The radish (Raphanus sativus) is an edible root vegetable of the Brassicaceae family that was domesticated in Europe in pre-Roman times. Radishes are grown and consumed throughout the world, being mostly eaten raw as a crunchy salad vegetable. They have numerous varieties, varying in size, color and the length of time they take to mature. They are sometimes grown as companion plants and suffer from few pests and diseases. They germinate quickly and grow rapidly, smaller varieties being ready for consumption within a month while larger daikon varieties taking several months. Some radishes are grown for their seeds: oil-seed radishes, for instance, may be grown for oil production. Others are used for sprouting and both roots and leaves are sometimes served cooked.
Varieties of radish are now broadly distributed around the world, but there are almost no archaeological records available to help determine its early history and domestication. However, scientists tentatively locate 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 3rd century B.C. Greek and Roman agriculturalists of the 1st century A.D. gave details of small, large, round, long, mild, and sharp varieties. The radish seems to have been one of the first European crops introduced to the Americas. A German botanist, reported radishes of 100 pounds (45 kg) and roughly three feet in length in 1544, although the only variety of that size today is the Japanese Sakurajima radish. The large, mild, and white East Asian form was developed in China but is mostly associated in the West with the Japanese daikon, owing to Japanese agricultural development and larger exports.
A variety of vegetables are cultivated in Pakistan. Potatoes, onions, tomatoes, melons and other cucurbits are some of the major vegetable species grown in Pakistan. Mainly vegetables are concentrated in the vicinities of big urban centers like Lahore, Karachi and Peshawar. Area and production of radish is concentrated in Sheikhupura around Lahore.
The radish (Raphanus sativus L.) belongs to the family of Cruciferae. The radish probably originated in central and western China and the Indo-Pakistan subcontinent. Radish is a favorite crop for kitchen gardening, because it is easily grown and is ready for use in three to six weeks after sowing. It is grown for its fleshy edible roots, which are eaten raw as salad, or cooked as a vegetable. Radish has a cooling effect, prevents constipation increases appetite and is tasty. Radish contains mostly protein, sugar, vitamin C and other important nutrients. It is recommended to patients suffering from piles, liver trouble, enlarged spleen and jaundice. Its leaves are cooked as leafy vegetables in different forms and are very rich in minerals and vitamins A and C. (Baloch, 1994).
Radish can be grown on all soil types, but grows well in light rich and moist soils. The major identified districts for radish production are Sheikhupura, Sahiwal, R.Y. Khan, T.T. Singh and Okara.
It was cultivated over an area of 10133 hectares producing 173806 tones (Anon., 2009). It is widely used as root vegetable; however, its immature young green pods are also used as a vegetable by a large population. Indigenous cultivars are mostly white having a triangular or cylindrical shape roots with more pungent taste than introduced types. Genetic variability of radish germplasm is not much investigated and only a few studies have been reported on phenotypic diversity (Nomura et al., 1996). As compared to other crucifer species, the diversity of radish is not yet characterized at genetic and molecular levels despite its world-wide economic importance (Rabbani et al., 1998; Rabbani et al., 2010). In the present study we report the genetic variation in radish germplasm from Pakistan and Japan, evaluated and characterized under field conditions for various qualitative and quantitative traits.
Climatic and Soil Requirement
Radish is essentially a cold-season crop and can be cultivated throughout the year but October to January is the best period. The high temperature of summer causes the plant to develop small tops, and roots rapidly become pithy and strongly pungent after reaching maturity. For this reason it is difficult to produce quality radish during midsummer.
Because radish grows rapidly, a rich, fertile sandy loam soil having capacity to retain moisture for a long period is considered the best for radish cultivation. The soil should be free of stones, clods, lumps, and non-decayed organic matter.
