Fescue toxicity problems were widespread, indicating that most tall fescue pastures were infested with the endophyte. The most immediate problem was how to reduce the toxicity problem in livestock consuming tall fescue. It was soon recognized that dilution with another forage species reduced the problem. With good clover growing conditions, daily gain of beef steers was increased 50% with white clover (Trifolium repens L.) or birdsfoot trefoil (Lotus corniculatus L.) and 50 to 80% with red clover (Trifolium pratense L.) planted in E+ tall fescue (Hoveland et al., 1981; McMurphy et al., 1990). Another approach was to produce E- seed for establishing nontoxic pastures. Since the endophyte dies after a year of normal seed storage, this was relatively easy to accomplish, provided the new seed production fields were free of volunteer infected plants. The first purposeful E- cultivar, AU-Triumph, was released in Alabama in 1982 (Hoveland et al., 1982). Several more cultivars soon followed. Animal performance on these pastures was excellent, so it was assumed that a solution was now available for producers who replanted their pastures. Farmers eagerly planted the new cultivars, but after several years farmers increasingly reported stand losses of E- tall fescue where pastures were grazed in summer similarly to the way they grazed their old E+ K-31 pastures. It soon became apparent that E- tall fescue was not as vigorous or as tolerant of drought and overgrazing as toxic E+ tall fescue. Endophyte free cultivars were not a simple solution and succeeded only where low grazing pressure or rest was used during the stressful summer period.