If a juniper landscape is the priority, then July-September fungicide applications would be warranted on the junipers. Spore sources can be reduced by removing junipers near apples, hawthorns or other hosts, or vice versa depending on which host you want the most. It is difficult, though, to eliminate infection sources completely, since the spores are carried by the wind. While Washington and cockspur hawthorns are resistant to the rust, there is another similar rust, cedar-quince rust, reported in Kansas that can attack these varieties. It appears to be most prevalent in northeastern Kansas.
Varieties of apple differ greatly in susceptibility to the fungus.
Resistant varieties, such as Delicious, Liberty, McIntosh, Priscilla, and Tydeman's Early Worcester, can be grown without chemical sprays for cedar-apple rust, whereas very susceptible cultivars, such as Golden Delicious, Jonathan, Prima, Rome Beauty, Twenty Ounce, and York Imperial suffer severe damage where the fungus is present and conditions are favorable for infection. Refer to S.A. 2.904, Juniper-hawthorn rust for more information. Growers follow the Cercospora forecast that is developed by University of Nebraska pathologists Dr. Eric Kerr and Myrt West at the Scottsbluff station. In addition to the forecasts, growers are advised to not spray if there are no leaf spots. So the combination of the forecast and actual field scouting provide the best management of the disease.