Occurrence of Acremonium coenophialum in Tennessee

Tall fescue (Festuca arundinacea Shreb.) plants were collected throughout Tennessee to determine the incidence and distribution of the fescue toxicity fungus, Acremonium coenophialum (Morgan-Jones and Gams). Eighty-three percent of the counties in Tennessee were sampled by taking two fescue plants from each of three different locations in each county, for a total of six fescue plants per county. An enzyme-linked immunosorbent assay (ELISA) was used to test for the presence of the fungus. This serological technique can be completed in two days and can be more quantitative for the amount of fungus present in fescue tissue than can be determined by microscopic examination. The ELISA test has been used in other states to determine if the fungus was present in fescue tissue. Researchers in Alabema and Kentucky have found 80-95% of the fescue samples tested to contain A. coenophialum. It was found through the use of ELISA that at least 30^ of all samples collected in Tennessee were infected with A. coenophialum. Microscopic examination of tissue first determined to be severely, moderately infected, or non-infected by the ELISA technique resulted in correspondingly high, moderate, and no occurrence of fungal mycelium in the fescue tissue stained and examined.