Swede, Turnip, and Radish
P Hadley, University of Reading, Whiretnights,
Reading, UK
R Fordham, Ludgvan, Cornwall, UK
Copyright 2003, Elsevier Science Ltd. All Rights Reserved.
Introduction
0001 The family Cruciferae includes some of the most
important temperate vegetables, of which there are
three commercially important root crops.
Swedes –
Brassica napus
L. var.
napobrassica Peterm
, Family Cruciferae
0002 Swede (also known as rutabaga, Swedish turnip, or
Lapland turnip) is usually considered to be a root
crop. However, the ‘root’ is mainly the swollen hyper-
cotyl of the plant. The crop is grown as an annual, as
a fodder crop, or for human consumption, and is
generally grown on a farm scale. It is thought to be
a relatively recent vegetable that originated as a nat-
ural hybrid of Brassica rapa (turnip) and B. oleracea
(cabbage). This hybrid may have occurred first in
Bohemia in the seventeenth century, although some
reports suggest that its origin is much earlier. The
swede was initially grown in Sweden (from where it
takes its name) and later spread to the rest of Europe
and North America. Swedes have an elongated globe
shape with a swollen neck bearing a number of leaf
scars; this neck differentiates swedes from turnips.
0003 Roots may be globe or tankard-shaped, or inter-
mediate between the two. The flesh is either white or
yellow/orange and has a milder flavor and a higher
sugar content than winter turnips. Yellow-fleshed
types are more commonly grown. The root develops
anthocyanin and/or chlorophyl in its outer skin where
it is exposed to the light, giving rise to a range of skin
colors. Four skin colors exist: green, light or dark
purple, and orange. Green-topped swedes are the
poorest croppers, but the best keepers, whilst the
reverse is true for purple-topped swedes.
Handling and Storage
0004 Swedes can be grown in a wide range of soils; how-
ever, the crop is best suited to a well-drained, medium
loam. The crop has a relatively low nutrient require-
ment and it rarely needs irrigation except on light,
sandy soil. In the UK, seeds are sown from March to
the end of June and are ready for harvesting 15–21
weeks later. Average yields are 32 t ha
1
and good
yields are typically 68 t ha
1
. The crop is pulled by
hand or is machine-harvested by digger elevators. The
root is removed and the neck is trimmed off. The
crop is sold for both the prepack and the wholesale
markets. For prepacking, small roots are required,
normally between 80 and 150 mm. Swedes for the
wholesale markets are normally marketed in nets
with minimum grading.
0005Storage normally commences in the autumn in
traditional clamped heaps covered with straw or soil
and is used to supply the market over the winter
period. Flavor is improved after the roots have been
exposed to early frosts. A more modern approach to
storage is to harvest into bulk bins and then surround
the bulk bins with straw bales. The crop is a low-
value crop and does not merit more sophisticated
storage conditions, although, for the longest storage
period, the roots can be stored in an insulated store
with forced ventilation at a temperature of 0
C and a
relative humidity of 90–95%. The crop can be left
standing in the field and harvested as required.
Domestic and Industrial Uses
0006Swedes are normally eaten as a cooked vegetable but
they can also be shredded raw in salads. They are
processed for canning, and included in pickles and
mixed and diced vegetables.
Food Value and Chemical Composition
0007Food value and chemical composition of raw swede
are summarized in Table 1.
Turnips –
Brassica rapa
, Family Cruciferae
0008Turnips are very similar vegetables to swedes and
the two crops are often confused. Roots are either
globe-shaped or have a more flattened shape, with
white or yellow flesh, and have a high water content.
The turnip is believed to have originated from a wild
form of Eurasian origin and has been known for
about 4000 years. The same species is believed to
have been responsible for Chinese cabbage and
other similar oriental vegetable crops. Although the
turnip (like swede) is described as a root, it is actually
a swollen hypocotyl and contains very little root
tissue. The color of the skin may be white, purple,
green, or mottled. The yellow-fleshed types are har-
dier than white types. Roots are generally small and
may be round, flat long, half long, or globe-shaped.
They rarely exceed 100 mm in diameter. The number
of different types allows turnips to be produced
throughout the year, although the crop is mainly
winter- or spring-grown.
Handling and Storage
0009Turnips tend to be an intensively grown crop. A sandy
loam soil is preferable for early-spring-sown crops;
5946 VEGETABLES OF TEMPERATE CLIMATES/Swede, Turnip, and Radish