Basic Storage & Handling Tips for Dry Bulb Onions:
Always handle onions with care. Do not drop onions as this often causes bruising and internal decay.
Bagged or boxed onions should be stored at least one foot away from walls and other pallets to allow proper air movement.
Keep stacks of bags or boxes at five feet or less.
Store onions in a cool, dry, well-ventilated area.
Maintain storage temperature of 45-55°F.
Do not wrap onions in plastic or store in plastic bags. A lack of air circulation will reduce shelf life.
Onions should feel firm and dry, be free of gray or black mold, and should not have any visible sprouting. Some loose skins are normal.
Do not store onions with potatoes or other produce items that release moisture.
Keep onions out of direct sunlight and other heat sources.
Cut onions will keep for several days if sealed in plastic bags or containers and refrigerated.
Onions are ready for harvest when the necks are reasonably dry and the tops have fallen over.
As onions mature, their dry matter content andpungency increase, with a resulting increase in storage potential.
Harvest onions when the weather is dry; harvesting after a rainfall, or when the humidity is high increases susceptibility to post-harvest disease. At harvest, bulbs must be firm, with mature necks and scales, and must be a good size. Defective onions (i.e. sprouted, insect damaged, sunscalded, green, bruised) should be discarded.For optimum storage quality, onions must be cured soon after harvest by placing them in a drying room at 20-30°C and 70% relative humidity for 12 to 24 h. Curing decreases the incidence of neck rot, reduces water loss during storage, prevents microbial infection, and is desirable for development of good scale colour.
The optimum temperature for long-term storage of onions is 0°C with 65-70% relative humidity. To ensure a storage life of up to 8 months, onions