by Muhammad Mahran Aslam, M. Imran Aslam and Asif Saeed
Onion (Botanical name; Allium cepavar.cepa L) is a biennial plant. We grow it as an annual plant. It can grow up to 70 cm in height but modern varieties have plant height range from 15 to 45 cm. Leaves are bluish green and inflorescence is umbel shaped of white to pink to pink flowers on its top. Its bulb is underground and has small, tiny roots. Its seed color is shiny black.
Vegetative Propagation and Reproductive Propagation are two type of propagation in onion. Vegetative propagation is through bulbs or bulbils. These are immature bulbs which are used for propagation and small bulbs are less prone to bolting. Planting should be deep 2cm, row-to-row distance should be 25cm and between sets 5-7.5cm. Reproductive propagation is through seeds and transplants. Direct seed of onion can be sown. Transplants are best produced in trays having 2 seeds in each cell. After germination, thinning should be done in order to keep one seed per cell. Transplants are planted when there is well developed root system so that soil binds it firmly. Transplant distance should be 10-13cm and row-to-row distance should be 30-45cm.
Primary metabolites and Secondary metabolites are two types of metabolites.They are involved in plant growth and development, respiration and photosynthesis. For example, Carbohydrates (Glucose, Stachyose and Mannitol), Amino acids (Histidine, Leucine, Methionine, Tryptophan and Valine), Organic acid (Ascorbic acid), Vitamin B complex (Riboflavin and Oxalic acid) and Fatty acids (Monounsaturated fatty acids) etc.
Secondary metabolites are active ingredients in plant cells and are not involved in plant growth and development. They are produced as bi-products with primary metabolites. For example Flavonoids (Quercetin), Lignans (Laiciresinol), Tocopherols & Tocotrienols (α –tocopherol and α -T3), Quinones (Phylloquinone) and Sterols (Campestrol) etc.
Onion has diuretic, antioxidant, expectorant properties. It is used to treat heart and diabetic patients. It is also useful for the treatment of bronchitis, cold, cough & flu. It is used against cardiovascular & osteoporosis disease. If we use onion in high amount with garlic, it protects the man from stomach cancer up to 40%. In winter, onion juice mixed in honey provides protection against cold. Fresh use of onion is beneficial for killing the germs in mouth. Chopped onion is used daily for cooking purpose. It is used in pickles, salad dressings. It is used as a thickening agent in gravies and curries. Onion is used in soups and onion chutneys. Onion pungent juice can be used as moth repellent and if we apply onion juice on our skin, it protects from insect bites. Onion use on scalp brings the hair elongation and if we use it on skin, it prevents pimples. Yellow-brown dye is produced by onion. Pouring of boiled water on onion and then the liquor can be used on plants for resistance against pests. It is used to prevent the iron from rust and it is used for glass polishing purpose.(Agriculture Hunt)
Health, Food, Nutrition, Onion, Crop