The Potato reference article from the English Wikipedia on 24-Apr-2004
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Potato

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Potato
Image:Potatoes.jpg
Scientific classification
Kingdom:Plantae
Division:Tracheobionta
Class:Magnoliopsida
Subclass:Asteridae
Order:Solanales
Family:Solanaceae
Genus: Solanum
Species: tuberosum
Binomial nomenclature
Solanum tuberosum L.

The potato (Solanum tuberosum) is a perennial tuber of the Solanaceae, or nightshade, family, which is one of the most widely used vegetables in Europe and North and South America. There are six other species of Solanum of minor importance. There are thousands of varieties of potato in cultivation.

The potato is unrelated to the sweet potato. In the United States it is sometimes referred to as the "Irish Potato" to distinguish it.

Table of contents
1 History
2 Varieties
3 Food value
4 Toxic compounds in potatoes
5 Cultivation
6 Recipes
7 References

History

The potato plant is thought to be native to the Andes and cultivated originally by the Inca and other Pre-Columbian people of the region, spreading over time throughout other Native American groups and becoming a staple food.

In the 16th century, the Spaniards introduced it to the rest of the world. The name "Potato" came from the Spanish word "patata" (the original quechua word was "papa"). Many other European languages took forms of this Spanish name. In the Americas, the word "papa" is more used in the Spanish language than "patata".

It has long been popularly taught that Sir Walter Raleigh was responsible for bringing the potato to England, but Sir Francis Drake is more likely to be responsible. In 1586, after battling the Spaniards in the Caribbean, Drake stopped at Cartagena in Colombia to collect provisions - including tobacco and potato tubers. Before returning to England he stopped at Roanoke Island, where the first English settlers had been attempting to set up a colony. The pioneers returned to England with Drake, along with the potatoes.

By 1650 potatoes were the staple food of Ireland, and they began to replace wheat as the major crop elsewhere in Europe, being used to feed both people and animals. The first mention of potatoes appearing in North America comes from Irish settlers in Londonderry, New Hampshire during 1719.

Augustin Parmentier is said to have popularised it in France in the 18th century, after his captivity in Prussia.

The potato was such an important food to the Irish that it is permanently associated with them today in the popular imagination, due to a single devastating event - the Irish potato famine. In the 1840s there was a major outbreak of potato blight, which swept through Europe, wiping out the potato crop in many countries. The Irish economy was so dependent on a single variety of potatoes as a staple at this time that the event led to terrible disease, death, famine, and subsequently emigration by many of the survivors to areas where there was more food. The blight marks an important, though tragic, point in Irish history.

Other theories that accept the possibility of pre-Columbian transatlantic contacts, attribute an earlier date of the very limited existence of potato in the Old World and Asia.

Varieties

Potatoes come in brown, yellow, pink, red, and purple (sometimes called "blue"). Their flesh may be white or colored like the skin. Small types are called "fingerling" or "new" potatoes, larger potatoes are often distinguished as "earlies" or "main crop", with the "main crop" being varietes that will store well. Individual varieties may be labeled "boiling", indicating that they retain some shape when boiled, "baking" indicating that they only hold their shape if baked, "roasting", indicating that they are flavoursome when roasted, "salad" to indicate that they are suitable for salad use (often firm and waxy fleshed when boiled), or "mashing" to indicate that when mashed they form a smooth consistency neither fibrous nor grainy.

Some common North American varieties are:

In the United States the term "Idaho potato" is often used, but does not denote a variety, but simply an origin in Idaho, that country's principal potato-growing region.

Some common British varieties are:

Image:Potato harvesting, painting by Carl Larsson (1853-1919).jpg
"Potato harvesting" by the Swedish painter Carl Larsson (1853-1919)

Food value

Potatoes have a high carbohydrate content and include protein, minerals (particularly potassium, calcium) and vitamins, including vitamin C. More vitamin C is found in freshly harvested potatoes than potatoes that have been stored.

A benefit of new and fingerling potatoes is that they contain less toxic chemcals. Such potatoes are an excellent source of nutrition. Peeled, long-stored potatoes fried by fast-food establishments have less nutritional value although they still have potassium and vitamin C.

