The age at which budded avocado trees come into bearing varies with the different races, and also among the varieties of the same race. Furthermore, experience indicates that many kinds will bear at an earlier age on the sandy soils of southern Florida than on the heavier lands of California. In the latter state, budded trees of the Mexican race frequently come into bearing the second or third year after they are planted in the orchard; the Guatemalan race shows greater range among the numerous varieties, some, for example the Lyon, commencing to bear within eighteen months or two years from the time of budding, while others, for example Taft, have not borne earlier than the fourth or fifth year. Trapp and several other West Indian varieties have been grown for four or five years in southern California without bearing fruit. They are sometimes injured by cold, but, allowing for setbacks from this cause, the West Indian race does not fruit so early in California as in Florida. The Mexican race usually fruits at an early age in both regions.
As a rule, budded trees of the West Indian race are precocious in Florida. Trapp is remarkable in this respect; and in addition it has a strong tendency toward over-production which must be checked during the first few years by thinning the fruit. Trapp trees will often produce a few fruits the year after they are planted in the orchard, and at three years from planting may begin to yield commercial crops. If grown under irrigation, so that their development has been rapid, the trees may be allowed to carry thirty or forty fruits the third year after planting, but during the first year it is best to remove all fruits, and the second year not more than half a dozen should be allowed to mature.When grown without irrigation, the tree is rarely large enough at three years of age to carry more than twelve or eighteen fruits without injury to itself, unless soil conditions have been very favorable. The mistake is often made of allowing Trapps to over-bear when young, with the result that they die back following the fruiting season.
Seedlings vary even more than budded trees in the age at which they begin fruiting. The Mexican race often fruits at two or three years from seed. The Guatemalan race, in California, has occasionally fruited at three or four years, but more commonly comes into bearing at six or seven years. The West Indian race, in Florida, does not usually come into bearing earlier than five or six years from seed.
In California, no figures showing the yield of a budded orchard have as yet been obtained, but in Florida, where the avocado industry is older, interesting data are available. While the figures given may not apply to both regions and will certainly vary greatly with different sorts, they serve at least to show what may be expected from one variety under certain conditions.
According to George B. Cellon, a Trapp tree seven to ten years old will yield, under good cultural treatment, between five and ten crates of fruit, counting forty fruits to the crate, which is about the average pack. The returns from one of the largest groves near Miami for two seasons, however, show an average of only one and one-half crates to a tree. This is a low yield, and should certainly be exceeded. Krome, who has kept careful crop records, finds that his Trapp trees at five years of age yield one to four crates a tree, two and a half crates being the average. Charles Montgomery of Buena Vista, Florida, has obtained yields of about the same amount, his estimate being that a mature Trapp grove should produce 500 crates to the acre.
The yield of other varieties in Florida is not so well known, since none except Pollock has been planted to any extent, and even this variety is grown in comparatively small numbers. In regularity of bearing Trapp excels Pollock, the latter showing a tendency to fruit in alternate years.
In Guatemala and Mexico, many seedling trees of the Guatemalan race tend to produce good crops only in alternate years. The feature is not so marked in trees of the West Indian race which have been observed, nor in those of the Mexican; nor is it true that all Guatemalans possess it. It is possible that over-production one season results in a crop failure the following one, and it is probable that unfavorable cultural conditions have something to do with the matter.