Switching from Fungus-Infected to Fungus-Free Tall Fescue

Abstract

Tall fescue (Festuca arundinacea Schreb.) is an important forage in the eastern USA. Fescue plants in most pastures and fields are infected with the endophytic fungus Acremonium coenophialum Morgan-Jones and Gams. Presence of the fungus is associated with substantial reduction in animal performance. Fertilization, inclusion of legumes in the sod, and appropriate management practices can improve productivity and quality of fescue fields. Another alternative for field improvement is the destruction of infested stands and reestablishment with fungus-free seed. This can be done with careful planning after infection levels are determined. Pastures or fields with 30% or more infestation are good candidates for reestablishment; those with lesser infestation levels can be improved with legumes. Systems that include tillage, intervening crops, and herbicide treatments are proposed and discussed. The importance of getting 100% kill of infested stands and preventing volunteer seedlings is stressed. The paucity of information on long-term survival of fungus-free fescue is noted. In no-till situations, glyphosate (Roundup) and paraquat (Gramoxone Super) are effective for initial kill, and must be followed with a second spraying at reseeding. Legumes should be reseeded with fungus-free fescue. Fungus-infected fescue is preferred in ornamental, recreational, or soil protection systems where grazing animals are not involved.