Apricot Bacterial Canker Disease
Apricots with bacterial canker are hardly rare, and the apricot bacterial canker disease is widespread in most places. This is a disease that often enters apricot trees and other stone fruit trees through wounds, often gardener-inflicted pruning wounds. You’ll know that your tree has apricot bacterial canker disease if you see necrosis girdling a branch or trunk. Keep your eye out for branch dieback and cankers in spring. You’ll sometimes also notice leaf spot and blast of young growth and orange or red flecks under the bark just outside canker margins. The bacterium causing the disease is a fairly weak pathogen (Pseudomonas syringae). It is so weak that trees are only susceptible to serious damage when they in a weakened condition or else dormant. They can be damaged from leaf drop through leaf budding.
Bacterial Canker Control
The key to bacterial canker control is prevention; and preventing bacterial canker on apricots isn’t as difficult as you might think. Prevention is the best way of treating apricot bacterial canker. Apricots with bacterial canker are usually trees in one of two situations: trees in orchards where ring nematodes flourish and trees planted in areas that get spring frosts. Your best bet at preventing bacterial canker on apricots is to keep your trees in vigorous health and to control ring nematodes. Use any cultural practice that is likely to keep your tree healthy, like offering sufficient irrigation and feeding with nitrogen. Nematodes stress apricot trees, making them weaker. Control nematodes by using pre-plant fumigation for ring nematodes. When you think about treating apricot bacterial canker, think prevention. It’s not that hard to take an important step toward preventing bacterial canker on apricots. One proven method of bacterial canker control is to avoid winter pruning. The entire disease begins in winter, when the trees are susceptible to the bacteria. If you prune the apricot trees in spring, instead, you can largely avoid the issue. Evidence suggests that pruning during the dormant season makes apricot trees vulnerable to this disease. Instead, prune after the trees start active growth in spring.
