Tebuthiuron Injury on Landscape Trees
In 2006, a Montcalm County, Michigan resident noticed several of his mature trees showing signs of decline. As the summer progressed, so did the injury on his maple, ash, oak, cottonwood and white pine trees. This resident had an ongoing dispute with his neighbor and was convinced this person was killing his trees.
Besides the obvious chlorosis, distortion and browning of the leaves followed by defoliation, there was a spot at the base of each tree that was barren of grass and weeds for several months. I suggested we analyze soil collected near the base of these trees for the presence of residual contaminants capable of causing the observed injury. Unfortunately for the trees, tebuthiuron was detected in the soil at 2.3 ppm.
Tebuthiuron (Spike) is a soil-applied herbicide for woody plant control in fencerows, utility rights-of-way, pipelines, pastures, rangelands and other non-cropland areas. Tebuthiuron controls unwanted trees, shrubs and vines after sufficient rainfall has occurred to move the product into the root zone.