Over-stimulated rosaceous plants (due to heavy pruning and/or high nitrogen rates) are at high risk for fire blight infections. In an infected planting, and while trees are dormant, remove all cankered wood, pruning 6 to 12inches below the last visible sign of the canker (avoid leaving a stump, remove the affected branch all the way to the trunk or nearest side branch that is at least 6 inches below the canker). Canker removal will eliminate a large part of the primary inoculum for the following year. Pruners do not need to be disinfected between cuts unless pruning is done during the growing season. If pruning is done during the growing season, 6-12 inches of healthy tissue should be removed along with the cankered areas. All prunig during the growing season must be carried out in hot & dry conditions.
Because young, succulent shoots are very susceptible to infection, avoid using high rates of nitrogen fertilizer, which promotes rapid shoot elongation. It is best to use a balanced fertilizer and to consider split applications of nitrogen (half before growth starts and half after petal fall). Copper compounds and antibiotics are available to help manage this disease in commercial settings such as nurseries and orchards. Copper compounds may be sprayed during green tip to prevent bark and bud colonization, while antibiotics are used during bloom to protect flowers. When establishing new plantings of rosaceous plants, look for resistance to fire blight as the most effective disease-control practice.