Brassica rapa L.
Syn.: Brassica campestris L.
Turnip, Turnip greens, Turnip rape, Field mustard
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
Turnips are one of the most commonly grown and.widely adapted root crops, as
general farm crop, truck crop, or home-garden crop. Roots eaten raw or cooked
as a vegetable, and tops as potherb like spinach. Roots also grown for feeding
to livestock during fall and winter.
The powdered seed is said to be a folk remedy for cancer. The root when boiled
with lard is used for breast tumors. The stems and leaves are said to be a
remedy for cancer, while a salve derived from the flowers is said to help skin
cancer. (Hartwell, 19671971).
Per 100 g, the root is reported to contain 30 calories, 91.5 g H2O, 1.0 g
protein, 0.2 g fat, 6.6 g total carbohydrate, 0.9 g fiber, 0.7 g ash, 39 mg Ca,
30 mg P, 0.5 mg Fe, 49 mg Na, 268 mg K, a trace of b-carotene equivalent,
0.04 mg thiamine, 0.07 mg riboflavin, 0.6 mg niacin, and 36 mg ascorbic acid
(Watt and Merrill, 1963). Per 100 g, the leaf is reported to contain 23
calories, 92.7 g H2O, 1.9 g protein, 0.2 g fat, 4.6 g total carbohydrate, 1.0 g
fiber, 0.6 g ash, 168 mg Ca, 52 mg P, 2.6 mg Fe, 78 mg Na, 420 mg K, 1330 mg
b-carotene equivalent, 0.10 mg thiamine, 0.18 mg riboflavin, 0.7 mg niacin,
and 47 mg ascorbic acid (Wu Leung et al., 1972). Seed oil contains large
amount of erucic, linoleic, and linolenic acids.
Occasionally suspected of poisoning bovines, sheep, and pigs.
Biennial herb with swollen tuberous white-fleshed taproot, lacking a neck;
leaves light to medium green, hairy or bristly, stalked, lyrate-pinnatifid,
3050 cm long, stem-leaves sometimes glaucous with clasping base; flowers
bright yellow, sepals spreading: petals 610 mm long, those in anthesis close
together and commonly overtopping the unopened buds; outer 2 stamens curved
outwards at base and much shorter than inner stamens; fruit 46.5 cm long, with
long tapering beak, on divaricate-ascending pedicels 3.26.5 cm long; seeds
blackish or reddish-brown, 1.52 mm in diameter. Fl. and fr. second spring.
Varieties may have white or yellow flesh, and outside crown may be white, green
or purplish-red. Most common white-fleshed varieties are: 'Purple Top White
Globe' and 'White Egg'. 'Shogoin' is a white-skinned, white-fleshed Japanese
variety, widely grown in the South for greens and salad. Yellow-fleshed
turnips include 'Golden Ball' or 'Orange Jelly', 'Amber or Yellow Globe' and
'Yellow Aberdeen'. 'Seven Top' is grown in South for useof greens. 'Purple
Top White Globe' is recommended for tropics. Brassica rapa subsp.
rapa, turnip, cultivated for its tuberous taproot, sometimes escapes as
a weed. Brassica rapa subsp. oleifera DC., Turnip rape, grown as
a fodder crop, has larger reddishbrown seeds and non-tuberous taproot.
Brassica rapa subsp. sylvestris (L.) Janchen (B.
campestris L., p.p.). Field mustard is a weed or ruderal in much of
Europe, native to Asia. Reported from the China-Japan, Eurosiberian, and
Mediterranean Centers of Diversity, turnip, or cvs thereof, is reported to,
tolerate aluminum, bacteria, disease, frost, fungi, high pH, low pH, laterite,
mycobacteria, photoperiod, smog, sulfur dioxide, virus, and weeds (Duke,
1978). Terrell (1977) divides Brassica rapa into the following groups:
Chinensis Grouppak-choi, Pekinensis Grouppe-tsai or "Chinese cabbage",
Perviridis Groupspinach mustard, Rapifera Groupturnip, and Ruvo Groupruvo
kale. (2n = 20)
Cultivated in Europe for over 4000 years, probably native to central and
southern Europe, now spread throughout world, including most parts of the
Turnip is basically a cool climate crop, resistant to frost and mild freezes.
