What Is Bacterial Canker and How to Control It?

Bacterial canker is a disease that affects many types of fruit trees, including cherries, plums, peaches, apricots, and almonds. The disease is caused by the bacteria Pseudomonas syringae, which infects the tree through wounds or natural openings in the bark. Once infected, the bacteria multiply rapidly and cause damage to the tree's tissues, resulting in cankers or sunken areas on the bark.

Symptoms of Bacterial Canker

The symptoms of bacterial canker vary depending on the type of tree that is infected, but some common signs to look out for are:

• Circular or elongated cankers on the trunk or branches
• Dark brown to black discoloration on the bark
• Gumming or oozing from infected areas
• Wilting or dieback of shoots or branches
• Yellowing or browning of leaves

How Bacterial Canker Spreads

Bacterial canker spreads through water, wind, insects, and contaminated tools or equipment. Rain or irrigation water can splash the bacteria from an infected tree onto nearby healthy ones, while wind can carry the bacteria for miles. Insects like bees and flies can also spread the bacteria as they move from flower to flower. Lastly, using unsanitized pruning tools or machinery can also transfer the bacteria from one tree to another.

Preventing Bacterial Canker

The best way to prevent bacterial canker is to maintain good tree health and reduce the risk of infection. Here are some tips to follow:

• Plant resistant varieties when possible
• Prune regularly to remove dead or diseased wood
• Sanitize tools and equipment before use
• Avoid over-fertilizing or over-watering
• Control insect pests and diseases

Controlling Bacterial Canker

If your tree is already infected with bacterial canker, there are several steps you can take to control the disease:

• Cut away infected branches or limbs at least 12 inches below the visible symptoms
• Sanitize pruning tools between cuts
• Apply a copper-based fungicide to the affected areas
• Avoid applying fertilizer or excessive water to the tree during the growing season
• Consider using antibiotics if the infection is severe

Bacterial canker on a peach tree

Bacterial canker is a serious disease that can devastate fruit trees if not properly managed. By taking preventive measures and early treatment, you can minimize the impact of bacterial canker on your orchard and ensure the health and productivity of your trees for years to come.

Bacterial canker, fruit tree disease, plant health, orchard management, Pseudomonas syringae