Turnip (brassica rapa)
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The turnip (Brassica rapa var. rapa) is a root vegetable commonly grown in temperate climates worldwide for its white, bulbous taproot. Small, tender varieties are grown for human consumption, while larger varieties are grown as feed for livestock. Turnips are notably popular in Europe, particularly in its colder parts, because they grow well in cold climates and can be stored for several months after harvest.
The turnip discussed here, a variety of Brassica rapa, is not the same plant as the rutabaga, though confusion occurs because of regional variations in usage: both may be referred to as "turnip" (see disambiguation page).
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Description
The most common type of turnip marketed as a vegetable in Europe and North America is mostly white-skinned apart from the upper 1–3 centimeters, which protrude above the ground and are purple, red, or greenish wherever sunlight has fallen. This above-ground part develops from stem tissue, but is fused with the root. The interior flesh is entirely white. The entire root is roughly spherical, about 5–15 centimeters in diameter, and lacks side roots. The taproot (the normal root below the swollen storage root) is thin and 10 centimeters or more in length; it is trimmed off before marketing. The leaves grow directly from the above-ground shoulder of the root, with little or no visible crown or neck (as found in rutabagas). Turnip greens are sometimes eaten, and resemble mustard greens, although they must be very fresh and so are normally removed before marketing. Varieties of Brassica rapa that have been developed specifically for use as leaf vegetables are called Chinese cabbage. Both leaves and root have a pungent flavor similar to raw cabbage or radishes that becomes mild after cooking.
Turnip roots weigh up to about 1 kilogram, although they can be harvested when smaller. Size is partly a function of variety and partly a function of the length of time that the turnip has grown. Most very small turnips (also called baby turnips) are specialty varieties. These are only available when freshly harvested and do not keep well. Most baby turnips can be eaten whole, including their leaves. Baby turnips come in yellow-, orange-, and red-fleshed varieties as well as white-fleshed. Their flavor is mild, so they can be eaten raw in salads like radishes.
Origin
The exact place where turnips were domesticated is unknown, but Afghanistan, Pakistan, and the Mediterranean region are candidates. Turnips were grown in Ancient Greece and the Roman Empire.
Nutrition
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Cultivation
Until the beginning of the eighteenth century, this valuable root was cultivated among us only in gardens or other small spots, for culinary purposes; but Lord Townshend, attending King George the First on one of his excursions to Germany, in the quality of secretary of State, observed the turnip cultivated in open and extensive fields, as fodder for cattle, and spreading fertility over lands naturally barren; and on his return to England he brought over with him some of the seed, and strongly recommended the practice which he had witnessed to the adoption of his own tenants, who occupied a soil similar to that of Hanover. The experiment succeeded; the cultivation of field turnips gradually spread over the whole county of Norfolk; and in the course of time it has made its way into every other district of England. The reputation of the county as an agricultural district dates from the vast improvements of heaths, wastes, sheepwalks, and warrens, by enclosure and manuring—the fruit of the zealous exertions of Lord Townshend and a few neighbouring land-owners—which were, ere long, happily imitated by others. Since these improvements were effected, rents have risen in that county from one or two shillings to fifteen or twenty shillings per acre (£10 or £20 to £180 to £250/km²); a country of sheep-walks and rabbit-warrens has been rendered highly productive; and by dint of management, what was thus gained has been preserved and improved even to the present moment. Some of the finest corn-crops in the world are now grown upon lands which, before the introduction of the turnip husbandry, produced a very scanty supply of grass for a few lean and half-starved rabbits. Mr. Colquhoun, in his "Statistical Researches," estimated the value of the turnip crop annually grown in this country at fourteen millions; but when we further recollect that it enables the agriculturist to reclaim and cultivate land which, without its aid, would remain in a hopeless state of natural barrenness; that it leaves the land so clean and in such fine condition, as almost to insure a good crop of barley and a kind plant of clover, and that this clover is found a most excellent preparative for wheat, it will appear that the subsequent advantages derived from a crop of turnips must infinitely exceed its estimated value as fodder for cattle.
