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.

Rose rosette disease is lethal to multiflora rose, a noxious weed occurring in pastureland in most of Iowa. The potential use of rose rosette disease as a biocontrol agent can be enhanced by grafting infected shoots onto plants in established stands (i.e., augmentation). However, questions arose about whether the disease could be spread to ornamental roses. This study probes the identity of the causal agent for the disease in hopes of determining whether fears of transmission to ornamental roses were valid.

Sclerotinia stem rot of soybeans (also known as white mold) is caused by a soil-borne fungus and has become a serious problem in northern Iowa. Another fungus, Sporidesmium sclerotivorum, acts as a parasite of the sclerotia and this research tested whether this mycoparasite could act as an effective deterrent to the soybean stem rot pathogen.