Third, flower preservation technology
The preservation of flowers has a great influence on the duration of flower preservation. Before and after flower packaging and transportation, attention should be paid to the preservation of flowers and delay aging.
1. Fresh-keeping methods and methods
To ensure that the freshness of flowers is as long as possible and not only after harvest, appropriate measures should be taken in the selection of varieties and cultivation measures in order to facilitate post-harvest storage and preservation.
1) Variety selection: In the cut flower preservation, the selection of varieties often has very important significance, such as the coarse stem varieties, more sugar reserves, maintaining longer respiration and longer shelf life.
2) Strengthen cultivation and management: Based on the selection of excellent cut flower varieties, strengthen management and improve cultivation measures, you can increase the dry matter content of cut flowers, and extend the freshness preservation time and vase life.
(1) Fertilization: Excessive nitrogen fertilizer will reduce the life of vase cutting. Therefore, less nitrogen fertilizer should be applied or stopped before the flower buds are colored to prevent the freshness of the leaves and the life of the vases from decreasing due to the softness of the branches and leaves.
(2) Watering: Keeping the soil relatively dry is not only beneficial to the development of the root system, but also can extend the post-harvest preservation period.
3) Pest control: Pests and diseases will reduce the time for fresh flowers and reduce the quality of flowers. The main reason for restricting international trade in cut flowers and leaves is the main reason for their international trade, because pests in cut flowers can cause major causes of their rapid decline. Therefore, methyl bromide fumigation is commonly used to cut flowers during export to prolong Its post-harvest life, but it is also quite harmful to many cut flowers, even if it does not cause visible physical damage, reducing its shelf life.
As an alternative, New Zealand’s flower-making producers post-harvest fresh cut flowers in a box for fumigation to control pests. The specific method is: Dissolve penicillin in CO2 (in a pressure tank), and put this “solution†into the tank with a pipe. With the volatilization of CO2, penicillin is coated on the surface of leaves or flowers to kill a lot of layers. Insects that are sensitive to the range.
The fumigant used was methyl bromide or penicillin. Since flowers are usually not consumed, the effects of post-harvest toxic chemicals should theoretically be smaller than that of fruits and vegetables used for food. For flowers, the main influence is the environment. Therefore, it is quite difficult to register hazardous chemicals. In addition, some consumers are concerned about the use of drugs. For these reasons, flower producers in many countries are striving to try to use non-chemical methods to kill insects, such as killing insects with certain insect pests, but this has brought quarantine problems to cut flower producers and has been restricted in development. .
The commonly used cutting flower post-harvest infestation treatment is ionizing radiation. Radiation is widely used to sterilize medical substances and equipment, and also used in food disinfection. The effect of using radiation to kill insects in cut flowers is not good. Even when the dose required to kill insects is low, ray treatment can also cause cut flower shelf life. Significantly lower. However, studies in Japan in recent years have shown that for chrysanthemums, the negative effects of ionizing radiation can be completely overcome by placing flowers in bottles containing sucrose solutions.
Another method for the non-chemical control of post-harvest insects is to regulate atmospheric composition (atmosphere storage), that is, to reduce O2 and increase CO2 content. This method has been studied in the United States in the past few years and is considered by insect control experts to be better. method.
4) Flowering regulation
In the sales process, special flowering liquids (also known as flowering liquids) are often required in order to allow flowers to bloom normally during flowering. There are many formulas for flowering liquid, but they are mainly composed of sugar and bactericide. Fungicides can inhibit the occurrence of diseases, sugar can ensure the nutrients needed for flowering, make flowers large and have a long life.
5) Preservation
(1) Cold preservation
After the flowers are transported from the production base to the consumption base, they should also be put into the cold storage immediately for storage. For example, the flower market in the largest flower wholesale market in China, the Laitai Flower Market, will be sold in cold storage at 2°C to 8°C. Low temperature can cut vital life of cut flowers, slow breathing, low energy consumption, ethylene production is also inhibited, thereby delaying the aging process, but also can avoid cut flowers discoloration, deformation and microbial breeding. Saw experiment observation, in the relative humidity of 85% ~ 90%, temperature 0 °C, chrysanthemum cut flowers can be preserved for 30 days, 2 °C fresh 14 days, 20 °C ~ 25 °C fresh 7 days. Various flowers have different storage temperatures. In general, the temperature of the temperate floral origin is 0°C to 1°C, and the suitable refrigerated temperatures for tropical and subtropical flowers are 7°C to 15°C and 4°C to 7°C, respectively, and the appropriate humidity is 90%~ 95%.
"Room cooling" is a simple, effective, and universal method of refrigeration. The principle is to release cold air into the room, usually horizontally below the ceiling. Cold air passes through products that need to be cooled on the floor. This method is commonly used and has the following advantages: (a) The product is refrigerated and stored in the same place, reducing the operation process. (b) Design, simple operation. (c) Refrigeration systems can be cooled faster at peak storage. In order to obtain the best cooling effect, the following principles must be followed: (a) Sufficient refrigerated air capacity to ensure a cold environment throughout the room. (b) Sufficient air quickly passes through and around the refrigerated container. (c) Container stacking design allows enough air to flow in it. Moderately air-flowing, well-ventilated containers are twice as fast as closed containers.
(to be continued)