Onions stored badly lose 30 to 40 percent of the crop before sale. Cure the bulbs in shade for 10 to 15 days, keep them in a dry ventilated structure, stack no higher than 5 feet, and sort out damaged bulbs every 15 days. Done properly, storage losses drop below 10 percent and you can hold stock until prices improve.
1. Cure before you store
Harvested onions carry field moisture in the neck and outer skin. Storing them straight away traps that moisture and rot spreads through the pile. Spread the bulbs in a single layer under shade with the tops still attached for 10 to 15 days, until the neck is tight and the outer skin is papery. Never cure in direct sun, which causes sunscald and dark patches that buyers reject.
2. Build the storage right
Onions need moving air more than they need cool air. A bottom-ventilated structure with slatted floors and side openings works better than a closed room. Keep the stack under 5 feet so air reaches the middle. Raise the floor at least one foot above ground to stop moisture rising during the monsoon. Avoid stacking against walls where air cannot circulate.
3. Sort every fortnight
One rotting bulb spoils everything around it. Check the stack every 15 days and remove soft, sprouted or discoloured bulbs immediately. Handle onions gently at every stage; bruised bulbs rot first. Farmers who sort regularly routinely hold stock for four to five months and sell into higher prices instead of dumping at harvest.
| Storage method | Loss after 4 months | Cost per ton |
|---|---|---|
| Open heap, no curing | 35–40% | ₹0 |
Frequently asked questions
- Q1 How long can onions be stored?
- Cured onions in a ventilated structure keep for four to six months. Uncured onions in a closed room rarely last past two months.