The radish ( Raphanus sativus) is a flowering plant in the mustard family, Brassicaceae. Its large taproot is commonly used as a root vegetable, although the entire plant is edible and its leaf are sometimes used as a leaf vegetable. Originally domesticated in Asia, radishes are now grown and consumed globally. The radish is sometimes considered to form a species complex with the wild radish, and instead given the trinomial name Raphanus raphanistrum subsp. sativus.
Radishes are often used raw as a crunchy salad vegetable with a pungency, slightly spicy flavor, varying in intensity depending on its growing environment. There are numerous varieties varying in size, flavor, color, and length of time they take to mature. Radishes owe their sharp flavor to the various chemical compounds produced by the plants, including glucosinolate, myrosinase, and isothiocyanate. They are sometimes grown as and suffer from few pests and diseases. They germinate quickly and grow rapidly, common smaller varieties being ready for consumption within a month, while larger daikon varieties take several weeks. Being relatively easy to grow and quick to harvest, radishes are often planted by novice gardeners. Another use of radish is as a Cover crop or catch crop in winter,
History
Varieties of radish are now broadly distributed globally, but almost no
archeological records are available to help determine their early history and domestication.
However, scientists have tentatively located the origin of
Raphanus sativus in
Southeast Asia, as this is the only region where truly wild forms have been discovered.
India, central
China, and
Central Asia appear to have been secondary centers where differing forms were developed. Radishes enter the historical record in .
Ancient Greece and Roman agriculturalists of the gave details of small, large, round, long, mild, and sharp varieties.
Folklore
Asaph the Jew noted that the radish, particularly its leaves, may be useful in traditional medicine to increase mucus.
During the Middle Ages,
Ibn Wahshiyya considered it a component of poison antidotes, while
Maimonides highlighted its possible uses as a treatment.
Al-Warraq's 10th-century cookbook includes radish as a side dish for ostrich meat and an ingredient in a chicken dish called
kardanāj.
Description
Radishes are annual or biennial
Brassicaceae crops grown for their swollen tap roots which can be globular, tapering, or cylindrical. The root skin colour ranges from white through pink, red, purple, yellow, and green to black, but the flesh is usually white. The roots obtain their color from
. Red varieties use the anthocyanin
pelargonidin as a pigment, and purple cultivars obtain their color from
cyanidin.
Smaller types have a few leaves about long with round roots up to in diameter or more slender, long roots up to long. Both of these are normally eaten raw in salads.
A longer root form, including oriental radishes, daikon or mooli, and winter radishes, grows up to long with foliage about high with a spread of .
The flesh of radishes harvested timely is crisp and sweet, but becomes bitter and tough if the vegetable is left in the ground too long.
Leaves are arranged in a rosette. They have a lyrate shape, meaning they are divided
with an enlarged terminal lobe and smaller lateral lobes. The white flowers are borne on a
raceme inflorescence.
The fruits are small pods which can be eaten when young.
The radish is a Ploidy species, and has 18 (2 n=18). It is estimated that the radish genome contains between 526 and 574 Mb.
Varieties
|
|
| Raphanus sativus var. sativus |
| Raphanus sativus var. caudatus |
| Raphanus sativus var. longipinnatus |
| Raphanus sativus var. niger |
| Raphanus sativus var. oleiformis |
| Raphanus sativus var. raphanistroides |
|
Cultivation
Radishes are a fast-growing, annual, cool-season crop. The seed
Germination in three to four days in moist conditions with soil temperatures between . Best quality roots are obtained under moderate day lengths with air temperatures in the range . Under average conditions, the crop matures in 3–4 weeks, but in colder weather, 6–7 weeks may be required.
Homegrown varieties can be significantly sharper.
Radishes grow best in full sun in light, sandy , with a soil pH 6.5 to 7.0, but for late-season crops, a clayey-loam is ideal. Soils that bake dry and form a crust in dry weather are unsuitable and can impair germination.[ hosted by the University of North Texas Government Documents Department Documents A to Z Digitization Project website. Retrieved on 2014-07-29.][Peterson, Cass. "Radishes: Easy to Sprout, Hard to Grow Right" . The New York Times, May 2, 1999. Retrieved February 5, 2018.] Harvesting periods can be extended by making repeat plantings, spaced a week or two apart. In warmer climates, radishes are normally planted in the autumn.
