Post harvest management of onion
Authors: Panchal Bhakti B. and Bhanderi, D. R.
Department of vegetable Science,
ASPEE College of Horticulture and Forestry,
Navsari Agriculture University, Navsari- 396 450, Gujarat, India

  • Introduction
  • The onion (Allium cepa) (Latin 'cepa' = onion), also known as the bulb onion or common onion, is used as a vegetable and is the most widely cultivated species of the genus Allium.
  • This genus also contains several other species variously referred to as onions and cultivated for food, such as the
  1. Japanese bunching onion (A. fistulosum),
  2. Egyptian onion (A. ×proliferum), and
  3. Canada onion (A. canadense).
  • More about Onion
  • The name "wild onion" is applied to a number of Allium species but A. cepa is exclusively known from cultivation and its wild original form is not known.
  • The onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its first growing season.
  • In India, Maharashtra, Bihar, Karnataka, Gujarat, Andhra Pradesh, Uttar Pradesh, Orissa and Madhya Pradesh are the states growing Onion.
  • India rank 2nd in Productions of Onion after China.
  • Importance of onion in Indian economy
  • Onion is an important vegetable crop grown and consumed widely across the world. As a culinary ingredient it adds to the taste and flavour in a wide range of food preparations and it is also used as a salad.
  • Thus there is a steady increase in the demand for onion across the world. China is the leading producer of onion constituting about 27 per cent of the world total production.
  • Due to lower yields, though India has the highest area under onion, it stands second in the production of onion in the world. Hence, there is a lot of potential for increasing the production of onion by improving the yields.
  • India is also the largest exporter of onion and hence, it is crucial to improve the yields for enhancing the export level, so that it helps in earning foreign exchange for the exchequer of the country.
  • Importance and Utility
  • Onion is used for treating digestion problems including loss of appetite, upset stomach, and; for treating heart and blood vessel problems including chest pain (angina) and high blood pressure; and for preventing “hardening of the arteries” (atherosclerosis).
  • It is also used for treating sore mouth and throat, whooping cough, bronchitis, asthma, dehydration, intestinal gas, parasitic worms, and diabetes.
  • Some people use it as a diuretic to increase urine output.
  • Harvesting
  • Onion is ready for Harvesting in 3-5 months and 2-3 months after transplanting for dry and green onion respectively.
  • Green onion are harvested when they are just ready for earthing.
  • Plants are uprooted by hand and their roots are cut.
  • They are washed and bundled as per market requirement.
  • Harvesting methods
  • There are two methods for harvesting:
  • by hand digging
  • by machine harvesting
  • In machine harvesting, time will save & quick harvesting is carried out.
  • Curing
  • Curing is essential operation after harvesting.
  • It will remove excess moisture from the outer skin and neck of onion bulbs.
  • It increase storage life of onion bulbs.
  • Curing also helps in improving colour of the skin.
  • Usually 10 to 15 days or so will be sufficient for curing the onion bulbs.
  • Post harvest treatment
  • In onion firstly done,
  • Sprouting in stored onion is always a serious problem. To avoid sprout inhibition, suppressant like Isopropyl N-Chlorophenyl Carbamate (CPIC), TNCB, MH are used.
  • The irradiation process has also been found effective for sprout inhibition.
  • Use of irradiation improves shelf-life of onions
  • Exposure of onion bulbs after harvesting when bulbs are in dormant stage with 60-90 Gy inhibit their sprouting regardless of crop season, environmental condition and type of storage.
  • However, to reduce the microbial and other losses, combined use of irradiation with improved storage and providing the irradiation facilities at production level are to be considered.
  • Onions when spoiled if not disposed off immediately cause nuisance and environmental pollution. Such spoiled bulbs, scales, peels and rejected portion of onion bulbs from processing units form a large quantity and thus conversion of this into compost or manure or vermicompost is suitable alternative.
  • Grading
  • After curing, onions are graded and classified by grading machine and hand.
  • Before storage, Doubled, broken, rotten bulbs having undesirable features are removed.
  • Grading and classification are necessary for both local market as well as for export.
  • Delhi market prefers big sized bulbs, Calcutta, Patna and Lucknow prefers medium size bulbs and Bhubaneswar, Guwahati prefer small sized Onion.
  • Packaging
  • Jute bags are used for onion packaging for sending to distant markets by trucks, trains or even by air.
  • Generally 40 kg capacity jute bags are used for transport within country, whereas for export, jute bags of 8-25 kg capacity are used.
  • Onion should be packed in 14-15 kg capacity cane baskets for export purpose.
  • Packing should be small for easy handling during transit and may vary according to market demand.
  • Onions are packed in jute (hessian) bags for transporting to yard or brought as loose.
  • For safe handling, 40 kg open mesh jute bags having 200-300 g weight should be used in domestic market.
  • For export, common big onions are packed in 5-25 kg size open mesh jute bags. Bangalore Rose and multiplier onions are packed for export in 14-15 kg wooden baskets.
  • Nylon net bags, when used for packing have resulted in less storage loss because of good ventilation
  • Storage
  • In Maharashtra, Gujarat, Haryana and Western Uttar Pradesh large-scale storage of onions is taken in conventionally-designed structures.
  • In other states, the storage is taken only on small scale but now showing increasing trend after the post-harvest technology and improved storage structures have been popularized by NHRDF.
  • Traditional storage practices result in substantial losses in stored onions; hence use of improved storage structures as well as use of good storer varieties, judicious use of fertilizers, timely irrigation and post-harvest technology is essential to reduce the losses in stored onions.
  • Transportation
  • Onion stocks are transported in bullock carts, tractor trolleys and trucks as also railway wagons are used for longer distance movement within the country.
  • Onions are transported in ventilated ships as well as sailing vessels / motorboats for export to Gulf and South-East Asian countries.
  • It is also shipped in 3.5m containers or 7m containers by loading on ships.
  • Export specification
  • Specifications
  • Color: Light and dark red color
  • Size: 30mm and 70mm
  • Packing
  • Packed in 5 Kg, 10 Kg, 20 kg, or 25 Kg mesh bag as per customer requirement


1. Rai, N. and Yadav, D.S. (2005). "Advances in Vegetable Production", Researchco Book Centre, New Delhi, p. 13.
2. Shaikh, J.A., Kathiria, K.B. and Acharya, R.R. (2011). Veg. Sci., 38 (2): 169175.

About Author / Additional Info:
Assistant Professor (Horticulture)