Thorough seedbed preparation is essential to insure uniform depth of planting. A fine, well-prepared seedbed is important for growing radish. Application of farm yard manure approximately six weeks before sowing of crop helps build up the water-holding capacity of the soil and balance the nutrient supply. The land should be leveled followed by two to three deep plugging and 20-30 cartloads of well-rotten farm yard manure per acre mixed in soil followed by watering.
Ridges should be made followed by two plugging. Before ridge making one bag of DAP, half bag of urea and one to two bags of sulphate of potash (SOP) per acre should be added so that fertilizer may get mixed in the soil. Ridges should be made at a distance of two to two and half feet apart with a height of about one to one and half feet. Two bags of urea should be given in three in three split doses i.e. at first, second and third weeding respectively.
Three to four kilograms of seed per acre is required. Most commonly growers grow Chinese and Japanese varieties. As per survey conducted by the Technology Transfer Institute, Tando Jam, 90 per cent growers in the Sultanabad area grow Chinese varieties whereas 10 per cent grow Japanese varieties. The best method of sowing seeds is that on both sides of ridges 2-3 cm deep lines are drawn and seed is drilled into these lines followed by covering with thin layer of soil.
To produce high quality radish, there is a need to maintain satisfactory soil moisture throughout the growth of the plant. After sowing of seeds water should be applied but it should be taken into account that water neither submerge the ridges nor remain below the seed surface because in both conditions germination will be badly affected. Excessive irrigation’s during the summer season lead to stunted growth. Irrigation’s should be applied at weekly interval in summer and at fortnightly during winter.
When after second irrigation germination becomes complete and plants attain a size of 5-7 cm thinning should be started and plant to plant distance maintained at 5-7 cm as well. Thinning should be done well in time because late thinning results in weaker plants and no thinning leads to reduced and distorted radishes.
In order to get rid of weeds first weeding should be done within 15-20 days after sowing and rest weeding should be done as per quantity of weeds and need. Weeds can also be controlled with knockdown herbicides prior to planting of radishes.
As a member of the Cruciferae family, radishes are attacked by the same pests which attack cabbages and cauliflowers. Major pests include cabbage white butterfly, aphids and diamondback moth. Other pests of crucifers can cause damage from time to time. Growers generally do two to three sprays to control these insect pests.
Diseases of Radish
Because of the short growing period, only a few diseases cause economic losses in radish. The most important is black rot, a disease caused by a soil-borne fungus. Dark irregular patches develop on the radish root and eventually give the entire root a black color. Long-rooted cultivars can be severely attacked. The round types may escape infection in infested soil but are not resistant. The disease is controlled by good soil drainage and crop rotations of 3–4 years. Radish is also attacked by white rust. This disease causes raised white pustules on the leaves, stems and flowers. It is controlled by the destruction of diseased crop residues, rotations of 3–4 years and the separation of young from old crops.
Harvesting and Marketing
Under normal conditions, harvest commences 40-50 days after planting. Roots are mature when they reach a satisfactory size. Turning of leaves from dark green to light green is the sign of maturity. The radishes are pulled and banded in the field
Harvesting should be done during the morning or evening time. Harvested produce should be thoroughly washed wrapped in bundles and marketed early in the morning. The bunch should be firmly tied with tape, string, twist-ties, or rubber bands. About eight to 12 roots are put in one bunch .Yield of 250-300 maunds per acre can be achieved.
Health Benefits of Radish
Radish, that common and beloved part of your salad, is a root crop, and it is pungent or sweet in taste with a lot of juice. Radishes can be white, red, purple or black, and in terms of shape, it can be long and cylindrical or round. They are eaten raw, cooked or pickled. The oil obtained from the seeds of radish is also used in a number of products and beneficial health applications.
The parts of radishes that are commonly consumed are the leaves, flowers, pods and seeds. The scientific name of radish is Raphanus Sativus which belongs to the Brassicaceae family. Radish is also known as Daikon in some parts of the world, primarily in Asian markets.