Radishes are a common garden crop in many parts of the world, and the fast harvest cycle makes them particularly suitable for children's gardens.
Companion plant
Radishes can be useful as
for many other crops, probably because their pungent odour deters such insect pests as
,
, tomato hornworms,
Coreidae, and
.
They can also function as a
trap crop, luring insect pests away from the main crop.
Cucumbers and radishes seem to thrive when grown in close association with each other, and radishes also grow well with
chervil,
lettuce,
, and
Tropaeolum. However, they react adversely to growing in close association with
hyssop.
Pests
As a fast-growing plant, diseases are not generally a problem with radishes, but some insect pests can be a nuisance. The larvae of
live in the soil, but the adult beetles cause damage to the crop, biting small "shot holes" in the leaves, especially of seedlings. The swede midge (
Contarinia nasturtii) attacks the foliage and growing tip of the plant and causes distortion, multiple (or no) growing tips, and swollen or crinkled leaves and stems. The larvae of the
Delia radicum sometimes attack the roots. The foliage droops and becomes discoloured, and small, white maggots tunnel through the root, making it unattractive or inedible.
Varieties
Radishes can be categorized into four main types according to the seasons when they are grown and a variety of shapes, lengths, colors, and sizes, such as red, pink, white, gray-black, or yellow radishes, with round or elongated roots that can grow longer than a
parsnip.
Spring or summer radishes
Sometimes referred to as European radishes or spring radishes if they are planted in cooler weather, summer radishes are generally small and have a relatively short three- to four-week cultivation time.
-
The 'April Cross' is a giant white radish hybrid that bolts very slowly.
-
'Bunny Tail' is an heirloom variety from Italy, where it is known as Rosso Tondo A Piccola Punta Bianca. It is slightly oblong, mostly red, with a white tip.
-
'Cherry Belle' is a bright red-skinned round variety with a white interior.
-
'Champion' is round and red-skinned like the 'Cherry Belle', but with slightly larger roots, up to , and a milder flavor.
-
'Red King' has a mild flavor, with good resistance to club root, a problem that can arise from poor drainage.
-
'Sicily Giant' is a large heirloom variety from Sicily. It can reach up to 5 cm (2 in) in diameter.
-
'Snow Belle' is an all-white variety of radish, similar in shape to the 'Cherry Belle'.
-
'White Icicle' or 'Icicle' is a white carrot-shaped variety, around long, dating back to the 16th century. It slices easily and has better than average resistance to pithiness.
-
'French Breakfast' is an elongated, red-skinned radish with a white splash at the root end. It is typically slightly milder than other summer varieties but is among the quickest to turn pithy.
-
'Plum Purple', a purple-fuchsia radish, tends to stay crisp longer than average.
-
'Gala' and 'Roodbol' are two varieties popular in the Netherlands in a breakfast dish, thinly sliced on buttered bread.
-
'Easter Egg' is not an actual variety, but a mix of varieties with different skin colors,
Winter varieties
'Black Spanish' or 'Black Spanish Round' occur in both round and elongated forms, and are sometimes simply called the
black radish (Raphanus sativus
L. var. niger (M.) S.K. or
L. ssp. niger (M.). D.C. var. albus D.C) or known by the French name
Gros Noir d'Hiver. It dates in Europe to 1548,
and was a common garden variety in England and France during the early 19th century.
It has a rough, black skin with hot-flavored, white flesh, is round or irregularly pear shaped,
and grows to around in diameter.
Daikon refers to a wide variety of winter oilseed radishes from Asia. While the Japanese name daikon has been adopted in English, it is also sometimes called the Japanese radish, Chinese radish, Oriental radish, or mooli (in India and South Asia).[ ] Daikons commonly have elongated white roots, although many varieties of daikon exist. One well-known variety is 'April Cross', with smooth white roots.[(2002-02-10.) "29 kg radish wins contest." Kyodo News, via highbeam.com (fee for full access.) Retrieved on 2007-09-28.]
