INCIDENCE OF ACREMONIUM-LOLII AND LACK OF CORRELATION WITH BARLEY YELLOW DWARF VIRUSES IN TASMANIAN PERENNIAL RYEGRASS PASTURES

The perennial ryegrass endophyte Acremonium lolii occurred in all ryegrass (Lolium perenne) pastures sampled in Tasmania. Cultivars tested included Ellett, Martlet, Tasdale, Tasmanian No. 1 and Victorian. The range in incidence was 4-94% (average 66%). Many pastures more than 4 years old caused perennial ryegrass staggers syndrome in livestock, and the range in incidence in these pastures was 79-94%. There was no correlation, positive or negative, between barley yellow dwarf virus infection and the incidence of A. lolii. There was good agreement between ELISA and microscopic examination of epidermal strips. However unlike previous studies, the ELISA test was specific for A. lolii and did not detect Acremonium coenophialum, the endophyte of tall fescue.