Discussion on Preservation, Storage and Transportation of Flower after Harvest (3)

Second, flower harvesting, grading, packaging and storage

In the modern ornamental horticulture industry, the production and sales of flowers in different places are becoming more and more common. The production and sales of flowers are continuously becoming internationalized. Therefore, the requirements for post-harvest packaging, storage, transportation, and preservation are getting higher and higher, and the storage, transportation, and preservation of flowers are also increasing. Technology is increasingly important. For many varieties of flowers, the preservation of cut flowers and ornamental plants is an important part of product sales. The purpose of storage is to prolong its viewing period and maintain a good quality. This is particularly important for cut flowers and potted flowers, as it is often necessary to keep them for a few days or weeks after harvesting, while meeting the standards of the local or international flower market. At present, the export volume of flowers in China is also increasing year by year. Many flower producers also recognize the importance of post-harvest packaging, storage and transportation of flowers.

For flower sellers, to achieve good market value, we must try to extend the post-harvest life of flowers. As far as possible, we can maintain a good level of flowers from the producer to the consumer. To achieve this, we must start from the harvesting process and adopt special pre-harvest and post-harvest preservation treatments, such as treatment with various chemicals. , light treatment, pre-cooling, etc., until reaching the hands of consumers. To master the storage and transportation technology, we should focus on the following aspects of the work.

The specific steps to be taken are harvesting - pretreatment - packaging - storage and transportation.

1. Harvesting

Cut flowers should be harvested at a suitable time. Harvesting too early or too late will affect the ornamental life of cut flowers. Under the premise of guaranteeing flowering, it should be harvested as soon as possible.

Harvested flowers should be put into water as soon as possible to prevent flowering. And should use clean facilities: such as clean water, clean barrels and keep the workshop clean. Before using the bucket in the cut flowers, it should be cleaned with a washing liquid or a brush to remove ash. Other containers should be washed with disinfectant or water. It is best to use a white bucket that can easily detect dust (possibly containing millions of bacteria). Where conditions permit, the water used preferably contains a bactericide. The pH of the water is preferably 3.5-4. The amount of the solution to be spent should be appropriate. Do not use the used solution together with the new one. Make the disease more serious after harvesting.

1) Harvesting at the flowering stage: Some flowers are suitable for harvesting at the flowering stage. If harvesting at the bud stage, the flowers cannot be completely opened. Such as rose, chrysanthemum, Gladiolus and so on.

2) Harvesting at the bud stage can be achieved on the premise that it can be harvested after harvesting. Some flowers are harvested at the bud stage and can also be well flowered, and the flower viewing period is also longer. Such as carnation, when harvesting buds can not be too small, should be harvested when the stem is 1.8cm - 2.4cm, otherwise it will affect the flowering degree. At present, bud harvest is mostly used for carnation, rose, chrysanthemum, Gladiolus, Gerbera, Strelitzia, Gypsophila, tulip, snapdragon, etc.

2. Rating

The cut flowers after harvest must be classified according to a certain standard due to their uneven quality. The classification is based on the length of the pedicel, the quality and size of the flowers, the degree of opening, the number of florets, the condition of the leaves, etc. Generally speaking, for the cut flowers, the thicker and longer the flower stalks are, the better the quality of the products is. For example, the classification standards for chrysanthemum, carnation and gladiolus in the United States are shown in the table:

3. Pre-storage and storage

Flowers harvested from the greenhouse should be pretreated as soon as possible to maintain the quality of flowers. Preprocessing includes the following steps.

Postharvest conditioning

After the flower stem leaves the plant, it will appear wilting due to moisture loss. To make flowers have a good shape, they should be put into water as soon as possible after they are harvested for conditioning to prevent loss of flower moisture and cause wilting.

The beginning of wilting flowers, immersed in water for about 1 hour will be able to restore normal cell swelling pressure. Conditioning containers and water should be cleaned. Where conditions permit, water containing fungicides can be used to regulate flowers, and the effect will be better.

Pretreatment

Before packaging, storage and transportation, short-term immersion treatment of the base of the stem with a sugar-based chemical solution is called pretreatment. It can achieve such a number of purposes: First, to improve the flowering quality and prolong the flowering period; Second, to allow the flowering buds to be harvested normally open, the third is to ensure the open quality after transportation or storage. Pretreatment often uses sucrose and silver thiosulphate. For example, a rose can be treated with about 10% sucrose at 20°C for 4 hours. ,

Pre-cooling

Pre-cooling is to quickly remove field heat before transport or storage. For highly perishable crops, such as cut flowers, pre-cooling is necessary. The higher the temperature, the faster the decay occurs, and the lower the transpiration rate of the crop at low temperatures. Therefore, pre-cooling before packaging, storage and transportation, and removal of field heat and respiratory heat can greatly reduce the decay and wilting during transportation. The faster the product is put into the ideal storage temperature after harvest, the longer it will be stored.

There are many methods for pre-cooling. The simplest is to set up a cold room at the edge of the field. The cold room is not packed with flower branches or closed boxes, so that the flower branches can dissipate heat until the desired temperature. The pre-cooling temperature is 0°C to 1°C and the relative humidity is 95% to 98%. The pre-cooling time differs depending on the type of flower, the size of the box, and the method of pre-cooling. After pre-cooling, the flowering branch should always be kept in a cool place so that the flower can maintain a constant low temperature. Pre-cooling methods in production also include:

Water cooling: Let ice water flow through the box and directly absorb the heat of the product to achieve cooling. It is best to add fungicide in water.

Air Cooling: Allow the cold air to pass through the unsealed box to lower the temperature, and pre-cool it before sealing. This method is widely used in Israel.

(to be continued)