Onion (Allium cepa L.), the most used flavoring vegetable for centuries, is believed to have originated in the tropical central or Western Asia. India is the second largest onion growing country in the world. The onion is one of the most important commercial vegetable crops grown in India. It is used both in raw and mature bulb stage as vegetable and spices. Maharashtra, Tamil Nadu, A.P., Bihar and Punjab are the important onion producing states.