Key Points and Detailed Methods for Garlic Scape Storage and Fresh-keeping Technology

From the current theoretical research and practical experience on garlic scapes, the combined storage and fresh-keeping technology of low temperature, restricted air, and preservatives is relatively successful, which can store high-quality garlic scapes for more than 270-300 days, or even achieve year-round storage, with a good shoot rate of 96%, and the stored garlic scapes have bright green color, crisp and tender texture, and excellent flavor.

1. Operating procedures

Cold storage disinfection and sterilization -> selection of storage-tolerant varieties -> determination of harvest period -> pre-harvest treatment -> harvesting and purchasing -> short-distance transport -> heat dissipation -> pre-storage processing -> pre-cooling and sterilization -> bagging -> storage period management -> determination of storage duration -> pest and disease control during storage -> out of storage -> long-distance transport

2. Cold storage disinfection and sterilization

A new cold storage used for the first time does not need disinfection and sterilization. Old cold storages, especially those that stored other fruits and vegetables the previous year, must be disinfected and sterilized before storing garlic scapes. Disinfection and sterilization work should be completed half a month before storage. The specific methods are as follows:

(1) Spray the cold storage with a 1-2% formaldehyde aqueous solution;

(2) Prepare a solvent with formaldehyde:potassium permanganate = 5:1, and fumigate the cold storage at a dosage of 5g/m3 for 24-48 hours;

(3) Spray the cold storage with a 1.0-2.0% bleaching powder aqueous solution;

(4) Add 1-2% copper sulfate to 10% limewater to prepare a solution, brush the cold storage walls with it, and let dry for later use;

(5) Ignite 10g/m3 sulfur powder to fumigate the cold storage for 24-48 hours;

(6) Fumigate the cold storage with 5% sec-butylamine at a dosage of 5ml/m3 for 24-48 hours;

(7) Brush and wash turnover crates, vegetable racks, colored strip cloth, and other cold storage utensils with 0.5% bleaching powder aqueous solution or 0.5% copper sulfate aqueous solution, and expose to sunlight until dry for later use;

(8) Spray walls, shelves, and floors with 0.5%-0.7% peracetic acid aqueous solution, or fumigate and disinfect with 20% peracetic acid at 5-10ml/m3 using an electric furnace.

(9) Methods (4) and (2) above can be used together, that is, brushing the walls first and then fumigating, which gives a better sterilization effect. After sterilization, the cold storage can only be used to store garlic scapes after the odor has dissipated. One or two of the above methods can be selected, and it is better to choose different sterilization methods each year.

3. Selection of storage-tolerant varieties

The provinces in China that currently produce garlic scapes mainly include Shandong, Jiangsu, Hebei, Shaanxi, Gansu, Henan, Liaoning, and others, with many varieties. Classified by storage tolerance, they are divided into three types: early scapes, storage scapes, and red scapes:

(1) Early scapes: used for early marketing, harvested in the Guanzhong area around April 20-May 5, with very poor storage tolerance;

(2) Storage scapes: mainly used for storage, such as Cangshan garlic scapes, Acheng garlic scapes, etc., harvested in the Guanzhong area around May 10-May 20, with good storage tolerance;

(3) Red scapes: have a certain degree of storage tolerance, harvested in the Guanzhong area around June 1-June 20, with reddened scape buds, and generally can be stored for about 90 days. For storing garlic scapes, choose storage scapes (Cangshan garlic scapes, Acheng garlic scapes, etc.)

4. Determination of harvest period

If garlic scapes are harvested too early, the stems are tender and easy to break, with high water content, failing to meet quality standards, with poor storage tolerance and poor marketability. If harvested too late, the scape buds enlarge, the base turns white and becomes fibrous, and the scape stems age, losing edible and commercial value. The maturity period of garlic scapes is short and growth changes quickly, generally with a harvest period of only 3-5 days. Harvesting must emphasize the word "fast," and should be done promptly when the base of the scape stem has not yet aged and the scape bud has not fully expanded. Common methods for determining the harvest period include:

(1) Determining the harvest period by growth period: The growth period of garlic scapes in the Guanzhong area of Shaanxi is about 275 days (August 15-May 15), and harvesting around May 15 is appropriate;

(2) Determining the harvest period by appearance changes: The upper part of the scape stem begins to bend, and an abscission layer forms between the lower part of the scape bud and the garlic neck, making it easy to break at the abscission layer when pulling the scape.

(3) Meteorological evaluation: One month before harvest, learn about the meteorological conditions during the harvest period from the meteorological department to provide a basis for decision-making and storage.

5. Pre-harvest treatment

Before harvesting garlic scapes, field sterilization work should be done well to kill mold. Sterilization is carried out twice, the first 20-30 days before harvest, and the second 1-5 days before harvest. At present, the agents with relatively good field mold control effects are:

(1) Spray 50% procymidone wettable powder 1500 times aqueous solution;

(2) Spray 40% compound carbendazim suspension 800 times aqueous solution;

(3) Spray 50% iprodione wettable powder 1000 times aqueous solution;

(4) Spray 70% thiophanate-methyl 600 times aqueous solution. For the above four methods, the same agent can be selected for both sprays, or different agents can be selected for each.

6. Harvesting and purchasing

1. Quality standards for garlic scapes: moderately mature, bright green color, crisp and tender texture, non-aged base, non-expanded scape bud, few white scape parts, no disease or mechanical damage, uniform thickness of scape stems, length below the scape bud not less than 30cm, generally 40-50cm is appropriate.

2. Harvest time: It is suitable to carry out at noon and in the afternoon on sunny days, because at this time the turgor pressure in the plant body decreases, the scape strips are soft, toughness is enhanced, and they are easy to pull out, and the scape strips are not easily mechanically worn during harvesting and transport. Harvesting from 10:00-18:00 each day is better, and harvesting after rain or with dew must be avoided.

3. Harvesting technique: Pull the scape stem by hand so that it breaks and is pulled out from the abscission layer (that is, pulling the scape). Garlic scapes cut with a shovel knife (that is, shoveled garlic) have cut scape stems and poor storage results, so this method should not be used.