Korean radish, also called Korean radish(무), is a variety of white radish with firm crunchy texture.
Seed pod varieties
The seeds of radishes grow in
(widely referred to as "pods"), following flowering that happens when left to grow past their normal harvesting period. The seeds are edible and are sometimes used as a crunchy, sharp addition to salads.
Some varieties are grown specifically for their seeds or seed pods, rather than their roots. The rat-tailed radish, an old European variety thought to have come from East Asia centuries ago, has long, thin, curly pods that can exceed in length. In the 17th century, the pods were often pickled and served with meat.
The 'München Bier' variety supplies seed pods that are sometimes served raw as an accompaniment to beer in
Germany.
Production
Using 2003–4 data, several sources report annual world production of radishes to be about 7 million
, produced mainly by
China,
Japan, and
South Korea, and representing roughly 2% of global vegetable production.
Nutritional value
In a reference serving, raw radishes provide of
food energy and have a moderate amount of
vitamin C (18% of
Daily Value), with other essential nutrients in low content (table). A raw radish is 95% water, 3%
, 1%
protein, and has negligible
fat.
Uses
Cooking
The most commonly eaten portion is the or
taproot, although the entire plant is edible and the tops can be used as a
leaf vegetable. The seed can also be
sprouting and eaten raw in a similar way to a
mung bean.
The root of the radish is usually eaten raw, although tougher specimens can be steamed or roasted. The raw flesh has a crisp texture and a pungent, peppery flavor, caused by and the enzyme myrosinase, which combine when chewed to form allyl isothiocyanates, also present in mustard plant, horseradish, and wasabi.
Radishes are mostly used in salads but also appear in many European dishes.
Radish greens are usually discarded, but are edible and nutritious, and can be prepared in several ways.
In Indian cuisine the seed pods are called "moongra" or "mogri" and can be used in many dishes.
Other uses
The seeds of radishes can be pressed to extract
vegetable oil.
Wild radish seeds contain up to 48% oil, and while not suitable for human consumption, this oil is a potential source of
biofuel.
The daikon grows well in cool climates and, apart from its industrial use, can be used as a cover crop, grown to increase soil fertility, to scavenge nutrients, suppress weeds, help alleviate soil compaction, and prevent winter erosion of the soil.
"Radi", a spiral-cut radish, served with salt and occasionally chives, is traditionally served with beer at the Bavarian Oktoberfest.
Culture
The
daikon varieties of radish are important parts of
East Asia,
Southeast Asia, and
cuisine. In
Japan and
Korea, radish dolls are sometimes made as children's toys. Daikon is also one of the plants that make up the Japanese Festival of Seven Herbs (
Nanakusa no sekku) on the seventh day after the new year.
Citizens of Oaxaca, Mexico, celebrate the Night of the Radishes ( Noche de los rábanos) on December 23 as a part of Christmas celebrations. This folk art competition uses a large type of radish up to long and weighing up to . Great skill and ingenuity are used to carve these into religious and popular figures, buildings, and other objects, and they are displayed in the town square.
Gallery
File:Daikon, Nara Prefecture, Japan.jpg|Daikon
File:Gegeolmu (Korean radish).jpg|Gegeol radish
File:Korean radish (mu).jpg|Korean radish
File:Chinese radish p1150393.jpg|Watermelon radish
File:Raphanus sativus-1.jpg|White and red
File:Pannier de radis noir, roses et blancs.jpg|Black, white and red
File:Raphanus sativus-2-xavier cottage-yercaud-salem-India.JPG|Sliced red
File:Colourful radishes.jpg|Multiple colors
File:CSIRO ScienceImage 2779 Radishes.jpg|Dark red
File:Raphanus sativus var. sativus Radish ハツカダイコン廿日大根、二十日大根 DSCF6410.JPG|Harvesting red
See also
Notes
Bibliography
External links
