Characterization of the Rose Rosette Disease causal agent: potential for biological control and multiflora rose
Rosa multiflora (multiflora rose), introduced to America from Japan for ornamental purposes 200 years ago, was promoted in Iowa during the mid-1930s as a "living fence" that would help to conserve soil and provide cover for wildlife. Multiflora rose has since naturalized, and today some two million acres of Iowa land are infested with this pest, which renders pastures unusable (dense stands exist in coun ties south of a line from West Pottawattamie through Winneshiek, affecting the southeastern two-thirds of the state). Cattle avoid the prickly stems, and grass dies beneath its thick growth. Although tillage can control the weed, land in permanent pasture or under the Conservation Reserve Program is at risk for the spread of multiflora rose.