Pecan

Naming

"Pecan" is from an Algonquian word variously referring to pecans, walnuts and hickory nuts. There are many variant pronunciations, some regional and others not. The most common American pronunciation is /pɪˈkɑːn/; the most common British one is /pɪˈkæn/. There is little agreement in the United States, even regionally, as to the "correct" pronunciation.

Reproduction

Active breeding and selection is carried out by the USDA Agricultural Research Service with growing locations at Brownwood and College Station, Texas. University of Georgia has a breeding program at the Tifton campus working to select pecan varieties adapted to subtropical southeastern U.S. growing conditions.

While selection work has been done since the late 19th century, most acreage of pecans grown today is of older cultivars, such as 'Stuart', 'Schley', 'Elliott', and 'Desirable', with known flaws but also with known production potential. Cultivars, such as 'Elliot', are increasing in popularity due to resistance to ''Pecan scab''. The long cycle time for pecan trees plus financial considerations dictate that new varieties go through an extensive vetting process before being widely planted. Numerous varieties produce well in Texas, but fail in the Southeastern U.S. due to increased disease pressure. Selection programs are ongoing at the state level, with Alabama, Arkansas, Florida, Georgia, Kansas, Missouri, New Mexico, and others having trial plantings.

Varieties adapted from the southern tier of states north through some parts of Iowa and even into southern Canada are available from nurseries. Production potential drops significantly when planted further north than Tennessee. Most breeding efforts for northern-adapted varieties have not been on a large enough scale to significantly affect production. Varieties that are available and adapted in zones 6 and farther north are almost entirely selections from wild stands. Kanza, a northern-adapted release from the USDA breeding program, is a grafted pecan having high productivity and quality, and cold tolerance.

Food

The seeds of the pecan are edible, with a rich, buttery flavor. They can be eaten fresh or used in cooking, particularly in sweet desserts, such as pecan pie, a traditional Southern U.S. dish. Pecans are a major ingredient in American praline candy. Other applications of cooking with pecans include pecan oil and pecan butter.

Pecan wood is used in making furniture and wood flooring, as well as a flavoring fuel for smoking meats, giving grilled foods a sweet and nutty flavor stronger than many fruit woods.

Evolution

The pecan, ''Carya illinoinensis'', is a member of the Juglandaceae family. Juglandaceae are represented worldwide by between seven and 10 extant genera and more than 60 species. Most of these species are concentrated in the Northern Hemisphere of the New World, but some can be found on every continent except for Antarctica. The first fossil examples of the family appear during the Cretaceous. Differentiation between the subfamilies of Engelhardioideae and Juglandioideae occurred during the early Paleogene, about 64 million years ago. Extant examples of Engelhardioideae are generally tropical and evergreen, while those of Juglandioideae are deciduous and found in more temperate zones. The second major step in the development of pecan was a change from wind-dispersed fruits to animal dispersion. This dispersal strategy coincides with the development of a husk around the fruit and a drastic change in the relative concentrations of fatty acids. The ratio of oleic to linoleic acids are inverted between wind- and animal-dispersed seeds. Further differentiation from other species of Juglandaceae occurred about 44 million years ago during the Eocene. The fruits of the pecan genus ''Carya'' differ from those of the walnut genus ''Juglans'' only in the formation of the husk of the fruit. The husks of walnuts develop from the bracts, bracteoles, and sepals, or sepals only. The husks of pecans develop from the bracts and the bracteoles only.Before European settlement, pecans were widely consumed and traded by Native Americans. As a food source, pecans are a natural choice for preagricultural society. As a wild forage, the fruit of the previous growing season is commonly still edible when found on the ground.

Pecans first became known to Europeans in the 16th century. The first Europeans to come into contact with pecans were Spanish explorers in what is now Louisiana, Texas, and Mexico. These Spanish explorers called the pecan, ''nuez de la arruga'', which roughly translates to "wrinkle nut". Because of their familiarity with the genus ''Juglans'', these early explorers referred to the nuts as ''nogales'' and ''nueces'', the Spanish terms for "walnut trees" and "fruit of the walnut". They noted the particularly thin shell and acorn-like shape of the fruit, indicating they were indeed referring to pecans. The Spaniards took the pecan into Europe, Asia, and Africa beginning in the 16th century. In 1792, William Bartram reported in his botanical book, ''Travels'', a nut tree, ''Juglans exalata'' that some botanists today argue was the American pecan tree, but others argue was hickory, ''Carya ovata''. Pecan trees are native to the United States, and writing about the pecan tree goes back to the nation's founders. Thomas Jefferson planted pecan trees, ''C. illinoinensis'' , in his nut orchard at his home, Monticello, in Virginia. George Washington reported in his journal that Thomas Jefferson gave him "Illinois nuts", pecans, which Washington then grew at Mount Vernon, his Virginia home.

Commercial production of pecans was slow because trees are slow to mature and bear fruit. More importantly, the trees grown from nuts of one tree have very diverse characters. To speed nut production and retain the best tree characteristics, grafting from mature productive trees was the obvious strategy. However, this proved technically difficult. The ''Centennial'' cultivar was the first to be successfully grafted. This was accomplished by a slave called Antoine in 1846 or 1847, who was owned by Jacques Telesphore Roman of the Oak Alley Plantation near the Mississippi river. The scions were supplied by Dr. A. E. Colomb who had unsuccessfully attempted to graft them himself.