Induced Resistance – Enhancing a Trees Immune System

Plants naturally resist infections through a process called Systemic Acquired Resistance (SAR). This is similar to our own immune system. The understanding of this phenomenon is quite complicated, involving numerous hormones, proteins and other compounds inside and outside of the plant. When a tree is attacked by pests, bacteria, or fungi, it activates internal defenses to stop the spread of disease. Even more impressive, this resistance can spread to other parts of the tree, helping protect it before another attack happens. Scientists have studied SAR for over a century, and today, research is revealing ways we can boost a tree’s immune system before it even gets sick. This approach, called Induced Resistance (IR), uses certain treatments to help trees strengthen their natural defenses. Treatments are being researched and are being implemented in several areas of agriculture. Tree care has begun to benefit from this research and more options may become available as more work is completed.

Why Does This Matter for Your Trees?

Trees in urban areas face many challenges—compacted and poor soil, pollution, and exposure to pests or injury. Healthy trees can fight off diseases better, but urban stress makes them more vulnerable. By using IR treatments, we may be able to help trees resist infections and even improve their overall health.
One promising material used in tree care is Potassium Phosphite, which has shown positive effects in reducing impacts of fungal infections while strengthening root growth and drought tolerance. A variety of other materials have also been found to create an induced response in trees. The knowledge of how well these materials work, at what time and how to apply is still in need of more effort before treatments can be recommended.

If you have concerns about your trees or want to learn more about available treatments, contact your Wachtel Tree Science Certified Arborist. Science is making tree care more effective than ever, and your trees could benefit from these advancements!

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