their system. Starting with fungus-free seed from a plant breeder, it is a simple matter to produce perennial ryegrass seed which is free of the endophyte. There are important agronomic advantages, however, for the presence of the endophyte. In New Zealand, insect resistance provided by the endophyte is so important that endophyte-free grass is not planted in many parts of the country. The P. chartarum fungus grows in the humid, protected dead material at the base of forage plants.
Fungal growth is favored by warm, wet, humid weather, or with heavy dews or irrigation.
Spore levels can rise rapidly under these conditions. The practice of intensive grazing increases the risk of facial eczema, because animals in closely-grazed pastures consume vegetative matter that may be heavily contaminated with fungus spores. Facial eczema is relatively common in areas of New Zealand. Perennial ryegrass is the grass species most associated with facial eczema. P. chartarum does not grow well in legumes.