study was undertaken with the objective of economy in time and matexial 

 in safely killing these larger trees. 



In order to test the reaction of trees to bark girdling and chemical 

 treatment, several experiments were outlined recognizing that bark is easily 

 separated from wood in a growing tree during the peeling season. This is 

 the period of rapid growth ordinarily beginning in the latter part of May 

 and continuing until late July or early August. 



A tool was made which is similar to the ordinary bark-peeling spud, 

 but smaller and lighter. With this tool, a section of the trunk of living trees 

 was girdled and the tree left standing. The extent of the peeled area on the 

 tree trunk depended considerably upon the natural bark characteristics and 

 resistance to peeling. Girdling by peeling in this manner takes only a few 

 seconds. 



The reaction of most trees to girdling is to continue for several years 

 in a healthv condition and in some species to develop a new coat of bark to 

 replace the one peeled away. Tamarack proved to be an exception to this 

 general rule. A test plot of 100 trees was girdled by peeling in 1950. Several 

 weeks after girdling, seasoning checks could be observed in the bare wood. 

 One year from the date of girdling most of the trees were dead. By the second 

 year 98 percent were dead. The two living trees had live branches below the 

 peeled area. White pine also reacted differently. Two plots of 50 trees each 

 were girdled and the bare wood was treated with 2-4-D and 2-4-5-T mixed 

 with fuel oil. This treatment was more effective. After two years only the 

 largest and most vigorous trees were still alive. 



A mixture of 2-4-D and 2-4-5-T in fuel oil was applied to the spud-girdled 



area of this white pine. 



Similar treatment to white oak, red oak, soft maple, hard maple, aspen, 

 and cherry produced poor results. Only a few of the sample trees were dead 

 after two years. 



