Commercial Juneberry production requires careful disease monitoring and prevention measures. Diseases are more prevalent in areas of higher rainfall than in dryer regions. Control recommendations emphasize cultural methods such as pruning since no chemicals presently are registered for Juneberries. Pruning tools should be disinfected after each cut in order to prevent infection of healthy tissue. To minimize losses from this disease, remove and destroy all mummified berries, fallen berries, leaves, infected twigs and pedicels.
Spores are windborne to junipers, the alternate host, where woody galls are formed on the branches.
To control blackleaf, rogue and destroy infected seedlings, cuttings and root sprouts. On established bushes prune all twigs, shoots and branches exhibiting symptoms of witches broom about 8 inches below the site of brooming. This may be done in early spring, prior to bud break, but is more easily done in fall immediately following leafdrop, since infected leaves tend to persist. Plants with infected root crowns must be rogued and destroyed. The affected leaves usually remain on the bush well into winter.