RUST ON BIRDSFOOT TREFOIL PARASITIZED BY SPHAERELLOPSIS FILUM

central Pennsylvania. Many rust pustules were blackened, and the discoloration often extended into areas of secondary sporulation. Segments of diseased leaves were surface disinfested, and the hyperparasitic fungus, Sphaerellopsis filum (Biv.-Bem.exFr.) Sutton was isolated from tissue adjacent to rust pustules. S. filum g but V-8 juice agar was best for d inoculum production. Cultures of S rew on potato dextrose, lima bean and carnation leaf agars, sporulation an. filum have been reactivated after storage for 4 years on silic tions, S. filum a gel beads. In controlled inocula from rust on birdsfoot trefoil parasitized rust pustules on white clove