|Brassica rapa subsp. rapa var.||Turnip|
- For similar vegetables also called "turnip", see Turnip (disambiguation).
The turnip or white 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.
The most common type of turnip is mostly white-skinned apart from the upper 1–6 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 conical, but can be occasionally tomato-shaped, about 5–20 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 leaves are sometimes eaten as "turnip greens" ("turnip tops" in the UK), and they resemble mustard greens in flavor. Turnip greens are a common side dish in southeastern US cooking, primarily during late fall and winter. Smaller leaves are preferred; however, any bitter taste of larger leaves can be reduced by pouring off the water from initial boiling and replacing it with fresh water. Varieties specifically grown for the leaves resemble mustard greens more than those grown for the roots, with small or no storage roots. Varieties of B. rapa that have been developed only for use as leaves 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.
It is hardy to zone 0 and is not frost tender. It is in flower from May to August, and the seeds ripen from July to September. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Bees. The plant is self-fertile.pf
|Standard Cyclopedia of Horticulture|
Turnip (Brassica rapa var. rapa) is a name somewhat loosely applied to two species of vegetables. In this country, and apparently properly, it is applied to vegetables characterized by thick light-fleshed roots that are usually more or less flattened or at least not greatly elongated, with leaves that are hairy and not glaucous. These vegetables belong to the species Brassica Rapa (see page 543). In the term is sometimes included the Swedish turnip or rutabaga, a plant that is characterized by having a more uniformly elongated-oval yellow-fleshed tuber with roots springing from its lower part, a thick elongated leafy neck, and glaucous-blue leaves that are not hairy. This plant is considered to be Brassica campestris var. Napo-Brassica. Whether these two species exist separately in wild nature is not positively known, but they appear to be well defined under cultivation. Both species tend to run wild in old fields and to lose their thickened roots. They are then sometimes, though erroneously, known as charlock. (The real charlock is Brassica [Sinapis] arvensis, one of the mustards). The nativity of these species is unknown, but they are almost certainly European or Asian in origin. Characteristic tubers of these two plants are contrasted. The former is commonly known here as "flat turnip" and the latter as rutabaga or merely "baga." According to Vilmorin, the plant that we know as rutabaga is known to the French as chou-navet and in England as Swedish turnip and turnip-rooted cabbage.
The culture of turnips and rutabagas is very similar, except that the rutabaga requires a longer season. The rutabaga is nearly always grown as a main-season crop, whereas the turnip may be sown very late for winter use or very early for late spring or summer use. Usually the flat turnip is not grown in the hot weather of summer. In the northern states it is sown from the middle of July to the middle of August for late crop, or on the first approach of spring in order that tubers may be had for the early vegetable market. The late or winter crop is ordinarily used for storing in cellars and also for feeding, whereas the early crop is often sold in bunches in the open market, and later by the basket or bushel.
The turnips and rutabagas are hardy; that is, the young plants can withstand some frost. They are cold-weather plants and demand loose moist soil. Usually the seeds are sown in drills that stand from 10 to 20 inches apart. In the drills the plants are thinned until they stand from 6 to 10 inches apart, depending on the variety. For general field operations, the rows are sometimes placed as far as 30 inches apart, to allow horse tillage. Sometimes the late or winter crop is raised from seed sown broadcast, but this method gives good results only when the soil is well supplied with moisture, very thoroughly tilled beforehand and is free from weeds, since subsequent tillage is impossible. The seeds of turnips and rutabagas are of similar size, two or three pounds being required to the acre for broadcasting. When sown in drills, one-half or one- third this amount may be sufficient. The yields will sometimes reach 1,000 bushels to the acre, although the average is much less than this.
The turnip needs no special care as to cultivation. The greatest difficulties are the root-maggot, which is the larva of a small fly, and the flea-beetle. The maggot may be killed by injecting bisulfide of carbon into the soil about the roots before the grubs have burrowed deeply into the tissues. In general field operations, however, this treatment is impracticable and one must rely on growing the crop in fields which are not infested with the maggot; that is, rotation is the chief recourse. The flea-beetle may be kept in check by spraying the plants with bordeaux mixture, or perhaps better by sprinkling them with paris green diluted with land-plaster (one part by bulk of paris green to fifty of plaster).
