AVOCADO Industry Is Rapidly Developing in Florida and California

The avocado is rapidly taking its place as a standard salad fruit and is no longer an expensive and rare luxury.  Its high nutritive value warrants its more extensive use in the dietary.  In oil content, ranging from 10 to 30 per cent, it far exceeds any other fruit eaten in the fresh state; while its 2 per cent of protein is more than double the protein in the commonly grown edible fruits. It possesses practically 75 per cent of the fuel value of cereals and has far more than that of lean meat or eggs.  It possesses twice the amount of mineral matter contained in any other fresh fruit and yields an excess of base-forming elements.

The avocado is a native of tropical America, where it occurs principally as a dooryard fruit tree growing as a seedling. Three distinct races are recognized—West Indian, Guatemalan, and Mexican.

The West Indian race, native of the moist lowlands, is the most tender. Despite its lack of hardiness it thrives in the warmer parts of southern Florida and constitutes the larger part of Florida plantings.  The fruits mature in the summer and fall months. While lower in oil content than the more hardy Guatemalan and Mexican varieties, its fruits are usually glossy green, of good size and attractive appearance, and meet a ready sale.

The Guatemalan and Mexican varieties, derived from higher altitudes of Central America, are able to stand a few degrees of frost.  They are chiefly grown in California, although a few varieties and hybrids of these races are now being grown in Florida for the late fall and winter market. Owing to soil and climatic differences, few if any if the varieties succeeding in California have proved to be well adapted to Florida, and the converse is also true.

For winter production in Florida, new varieties have had to be originated, the best of which are hybrids, the Winslowson and Collinson, showing evidence of both West Indian and Guatemalan stock. The Fuerte variety, a Mexican-Guatemalan hybrid, has proved to be the preeminent variety for California planting, but it has been a practical failure in Florida. The result of these limitations is in the main fortunate the production for market in Florida being heaviest in the fall and early winter months, while the bulk of the California shipping crop matures in the winter, spring, and early summer months.

Between 4,000 and 5,000 acres are now set to avocados in California, with about 75 per cent of this acreage yet to come into bearing.  About 1,000 acres are planted in Florida, and the prospect is that this acreage will be rapidly extended. Only budded trees are planted, the Mexican stock being used in California and the West Indian in Florida.  Despite the fact that avocados have been grown for 50 years or more both in California and in Florida, it is only through decades of expensive failures that enough has been learned as to methods of propagation, cultivation, and the best varieties and stocks to warrant the present commercial expansion of the industry. There is still much to be earned, but a few limiting factors are recognized as vital.

FIGURE 12.—Trapp avocado, the first named variety to be propagated by buddmg and grafting.  Selected and propagated by George B. Cellon, of Miami, Fla., in 1901

All Varieties Need Frost Protection

1. Frost protection.—Even the so-called hardy varieties, such as the Fuerte, suffer from freezing weather and are about as tender as lemon trees. Sites must be chosen favored by latitude or topography to avoid cold injury, and in addition some form of grove heating is generally a paying investment.
2. In Florida drainage is next in importance.—No fruit tree is more easily injured by a high water table than the avocado. At the same time the tree must have ample soil moisture to draw on all the time.  In California irrigation is universally practiced, and provision for irrigation would pay well during most seasons in Florida. Even with irrigation the avocado will not thrive in hot, arid regions, as it prefers a fairly humid, equable climate.
3. Varieties for planting.—Scores of varieties at one time considered promising have been discarded, and the process is still going on.  For California, the leading commercml varieties are Fuerte, Puebla, Nabal, Queen, and Taft. In Florida, Pollock, Trapp, Winslowson, Collinson, and Lula are now most commonly planted. Interplanting varieties to facilitate cross-pollination increases the chances for fruit setting, especially with certain varieties more or less self-sterile particularly when they are grown in regions having warm sunshiny weather during the avocado flowering season. This self-sterility in the avocado is of a unique type, due to the synchronous opening and closing of the flowers, pollen not being shed until the second flower opening. Some varieties are morning pollenizers, and others shed pollen in the afternoon. By interplanting such reciprocating varieties, pollination is rendered more certain.

The rapid expansion of the avocado industry now taking place will necessitate the development of hitherto untouched markets through a cooperative program of advertising and education to make known the remarkable qualities of this truly American fruit. To this end cooperative associations are already functioning both in California and Florida, thus affording a reasonable hope of financial success in the effort to add this unique fruit to our national menu. As a step toward diversification through the planting of noncompetitive special crops, this effort deserves encouragement and success.