THE AVOCADO IN" GUATEMALA. 33 
have withstood without serious injury. In general, nothing was 
found to indicate that certain strains of the Guatemalan race are 
particularly hardy or that certain individual trees appear to be char- 
acterized by greatly superior frost resistance. One tree was found 
in Totonicapam (8,500 feet) which gave evidence of being somewhat 
hardier than the average, and bud wood' was obtained for introduc- 
tion into the United States. 
It is true that the avocado is cultivated in Guatemala a full thou- 
sand feet above the zone in which citrus fruits, even the orange, are 
grown. It must not be assumed, however, that this indicates greater 
hardiness in the avocado than in the orange. Experience in the 
United States does not lead to any such conclusion, and though the 
varieties found at high elevations in Guatemala may be slightly 
hardier than those at present grown in the United States, it may also 
be true that the Guatemalans have not pushed orange culture to its 
uppermost limit. It is the custom in California and Florida to 
grow tropical fruits right up to the frost line, so to speak; they 
are planted where protection is necessary in winter and where severe 
losses are experienced occasionally from an unusual degree of cold. 
In Guatemala conditions are different. If the orange when left to 
care for itself did not succeed at 7,000 feet, it would die off, and its 
culture would be restricted to lower levels. With attention and slight 
protection it might succeed far above 7,000 feet, but since this atten- 
tion and this protection are lacking in Guatemala, it would not be 
found far above 7,000 feet by the traveler who chanced to pass 
through the country. 
The question of hardiness in the avocado seems to depend to a much 
greater degree upon race than upon variety. No variety of the West 
Indian race has yet been found which is nearly as hardy as many of 
the Guatemalan, and no variety of the Guatemalan has been discov- 
ered which will stand as much cold as the Chappelow or other varie- 
ties of the Mexican race. For this reason the proper classification of 
varieties is essential. Within the race there doubtless is a certain 
variation in hardiness, but experience indicates that the amount of 
variation is not so great, expressed in degrees of temperature, as the 
difference in the average hardiness of the three races now known to 
horticulture. 
ENEMIES OF THE AVOCADO. 
Everything considered, the avocados of Guatemala are less subject 
to the attacks of insect and fungous parasites than would be expected. 
Citrus trees in all parts of the highlands are commonly infested with 
scale insects (notably the purple scale, Lepidosaphes heckii) to a 
severe degree. Avocados in the same region are comparatively free 
from serious parasites. This is not saying that the avocado does not 
79774°— 19— Bull. 743 3 