The 1881 Household Cyclopedia gives these instructions for field cultivation of turnips:
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- The benefits derived from turnip husbandry are of great magnitude; light soils are cultivated with profit and facility; abundance of food is provided for man and beast; the earth is turned to the uses for which it is physically calculated, and by being suitably cleaned with this preparatory crop, a bed is provided for grass seeds, wherein they flourish and prosper with greater vigor than after any other preparation.
- The first ploughing is given immediately after harvest, or as soon as the wheat seed is finished, either in length or across the field, as circumstances may seem to require. In this state the ground remains till the oat seed is finished, when a second ploughing is given to it, usually in a contrary direction to the first. It is then repeatedly harrowed, often rolled between the harrowings and every particle of root-weeds carefully picked off with the hand; a third ploughing is then bestowed, and the other operations are repeated. In this stage, if the ground has not been very foul, the seed process generally commences, but often a fourth ploughing, sometimes a fifth is necessary before the ground is sufficiently clean. Less labor, however, is necessary now than in former times, when a more regular mode of cropping was commonly followed.
- The next part of the process is the sowing of the seed; this may be performed by drilling machines of different sizes and constructions, through all acting on the same principle. A machine drawn by a horse in a pair of shafts, sows two drills at a time and answers extremely well, where the ground is flat, and the drills properly made up. The weight of the machine insures a regularity of sowing hardly to be gained by those of a different size and construction. From two to three pounds of seed are sown upon the acre (2 to 3 kg/hectare), though the smallest of these quantities will give many more plants in ordinary seasons than are necessary; but as the seed is not an expensive article the greater part of farmers incline to sow thick, which both provides against the danger of part of the seed perishing, and gives the young plants an advantage at the outset.
- Turnips are sown from the beginning to the end of June, but the second and third weeks of the month are, by judicious farmers, accounted the most proper time. Some people have sown as early as May, and with advantage, but these early fields are apt to run to seed before winter, especially if the autumn be favorable to vegetation. As a general rule it may be laid down that the earliest sowings should be on the latest soils; plants on such soils are often long before they make any great progress, and, in the end, may be far behind those in other situations, which were much later sown. The turnip plant, indeed, does not thrive rapidly till its roots reach the dung, and the previous nourishment afforded them is often so scanty as to stunt them altogether before they get so far.
- The first thing to be done in this process is to run a horse-hoe, called a scraper, along the intervals, keeping at such a distance from the young plants that they shall not be injured; this operation destroys all the annual weeds which have sprung up, and leaves the plants standing in regular stripes or rows. The hand hoeing then commences, by which the turnips are all singled out at a distance of from eight to twelve inches, and the redundant ones drawn into the spaces between the rows. The singling out of the young plants is an operation of great importance, for an error committed in this process can hardly be afterwards rectified. Boys and girls are always employed as hoers; but a steady and trusty man-servant is usually set over them to see that the work is properly executed.
- In eight or ten days, or such a length of time as circumstances may require, a horse-hoe of a different construction from the scraper is used. This, in fact, is generally a small plough, of the same kind with that commonly wrought, but of smaller dimensions. By this implement, the earth is pared away from the sides of the drills, and a sort of new ridge formed in the middle of the former interval. The hand-hoers are again set to work, and every weed and superfluous turnip is cut up; afterwards the horse-hoe is employed to separate the earth, which it formerly threw into the furrows, and lay it back to the sides of the drills. On dry lands this is done by the scraper, but where the least tendency to moisture prevails, the small plough is used, in order that the furrows may be perfectly cleaned out. This latter mode, indeed, is very generally practiced.
External links
- Multilingual taxonomic information from the University of Melbourne (http://www.plantnames.unimelb.edu.au/Sorting/Brassica_rapa.html#rapa)