Radish is rich in ascorbic acid, folic acid, potassium and vitamin C. It is a good source of vitamin B6, riboflavin, and minerals like sulphur, iron, iodine, magnesium, copper, and calcium. A hundred gram of radish (raw root) contains carbohydrates 3.4 g, sugars1.86g, dietary fiber 1.6 g, fat 0.10 g, protein 0.68g, thiamin (vit.B1) 0.012mg, riboflavin (vit.B2) 0.039 mg, niacin (vit.B3) 0.254 mg, pantothenic acid (B5) 0.165 mg, vitamin B6 0.071 mg, folate (vit.B9) 25 mg, vitamin C 14.8 mg, calcium 25 mg, iron 0.34 mg, magnesium 10 mg, phosphorus 20 mg, potassium 233 mg and zinc 0.28 mg.
Benefits of Radish Are,
The benefits of radishes in the treatment or prevention of certain ailments and on certain body parts are listed below:
Radishes are very good for the liver and stomach, and it acts as a powerful detoxifier too. That means that it purifies the blood and eliminating toxins and waste. It is extremely useful in treating jaundice because it removes bilirubin and also keeps its production at a stable level. It also reduces the destruction of red blood cells that happens to people suffering from jaundice by increasing the supply of fresh oxygen to the blood. Black radishes are more preferred in the treatment of jaundice, and radish leaves are also very useful in the treatment.
Radishes are considered roughage, which means that it is composed of indigestible carbohydrates. This facilitates digestion, water retention, and it fixes constipation, which is one of the major causes of piles. As such a good detoxifier, it helps heal the symptoms of piles very quickly. Its juice also soothes the digestive and excretory system, further relieving the symptoms of piles.
Radishes are diuretic in nature, which means that they increase the production of urine. Juice from radishes also cures inflammation and a burning feeling during urination. It also cleans out the kidneys and inhibits infections in the kidneys and urinary system, thus helping the treatment of various urinary conditions that are exacerbated by excess toxins in the system.
Radishes are very filling, which mean that they satisfy your hunger without running up your calorie count. They are also low in digestible carbohydrates, high in roughage and contain a lot of water, making radishes a very good dietary option for those who are determined to lose weight. Furthermore, they are high in fiber and low on the glycemic index, which means that they increase regular bowel movements, which helps in weight loss, and increases the efficiency of the metabolism for all bodily processes.
Radishes are a great source of anthocyanins, which are a type of flavonoids, which not only give color to radishes, but also provide numerous health benefits. Anthocyanins have been the subject of numerous medical studies, and have been positively linked to reducing the occurrence of cardiovascular disease, and they have also displayed anti-cancer and anti-inflammatory properties.
Since radishes are detoxifiers and are rich in vitamin-C, folic and anthocyanins, they have been connected to treating many types of cancer, particularly colon, kidney, intestinal, stomach and oral cancer. Radishes are part of the Brassica family, and like the other members of that taxonomic classification, these cruciferous vegetables are packed with antioxidants. Furthermore, the isthiocyanates found in radishes have a major impact on the genetic pathways of cancerous cells. They alter the pathways so much, in fact, that they can cause apoptosis, cell death, thereby eliminating cancerous cells from reproducing.
The detoxifying and anti-carcinogenic properties of radishes make them useful in the treatment of Leucoderma. The radish seeds are used in this treatment method. They should be powdered and soaked in vinegar, ginger juice, or cow’s urine and then applied on the white patches. You can eat radishes as well to aid the treatment of Leucoderma.
Radishes are very high in fiber, which means that they add considerable bulk to bowel movements, which promotes regular excretory patterns and relieve symptoms of constipation. They can also help to firm up loose bowels and get rid of loose stool or diarrhea. Furthermore, radishes are known to promote the production of bile. Bile is one of the most important parts of good digestion, and also helps to protect both the liver and the gallbladder.
