1.2-SpeciesAllium fistulosum - Welsh Onion, Bunching Onion + Overview Allium fistulosum L. (Welsh onion, Japanese bunching onion, bunching onion) is a species of perennialonion. The common name Welsh onion is rather a misnomer, as the species is native to China, though cultivated in many places and naturalized in scattered locations in Eurasia and North America. The species is very similar in taste and odor to the related common onion, Allium cepa, and hybrids between the two (tree onions) exist. The Welsh onion, however, does not develop bulbs, and possesses hollow leaves (fistulosum means "hollow") and scapes. Large varieties of the Welsh onion resemble the leek, such as the Japanese negi, whilst smaller varieties resemble chives. Many Welsh onions can multiply by forming perennial evergreen clumps. Next to culinary use, it is also grown in a bunch as an ornamental plant. Historically, the Welsh onion was known as the cibol. In Cornwall, they are known as chibbles. Allium fistulosum is not indigenous to Wales or particularly common in Welsh cuisine (the green Allium common to Wales is the leek, Allium ampeloprasum, the national vegetable of Wales). "Welsh" preserves the original meaning of the Old English word welisc, or Old Germanwelsche, meaning "foreign" (compare wal- in "walnut", of the same etymological origin). + Synonyms Allium bouddae Debeaux Allium kashgaricum Prokh. Cepa fissilis Garsault Cepa fistulosa (L.) Gray Cepa ventricosa Moench Kepa fistulosa (L.) Raf. Phyllodolon fistulosum (L.) Salisb. Porrum fistulosum (L.) Schur
3- The Uses of Welsh Onions
3.1- Culinary Uses The Welsh onions may be cooked or used raw as a part of salads, salsas, or Asian recipes. Diced scallions are used in soup, noodle and seafood dishes, as well as sandwiches, curries or as part of a stir fry. - In Asia The Welsh onion is an ingredient in Asian cuisine, especially in East and Southeast Asia. It is particularly important in China, Japan, and Korea, hence the other English name for this plant, Japanese bunching onion. The Japanese name is negi. Common onions were introduced to East Asia in the 19th century, but Allium fistulosum remains more popular and widespread. It is used in miso soup, negimaki (beef and scallion rolls), among others, and it is widely sliced up and used as a garnish, such as on teriyaki or takoyaki. In South-East Asia (Java) the plants are also eaten whole, either steamed or after heating over a fire for a short time, and in Japan seedlings of 7 - 10 cm tall are used in special dishes. Allium fistulosum has not been used in a processed form until recently, when a dehydration industry started. The product is mainly used as an additive to preprocessed food such as instant noodles. The young inflorescence is sometimes deep-fried and eaten as a snack. In Vietnam, Welsh onion is important to prepare dưa hành (fermented onions) which is served for Tết, the Vietnamese New Year. A kind of sauce, mỡ hành (Welsh onion fried in oil), is used in dishes such as cơm tấm, bánh ít, cà tím nướng, and others. Welsh onion is the main ingredient in the dish cháo hành, which is a rice porridge dish to treat the common cold. - In the West, the Welsh onion is primarily used as a scallion or salad onion, but is widely used in other parts of the world, particularly East Asia. In many Eastern sauces, the bottom half-centimetre (quarter-inch) of scallions roots is commonly removed before use. - In Russia: Welsh onions are used in Russia in the spring for adding green leaves to salads. - In Jamaica: Known as escallion, the Welsh onion is an ingredient in Jamaican cuisine, in combination with thyme, scotch bonnet pepper, garlic, and allspice (called pimenta). Recipes with escallion sometimes suggest leek as a substitute in salads. Jamaican dried spice mixtures using escallion are available commercially. The Jamaican name is probably a variant of scallion, the term used loosely for the spring onion and various other plants in the genus Allium.
3.2- Medicinal Uses The therapeutic qualities attributed to Allium fistulosum are many, especially in Chinese medicine. It is used to improve the functioning of internal organs and the metabolism, for the prevention of cardiovascular disorders, and to prolong life. It is further reported to improve eyesight, and to enhance recovery from common colds, headaches, wounds and festering sores. The bulb contains an essential oil that is rich in sulphur compounds. It is antibacterial, antiseptic, diaphoretic, diuretic, galactagogue, stomachic, vermifuge and vulnerary. It is used in the treatment of colds and abdominal coldness and fullness. A tea made from the roots is a children's sedative. Use of the bulb in the diet impedes internal parasites. Externally, the bulb can be made into a poultice to drain pus from sores, boils and abscesses.
3.3- Other Uses The plants are said to reduce or prevent termite infestation in gardens. Diluted pressed juice is used against aphids in China. The juice of the plant is used as a moth repellent. The whole plant is said to repel insects and moles.
