Discussion on Preservation, Storage and Transportation of Flower after Harvest (5)

6. Potted plants for storage and transportation

The tools currently used for the transportation of ornamental plants in close quarters are mainly trucks and ships. Ships by sea or trucks are more economical than airplanes, but they take longer. Longer-term transport problems are the same as long-term storage. Such as leaves, flowers fade, fall off, calyx can not be opened, the rapid development and spread of disease.

Maintaining the quality of potted plants and planting conditions is closely related to the transportation process. Among the planting factors, the most important is light and fertilization. When planting, potted plants are exposed to high levels of photosynthesis intensity (PAR). When transported and sold, PAR is low, usually lower than the light compensation point. For foliage plants, low light intensity results in leaf chlorosis and shedding, while reducing carbohydrate and chlorophyll content. When light intensity is low, damage can be partially avoided if the temperature is appropriate.

For long-distance sales, the plants need to have very good quality and there are no pests in the root system. Plants should be watered the day before transport and the relative humidity of the freezer should be kept above 90% to prevent degradation of the plants.

Potted plants are transported in a controlled environment. They should maintain stable temperatures, air circulation and ventilation. It is packaged in boxes and transported on open trucks. This method is also commonly used to transport larger potted plants. Some plants are more resistant to physical damage and can be transported horizontally or in crates. A relatively new method is bare root transport, which can reduce transport costs by removing transportation media and containers, and can reduce transport space and weight by more than 50%. This transport method is also used for hydroponics to produce plants that meet the hygiene requirements set by some countries and prevent the spread of soil-borne pathogens.

Treatment of plants with ethylene activity inhibitors (STS) prior to long-term transport can reduce ethylene hazards. For some plants, treatment with NAA can also reduce the shedding of various plant organs, resulting in a synergistic effect between NAA and STS. Flowers that are fully open are more sensitive to ethylene than flowers in the calyx stage. Therefore, it is very important that flower-seeking potted plants are transported during flowering.

In the international market, potted plants are sold out, and they are often sold far away from the place of production. Therefore, they need to be transported. For some ornamental potted plants, storage may delay flowering to meet special festival needs (such as lily).

7. Problems in storage and transportation

In the process of storage and transportation, the life activities and aging of flowers have not stopped, resulting in some changes in the storage and transportation of flowers. The transportation methods for fresh horticultural plants include: railways, trucks, airplanes, ships, and several transportation methods. When shipping, several products are often mixed, but as far as possible, this should be avoided as much as possible. When transporting, the plants should be kept in a cold environment as much as possible, and keep the temperature stable so that the plants are always in a “cold chain” environment after harvesting. At the same time, care should be taken to maintain air circulation and ventilation. Larger potted plants are often transported by open trucks. At present, the latest transportation method is bare root transport. Due to the removal of transport media and containers, transportation costs are greatly reduced, and transportation space and weight can be reduced by more than 50%. This method of transport is also used for hydroponics to produce plants that meet the hygiene requirements specified by some countries and prevent the spread of soil-borne pathogens.

Different plant varieties have different optimal transport temperatures, but also depend on the length of the transport period. Too low temperatures can cause freezing damage to many tropical plants. Flowering plants are less tolerant of long-term transport than foliage plants, and they lose their quality when left in the dark for a few days.

Ethylene produced during storage and transportation also induces flower buds and leaves to fall off, increasing flower malformation. The severity of ethylene depends on its concentration, exposure period and temperature. The decrease in transportation temperature (above the freezing point) can reduce the loss of leaves and flowers. Therefore, treatment of plants with inhibitors of ethylene activity (STS or 1-MCP) before long-term transport reduces the risk of ethylene. For some plants, treatment with naphthalene acetic acid can also reduce the shedding of various plant organs. Flowers that are fully open are more sensitive to ethylene than flowers in the calyx stage. Therefore, it is very important that flower-seeking potted plants are transported during flowering. Only when the product is close to the optimal storage temperature can it be put together and its adverse interactions, such as the release of ethylene, odors and different requirements for relative humidity during storage, must be prevented. The most economical and optimal transportation method should be considered when transporting. The main problems encountered for longer-term transportation are: discoloration and loss of leaves and flowers, failure to open flower buds, bending to the ground, and rapid development and spread of diseases.

(to be continued)