Facilities Management (FM) Outdoor Services staff this month will conduct a soil injection aimed at treating 15 to 20 cottonwood trees on Main Campus that are infected with Cytospora fungal canker. The health and appearance of these trees has steadily declined each year. Four other infected trees were removed over the winter because they had become structurally unsound due to canopy dieback.
Weather permitting, on or after Friday, April 20, FM staff will facilitate applications of the plant growth regulator Cambistat, EPA Reg. No. 74779-3. The active ingredient is Paclobutrazol. The trees being treated are along the southern edge of Main Campus between the Wolf Law building and Baseline Road.
It is important to address this situation because the health, appearance and structural integrity of these trees are being negatively impacted to a significant degree, and the campus is currently at risk of losing several mature cottonwood trees. FM hopes to mitigate any further establishment of this fungal disease.
Rainbow Treecare Scientific Advancements has been hired to conduct the soil injections. FM staff will accompany the vendor to ensure only predetermined locations receive treatments, applications are halted as pedestrians pass by, and that all necessary precautions are taken to avoid non-target impacts.
Guidelines for pesticide use are generally described in the campus Pest Control Policy. This application is just one of many tools used as part of an integrated approach to landscape management. These trees will continue to receive supplemental watering and cultural care. Following treatment, they will be closely monitored for secondary pest or health problems. Many of the trees to be treated, as well as other nearby cottonwoods, have been pruned over the last several years to remove dead and dying wood in an attempt to further limit spread of this fungal disorder.
FM staff will be placing yellow application notice flags that will indicate where the application was made. Law requires these flags remain in place for 24 hours after an application has been made. In the interest of keeping the campus community informed, staff will leave these flags in place for one full week after the application occurs.
Contact Assistant Director of Outdoor Services Don Inglis at 303-735-6311 or Assistant Director of Environmental Services Rob Lenahan at 303-735-3627 if you have any questions or concerns.
