Crops
Allium cepa L.- Common onion, Garden onion.
Taxonomic position.
Family Alliaceae J.Agardh, genus Allium L.Synonyms:
A. esculentum Salisb., Cepa vulgaris Renault.Morphology and biology.
Perennial plant. Fibrous root system. Leaves range from 3-4 to 15-18 in number on an annual bulb, tubular, large, often covered with a waxen bloom, up narrowed, 0.5-2.2 cm in diameter, 10-52 cm in length. Base of leaves appear as juicy scales and are proliferative and fleshy. Leaves densely cover each other and form a bulb. External scales are dry. All scales are located on the corm. Axils of juicy scales form buds on the corm and give rise to bulbits, forming a nidus of several bulbs. In southern areas large bulb forms within one year; in northern areas fine bulbil forms within one year; the large bulb grows for 2-3 years only. Weight of bulb is 20-250 (up to 1000) g. Flowerstalk forms for 2-3 years. It is 1.5 m in height, hollow, inflated, and terminates in multifloral umbel-type inflorescence, diameter 4-5 (up to 15) cm, with 250-900 flowers on long pedicels. Perianth is greenish-white color up to 1 cm in diameter, with 6 leaflets, 6 stamens and 1 pestle. Superior ovary. Cross-pollinates. Sometimes fine bulbils are formed except for flowers in inflorescence. Fruit is a 3-camerate capsule and contains up to 6 fine, black, wrinkled seeds. Weight of 1000 seeds is 3-5 g. Propagates vegetatively, by seeds and bulbils.Varieties differ by form (spherical, flat-spherical etc.), size of bulbs, coloring of external scales (white, yellow, cream, brown, violet), number of rudiments germs, duration of the vegetative period, and taste. More than 150 varieties in the former USSR. Wide-spread pungent grades: Strigunovskij, Bessonovskij, Rostovskij mestnyj repchatyj, Rostovskij mestnyj kubastyj. Semipungent grades: Kaba, Miachkovskij, Danilovskij 301, Skvirskij. Sweet grades: Leinabadskij, Ispanskij 313, Yaltinskij. Local grades in northern areas: Kanchezerskij, Sujsarskij, Kotlasskij zheltyj, Kotlasskij fioletovyj, Pizhemskij. 2n=16Distribution.
Common onion not found in the wild. Middle Eastern origin. In Russia, cultivation began in the 12-13th centuries. Former USSR plantings occupy about 170 thousand hectares. Plant is raised everywhere, including the Arctic Circle. Southern and central areas are most proper. General plantations exist in Turkmenia, Azerbaidzhan, Uzbekistan, Kirgizia, Moldova, Belorussia, and Baltic states.Ecology.
Does not require warm temperatures to grow. Adult plant tolerates up to minus 6-7 °C. Seeds sprout at 2-5 °C. Optimum growth temperature is 22-28 °C. Photoperiod sensitive; plant needs long day to flower. Vegetative period is 13-15 days in southern regions, 15-18 days in northern regions. Requires humid, fertile soil. Prefers light-loamy and sandy soils with pH 6.0-6.4. Does not tolerate salinated soil. Vegetative period from seed 170-200 days; from small bulb, 90-120 days.Utilization and economic value.
One of the major vegetable crops . Used for food; can be served fresh, cooked, baked, fried, salted, pickled, and dried. Also used as seasoning. Leaves used as potherb. The bulb contains 8-14 % sugars, 1.5-2 % protein, 2-14 mg % of vitamin C, carotin, vitamins B1, B2, PP, U, mineral salts, and amino acids. Green leaves contain1.5-4 % sugars, about 1 % protein, 25-48 mg % vitamin C. The plant contains essential oils (0.012-0.162 %), which give it a specific smell and pungent taste. Has tonic and bactericidal action. Used in folk and scientific medicine. Dry colored scales used as dye. Productivity of bulbs 10-25 (in southern areas up to 50) ton per hectare, green leaves 30-50 (up to 60) ton per hectare.Reference citations.
Alekseeva M.V. Onions. Moscow, 1982 (in Russian).Bekseev Sh. Vegetable cultures of the world. The encyclopedia of truck farming. St.Petersburg, 1998 (in Russian).
Ershov I.I. Onion; Garlic. Moscow, 1978 (in Russian).
Ganichkina O.A. Onion and garlic. Moscow, 2000 (in Russian).
Kazakova A.A. Onion //Cultural flora of the USSR. Ed. by D.D.Brezhnev. Leningrad, 1978 (in Russian).
Kuzljakina V.M. Industrial technology of onion cultivation. Moscow, 1980 (in Russian).
Onion; garlic. Comp. T.E.Lushchits. Minsk, 2001 (in Russian).
Vasetskij V.F. Industrial technology of onion cultivation. Kishinev, 1988 (in Russian).
Vehov V.N., Gubanov I.A., Lebedeva G.F. Cultural plants of the USSR. Moscow, 1978 (in Russian).