Orchid flask seedling cultivation and growth management methods

1. Flask seedling acclimatization

Acclimatization of plant seedlings is essentially a matter of regulating temperature and sunlight; young seedlings must undergo seven to ten days of natural environment acclimatization before being removed from the flask. Because flask seedlings are generally kept in an environment at about 25°C and in relatively dark places, if the environment is changed too drastically at once, they are easily sunburned or unable to adapt to the new growing site, resulting in losses. Therefore, when flask seedlings are purchased, they should first be placed on thecultivationbench where they will be grown in the future for seven to ten days of natural environment acclimatization, and only then removed from the flask and planted. The sunlight required for flask seedling acclimatization is about 30%-40% of full sun.

2. Removal of young seedlings from the flask and planting

After flask seedlings have completed acclimatization, they can be removed from the flask and planted. Open the bottle cap and use long tweezers; the young seedlings can then be easily taken out with care. As far as possible, do not break the leaves or injure the plants. There is no need to wash the young seedlings with water unless necessary. Never use groundwater or water with a large temperature difference to wash the seedlings. When removed from the flask, the young seedlings are delicate and sterile. Groundwater often contains large amounts of miscellaneous bacteria and unknown minerals, and its pH often exceeds the range suitable for the seedlings, easily causing damage; using water with too great a temperature difference will also affect the future growth of the seedlings. When the young seedlings are taken out of the bottle, no culture medium may remain on the roots. If they are washed clean with water, they may first be soaked for about a few seconds in 2000 times diluted Hyponex No.1, Peter or Suzhi, then lifted out, placed on newspaper, and put in a cool place to allow natural ventilation. Planting may be carried out only after the moisture has completely dried. ?Our company recommends that it is better not to wash the young seedlings, and also not to soak them in any nutrients; flask seedlings are sterile, so there is even less need to carry out any disinfection measures?

3. Preparation of potting materials

Plastic pots or plug trays; for planting a single seedling, a pot with a mouth diameter of about 4.5 cm is sufficient, and after three to five months, a larger pot may be used as appropriate ?6 or 9 cm pots?; the bottom of the plastic pot must have drainage holes.

Sphagnum moss; better quality sphagnum moss should be used, because good sphagnum moss has higher water permeability and is not easily subject to rot, making it suitable fororchidaerial root growth. First wash the sphagnum moss clean with tap water, and soak it in disinfectant for about one hour, then wring it dry or use a spin dryer to dehydrate it thoroughly before use.

4. Planting method for flask seedlings

Use sterilized scissors to trim off roots that are too long or excess roots, then take a small pinch of sphagnum moss and a small seedling, wrap the roots with the sphagnum moss, and plant it into the plastic pot or the hole of the plug tray. The part wrapped with sphagnum moss should be kept as low as possible below the growth point. Use only as much sphagnum moss as is needed to make the plant stand firmly upright. If it is too loose, the water-holding capacity is poor; if it is too tight, watering is difficult, and at the same time it will hinder normal root growth. After planting them one by one, the plastic pots should be placed in trays for easy transport and a neat, attractive appearance. After planting is completed, do not water before the sphagnum moss has dried.

5. Basic management of young seedlings

Place the planted young seedlings in a relatively ventilated and cool place. If placed in a standard greenhouse, both the inner and outer shade nets should be fully drawn. At this time the light used for the young seedlings is about 35%-45% ?5,000-10,000 lx (950 ft-c)? or so. After two or three days, wait until the sphagnum moss is almost completely dry, then water by spraying, and thereafter follow this routine. However, about every 7-10 days, watering by pouring should be used to thoroughly wash and flush away algae gas in the pot, lower acidity, and reduce the occurrence of root rot; at the same time, fertilize, and this can promote root growth.

Sixty days after removal from the flask, Phalaenopsis has already entered the intermediate seedling stage, so light should be increased to about 50%-60% ?15,000 lx (1,400 ft-c)? or so. After 180 days, when intermediate-to-large seedlings have become mature plants or flowering plants, light should be slightly increased to about 60%-70% ?20,000 lx (1,900 ft-c)? or so. Oncidium, Cattleya, Dendrobium, Epidendrum, large-floweredCymbidiumafter sixty days out of the flask, light should be increased to 60%-70%. Mature plants or flowering plants require higher light, about 70%-85%, and even some orchid genera require about 90%-100% light to produce good flowers.

6. Humidity

Orchidaceae plants all prefer environments with higher humidity; generally a relative humidity of 50%-85% is best.

7. Temperature

The environment more suitable for the young seedling growth period of Orchidaceae plants is a temperature of 23°C-28°C; after plants mature, the various orchid genera differ slightly.Growing orchidsThe main causes of failure are frost damage when cold waves strike, and losses from disease easily arising under high temperatures.

8. Ventilation

Orchids are aerial-root plants and by habit prefer clean air; good ventilation facilities will reduce the occurrence of leaf rot.

9. Fertilization

It is divided into foliar fertilization and slow-release fertilization. Never use organic fertilizer. For young seedlings or mature plants, emphasis should be placed on foliar fertilization, spraying about once or twice a week, within thirty minutes after watering. Slow-release fertilization is used to make up for the shortcomings of foliar fertilization, adopting the method of placing fertilizer into the pot; generally slow-release granular fertilizers such as Magic Fertilizer are used...

For general young seedling foliar fertilization, use Hyponex No.1, Peter or Suzhi.

For intermediate seedlings or mature plants, nitrogen fertilizer may be added to foliar fertilization.

If foliar fertilization is applied to flowering plants, use a fertilizer high in phosphorus and potassium.

10. Environmental hygiene

Orchidaceae plants also prefer cleanliness. If they are cultivated commercially as an economic crop, different genera should be planted separately; besides making management easier, they are also less likely to become diseased.

11.Pests and diseasesPrevention and control

Before a greenhouse is used, it should be thoroughly disinfected; for old greenhouses this should be strengthened even more. Greenhouses should be fitted with screen windows to prevent insects from entering. Yellow sticky insect paper should be added beside the benches. Lime and sulfur should be scattered around the outside of the greenhouse to prevent ants and other crawling insects from invading. Generally, once a greenhouse has insect pests, it will bring bacterial infection.

Newly flask-removed young seedlings should as far as possible not share a greenhouse with mature plants. Externally purchased potted seedlings must undergo isolation and disinfection, and only after it is confirmed that they carry no bacteria may they enter the greenhouse to be cultivated together with other orchid plants.

Every two to three weeks, insecticide should be sprayed once inside and outside the greenhouse to prevent the occurrence of insect pests.

Every month, to prevent bacterial infection, a fungicidal liquid should be sprayed once to prevent bacteria from growing and harming the plants.

If infection is found, the whole site should be disinfected immediately, for three or more consecutive times ?once every week?. It is best to change the fungicide each time to increase the disinfection effect and avoid the development of bacterial resistance.

If diseased plants are found, they should be eliminated immediately, or the infected leaves should be cut off and sent for testing, so as to find the cause of the disease as quickly as possible.

Non-essential personnel must not enter the cultivation greenhouse; staff entering and leaving the greenhouse must clean the tools and shoes they carry; tools must not be casually moved to other greenhouses, so as to prevent bacterial infection.

Cutting tools must be reliably sterilized, and each tool must not be used to continuously prune a second plant. Before use, sterilize with a mixture of 5% formalin and 5% sodium hydroxide, soaking for about 1-2 minutes each time, to avoid bacterial transmission. Regarding pest and disease control, a separate chapter will introduce this in detail and discuss it specially.