Written by Maggie
Feb 06 2021
Welsh Onion is the stem and leaf of perennial herbaceous green onion, upper part is green green leaf, lower part is white green onion white. According to the length of the onion, Welsh Onion can be divided into two types, the Welsh Onion and the spring onion. Welsh Onion is a tall, white and sweet onion. It is cultivated in the north.
Roots: Roots of Welsh onion are white, stringed, lateral roots few and short. The number, length and thickness of roots increased with the growth of the plant and the total number of leaves. Welsh Onion grows rapidly and has more than 100 roots.
Stem: Stem of Welsh Onion is extremely short globose or oblate globose, solitary or clustered, 1~2cm thick, outer coat white, membranous, not ruptured. The upper part of Welsh Onion has a multilayer tubular leaf sheath, and the lower part has dense fibrous roots. When the growing point of the seedling tip differentiates into Flower buds, the flower stem will gradually develop. Welsh Onion has a stout, hollow, unbranched flower stem, 30 -- 50cm long.
Leaves: Leaves of Welsh Onion consist of a body and sheath, long conical, hollow, green or dark green. The individual leaf sheaths are cylindric. Multilayer nesting leaf sheaths and their inner encased 4-6 unsheathed young leaves, forming a clavelike pseudostem.
Flowers A developing umbel embedded in the involucre, borne at the apex of the flower stem before flowering. The Welsh Onion with full growth of vegetative organs has 400-500 flowers in one inflorescence, or more than 800 flowers. Bisexual flowers, cross-pollinated. Each flower has 6 perianth and 6 stamens. Pistil mature, style 1cm long. Ovary of Welsh Onion is superior, 3 locules, 2 in each locule.
Welsh Onion is one of the onion vegetables with high yield, easy cultivation, fewer diseases and insect pests, and is resistant to storage and transportation. Welsh Onion is a very popular vegetable and important condiment, not only sold well all over the country, but also can be exported in large quantities to exchange for foreign exchange.
Welsh Onion has small seeds, thick seed coat, unearthed cotyledon, slow seedling growth and long seedling stage. In order to shorten the occupation time and facilitate management, seedlings are transplanted. Seedbed ground for Welsh Onion can not repeat stubble. After the previous harvest, deep fertilization, generally made of wide (even ditch) 1.4 meters of high bed. Seedbed should be fine finishing, before sowing bed surface infiltration water, with new seed seeding, per mu of field seeding amount is 75-100 grams. After sowing, cover soil 2 cm, and then cover straw or film, in order to increase the temperature and moisture, speed up the emergence of seedlings.
The insect pests of Welsh Onion cultivated out of season mainly include leaf miner fly, onion thrips, Beet night moth, etc. Prevention and control methods: in the peak of nymphal occurrence, spraying 10% imidacloprid wettable powder 2 000 ~ 2 500 times, once every 7 ~ 10 days, continuous control for 2 ~ 3 times.In the incipient stage of adult development and larval leaf-latent stage, the control was carried out by spraying 2 000 ~ 3 000 times of 1.8 % abamectin emulsion once every 7 ~ 10 days for 2 ~ 3 consecutive times.
Welsh Onion diseases are mainly purple spots, downy mildew, virus disease and so on.
Purple spot disease: timely pull out the disease plant or remove the disease leaves of Welsh Onion, disease pedicel, and it's deep buried or burned; At the beginning of the disease, spray 75% chlorothalonil, wettable powder 500 ~ 600 times liquid or 70% mancozeb wettable powder 500 times liquid or 64% anti toxicant alum wettable powder 500 times liquid, etc., the above agents are used alternately, every 7 ~ 10 d spray 1 time, continuous control 2 ~ 3 times.
Downy mildew: in the early stage of the Welsh Onion disease, spray 25% metaloxalin WP or 75% chlorothalonil WP 500 ~ 600 times liquid, every 7 days spray 1 time, continuous spray 3 ~ 4 times.
Viral disease: early detection of disease strains in time to pull out, concentrated deep buried or burned. Strengthen management of fertilizer and water to prevent and control aphids in time. In the early stage of the Welsh Onion disease, spray 20% virus A wettable powder 500 times liquid, continuous spray 2 ~ 3 times.