Fire blight is prevalent due to the lack of regular moisture and drought, followed by a heavy December rain that spread the disease from last year’s infection. Both fruiting and ornamental pear trees are the predominant victims.
With the rain in December and the continued dry weather it has run rampant. There are many dead trees already and many more that will die. If the tree has not leafed out…it’s gone. If it’s 80% gone, it’s gone. We can only work with the ones that are leafed out now.
Pruning out the damage and spraying is the regimen now. It is also important that the trees be deeply watered. Bonide Copper spray can be applied 7 to 10 days all through the season. The best spraying time is when the trees are dormant but that period has lapsed. If there is fruit, we suggest taking it off as this will put the energy back into the plant. The spray may cause russeting or spotting on light colored fruit such as apples. We suggest that apples and Pyracantha be sprayed too if there are concerns about fire blight spreading.
A tank sprayer applies the product where it is needed and allows for thorough applications. A good tip for mixing the product is to use warm water. Fill the tank with half the water required for the particular application, then add the Bonide Copper Fungicide and then the rest of the required water. This ensures a proper mixing of the ingredient with the water. Hose end applicators are very convenient in mass plantings and are very useful to reach into trees and tall plants. The fungicide/bactericide just controls the disease and is not “magic”. It will not make the damage go away. The Ready-to-Use formulation can be used as well, but it is difficult to get the coverage needed.
Bonide Copper Fungicide can be used right up to the day of harvest. It is listed “for organic gardening” by the USDA National Organics Program.