EFFECTS OF PRE-HARVEST TREATMENTS AND STORAGE CONDITIONS ON QUALITY AND SHELF-LIFE OF ONIONS

Onion storage is important to provide product for fresh market, export and processing. Storage potential of onions mainly depends on the cultivar, climate conditions during growing season, growth regulator treatments and storage methods. Sprouting and rooting are the main processes which cause losses during long term storage as well as a decrease of the market quality of onions. The effects of seasonal influences, cultivars, growth regulator treatments (MH, Ethephon, herbal extracts) controlled atmosphere (CA) on quality changes, sprouting, rooting and respiration rate of brown onion (Allium cepa L.) ‘Sochaczewska’ were investigated. Storage temperature and maleic hydrazide treatments not only have an influence on marketable amount of onions after storage period but also on further shelf-life at higher temperature. Sprouting and rooting were reduced by some growth regulators as well as CA containing an ultra low concentration of O₂. Controlled atmosphere containing 3% CO₂ and 0.5% O₂ or 3% CO₂ and 1.0-2.0% O₂ as well as MH were most effective for inhibition sprouting during storage and 3 weeks of shelf-life at 20°C.