'Jf^uJs. FOREST SERVICE RESEARQH NOTE NE-8 



ortneastern xorest 

 £ xperiment Station u. S. KF^- 



FIELD TRIAL OF A TREE INJECTOR 

 IN A W EEDING IN WEST VIRGINIA 



In June I960 a 5-acre plot of mixed hardwoods under intensive selec- 

 tion management on the Fernow Experimental Forest in West Virginia 

 was weeded to eliminate poor-quality stems that were competing directly 

 with desirable regeneration. Treatment was confined to stems in the 1- to 

 5-inch diameter (at breast height) classes. 



A solution of 2,4, 5-T (propylene glycol butyl ether ester) at 40 pounds 

 acid equivalent per 100 gallons in diesel oil was applied in circumbasal 

 cuts, one per inch of tree diameter, with an automatic tree injector. The 

 work was done as a production job, and no special measures were taken 

 to assure exactly uniform applications of the silvicide. 



The injector used was a Tree-Di, manufactured by the Parker-Clower 

 Company, Troy, Ala. This device is a 5-foot-long cylinder with a semi- 

 circular cutting bit at one end (fig. 1). The silvicide is released from 

 the cylinder by a spring-loaded valve that is actuated by the impact when 

 the cutting bit is struck into the tree stem. 



Thirteen species were treated. However, 70 percent of the stems treated 

 were sugar maple (Acer saccharum Marsh.) and beech (Fagus grandi- 

 jolia Ehrh.) . 



After two growing seasons, 134 randomly selected stems were observed 

 to determine kill by species and diameter class. The table shows, by 

 diameter classes, the percentage of kill for all species and for beech and 

 sugar maple separately. None of the dead trees showed any evidence of 

 sprouting. 



These results indicate that small stems are easier to kill than large ones. 

 However, this apparent resistance among the larger stems may reflect 



1 



