Bacterial canker in cherries
I have a small mixed orchard planted by a previous owner. Some of the cherry trees are infected with bacterial canker. I had hoped to keep them until new trees could replace them but the fruit is getting infected, resulting in poor quality harvests. Is there any treatment I can employ to improve the health of the trees or should I admit defeat and destroy them? Is it necessary to destroy the roots as well or can I leave the stumps? I won't plant new cherry trees in the old locations. I have read that the same bacteria can infect pears. Are there any other fruit or nut trees that I should avoid planting where the cherry trees were? I have downloaded and studied EM9007: Bacterial canker of sweet cherry in Oregon - DISEASE SYMPTOMS, CYCLE, AND MANAGEMENT. I will use that information when replanting to minimize the chances of new trees becoming infected. Thanks for your help
It is difficult to grow cherries in Lane County due to the rain that increases the bacterial canker pressure. Once a tree is infected you may be able to nurse it along for a few years, but there is nothing that can be done to make it healthy again. The pathogen that causes bacterial canker is all around us, so there is no problem in planting cherries, or other susceptible species back into the same ground where a tree was removed. In taking out an infected tree, it is only necessary to cut it down and take the wood out of the orchard. You do not need to remove all of the roots. The bacteria can spread through insects or rain splashing when it is in close proximity to other susceptible trees. Besides cherries and pears, apricots and peaches are also susceptible. The most important thing that you can do to reduce the incidence of bacterial canker is to keep the trees healthy through proper irrigation, fertilization and weed control. It is also, extremely important not to prune in the rain or within of week of rain prediction. For other control measures, be sure to follow the suggestions in EM 9007.