Postharvest fresh-keeping packaging, storage and t

Postharvest preservation, packaging, storage and transportation of flowers (V)

(3) decompression storage and preservation

when reducing the atmospheric pressure around agricultural products, it also reduces the content of various gases in the atmosphere. This means that by reducing the air pressure, for example, to half of the normal atmospheric pressure, the level of O2 in the air is also reduced to nearly 10.5%. The effect of CA storage can also be obtained through low-pressure storage, and the ethylene content is reduced. The study of avocado low-pressure storage (LPS) showed that although low-pressure storage made the fruit have a longer storage period, it still had adverse negative effects, such as the reduction of avocado water and hardening at 50mmhg. The most important factor for the non popularization of this method is the economic factor. It costs a lot to build a storage room, and there are many technical problems. Moreover, the advantages of this method are not great and its operation and maintenance are complex

reducing the air pressure to below the standard atmospheric pressure can delay the aging process of cut flowers in the storage room, and its life span is much longer than that under normal pressure. Experiments show that Gladiolus can be stored for 7 ~ 8 days at 0 ℃ under normal pressure, and for 30 days at -2 ℃ ~ 1.7 ℃ under 60mmhg

(4) radiation preservation

radiation of cut flowers such as rose, chrysanthemum and Dahlia with gyco60y rays has an effect on preservation. For example, the preservation rate of cut rose after 10GY irradiation is 75% after 15 days of bottle insertion

(5) chemical preservation

(a) use of antitranspirant: it can reduce the transpiration of cut flowers, and antitranspirant can prevent the stomata of plants from opening, thus enhancing the drought resistance of cut flowers. Achieve the purpose of prolonging the service life

(b) using cut flower preservative: (IEC 60695 ⑵ ⑴ 2) gwfi: (0.4mm) 960 ℃ cut flower preservative is a cut flower preservation method developed in recent years. It uses protective chemicals to solve the physiological obstacles in cut flowers. It can be divided into three kinds:

pretreatment solution the preservative solution used for pretreatment before harvesting and transportation of cut flowers. Its main purpose is to promote water absorption, sterilization and reduce ethylene damage during transportation and storage

flowering liquid, also known as flower inducing liquid, can promote the opening of cut flowers collected at bud stage

vase liquid, also known as retention liquid, is the fresh-keeping liquid used by cut flowers during the vase viewing period. The composition and concentration of the formula vary with the variety of cut flowers

(c) preservative ingredients

water: it is an indispensable ingredient in preservatives. Because sodium, calcium, magnesium and fluorine plasma in water have toxic effects on some kinds of cut flowers, such as sodium ion is harmful to roses and carnation. Therefore, the downstream rolling mill should try to limit production, reduce production, and increase the use of distilled water or deionized water, which can increase the vase life of cut flowers,

sugar: the most commonly used is sucrose. The tortuosity modulus of 40% mixed long fiber composed of 20% long glass fiber and 20% long carbon fiber with different cut flowers and different preservatives is 17930mpa degrees. Generally, the longer the treatment time is, the lower the sugar concentration is. Therefore, the order of sugar concentration of different preservatives is pretreatment liquid, flowering liquid and bottle inserting liquid. The main function of sugar is to supplement energy, improve the nutritional status of cut flowers and promote life activities

fungicides: in order to reduce the impact of microorganisms on flower branches, all preservative formulas contain fungicides, such as 8-hydroxyquinoline (8-HQ), which can kill all kinds of fungi and bacteria, and reduce the physiological blockage of vascular bundle tissue of flower stems

inorganic salts: many inorganic salts can increase the osmotic potential of solution and the swelling pressure of petal cells, which is conducive to the water balance of flower branches and prolong the vase life. For example, aluminum salt can promote stomatal closure, reduce transpiration, and is conducive to water balance

organic acids and their salts: the pH value of preservative has a certain impact on cut flowers. Low pH value can inhibit the growth of microorganisms, prevent the blockage of vascular bundles of flower stems, and promote the water absorption of flower branches. Organic acids can reduce the pH value of fresh-keeping liquid, and some also inhibit the production of ethylene

ethylene inhibitors and antagonists: such as ag+, STS, AVG, AOA, ethanol, etc., can inhibit the production of ethylene and interfere with its effect, delaying the aging process of cut flowers

plant growth regulators: the senescence of cut flowers is controlled by hormone balance. Adding some plant growth regulators to preservatives can delay the senescence of cut flowers, And improve the [quality of cut flowers. Cytokinins are widely used in the preservation of cut flowers, such as KT (kinetin), BA (6-benzylpurine), IPA (isoamyl if 3-point zigzag experiment alkenyladenosine) Etc. They can delay the aging of many cut flowers, such as carnation, rose, tulip, chrysanthemum, etc

2. Preservation of bottle cut flowers

to prolong the viewing time of bottle cut flowers, the time of cutting flower branches should be in bud, and the flower branches should have some leaves. Except for woody flowers, which should be cut with scissors, flowers with brittle branches should be gently broken to avoid crushing the stem conduit and affecting the transmission of water and nutrients. The cut flower branches should be immediately inserted into the bucket containing clean water

there are several simple treatment methods to prolong the life of flower branches:

1) heat treatment method: partial soaking and scalding method and burn method. Scalding method is to immerse the branch base of herbaceous flowers (such as gladiolus, evening jasmine, dahlia, etc.) in 80 ℃ hot water, take it out for about 2min ~ 3min and insert it into the bottle, so that the end immersed in water is not easy to be infected by bacteria, and at the same time, it will not make the mucus in the flower branches flow out and block the catheter, so as to prolong the flowering period. Burn method is to burn the ends of woody flowers on the flame, then cut some of the burnt parts, soak them in alcohol for about 1min, take them out, rinse them in clean water, and insert them into the bottle

2) pruning method: cut the sticky ends of flowering branches every day or the next day to keep the incision fresh and keep the water absorption function unblocked

3) end smashing method: some woody flowers, such as magnolia, clove, peony, etc., can be gently smashed at cm at the end of their flower branches to expand the water absorption surface and prolong the life of flower arrangement

4) deep water first aid method: when the flower branches just begin to wilt, 3cm ~ 6cm at the end of the flower branches can be cut off, and then placed in a container full of cold water. Only the flower heads are exposed on the water surface, and it will recover after about 1 ~ 2 hours

5) salt coating method: a little salt (or light salt water) can be applied to the flower branch incision. This method can be used for Platycodon grandiflorum, color leaf taro, lily, Calla Lily, etc

6) vinegar soaking method: soak the cut of flower branches in edible vinegar for about 10 seconds before flower arrangement. This method can be used for Persian chrysanthemum, hydrangea, rose, Christmas flower, silver willow, etc

7) drug method: the florescence of cut flowers can be prolonged by 10 ~ 15 days with the following treatment

8) detergent solution culture method: use detergent and warm water at about 25 ℃ to prepare a solution of about 4%, put the obtained flower arrangement material in it, cut it again as needed, and then quickly insert it into detergent solution of the same concentration to maintain a water depth of about 4 cm, because the main components of detergent are surfactant, trace salt and essence. The pH of the solution is neutral. It has the effects of decontamination, sterilization and activation of water quality. It can kill bacteria in the water, eliminate pollution, dissolve pectin from the cut of flower arrangement material, keep its vascular bundle cells unblocked, and make it fully absorb water. In the high temperature season, the flower arrangement solution must be replaced once every 2-3 days, and at least once a week in the low temperature season, so as to keep the water fresh and play the fresh-keeping role of detergent. Most flowers are suitable for this method, which can prolong the life of flower arrangement by 2 ~ 3 times

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