IN THE ARBORETUM TODAY -- AVOCADOS
By Alfredo Chiri
AVOCADO - Persea americana - Lauraceae
(1) cv. "Daily 11" CRFG/Teague/Haluza. Planted in 1982 (r.f.-03)
(2) cv. "Littlecado" CRFG/Haluza/La Verne Nur. Planted in 1985(r.f-03)
Common names: Avocado, alligator-pear, aguacate (Spanish), palta (Spanish-Castillian).
Avocados are indigenous to tropical America and have been cultivated since pre-Columbian times. The name of "Avocado" comes from the Aztec word "Ahuacatl," roughly translated as "green testicles." The Aztec Indians believed that avocados had aphrodisiac qualities, and all unmarried women were sequestered during the peak-growing season. Avocados are grown in tropical and subtropical areas of the world. Avocado varieties are classified in three groups, known as the West Indian, Guatemalan, and Mexican "races", each one with distinct characteristics.
West Indian - Origin: Tropical low lands. Skin texture: Leathery-smooth
Guatemalan - Origin: Tropical highlands. Skin texture: Woody-rough
Mexican - Origin: Tropical highlands. Skin texture: Papery-smooth
The tree grows from a 30 ft to a 65 ft in height. Avocado trees are classified as evergreen, although some varieties lose their leaves for a short time before flowering. The tree canopy ranges from low, dense and symmetrical to upright and asymmetrical. Leaves are 3 to 16 inches in length and variable in shape and often reddish when young, then become dark green when mature.
The fruit is a berry, consisting of a single large seed, surrounded by a buttery pulp containing in some varieties from 3 to 30% oil. The skin is variable in thickness and texture depending on the variety. The fruit does not generally ripen until it falls or is picked from the tree. The fruit is considered sufficiently mature for harvest when it reaches a specified oil % or dry weight %. Calender date, color, or loss of shine, or seed coat turning brown are other indications.
The Avocado pollination varieties are classified into A and B types according to the time of day when the female and male flower parts become reproductively functional.
Type A: 1st day: Flower opens, and the stigma is receptive in the morning. Flower closes in the afternoon and night. 2nd day: Flower is closed in the morning, and in the afternoon the flower opens again, pollen shedding.
Type B: 1st day: Flower opens, and the stigma is receptive in the afternoon. Flower closes in the night. 2nd day: Flower opens again, pollen shedding in the morning.
Avocado varieties do not come true from seed, so they must be propagated vegetatively. Grafting is most successful during the cooler months. Propagation by cuttings and air-layering has not been successful.