24 
BULLETIN 1225, U. S. DEPARTMENT OF AGRICULTURE. 
phor thrips. Without a single exception all trees cut near the ground 
sent up snoots from the crown, and in no instance did these shoots 
originate near the cut end of the stump. It is the nature of the trees 
to sprout from the crown instead of from any other place on the body 
of the tree. After a year or more these sprouts became rather large 
and vigorous and showed practically no damage from thrips. (PL VI, 
B; fig. 7.) 
The camphor trees on a 60-acre tract at Satsuma were cut off at the 
level of the ground in November. The tops were not removed imme- 
diately, however, but were allowed to remain a few days after being 
cut down. This probably permitted some of the insects to reinfest 
the field. Neither were all of the small shoots growing near the base 
of the trees cut off, and they furnished a food supply for such insects 
as escaped from the cut tops. The work, however, was done on a 
Fig. 7. —A field of camphor trees three months after being cut off at level of ground. The new growth 
originates at the erown and grows rapidly. 
good commercial basis and no doubt was carried on as efficiently as 
could be expected. Repeated visits to this field showed that every 
tree sent forth sprouts from the crown and about a year afterward 
these were from 5 to 7 feet high. To be sure, some injury from thrips 
was noticed, but the damage was very slight. The greatest injury 
was on those trees located nearest the old unpruned trees across the 
road. The stumps were not treated with any material to prevent 
wood decay or kill thrips. 
Pruning experiments were also conducted in a 10-acre field which 
had three sides not bordered by camphor trees. The trees in this 
field, also, were cut down at the level of the ground and all tops 
removed at once. All small shoots growing near the base of the 
stump were likewise carefully destroyed. In so far as was possible 
all sources of reinfestation from insects within the field were removed. 
Repeated visits to this field showed that all trees put forth sprouts 
from the crown and after the expiration of a year had attained a 
