Mycorrhizae generally are regarded as beneficial fungi in that they assist plant roots in absorbing minerals. Tall fescue plants infected with N. coenophialum (Guo et al., 1992) and N. lolii-infected perennial ryegrass plants (Liu et al., 2007) had considerably less colonization of roots by the mycorrhizae Glomus macrocarpum Tul. & C. Tul. and G. mosseae (T.H. Nicolson & Gerd.) Gerd. & Trappe than noninfected plants. Sporulation of mycorrhizae also was reduced in E+ tall fescue.