• Dagget, R Howard.
  University of Maine Graduate School
  

The long-term effect on the development of spruce-fir stands in Maine from combinations of herbicide (Glyphosate, Triclopyr, 2,4-D,2,4,5-T, MSMA, Picloran, Water, and Control) and pre commercial thinning (PCT and no PCT) treatments was examined 22 years after herbicide application and 13 years after PCT. The study originated in 1977 with the aerial application of herbicide treatments to a 7-year old clearcut of a spruce-fir stand in western Maine. Twenty eight original experimental units 2.64 A (3.3 chains x 8.0 chains) in size were comprised of 14 different combinations of herbicides and application rates each replicated twice. In 1986 (year 16) the original experimental units were split in half (3.3 chains x 4.0 chains) and one half received PCT treatment while the other half was left unthinned resulting in 56 experimental units each 1.32 A in size.