Grown as a spring or fall crop throughout the United States. Temperatures
below 10°C cause bolting. Turnips do well in deep, friable, highly
fertile soil with pH 5.56.8; sandy loams are used for early markets roots and
greens. Short growing season makes them very adaptable as a catch crop.
Ranging from Boreal Moist to Rain through Tropical Thorn to Moist Forest Life
Zones, Brassica rapa is reported to tolerate annual precipitation of 3.5
to 41.0 dm (mean of 75 cases = 9.1), annual temperature of 3.6 to
27.4°C (mean of 75 cases = 10.7), and pH of 4.2 to 7.8 (mean
of 66 cases = 6.2) (Duke, 1978, 1979).
Seed sown thinly in spring, summer or fall in drills at seed rate of 1.12.2
kg/ha. Seedlings then thinned to stand 515 cm apart in rows 0.30.9 m apart.
Cultivate shallowly for weed control. Add lime to soil to correct pH to
5.56.8. Only light applications of fertilizer are justified, as 450675 kg/ha
of 4124. When turnips are seeded as a fall crop following a crop that has
been well fertilized, no additional fertilizer may be necessary. Seed may be
broadcast on fertile, well-prepared seedbeds where weed control will not be
difficult. Turnips may be intercropped with corn, and as such they are
shade-tolerant, or they may be used as a catch crop after early vegetables. It
is not advisable to grow turnips after a root crop. Good rotation, helps to
control diseases. Best grown after clover, beans, peas or grass crop (Reed,
Roots may be harvested in 4580 days. They are harvested for bunching when 5
cm in diameter, and for topped turnips when 7.5 cm in diameter. Turnip greens
may be harvested when plants are young and tender. For early spring market,
turnips are pulled, washed, their tops left on, tied in bunches, and marketed.
Topped turnips for the general market are sold by the bushel or the
hundredweight. Flavor and texture are not improved by storage. They should
not be left in the ground where temperatures near freezing occur; in milder
areas they may be left in field until desired. They may be stored in pits or
piles, in well-drained soils. Piles should not be more than 2.6 m wide nor
more than 2 m deep to prevent heating at the center. For good aeration, wooden
chutes are inserted at intervals of 2.53 m in the pile. A ditch is dug around
the base of pile for water runoff. Alternate layers of straw and soil are used
as covering for pit storage. For indoor storage, crates or small piles laid on
earth cellar floors are satisfactory. Small quantities of turnips may be
stored in a cool cellar and covered with moistened clean sand to keep them from
drying out. Storage temperature in a cellar or in a cold storage room should
remain between 0° and 1.5°C, with a relative humidity of
Good yields are 12.5 tons/bunched or 25 tons/topped per hectare in the United
States. However, these figures do not represent true yields since it is
difficult to determine what proportion of a crop is sold topped, bunched or fed
to livestock. Turnip crop in 1969 was ca 60,000 MT; the 1971 consumption was
ca 50,000 MT. The national consumption for both turnips and rutabagas (these
are usually reported together) is ca 200,000 MT, not counting quantities used
for animal feed. Turnips and turnip greens are available all year, with peak
production in October and November. Duke (1978) reports fresh turnip yields of
According to the phytomass files (Duke, 1981b) annual productivity ranges from
4 to 11 MT/ha. Indian studies showed DM yields of 5301,260 kg/ha after 38
days with 61191 kg extractable protein; 8202,090 kg/ha after 52 days with
90265 kg extractable protein. If this much were available in 45 days, and
plots were cropped continuously (perhaps impractical, if not impossible), DM
yields might run 616 MT/ha with ca 8002,000 kg/ha, the residues remaining for
potential energy conversion. Seed yields in Minnesota and Canada run over
1,000 kg/ha/yr, and the oil from such seeds is being considered for energy
purposes (Matai et al., 1973).
Cross pollination, by various insects, is necessary for good seed production.
