Survival of Ophiobolus graminis on artificially infected straw of several hosts was studied under field and laboratory conditions over a period of 24 weeks. Survival, estimated by percentage of straws containing viable hyphae of O. graminis, was greater on barley than on wheat, Hordeum leporinum, Lolium rigidum, and Vulpia myuros. Survival was higher under laboratory than summer field conditions, and in the field was greater at 1 than at 6 in. below the surface; survival was increased under laboratory conditions by nitrate enrichment of soil