Bacterial canker is a fast-spreading garden fungal disease that causes crop yields to decrease substantially. Detecting the initial signs of bacterial canker early can help save your plants – and by extension the groceries you are attempting to grow.
Stone fruit trees are especially susceptible to bacterial canker. Cherry, apricot, plum, peach trees, and even citrus trees can be destroyed quickly if this garden fungal disease is not detected and treated promptly.
The fungal bacteria spaws a canker known as Pseudomonas syringae. It infiltrates a fruit tree through bark that has been wounded due to frost damage, insect damage, or pruning injuries. The bacteria may also be spread from fruit tree to fruit tree via contaminated pruning tools, rain, and during watering.
Bacterial canker most often presents from the fall months through the early weeks of spring when the weather is both colder and far more damp. The cankers are hardy enough to survive the winter and then infect emerging buds on the fruit tree.
As the bacterial cankers grow and strive to take over the entire fruit tree they become ar darker – making them significantly easier to spot. But, if you do not catch the bacterial canker infestation until the growths mature, it is most likely too late to save your tree.
The bacterial fungus exists on the surface of leave, especially during wet patches of weather in the spring through early summer. The bacteria often enter the leaf stomata (pores) and causes an infection in young leaves.
Once the leaf starts to grow, the bacterial infection becomes visible as tiny areas of dead tissue. The dead tissue ultimately falls out of the leaf, leaving behind what is commonly referred to as a “shothole.”
The bacterial cankers left behind then garner access to the fruit tree via leaf scars or bark wounds.
Signs Of Bacterial Canker
- lesions that are gummy in texture that appear on either the trunk or twigs of fruit trees;
- dripping sap with a pungent sour smell dripping from wounds or crack on the fruit tree;
- the bacterial canker girdles around the trunk or an infected branch and the leaves above the girdle of growth turn yellow;
- moist tissue either exposed or present when pulling back bark, of a fruit tree;
- the appearance of tree lesions that are either sunken in or boast a waterlogged texture.;
- red or brown tissue develops around injuries or cracks on the tree;
- the development of dead limbs shortly after the new growth emerges.
How To Eradicate Bacterial Canker
- Prune your fruit trees while they are still blooming. If you wait until after the harvest in the fall any wounds that occur will not have time to heal before cold and wet weather rolls in. The bacterial cankers are in their most active state during both the fall and spring, never prune at this time unless it is essential for safety reasons.
- Remove all wilting or dead limbs beneath the presence of bacterial cankers to curtail spread.
- Always treat pruning injuries when they occur and monitor the area closely for the need of additional treatment.
- Paint the bark on the trunk of the fruit tree with white paint that has been diluted with water to decrease the possibility of the area being damaged by cold and damp weather fluctuations – and as a visual guide to avoid trimming too close the trunk and nicking it.
- Always disinfect all gardening and pruning tools after using them on a fruit tree before moving along with the chore, and taking care of another tree or plant.
- Placing a breathable wrap around the trunk of fruit tree can also serve as a weather and visual trimming guide protective covering. Placing staked chicken wire or hardware cloth around the trunk of the tree will help prevent injuries when moving or trimming.
- Remove garden debris, and keep the area around the trunk tightly trimmed to increase air circulation around the tree trunk, especially when cultivating young trees.
- Using copper-based fungicides on fruit trees may help prevent bacterial canker infestations.
Cutting the grass around your fruit trees low to the ground cannot be recommended highly enough. An heavy early spring rain or thunderstorm will blow the bacterial canker fungus on anything within its path, do not offer it ample bedding to rest upon…and grow.
Since we cannot control the weather, the main course of action needed to prevent bacterial canker from killing fruit trees is diligence. Keeping garden tools clean, and disinfecting them after use on even a single fruit tree (as time-consuming as that may be) will help prevent the spread of an unnoticed canker infestation perhaps better than anything else.