Potatoes can be prepared for eating in numerous ways, either with their skin on or peeled, whole or cut into pieces, and with seasonings or without. All that is required is that they be cooked to break down the starch and make them edible. Potatoes are generally eaten hot, but several basic potato recipes involve cooking the potatoes and then eating them cold - potato salad and potato chips. One of the commonest presentation methods is 'mashed potatoes'. These are peeled, boiled then mashed and mixed with butter, cream, or other seasonings before serving. Potatoes can also be baked whole; cut into cubes and roasted; grated and formed into dumplings or potato pancakes; and cut into long, thin pieces and fried or baked (Chips, called "French fries" in the US).

Potatoes also provide starch, flour, alcohol (when fermented), dextrin, and livestock fodder.

Toxic compounds in potatoes

Potatoes also contain glycoalkaloids, toxic compounds, of which the most prevalent are solanine and chaconine. These are partly destroyed by cooking at high temperatures (over 170 degrees C). Glycoalkaloid concentrations are highest just underneath the skin of the tuber and increase with age and exposure to light. Glycolakloids may cause headaches, diarrhea, cramps and in severe cases coma and death; however, poisoning from potatoes is very rare. Light exposure also causes greening, thus giving a visual clue as to areas of the tuber that may be toxic, however, this is not a definitive guide as greening and glycoalkaloid accumulation can occur independently of each other. Some varieties of potato contain greater glycolalkaloid concentrations than others; breeders developing new varieties test for this, and sometimes have to discard an otherwise promising cultivar.

Breeders try to keep solanine levels below 0.2 mg/g (200 ppm). However, when even these commercial varieties turn green, they can approach concentrations of solanine of 1 mg/g (1000 ppm). Some studies suggest that 200 mg of solanine can be a dangerous dose. This dose would require eating 1 average-sized spoiled potato or 4-9 good potatoes (over 3 pounds) at one time. The National Toxicolgy Program suggest that the average American consumes 12.5 mg/person/day of solanine from potatoes. Dr. Douglas L. Holt, the State Extension Specialist for Food Safety at the University of Missouri - Columbia notes that no cases of potato-source solanine poisoning have been reported in the U.S. in the last 50 years and most cases involved eating green potatoes or drinking potato leaf tea.

Cultivation

Potato plants are low-growing and have white flowers with yellow stamens. They grow best in cool, moist climates such as Maine, Idaho, New Brunswick, Prince Edward Island, Germany, Russia, and Poland, though they are widely adaptable and are grown on a small scale in most temperate regions.

The tubers are covered with buds called "eyes". Common varieties of potatoes do not produce seeds; the flowers are sterile. Instead, they are propagated by planting pieces of existing tubers, cut to include at least one eye. Confusingly, these pieces are called "seed potatoes".

Potato plant thumbnail
potato plant
(Larger)

The 1881 Household Cyclopedia adds:

Ground Preparation

To reduce the ground till it is completely free from root-weeds, may be considered as a desiderutum in potato husbandry; though in many seasons these operations cannot be perfectly executed, without losing the proper time for planting, which never ought to be beyond the first of May, if circumstances do not absolutely interdict it. Three ploughings, with frequent harrowings and rollings, are necessary in most cases before the land is in suitable condition. When this is accomplished form the drills as if they were for turnips; cart the manure, which ought not to be sparingly applied, plant the seed above the manure, reverse the drills for covering it and the seed, then harrow the drills in length, which completes the preparation and seed process.

Seed Quantity

It is not advantageous to cut the seed into small slips, for the strength of the stem at the outset depends in direct proportion upon the vigor and power of the seed-plant. The seed plant, therefore, ought to be large, rarely smaller than the fourth-part of the potato; and if the seed is of small size, one-half of the potato may be profitably used. At all events, rather err in giving over large seed than in making it too small because, by the first error, no great loss can ever be sustained; whereas, by the other, feeble and late crop may be the consequence. When the seed is properly cut, it requires from ten to twelve hundredweight of potatoes to plant an acre (1.2 to 1.5 t/ha) of ground, where the rows are twenty seven inches (700 mm) apart; but this quantity depends greatly upon the size of the potatoes used; if they are large, a greater weight may be required, but the extra quantity will be abundantly repaid by the superiority of crop which large seed usually produces.

