Key Points of Onion Preservation Techniques: How to Extend Storage Time
Onions are mainly grown for their underground bulbs, so after harvest, onions must be stored properly and kept in suitable conditions to stay fresh without aging or losing water, and to avoid sprouting during storage. Through long-term growing experience, our working people have also accumulated many preservation methods. Next, let us learn together what preservation methods exist and what needs attention in preservation.
1. Heap Storage Method
Store in a dry, ventilated empty room. Find some straw and spread it on the ground, place the sun-dried onions on top, do not cut off the dried aboveground parts of the onions, and stack them in alternating layers. You can pile up several layers, and the top should be covered with a mat for insulation. In high temperatures, ventilate; in low temperatures, add more straw covering. Before winter, they can be stored outdoors first, and once winter arrives, move them indoors.
2. Basket Storage Method
When harvesting onions, harvest them with the leaves. After harvest, tie them into bundles and stack them, then place them with the leaves facing down and the stems facing up in a cool, well-ventilated place to dry. After the bulbs are dry, remove the leaves, put them into baskets, and then store them in a cellar for preservation. The low temperature of the cellar can relatively well inhibit respiration.
3. Stack Storage Method
Find a high, dry place, place wood on the ground, then spread straw on top, put the onions with leaves still attached on the straw in alternating layers, then pile them up layer by layer, about 3 to 4 layers is enough. Finally cover with mats and tar felt, and cover the surroundings with mats as well, then tie them securely with rope and seal with mud, making sure it is sealed tightly. After rain, you can check it, and you can open it to replace the straw, wood, and mats, and let them air out.
4. Hanging Storage Method
Dry the onions with their leaves in the sun, then braid them like corn and hang them in a dry, very well-ventilated place without rain. This way they can stay dry continuously, so they will not spoil or sprout. Note that one braid should not exceed 1 m, and one braid should have about 80 bulbs, not too many. You can set up a rack to hang them.
5. Chemical Treatment
Within two weeks before harvest, spray 0.2% maleic hydrazide, about 80 to 100 jin per mu. If heavy rain occurs after spraying, respray. Do not water within one week before spraying, otherwise the effect will be poor. The main purpose of spraying this chemical is to inhibit the respiration of onions so they do not sprout during storage.
Many methods are used to preserve onions, but all of them require keeping them dry, with no moisture. The main purpose is to inhibit the respiration of onion bulbs and prevent them from sprouting during storage. So each method actually has the same goal, but the effects are not entirely the same.