Description:
Eradication of Ribes spp. to control white pine blister rust in
Yellowstone National Park was started in 1947. In 1968 this study
was initiated to evaluate the previous control effort. Ribes eradication
was suspended in 1968 in 18 white pine stands and Ribes and
rust were allowed to increase within rust control units. Eleven
stands outside eradication units were selected as checks. In 1968,
and again in 1978, percent rust infection on pine and the importance
of Ribes were determined. Neither rust nor Ribes increased during
the 10-year period; both were essentially absent from the "eradicated"
stands in 1968 and 1978. Even though Ribes populations were comparatively
high in the noneradicated stands, incidence of rust was nearly
absent. The data show that the eradication of Ribes in Yellowstone
has had little or no effect on spread and intensification of rust in
the Park.