Rutabagas have firmer and richer flesh than the turnips. They are usually more prized for consumption in winter, and turnips are usually more popular in the spring and early fall markets. Rutabagas are also more prized for stock-feeding. They yield heavily, are rich and succulent and keep well in any ordinary cellar. Rutabagas started in the middle or last of June in the northern states will reach their full growth by October. They are usually not harvested until heavy frosts have come. The roots of rutabagas and turnips sometimes persist through the winter, even though they have been solidly frozen, and send up flower-stalks in the spring; but unlike salsify and parsnips the roots should not be left in the ground to freeze if they are to be used. CH
The plant prefers light (sandy), medium (loamy) and heavy (clay) soils and requires well-drained soil. The plant prefers acid, neutral and basic (alkaline) soils and can grow in very acid and very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It requires moist soil.
Turnip is basically a cool climate crop that is resistant to frost and mild freezes. The plants are very easily grown, provided they grow quickly when young and the soil is not allowed to dry out. They succeed in full sun in a well-drained fertile preferably alkaline soil. Turnips grow best in deep, friable, highly fertile soil with pH 5.5 - 6.8. They are said to prefer a light sandy soil, especially when grown for an early crop in the spring, and dislike a heavy soil[37, 269]. They prefer cool moist growing conditions. Turnips tolerate an annual precipitation of 35 to 410cm, an annual average temperature range of 3.6 to 27.4°C and a pH in the range of 4.2 to 7.8. Temperatures below 10°C cause the plants to run to seed, even if they have not yet formed an edible root. The turnip is often cultivated, both in the garden and commercially, for its edible root. A fast growing plant, it can take less than ten weeks from sowing to harvesting. Its short growing season makes turnips very adaptable as a catch crop. There are several named varieties and by careful selection and successional sowing it is possible to harvest roots all year round. The roots are fairly cold hardy and can be left in the ground during the winter, harvesting them as required. However, they can be troubled by slugs and other creatures so it is often better to harvest them in late autumn or early winter and store them in a cool but frost-free place. This species has long been cultivated as an edible plant and a large number of forms have been developed. Botanists have divided these forms into a number of groups, and these are detailed below. Separate entries in the database have been made for each group. B. rapa. The species was actually named for the cultivated garden turnip with its edible swollen tap root. This form is dealt with on this record. B. rapa campestris. This is the wild form of the species. It does not have a swollen root and is closest to the forms grown for their oil-rich seeds. B. rapa chinensis. Pak choi has long been cultivated in the Orient for its large tender edible leaves which are mainly produced in the summer and autumn. B. rapa dichotoma. Cultivated in the Orient mainly for its oil-rich seeds. B. rapa narinosa. Chinese savoy is another Oriental form. It is grown for its edible leaves. B. rapa nipposinica. Mizuna is a fast-growing cold-hardy form with tender edible leaves that can be produced all year round. B. rapa oleifera. The stubble turnip has a swollen edible root, though it is considered too coarse for human consumption and is grown mainly for fodder and as a green manure. It is also cultivated for its oil-rich seeds. B. rapa parachinensis. False pak choi is very similar to B. rapa chinensis with tender edible leaves, though it is considerably more cold-hardy. B. rapa pekinensis. Chinese cabbages are widely grown in the Orient. The large tender leaves often form a cabbage-like head. B. rapa perviridis. Spinach mustard is grown for its edible leaves. A very cold-hardy plant, and also able to withstand summer heat, it can provide a crop all year round. B. rapa trilocularis. Indian colza is mainly grown for its oil-rich seeds. Grows well with peas but dislikes growing with hedge mustard and knotweed[18, 20]. A good bee plant.
Seed - sow in situ from early spring to late summer. The first sowing can be made under cloches in late winter and will be ready for use in early summer. The latest sowings for winter use can be made in mid to late summer.
Pests and diseases
There are many named varieties of this annual vegetable, with new forms being developed each year.
- Plants for a Future - creative commons text incorporated
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963