Bacterial cancer: Always on the lookout

Image: Hector Garcia.

The bacterium Pseudomonas syringae pv syringae (Pss) can cause economic losses of 75% in the first years of planting and between 10-20% in adult plants.

Bacterial canker in cherry trees is a serious disease caused by the bacteria Pseudomonas syringae pv. syringae. This disease primarily affects cherry trees, causing lesions on branches and trunks, which can lead to the death of the tree if not properly controlled. Here are some important notes about bacterial canker in cherry trees:

1. Symptoms: Symptoms of bacterial canker in cherry trees include the formation of tumors or bumps on branches and trunks, which may be moist and gummy. Over time, these lesions can grow and eventually cause the death of the affected part of the tree.
2. Dissemination:The bacterium Pseudomonas syringae pv. syringae can be spread by rain, wind, contaminated pruning tools, and tree injuries. Bacterial spores can enter the tree through wounds or natural openings in the bark.
3. Favorable conditions: Bacterial canker tends to be more problematic in cold conditions that favor the growth and spread of the bacteria. Injuries caused by winter, microcracks, can also provide entry points for infection. In addition, it is one of the bacteria with the greatest capacity to nucleate ice.
4. Control: Control of bacterial canker in cherry trees involves both preventative and management measures. This may include proper pruning to remove infected branches, applying antibacterial treatments to pruning wounds, using cultural management practices to reduce humidity, and promoting overall tree health through proper fertilization and irrigation.
5. Research and resistance: Research is being carried out to develop cherry varieties resistant to bacterial canker and to improve control strategies. However, integrated management and continuous monitoring remain essential in the prevention and control of this disease. In fact, in November 2023, experts from INIA Rayentué announced strategies for the control of bacterial canker in cherry trees.

Bacterial canker in cherry is the disease that most concerns one of the most important fruit sectors in Chile and that produces the greatest commercial movement, especially in the central part of the country. For this reason, and within the framework of the launch of a project executed by INIA Rayentué with contributions from the National Agency for Research and Development (ANID), a seminar was held last November that brought together prominent scientists and researchers in the field.

“Can Bacterial Cancer in Cherry Trees Be Controlled?: Current and Future Recommendations” was the name of the activity, which included an opening keynote lecture by the renowned plant pathologist Dr. Andrés France, who presented the main recommendations for controlling the disease.

The bacteria Pseudomonas syringae pv syringae (Pss) can cause economic losses of 75% in the first years of planting and between 10-20% in adult plants. The losses caused by the disease are the most significant from a health point of view, without the industry having effective tools for its control. Currently, the loss of productivity is estimated at orders of 5-50% of the productive potential, depending on the property, the location, the management of the orchard and the rootstock-variety combination.