Speaker: Glynn Percival, Ph. D., Bartlett Tree Research Laboratory

During their lifetime, trees planted within urban landscapes are susceptible to pathogenic fungi and bacteria that, if uncontrolled, can result in tree decline and eventually death. Presently, conventional management relies heavily on repeat application of insecticides and/or fungicides applied as foliar sprays, trunk injection or soil drenches. Build-up of pathogen resistance coupled with environmental concerns means alternative methods of pest and disease management are warranted.

Trees possess a range of active defense systems that can “switched on” prior to infection by a plant pathogen by the application of specific organic compounds. This concept of boosting a tree’s own inherent immunity is known as induced resistance (IR). The IR response is critical and can reflect the difference between coping and succumbing to necrotizing pests and pathogens. This presentation will discuss the range of inducing agents available for professionals involved in tree management as well as their effectiveness, time of application and strategies for use within urban landscapes.