the nearest one-tenth of a foot and diameters 
were measured to the nearest one-tenth of an 
inch at a height of 3 feet (to include as many 
of the small trees as possible). Average 
height, diameter, and crown spread incre- 
ments were calculated for each year after the 
start of cultivation. 
After one year’s cultivation, growth in- 
crements of some of the species showed slight 
gains for the cultivation treatments over the 
control. After 2 years the beneficial effects 
of the cultivation were much more _ pro- 
nounced (tables 1 and 2). 
All species have benefited in height 
growth from all degrees of cultivation. This is 
July 1963 
particularly true of the faster growing Ameri- 
can elm, boxelder, and green ash. Compara- 
tive gains between the complete and moder- 
ate cultivations are not as clearly defined, 
however, and further trial and study will be 
necessary to determine whether complete sod 
removal is necessary or even advisable. 
Growth, measured in terms of diameter and 
crown spread, is also generally better in the 
cultivations than in the check. Growth losses 
in the check are the result of widespread 
dieback, resulting probably from drought 
conditions of the 2 previous years coupled 
with the effects of the competing grasses. 
HOWARD M. | PHIPPS 
Research Forester 