Raising Methods

The earth should be dug twelve inches deep, if the soil will allow it; after this, a hole should be opened about six inches (150 mm) deep, and horse-dung or long litter should be put therein, about three inches (75 mm) thick; this hole should not be more than twelve inches (300 mm) in diameter. Upon this dung or litter a potato should be planted whole, upon which a little more dung should be shaken, and then the earth should be put thereon. In like manner the whole plot of ground must be planted, taking care that the potatoes be at least sixteen inches apart. When the young shoots make their appearance they should have fresh mould drawn around them with a hoe; and if the tender shoots are covered, it will prevent the frost from injuring them; they should again be earthed when the shoots make a second appearance, but not covered, as in all probability the season will be less severe.

A plentiful supply of mould should be given them, and the person who performs this business should never tread upon the plant, or the hillock that is raised round it, as the lighter the earth is the more room the potato will have to expand.

A gentleman obtained from a single root, thus planted, very nearly forty pounds weight of large potatoes, and from almost every other root upon the same plot of ground from fifteen to twenty pounds weight; and, except the soil be stony or gravelly, ten pounds or half a peck of potatoes may generally be obtained from each root by pursuing the foregoing method.

But note--cuttings or small sets will not do for this purpose.

Storing

Potatoes are generally dug up with a three-prong grape or fork, but at other times, when the weather is dry, the plough is used, which is the most expeditious implement. After gathering the interval, the furrow taken by the plough is broken and separated, in which way the crop may be more completely gathered than when taken up by the grape. The potatoes are then stored up for winter and spring use; and as it is of importance to keep them as long through summer as possible, every endeavor ought to be made to preserve them from frost, and from sprouting in the spring months. The former is accomplished by covering them well with straw when lodged in a house, and by a thick coat of earth when deposited in a pit, and the latter, by picking them carefully at different times, when they begin to sprout, drying them sufficiently by exposure to the sun, or by a gentle toast of a kiln.

Ireland Cultivation

The drill system, in the cultivation of potatoes in Ireland, is particularly recommended by Lord Farnham, in a letter to Sir John Sinclair. The small farmers and laborers plant them in lazy-beds, eight feet wide. This mode is practised on account of the want of necessary implements for practicing the drill system, together with a want of horses for the same purpose.

They are cut into sets, three from a large potato; and each set to contain at least one eye. The sets are planted at the distance of seven inches asunder, six and a quarter hundredweight are considered sufficient seed for a British acre. Lord Farnham recommends rotten dung in preference to any fresh dung. If not to be procured, horse-dung, hot from the dunghill. In any soil he would recommend the dung below the seed.

When the potatoes are vegetated ten inches above the surface, the scuffler must be introduced, and cast the mold from the potato. If any weeds are found in the drills they must be hand-hoed; in three days afterwards they must be moulded up by the double-breasted plough, as high as the neck of the potato. This mode must be practiced twice, or in some cases three times, particularly if the land is foul. I do not (says Lord Farnham) consider any mode so good as the drill system.

General Observation

To prepare for the drill system either oat or wheat stubble, it should be ploughed in October or the beginning of November; to be ploughed deep and laid up for winter dry. In March let it be harrowed, and give it three clean earths. Be very particular to eradicate the couch grass. The drills to be three feet asunder; drill deep the first time that there is room in the bottom of the furrow to contain the dung. The best time to begin planting the potatoes is about the latter end of April by this system. It is as good a preparation for wheat as the best fallows.

Three feet and a half for drills are preferable to four feet. Mr. Curwen prefers four feet and a half. He says the produce is immense. Potatoes ought to be cut at least from two to three weeks before being planted; and if planted very early whole potatoes are preferable to cut ones, and dung under and over. Some agriculturists lately pay much attention to raising seedling potatoes, with the hope of renewing the vigor of the plant.

Early potatoes may be produced in great quantity by resetting the plants, after taking off the ripe and large ones. A gentleman at Dumfries has replanted them six different times in one season, without any additional manure; and, instead of falling off in quantity, he gets a larger crop of ripe ones at every raising than the former ones. His plants have still on them three distinct crops, and he supposes they may still continue to vegetate and germinate until they are stopped by the frost. By this means he has a new crop every eight days, and has had so for a length of time.

Recipes

References