In USSR, 1617 colonies of bees/ha are used, but 2 or 3 hives are sufficient to
increase pollination and to insure good seed set. Isolation of varieties
necessary for pure seed production; in England at least 900 m; in New Zealand,
400 m. Should be well-isolated from all other forms of B. juncea, B.
campestris, and B. napus. Clubroot (Plasmodiophora
brassicae) and Black rot are the most serious diseases. Other fungi
attacking turnips include: Albugo candids, Alternaria brassicae, A.
brassicicola, A. oleracea, A. herculea, A. tenuis, Botrytis cinerea, Cercospora
albo-maculans, C. brassicicola, C. brassicae, Choanephora cucurbitarum,
Cladosporium cladosporioides, Colletotrichum higginsianum, Corticium solani,
Cystopus candidus, Curvularia inaequalis, Erysiphe polygone, E. communis,
Fusarium oxysporum, F.conglutinans, Gloeosporium concentricum, Leptosphaeria
napi, Macrophomina phaseoli, Macrosporium macrosporum, Mycosphaerella
brassicicola, Oidium erysiphoides, Peronospora parasitica, P. brassicae, Phoma
lingam, Phymatotrichum omnivorum, Pythium ultimum, Rhizoctonia sp., Sclerotinia
sclerotiorum, Sclerotium rolfsii, Septomyxa affine, Stemphylium botryosum,
Streptomyces scabies, Spongospora subterranea. Turnips may be parasitized
by Orobanche cernua, or attacked by the following bacteria:
Agrobacterium tumefaciens, Bacterium aroideae, Erwinia carotovora, E.
aroideae, Pectobacterium carotovorum, Pseudomonas maculicola, P. madrasensis,
Xanthomonas campestris, and X. vesicatoria campestris, and
X. vesicatoria. Viruses isolated from turnips include: Beet mild
yellowing, Beet ringspot, Cabbage blackspot, Cauliflower mosaic, Crinkle
mosaic, Cucumber mosaic, Kukitachina mosaic, Turnip latent, Turnip mosaic and
Curly top. Nematodes attacking turnips include: Belonolaimus longicaudatus,
Ditylenchus dipsaci, Helicotylenchus dihystera, H. pseudorobustus, Heterodera
cruciferae, H. schachtii, Meloidogyne arenaria, M. hapla, M. incognita, M. i.
acrita, M. javanica, Nacobbus aberrans, Pratylenchus neglectus, P. penetrans,
P. projectus, and Trichodorus christiei. Turnip aphid, root maggot and
flea beetles are the most injurious insect pests.
Complete list of references for Duke, Handbook of Energy Crops
- Duke, J.A. 1978. The quest for tolerant germplasm. p. 161. In: ASA Special
Symposium 32, Crop tolerance to suboptimal land conditions. Am. Soc. Agron.
- Duke, J.A. 1979. Ecosystematic data on economic plants. Quart. J. Crude Drug
- Duke, J.A. 1981b. The gene revolution. Paper 1. p. 89150. In: Office of
Technology Assessment, Background papers for innovative biological technologies
for lesser developed countries. USGPO. Washington.
- Hartwell, J.L. 19671971. Plants used against cancer. A survey. Lloydia 3034.
- Matai, S., Bagchi, D.K., and Chandra, S. 1973. Optimal seed rate and fertilizer
dose for maximum yield of extracted protein from the leaves of mustard
(Brassica nigra Koch) and turnip (Brassica rapa L.). Indian J.
Agr. Sci. 43(2):165169.
- Reed, C.F. 1976. Information summaries on 1000 economic plants. Typescripts
submitted to the USDA.
- Terrell, E.E. 1977. A checklist of names for 3,000 vascular plants of economic
importance. Ag. Handbook 505. ARS, USDA. USGPO, Washington, DC.
- Watt, B.K. and Merrill, A.L. 1963. Composition of foods. USDA, ARS, Washington,
DC. Agr. Handb. 8.
- Wu Leung, Woot-Tsuen, Butrum, R.R., and Chang, F.H. 1972. Part I. Proximate
composition mineral and vitamin contents of east Asian foods. In: Food
composition table for use in east Asia. FAO & U.S. Dept. HEW.
Last update Tuesday, December 30, 1997