Detailed Explanation of Key Techniques for Cultivating Gastrodia elata in Plastic Bags

Plastic bag cultivation of Gastrodia elata is generally carried out in October-November.

1. Method of planting Gastrodia in plastic bags with fungus sticks inside: Make polyethylene plastic bags 45-50 cm long and 28 cm wide. Disinfect the inside of the plastic bag with a 0.2% potassium permanganate aqueous solution, place a small amount of basic culture material and small wood blocks (preferably humus soil) at the bottom layer, then stand 2 high-quality fungus sticks with a diameter of 5-6 cm and a length of 20 cm upright inside (if the fungus stick diameter is greater than 7 cm, 1 stick can also be placed). While filling the bag with humus soil, place small Gastrodia tubers around the fungus sticks, and put all 25 g of small Gastrodia tubers into the culture material until the culture material reaches a height of 20 cm. Plug in a cotton ball, tie the opening gently with string, and place all the plastic bags on the bed frame. The bed frame is the same as that used for bottle cultivation of Gastrodia elata.

This planting method must use high-quality fungus sticks free from contamination by miscellaneous fungi. The humidity at planting time should be 30%-35% to induce dormancy. When the growth period arrives, increase water so that the humidity reaches 65%. Temperature management is the main concern in bag cultivation of Gastrodia elata. During the period of vigorous growth of Gastrodia elata, the temperature inside the bag should be controlled at 25°C and must not exceed 25°C, until the tubers are harvested in autumn.

In the late growth stage, once the Armillaria mellea inside the bag is found to have aged and no new rhizomorphs grow out, this indicates insufficient oxygen inside the bag; several small holes can be pricked around the plastic bag to improve ventilation. In autumn, the holes should be made more numerous and larger to cause water loss inside the bag and prevent tuber rot.

The room should be disinfected frequently, kept sanitary, and protected against damage by rats.

2. Method of planting Gastrodia in plastic bags with wood blocks: The size of the plastic bag is the same as above. Fill a polypropylene plastic bag with the following culture material: miscellaneous wood sawdust 91%, cornmeal 5%, superphosphate 2%, white sugar 2%. Mix the material with 10% potato water so that the humidity reaches 65%. Fill to 1/4 of the bag, sterilize under high pressure, cool, and inoculate with Armillaria mellea spawn. Cultivate at 20-25°C for 2 months, until the mycelium and rhizomorphs have covered the entire surface of the material.

In a sterile room, open the plastic bag that has no contamination by miscellaneous fungi and in which Armillaria mellea is growing well. First put in various small wood blocks and fresh tree bark that have been sterilized with potassium permanganate (pine wood cannot be used), then put in humus soil and plant the Gastrodia, then put in tree bark, wood blocks, and humus soil, and then plant Gastrodia again. The amount of planted tubers is 25 g. The bag should be mainly composed of wood blocks and tree bark, with humus soil serving only as a filler. After planting, make the bag 20 cm high, plug the opening with a cotton plug (leave a small gap between the cotton plug and the humus soil), and tie the plastic opening gently with string. To increase air permeability, it is best to add a small amount of clean sand grains to the humus soil. The culture humidity at planting time should be about 35%.

Place all the filled plastic bags on the bed frame. The size and height of the bed frame are the same as above. After placement (October-November), let the Gastrodia elata enter dormancy. After 50 days, the dormancy period has passed, and the Armillaria mellea inside the bag gradually grows upward under suitable temperature conditions, covering the entire bag after 20-30 days and connecting the Gastrodia elata to the Armillaria mellea, after which the Gastrodia elata begins to sprout; when the temperature inside the bag reaches 25°C and the humidity is 65%, the Gastrodia elata begins to enter its peak growth period.

Management during the growth period of Gastrodia elata: During the growth process, if the moisture inside the bag is suitable, there is no need to water; the main task is temperature management, keeping the temperature inside the bag at a constant 25°C. If there is contamination by miscellaneous fungi inside the bag, a syringe can be used to drip 0.02% potassium permanganate aqueous solution; inject wherever there is contamination, but do not inject too much. Preventing contamination by miscellaneous fungi is the key to the success or failure of plastic bag cultivation of Gastrodia elata. In the middle and late stages of Gastrodia elata growth, several small holes can be pricked around the plastic bag to improve ventilation and promote good growth of Gastrodia elata.