On this Wikipedia the language links peanut butter peach pie at the top of the page across from the article title. This article is about the crop. For the comic strip, see Peanuts. For Peanut allergen powder, see Peanut allergen powder-dnfp.

For the folk song, see Goober Peas. Peanuts are similar in taste and nutritional profile to tree nuts such as walnuts and almonds, and, as a culinary nut, are often served in similar ways in Western cuisines. The Arachis genus is native to South America, east of the Andes, around Peru, Bolivia, Argentina, and Brazil. The process of domestication through artificial selection made A.

The domesticated plants are bushier, more compact, and have a different pod structure and larger seeds. The oldest known archeological remains of pods have been dated at about 7,600 years old, possibly a wild species that was in cultivation, or A. They were found in Peru, where dry climatic conditions are favorable for the preservation of organic material. In the English-speaking world, peanut growing is most important in the United States. Peanut butter was developed in the 1880s and 1890s in the United States and Canada. The flowers are 1 to 1.

They are borne in axillary clusters on the stems above ground and last for just one day. Peanut fruits develop underground, an unusual feature known as geocarpy. Peanut pegs growing into the soil. The tip of the peg, once buried, swells and develops into a peanut fruit. Peanuts grow best in light, sandy loam soil with a pH of 5.

Their capacity to fix nitrogen means that providing they nodulate properly, peanuts benefit little or not at all from nitrogen-containing fertilizer, and they improve soil fertility. To maximize yield, the timing of harvest is important. The main yield-limiting factors in semiarid regions are drought and high-temperature stress. The stages of reproductive development before flowering, at flowering, and at early pod development are particularly sensitive to these constraints. In mechanized systems, a machine is used to cut off the main root of the peanut plant by cutting through the soil just below the level of the peanut pods.

The machine lifts the “bush” from the ground, shakes it, then inverts it, leaving the plant upside down to keep the peanuts out of the soil. After the peanuts have dried sufficiently, they are threshed, removing the peanut pods from the rest of the bush. There are many peanut cultivars grown around the world. The market classes grown in the United States are Spanish, Runner, Virginia, and Valencia. Certain cultivar groups are preferred for particular characteristics, such as differences in flavor, oil content, size, shape, and disease resistance. Most peanuts marketed in the shell are of the Virginia type, along with some Valencias selected for large size and the attractive appearance of the shell.

The small Spanish types are grown in South Africa and the southwestern and southeastern United States. US state of Georgia were Spanish types, but the trend since then has been larger-seeded, higher-yielding, more disease-resistant cultivars. 14′, ‘Spanco’, ‘Wilco I’, ‘GG 2’, ‘GG 4’, ‘TMV 2’, and ‘Tamnut 06′. Since 1940, the southeastern US region has seen a shift to producing Runner group peanuts. This shift is due to good flavor, better roasting characteristics, and higher yields when compared to Spanish types, leading to food manufacturers’ preference for the use in peanut butter and salted nuts.