Detailed Explanation of Garlic Storage Principles and Technical Methods

After garlic is harvested, its dormancy period lasts only 2 to 3 months, after which the young sprouts inside the thick fleshy bulb begin to grow. The nutrients needed for the young sprouts to extend and push through the top opening come entirely from the outer garlic cloves. The cloves gradually change from their original crisp and fresh state to soft and loose, the commercial quality declines noticeably, and they are prone to sprouting and mold.

I. Storage Principles

Garlic is eaten for its enlarged bulb. When mature, the outer bulb layers dry out and become fatty and membranous, which can prevent internal moisture evaporation, entry of external rainwater and mechanical damage, and is conducive to dormancy; this is a self-protective function.

After garlic emerges from the soil, it is still a living organism and must continue to maintain life activities, namely after-ripening and aging. Its main life activity is that respiration continues unceasingly. Respiration is necessary to maintain life activities, and at the same time it consumes large amounts of organic matter, causing the flavor and quality of the garlic bulbs to deteriorate. Therefore, the central link in storage and preservation is to create conditions that reduce respiration to the lowest possible level while still maintaining its life activity level, so as to extend the dormancy period of garlic and inhibit sprouting.

II. Factors Affecting Storage

1. Storage-tolerant varieties.

Garlic in China is generally relatively storage-tolerant, and the storage tolerance of garlic from northern production areas is higher than that from the south. Applying nitrogen fertilizer late, excessive watering, pest and disease damage, and mechanical injury all affect the storage tolerance of garlic. Late-maturing varieties and bulbs with higher hardness keep better; small and medium-sized bulbs keep better than large bulbs.

2. Harvest at the proper time and precool promptly.

Harvesting at the proper time and precooling promptly can extend the storage period. If harvested too early, the degree of maturity is insufficient, yield is low, and losses during storage are large; if harvested too late, the cloves tend to separate and the small sprouts are prone to germinating and growing, which is extremely unfavorable for storage.

3. Control of temperature and humidity.

Garlic has strong cold resistance, and the bulb can withstand low temperatures of -6°C to -7°C. The suitable storage temperature is -1°C to -3°C. Garlic likes dryness, and the suitable relative humidity of the air is 70% to 75%. The freezing point of garlic is -3°C. If the storage temperature is below -7°C, garlic will suffer freezing injury. Storage amount fluctuations should be as small as possible; large temperature fluctuations easily cause physiological disorders. In addition, garlic has relatively strict temperature requirements. If the relative humidity is too high, the bulb absorbs water and becomes damp, the surface of the garlic is prone to mold, and this gradually affects the internal quality; if the relative humidity is too low, dry loss is large and the garlic tends to shrivel.

4. Gas composition.

Suitable gas indicators for garlic storage: oxygen concentration 2.2% to 4.3%, carbon dioxide 3% to 5%. If oxygen is below 1% and carbon dioxide is above 7% to 13%, the storage effect is poor.

III. Storage Methods

There are many storage methods for garlic, such as hanging storage, cellar storage, chemical solution treatment (spraying maleic hydrazide one week before harvest), radiation treatment, and so on.

1. Hanging storage. This method is simple and easy to carry out, the garlic is not turned during storage, and management is extensive. After harvesting, select garlic with plump cloves, white color, and no disease spots or wounds for storage. First dry it in the sun for 2 to 4 days, then braid every 40 to 4 garlic bulbs into one group, combine every two groups together, and never bundle them. Set up a rack in a cool, dry, well-ventilated house or shade shed, hang the garlic braids on the rack, surround them with mats, and do not let them lean against the wall, to prevent rain or water soaking.

2. Cellar storage. Most storage cellars are underground or semi-underground. The cellar site should be chosen in a dry place with high terrain, no standing water, and good ventilation. The temperature inside the cellar is determined by the depth of the cellar. There are many kinds of cellars; the more commonly used ones are cave cellars and well cellars. Garlic can be piled loosely in the cellar or stacked in mounds. It is best to spread a layer of dry wheat straw or grain husks on the cellar bottom, then alternate a layer of garlic with a layer of wheat straw or grain husks. Do not pile it too thick. Set ventilation holes in the cellar, clean the cellar frequently, and promptly remove diseased and rotten garlic.