16 BULLETIX 743, U. S. DEPARTMENT OF AGEICULTrEE. 
with a spread of about 20 feet when they are of the slender type 
(PL V). Such trees as these have trunks 12 to 18 inches thick. 
A tree 50 feet in height may be considered large, and one which is 
60 feet has probably reached its maximum development under most 
conditions. The trunk of such "a tree may be 1 feet thick, and the 
crown may be 50 or 60 feet in spread. Probably these dimensions are 
not attained until a tree is at least 50 years old. 
There are differences in the character of the growth — its stiffness, 
brittleness. size, and so on — which do not appear of importance in old 
trees, but which will stand cut more prominently when young budded 
trees are planted in the orchard and must be trained to a desirable form. 
In some trees the growths are long and slender, supple, and scarcely 
able to bear their own weight. Ultimately these growths tend to 
produce descending branches, keeping the crown close to the ground. 
Other trees make very short, weak growths, seeming to indicate a 
lack of vigor. In still others the wood is so brittle that the branchlets 
snap off when bent. The best trees make strong, healthy-looking 
growths, smooth and round (angular branchlets frequently indicate 
a weak grower ), with the leaves placed about an inch apart and the 
axillary buds short, plump, and well developed. 
CULTURAL PRACTICES. 
The amount of systematic attention given the trees by Guatemalan 
avocado growers is almost negligible. It is of interest, however, to 
consider the cultural conditions under which the trees occur and the 
apparent effect of these conditions upon growth as well as fruit 
production. 
As already stated, comparatively few avocados in Guatemala are 
planted intentionally. It speaks well for the climate and soil that 
trees which develop under such conditions can reach large size and 
produce fruit. They do not receive the least attention from any one ; 
the ground is never cleared of weeds or undergrowth, and the tree 
must in some instances carry on a constant struggle for existence. 
In coffee plantations or in dooryards of the natives, however, con- 
ditions are more favorable. Especially is this true of coffee planta- 
tions, since the cultural attention given the coffee bushes necessarily 
affects the near-by avocado trees as well. Two or three times a year 
the ground is cleared of weeds with a heavy hoe. It is never culti- 
vated deeply, and. in fact, the surface beneath avocado trees in 
many instances is not even scratched, since a heavy mulch of leaves 
collects and few weeds require to be removed. 
The only pruning practiced is the removal, when the trees are 
young, of the lower branches, in order that the crown may be formed 
above the tops of the coffee bushes. This means that the trunk 
frequently does not give off any branches at less than 8 to 12 feet from 