4- Growing Welsh Onion on the World
4.1- History Cultivation of Allium fistulosum dates back to at least 200 BC in China. It reached Japan before 500 AD and spread further to South-East Asia and Europe. In China Allium fistulosum is the most important Allium species fulfilling the culinary role of both the common onion and leek in Europe; in Japan it is now second in importance to the bulb onion (Allium cepa L.). ‘Welsh’ in the name welsh onion is probably related to the old German ‘welsche’ meaning foreign, and has no connection with Wales in the United Kingdom. Historically, the Welsh onion was known as the cibol. The name "Welsh onion" has become a misnomer in modern English, as Allium fistulosum is not indigenous to Wales. "Welsh" preserves the original meaning of the Old English word "welisc", or Old German "welsche", meaning "foreign" (compare wal- in "walnut", of the same etymological origin). The species originated in Asia, possibly Siberia or China. Ironically in Wales, the spring onion has a dialectical variation, jibbons or sibwns (pronounced 'shiboons') which originates from the French 'ciboule.' Next to culinary use, it is also grown in a bunch as an ornamental plant.
4.2- Varieties and Cultivars Two types of Allium fistulosum are grown and sometimes distinguished as cultivar-groups: Japanese Bunching Group and Welsh Onion Group. Japanese bunching onion is grown mainly in eastern Asia for its thick, blanched pseudostems and is eaten as a potherb, e.g. in sukiyaki and chicken dishes. Japanese bunching onion have a mild flavor, which is not too strong as of garlic or Chinese chive. Its raw chopped leaves, esp. soft green leaves, are good as a seasoning for light-taste Japanese foods such as 'soba', 'udon', 'suimono'. Cooking destroys its pungency and, as a result, enhance its sweet flavor. Its etiolated pseudo-stem is good for various kinds of cuisine such as 'sukiyaki', 'nabe', and shish-kabob, removing bad smells of meet and fish and giving an appetit e-stimulating flavor. Welsh Onion Group is most common in Africa. Welsh onion is grown for its green leaves, which are used in salads, or as a herb to flavour soups and other dishes. In the Brazzaville-Kinshasa area (Congo and DR Congo), whole plants are harvested and eaten as a boiled vegetable.
4.3- Growing Welsh Onion + Materials for growing There ate two methods of growing: 1- Growing from seeds. 2- Growing from sets (or tillers). In the tropics Allium fistulosum is propagated mainly by basal tillers and can be planted the whole year round. Although seed production is possible at elevations above 1000 m, and imported seed of Taiwanese and Japanese cultivars is also available, plants are rarely raised from seed because this is more difficult under tropical conditions and is more time-consuming. However, in the Brazzaville-Kinshasa area, both tillers and seed of local cultivars are used. 1- Growing from seeds: In temperate areas where seed production is more successful, propagation is mainly by seed, which is either sown directly into the field or first in nurseries. When growing from seed you can either direct sow in their final position in April or start off Welsh onion seed under protection in March. Using a good quality compost such as John Innes 'Seed and Cutting' fill a modular seed tray and gently water in. - Preparing seeds The weight of 1000 seeds is 2.2 -2.5 g. Seed requirements are 8 - 16 kg/ha for direct seeding and 2 - 4 kg/ha in the case of transplanting. In nursery beds, seeds are either broadcast or sown in rows or in 5 - 6 cm wide bands. The area of nursery required is 10 - 12% of the field area. - Sowing seeds Spring-sown seedlings first to 2.5 cm (1 in) then when the seedlings have straightened up to 5 to 10 cm (2 to 4 in) apart. Autumn sown onion seedlings to about 2.5 cm (1 in) in the autumn. Further thin to about 5 to 10 cm (2 to 4 in) between plants in the Spring. You can expect the seedlings to appear in a week to ten days. Once germinated, growth them on for a further 4 weeks before hardening them off for planting outside. - Transplanting Seedlings raised under glass should be transplanted 10 cm (4 in) apart, leaving about 25 to 30 cm (10 to 12 in) between rows. The roots must fall vertically in the planting hole and the bulb base should be about 1cm (½ in) below the surface. In garden, seedlings are ready for transplanting when 25 - 30 cm tall and thick as a pencil. Watering very gently if the soil is dry, and cover with soil. When large enough to handle, thin the crop in two stages. Close spacing will give smaller onions than wider spacings. Lift the seedlings carefully - the soil should be moist and all thinnings removed to deter onion fly. 2- Growing from sets (or tillers): Welsh onion sets can be planted out in March and April. As with the seedlings, planting distances are about 20 cm × 25 cm (200,000 plants per ha). About one-third of the top part of the tiller is usually trimmed to reduce transpiration. Watering regularly during dry weather, but it will not be necessary to fertilize the crop for the rest of their production.
