POTATO (from Sp. potato, white potato, batata, sweet potato, from Haytian batata, sweet potato). An important cultivated plant, raised in temperate climates for its esculeut tubers. It is often called Irish potato because of its general cultivation and use in Ireland. It belongs to the order Solanacex. o• nightshade family. which also includes tobacco, belladonna, tomato, egg plant, and pepper. The potato (Solanum tuber °sum) is a native of the mountainous districts of tropical and subtropical America, from Chile to Mexico, a form of it even occurring as far north as southern Colorado. It is difficult, how ever, to determine where it is really and where it has been introduced by man. Like maize, it was cultivated and its tubers used for food before the discovery of America. It seems to have been first brought to Europe from Peru by the Spaniards early in the sixteenth Cen tury, and to have spread from Spain into Hol land, Burgundy, and Italy, but only to be culti vated in a few gardens as a curiosity. In nearly all European countries it was called batata, by which name sweet potato is designated by Eng lish writers down to the middle of the seven teenth century. The data concerning its intro duction into Europe are not very definite. It appears to have been brought to Ireland from Virginia by Hawkins, a slave trader, in 1565, and to England by Sir Francis Drake in 1585. Sir Walter Ralegh is said to have taken some tubers to England in 15S6 and brought them to the at tention of Queen Elizabeth. It was not until a long time after its introduction that the cul ture of the potato became general. Gerard in his Lierball, published in 1597, described it under the name of Batata Virginiana, but so little were its merits appreciated that it was not even men tioned in The Complete Gardener, a work pub lished in 1719. At first it was regarded chiefly as a food for swine and cattle, but later on it was thought that on account of its great yield it might be useful as food for poor people and for the prevention of famine due to failures of the grain crops. The Royal Society of London in 1663 adopted measures for the extension of its culture in accordance with this idea. Its culti• vation first became most general in Ireland, but it was not until about the middle of the eighteenth century that it acquired any real importance on the Continent of Europe, and not until the end of that century (lid it become important as a field crop in Germany and France, which are to-day two of the greatest potato-producing countries' of the world. In France the extension of potato culture was mainly due to the efforts of Parmen tier, a prominent agriculturist and economist.
Historical data concerning the development of the potato as a crop in North America are even umo•e meagre. In 1771 only a white and a red variety were mentioned in the most important English work on gardening, while to-day at some of the experiment stations in Europe and America tests are made of 150 to 200 varieties at one time. Apart from the abnormal development of the tubers and the very much reduced production of seed, it is believed that there have not been great changes in the potato plant since its cultivation became general.
The potato is a perennial plant with smooth herbaceous stems from one to three feet high, pinnate leaves, and white or purple flowers about one inch wide, and producing a globular, purplish fruit or seed-ball of the size of a gooseberry. See Plate of VEGETABLES. The timbers are distinct from the roots, being underground stems of consider able size even when the plant is in its native state; under the influence of cultivation they have become enlarged through the accumulation of starch for the use of the plants grown from the eyes, or buds. Owing to its wide distribution. from the cooler tropics to the cooler temperate zones, it is grown on a great variety of soils, but the soil best suited to the crop is a rich, sandy loam, well supplied with organic matter and well drained. It responds to liberal manuring, but since a direct application often injures the quality of the tubers, barnyard manure is preferably ap plied the previous year; otherwise complete com mercial fertilizers, containing nitrogen, phos phoric acid, and potash, are applied.
The land should be plowed as deeply as possible without turning up the subsoil. The tubers are generally planted in drills wide enough apart to admit of cultivation with the ho•se hoe, or culti vator, and from 12 to 16 inches apart in the row. The pieces of the tuber used for planting, called sets, cuttings, o• seed pieces. are covered about 4 inches deep. Planting is generally done by hand, but where the crop is grown on a large scale potato planters are used. The crop is planted in the spring when danger of injury by frost has passed. After planting, the soil is har rowed frequently until the plants are all up, when the cultivator is used until the vines shade the ground. The results of experiments at dif ferent experiment stations in the United States indicate that the use of half the tuber as a seed piece is preferable to using smaller cuttings or the whole tuber. In the Southern United States two crops of potatoes are sometimes produced on the same land in one year.