Onion is an important vegetable crop grown all over the world. Its demand is world wide. The onion is grown for consumption in the green stage as well as mature bulb. It is grown especially in South and Central India. Onions are a major crop in many tropical countries, being valued for its flavoured nutritive value. It is probably a native of Asia, perhaps from Palestine to India. The crop has been known for its various uses in Egypt since 600 B.C. There are some religious books like Holy Bible, which describes its importance as food, medicine I and mummification.

Onion is grown and distributed in all parts of the world. The important onion growing countries of the world are China, India, USA, USSR, Japan, Netherlands, Spain, Turkey, Brazil and Egypt. China and India are the leading onion producing countries.

In India, onion is cultivated very extensively in Maharashtra and Gujarat as a cash crop due to its high potential for export. More than 20 % of the area under its cultivation is found in Maharashtra which accounts for 30 % of total onion production. The other states are Himachal Pradesh, Orissa, Kamataka, Uttar Pradesh, Tamil Nadu and Madhya Pradesh.