+ Management and care For green leaf production, land preparation is light. Tillers or seedlings are transplanted into raised beds or ridges, which are alternated with furrows for irrigation and drainage. Planting holes are filled with 50 - 100 g of manure (10 - 20 t/ha) and the shoots inserted slanting to stimulate tillering. Urea or ammonium sulphate at a rate of 3 g per plant (about 600 kg/ha) is applied 3 weeks after planting, and again at 6 weeks after planting if soil fertility is low. Weeding and earthing up are usually practised 6 - 7 weeks after planting. Allium fistulosum needs plenty of water. At lower elevations, it is usually grown during the rainy season. Daily irrigation is necessary during the dry season. Mixed cropping with white cabbage, carrot and potato is common in the highlands. For blanched pseudostem production, fields are deeply cultivated. Furrows of 10 - 20 cm deep are made, the soil being thrown to one side forming a ridge which will support the young plant and facilitate earthing up later. Earthing up is essential to blanch and soften the leaf-sheath cylinder. As earthing up also affects aeration of the roots and thus checks growth, it should be done gradually and not be started too early.
+ Growth and development Allium fistulosum is a perennial plant, grown commercially mostly as an annual, but in home gardens also as a perennial. It does not have a long-day dormant stage like Allium cepa, so it continues its vegetative growth and does not develop a real bulb. However, some cultivars which originated from cold temperate areas show short-day dormancy. They stop growing and their leaves dry out and die off under short days, even when the temperature would permit normal growth. The lateral buds in the leaf axils elongate and develop as tillers to form a clump. This tillering characteristic is more pronounced in cultivars grown for the green leaves than in those grown for the long blanched pseudostems. Flower induction is controlled by temperature and daylength. Low temperatures and short days induce flowering, but requirements vary strongly with the origin of cultivars. Flowering is generally induced by temperatures below 13°C, when seedlings have formed a certain number of leaves or a pseudostem of a certain thickness. In the tropics, where conditions favour vegetative rather than generative growth, only some well-adapted cultivars will flower. Roots are readily colonized by arbuscular mycorrhizal fungi, which enhances P uptake and stimulates growth.
+ Control Pests and Diseases - Pests The beet army worm (Spodoptera exigua) and the American bollworm (Heliothis armigera) are the most serious pests. They are difficult to control because the larvae hide inside the hollow leaves and the waxy layer on the leaves hinders wetting. Onion thrips (Thrips tabaci) may cause considerable damage. Thrips damage is stimulated by pesticide sprayings against Spodoptera, which kill the natural enemies of the thrips. Overhead sprinkling reduces thrips damage. - Diseases Although Allium fistulosum is generally a healthy crop, it may be affected by a number of diseases, many of them common to most Allium crops. Purple blotch (Alternaria porri), which causes characteristic concentric spots on the leaves, and downy mildew (Peronospora destructor) may cause severe problems. White rot (Sclerotium cepivorum) may cause serious losses under successive or repeated cropping, as the pathogen is very persistent in the soil. Poor, unbalanced nutrition and heavy rains stimulate the development of the diseases. The practice of vegetative propagation is conducive to virus infestation, but many landraces seem to be relatively tolerant. Diseased plants should be removed by rigorous visual inspection of the planting material. Allium fistulosum is resistant to the onion yellow dwarf virus (OYDV), but susceptible to the welsh onion yellow stripe virus (WoYSV), occurring e.g. in Japan and Indonesia. It causes similar mosaic-type symptoms, including chlorotic mottling, streaking and stunting, and distorted flattening of the leaves. Relative tolerance is found in cultivars of Kujyo Group. Allium fistulosum is resistant to several diseases affecting other Allium spp. including pink root caused by Pyrenochaeta terrestris, neck rot caused by Botrytis spp. and leaf rot caused by Botrytis squamosa. Partial resistance has been found to anthracnose (Colletotrichum gloeosporioides).
+ Harvesting The entire plant may be pulled and eaten like a green onion as early as when 8 to 10 cm (3 to 4 in) high, or leaf portions may be snipped off as needed for flavouring. If pulled as a green onion, 4 to 5 months are required from seeding to harvesting. In the tropics Allium fistulosum can be harvested year-round; in the Brazzaville-Kinshasa area it is mainly harvested during the rainy season. Plants are pulled out about 2.5 months after planting the tillers. The part used as planting material for the next crop is left in the field until it is needed. Harvesting is a labour-intensive operation, especially for pseudostems, which have to be dug up, cleaned and bundled. Mechanized harvesting equipment has been developed in Japan.
+ The Yield Yield data for countries in Africa are not available. Average yields in Japan and Korea are about 25 t/ha, in Taiwan 10 -15 t/ha. In Indonesia, they are considerably lower, averaging 7 t/ha, but they may reach 15 t/ha; however, the growing period is only 2.5 - 3 months compared to 9 months in East Asian countries. After harvesting, leaves and pseudostems are cleaned, dried or damaged leaves are removed, and the plants are bunched and packed in boxes or baskets for transport to the market.