A Detailed Guide to Orchid Cultivation Techniques and Fresh-Keeping, Storage and Transport Methods

CultivationOrchidgrowing media turns acidic very easily - how can this be overcome?
　　
When sphagnum moss is used to grow orchids, after a few days the moss becomes contaminated by organic-acid-producing bacteria and turns acidic, and then the orchid root zone is prone to developing black tip symptoms (Fusarium infection).
　　
When growingorchids,the
　　
Some orchid nurseries boil the sphagnum moss or sterilize it at high temperature before planting orchids. Although this can temporarily kill bacteria and insect eggs, after planting the moss still turns acidic, causing the orchid root zone to easily develop black tip symptoms. This is because after the orchids are planted they are still contaminated by organic-acid-producing bacteria.
　　
How can black tip problems be reduced when growing orchids?
　　
Black tip symptoms in the orchid root zone occur mainly because the media, sphagnum moss, etc. are contaminated by organic-acid-producing bacteria, causing the media to turn acidic and causing Fusarium to multiply in large numbers (Fusarium grows best at around pH 4). Therefore, raising the pH of the media can reduce Fusarium infection.
　　
How can black tip symptoms be effectively reduced?
　　
Apply small-molecule water-soluble chitosan and actinomycetes diluted 2000 times with water to irrigate orchids, which can effectively reduce black tip symptoms in orchids. Soak media such as sphagnum moss in small-molecule water-soluble chitosan and actinomycetes diluted 1000 times for 1-5 minutes, drain, and then plant.
　　
What is small-molecule water-soluble chitosan? What benefits does it have for orchids?
　　
Chitin is extremely widely distributed in nature. For example, the outer shells of crustaceans (shrimp, crabs, etc.), the outer shells of insects (cockroaches, butterflies), and the outer shells (clams, oysters) and internal skeletons (squid) of mollusks all contain chitin. After acid and alkali treatment to remove calcium and protein, chitin is obtained. After chitin is treated with high temperature and high alkali to deacetylate it, chitosan is obtained. Chitin and chitosan are collectively called chitin.
　　
Advantages of using chitin on orchids:
　　
1. Enables continuous cropping of the media - chitin can increase beneficial microorganisms in the media, such as actinomycetes, reduce harmful bacteria such as Fusarium, and can eliminate root-knot nematodes, reducing the troubles of continuous cropping obstacles in the media.
　　
2. Promotes healing and development of root wounds, increases root hairs, and increases nutrient absorption capacity. Promotes plant growth.
　　
3. Induces the production of phytoalexin, improves crop disease resistance and antibacterial capacity, thereby reducing the amount of pesticides used.
　　
4. Increases the calcium content of orchids, which can increase stiffness.
　　
5. Enhances the absorption of trace elements, thereby increasing the reducing sugar content of leaves, advancing harvest, improving quality, and extending the fresh-keeping period.
　　
Actinomycetes are Gram-positive bacteria that are extremely common in natural soil. More than four hundred species are known. Because most have the ability to produce antibiotics, their application in crop disease control has continued for more than half a century since the earliest report by Waksman in 1943. Similar successful developments have mostly focused on producing antibiotic preparations. The best known is streptomycin, applied to the control of bacterial diseases in many fruits, vegetables and flowers. In addition, actinomycetes can decompose organic matter and produce extracellular enzymes to break down proteins, cellulose, lignin and chitin, so this property can be used against microorganisms with chitin cell walls. For example, adding chitin to soil can control Fusarium, mainly because the chitin-decomposing enzymes secreted by actinomycetes can cause lysis of pathogen hyphae.
　　
What are the benefits for orchids of using small-molecule water-soluble chitosan and actinomycetes at the same time?
　　
When chitin and actinomycetes are used together to irrigate orchids, chitin has an antibacterial effect and can promote the growth of actinomycetes, inhibit the growth of Fusarium, and promote wound healing. For example, it is very effective against anthracnose, which causes black leaf spots.
　　
What effect does ethylene have on orchids?
　　
Orchids are quite sensitive to ethylene. Just 0.01 ppm of ethylene can cause Vanda flowers to wilt. Southeast Asian orchids are next. Dendrobium, Phalaenopsis and Paphiopedilum come after that. Oncidium is not sensitive to ethylene. Phalaenopsis produced in the province, when treated with 0.09 ppm ethylene, can be induced to age, producing symptoms such as flower drop and dehydration wilt. Ethylene causes the tips of orchid sepals to wither and the lip to turn red. The early symptoms of aging are transparent sepals and petals, followed by prominent veins and the formation of an abscission layer, leading to floret drop.
　　
In addition, as flowers mature or after dehydration, high temperature, disease, etc., their sensitivity to ethylene increases.
　　
Why do budded potted orchids turn yellow and drop buds during storage and transport?
　　
Yellowing leaves and dropped buds in budded potted orchids during long-distance transport are mainly caused by excessive ethylene concentration and bacterial infection.

How can yellowing leaves and dropped buds be avoided?
　　
Place a small packet of ethylene absorbent at the geometric center of the cardboard box or where it is most sensitive to ethylene, to absorb the ethylene produced by the flowers in the box. Or use 1-methylcyclopropene (MCP) ethylbloc fumigation treatment for several hours. Do not keep them in the same room as fruits that produce large amounts of ethylene.
　　
What effects and benefits does using an ethylene absorbent have?
　　
1. Ethylene absorbent can absorb the ethylene released by fresh fruits, vegetables and flowers, inhibiting the plant's continued aging, softening, yellowing, wilting and flower drop.
　　
2. Improves product quality - if the ethylene absorbent is used properly, it can absorb most of the ethylene, so flowers can be harvested at a higher degree of maturity, that is, with more vivid flower color, and the products transported to market will be in better condition.
　　
3. Reduces costs for long-distance transport - it can withstand long-distance transport and more economical transport methods, or air transport can be abandoned in favor of sea transport.
　　
When does the ethylene absorbent need to be replaced?
　　
Fresh ethylene absorbent is purplish red. After the ethylene absorbent oxidizes, its surface turns brown-black, gradually extending to the center of the ethylene absorbent.
　　
Packaging methods and scope of application of ethylene absorbent
　　
Ethylene absorbent comes in different packaging methods. It can be placed in the air passage of a storage room (using a wave type) so that airflow surrounds the product, or a mini packet can be placed in a packing box or bag so that the absorbent controls harmful ethylene gas and extends the storage and transport period of fresh products.
　　
In winter greenhouses that are tightly closed, flowers easily develop black spots and easily show prominent veins and form an abscission layer, causing small buds to drop. How can this be avoided?
　　
Especially in North China, winter greenhouses are tightly closed and humidity is extremely high. Flowers easily develop black spots (gray mold) and easily show prominent veins and form an abscission layer, causing small flowers to drop. You can use Yongxin antibacterial agent diluted 1000 times to spray the flowers and hang a wave-type ethylene absorbent in a place with air circulation.
　　
How should orchids with buds be handled during transport?
　　
Use Yongxin orchid bagging, with one side non-woven fabric (breathable) and one side PP film (transparent), and place a mini packet of ethylene absorbent (6 mg/packet) together in the packing box.