Respiratory Disorders, Bronchitis and Asthma
Radishes are an anti-congestive, meaning that it decreases congestion of the respiratory system including irritation of the nose, throat, wind-pipe and lungs that can come from colds, infections, allergies and other causes. They are a great disinfectant and rich in vitamins, which further protects the respiratory system from infections.
Radishes are a very good source of potassium, which contributes to a large list of health benefits. Potassium has been positively connected to reducing blood pressure, because when it interacts with the arterial supply of vascular beds, it can relax the blood vessels, and therefore increase blood flow. It reduces the blood pressure by widening the flow of the blood, instead of forcing it through narrow, constricted channels.
Radishes have long been known to have a low glycemic index, which means that eating it does not impact blood sugar levels. It also helps regulate the absorption of sugars into the bloodstream, meaning that diabetics don’t have to worry as much about sudden spikes or drops when eating, or being away from food for a certain amount of time.
Vitamin-C, phosphorus, zinc and some members of vitamin-B complex that are present in radishes are good for the skin. The water in radishes also helps to maintain healthy moisture levels in the skin. Smashed raw radish is a good cleanser and serves as an efficient face pack. Due to its disinfectant properties, radishes also help clear up skin disorders like dry skin, rashes, and cracks.
Radishes lower body temperature and relieve inflammation from fevers. A good method of intake is drinking radish juice mixed with black salt, and since they act as good disinfectants, radishes also fight infections that can cause fever.
As a diuretic, cleanser, and disinfectant, radishes help in the treatment of many kidney disorders. Its diuretic properties help wash away the toxins accumulated in the kidneys and they decrease the accumulation of toxins in the blood, thereby decreasing their concentration in the kidneys. Its disinfectant properties protect the kidneys from any infections as well.
Radishes have anti-purity properties and can be used as an effective treatment for insect bites and bee stings. Radish juice also reduces pain and swelling and soothes the affected area.
Radishes are mostly composed of water, and they are a great way to keep your body hydrated, which is beneficial to many different parts of health. One of the most important parts of staying hydrated is the impact of water on the digestive system. Staying hydrated relieves constipation, improves the efficiency of digestion, and ensures proper uptake of nutrients from the food we eat.
Respiratory Conditions and Sore Throats
Radishes have a strong, natural spice to them, and they are also quite pungent, which is very good for preventing illness, and it also eliminates excess mucus in the throat. Furthermore, radishes have been known to soothe sore throats and relieve congestion by clearing the sinuses.
Vitamin-C and Immune System Health
There are countless reasons why radishes are a good addition to your diet, but improving your immune system is one of the most important. A half cup of radishes per day in a salad or just as a snack is nearly 15% of your daily intake of Vitamin-C. Consistently maxing out your daily dose of Vitamin-C intake can rejuvenate your immune system by replacing many of the antioxidants and white blood cells which are so integral in fighting off every illness from the common cold to cancer.
Vitamin-C does not only boost your immune system, but it also is considered a super vitamin because of all the other high-impact effects it has on the body. It helps regulate your metabolism, which changes fat into usable energy, and it is a main contributor in the creation of collagen, which is an essential protein that strengthens blood vessel walls and reduces the chances of arthrosclerosis and various other heart diseases.
Liver & Gallbladder
Radishes are especially beneficial for liver and gallbladder functions. They regulate production and flow of bile and bilirubin, acids, and enzymes. Furthermore, it also removes excess bilirubin from the blood, and it contains enzymes like myrosinase, diastase, amylase and esterase. Regular consumption of radishes protects your liver and gallbladder from infections and ulcers.
Apart from the benefits outlined above, radishes work as a good appetizer, mouth and breath freshener, laxative, and metabolism regulator. People whose weekly diets are supplemented with normal amounts of radish see an improvement in blood circulation, and radishes are a good treatment for headaches, acidity, constipation, nausea, obesity, sore throat, whooping cough, gastric problems, gall stones, and dyspepsia.