Imprelis Damage Continues in 2012

Posted: June 12, 2012

I visited a site this morning that had significant Imprelis damage in 2011. I am seeing an array of symptoms that I believe are tied to the original application of Imprelis in April 2011.
Imprelis Damage to Norway Spruce

Imprelis Damage to Norway Spruce

Symptoms that I observed this morning include:

  • Continued leaf distortion on honey locust, pin oak, Japanese maple, and redbud
  • Fasciation of maple shoots
  • Terminal bud mortality on oaks and maples
  • Stem dieback on honeylocust
  • Witches brooming on oaks
  • Thin canopies (oaks and redbuds) (Oak trees have been treated preventatively for anthracnose by an arborist)
  • Abnormally high production of acorns on red oaks in treated areas, little acorn production in red oaks at other sites on property
  • Abnormal growth and development of shoots. Terminal growth stunted, lateral shoots elongated
  • Norway Spruce, needle regeneration at the base of dead shoots. (Approximately 12-18" below the dead shoots)
  • Dieback on terminal growth of deciduous trees
  • Longitudinal cracks on red oak trunks which are shaded by the house to prevent south-side bark splitting
  • Leaf distortion in viburnums and Japanese cherry

Also, one turf professional informed me this afternoon that witches brooming is reportedly being seen by turf companies at sites treated with Imprelis in 2011. I will try to verify this as I visit other sites.

Contact Information

Thomas Ford
  • Senior Extension Educator
Phone: 814-472-7986