Onion (Allium cepa L) is one of the important ingredients used in daily meals all over Pakistan. Onions are used in soups, salads, sauces and for seasoning foods. Onions as a part of diet may play a part in preventing heat disease and other ailments (suggested by medical research). It is rich in phosphorus, calcium and carbohydrates. Onion is an important crop all over the world. In Pakistan, the major growing areas are Kasur, Gujranwala, Sheikhupura, Vehari, Khaniwal, D.G. Khan, and Jhang in Punjab, Hyderabad, Mirpurkhas, Sanghar, Sukkar, Naushero Feroze and Badin in Sindh, Swat in NWFP and Mastung, Kalat, Chagi, Khuzdar and Turbat in Balochistan. More than 50 percent of the total production comes from seven districts, namely, Hyderabad, Mirpurkhas, Sanghar, Swat, Mastung, Kalat and Turbat.