The effectiveness of treatment decreased with increasing stem size: we 

 killed or severely damaged only about half the stems in the class 15 

 feet tall to 5.0 inches d.b.h. (table 1). This was somewhat less effective 

 than Tierson's work in New York State, where spray applied with back- 

 pack mistblowers deadened beech up to 20 feet in height. 



Using a labor cost of S2.00 an hour and the appropriate 1967 cost of 

 materials, the total treatment cost per acre of applying 7-1/2 gallons of 

 spray was $5.50 (travel time to and from the area not included) . Though 

 this cost was determined for only 5 acres, it compares closely to Tierson's 

 cost of $6 to S7 per acre. 



Of the species heavily represented in the understory, the following 

 were especially susceptible to the spray treatment: beech, hornbeam, red 

 maple, striped maple (Acer pensylvanicum L.), and hickory (Carya sp.). 



Two years after treatment, the dense stand of small stems was almost 

 leafless. Closer examination showed that the heavily damaged sugar 

 maple stems were beginning to recover by putting out new shoots from 

 the lower stem. The heavily damaged beech, on the other hand, appeared 

 to be dying. 



Discussion 



Results of this work show that a mistblown understory spray will 

 greatly reduce the density of the small stems beneath the main stand. 

 Where this understory is composed of undesirable species, and where a 

 seed source of the desired species is available, this treatment should 

 greatly improve the chances of obtaining reproduction of the desired 

 species. 



The mistblowing should be done in the summer, one or two seasons 

 before the harvest cutting. The big advantage of spraying 2 years before 

 logging is to give new black cherry and yellow-poplar seedlings a chance 

 to get started in the absence of dense forest-floor competition. Spraying 

 earlier than two growing seasons before cutting would give many of the 

 damaged understory sugar maples a chance to recover their competitive 

 position; it would also provide time for other undesirable tolerant veg- 

 etation to build up. 



This treatment is not applicable to all situations. Two particular ex- 

 amples come to mind. In oak stands where oak reproduction is the ob- 

 jective, this treatment, applied a couple of years before a clearcut harvest, 

 would in most cases preclude obtaining a new oak stand. Oak reproduc- 

 tion is usually either on the ground when a stand is cut, or it is not ob- 



5 



