Detailed Guide to Black Fungus Cultivation Techniques: Planting Methods and Management Key Points

I. Cultivation Techniques

1. Cultivation time: The choice of cultivation time is the key to the success or failure of black fungus cultivation, and is closely related to yield and quality. Bag making should be chosen from early October to November, and can be appropriately advanced in high mountain areas. This period is relatively ideal, when the room temperature is 28-15°C, the relative air humidity is about 65%, and the temperature gradually drops. The activity of contaminating microorganisms is at a low ebb, which is beneficial for the colonization of black fungus mycelium to absorb nutrients, and also beneficial for fruiting in early spring.

2. Raw material ratio: Black fungus is a wood-rotting fungus. Using sawdust as the culture substrate, its nutritional components can meet the needs of black fungus growth and development. Tree species suitable for cultivating shiitake mushrooms and wood ear are all suitable for cultivating bag-cultivated black fungus. Pine, fir, cypress, etc. contain oils, alcohols, ethers and other substances, and tree species of the Lauraceae family and aromatic spice trees also contain aromatic substances. The sawdust of these tree species must be treated before they can be used for cultivating black fungus; otherwise, they should not be selected.

Sawdust is best crushed into granular form in one pass with an 8 mm mesh screen. Cottonseed hulls and rice husk powder are also ideal cultivation materials. Bran, rice bran and other auxiliary materials make up the culture medium. Raw materials are required to be fresh and free of mold. The formulas are as follows:

(1) Mixed wood sawdust 80%, bran 18%, gypsum powder 1%, sucrose 1%, appropriate amount of water.

(2) Mixed wood sawdust 68%, rice husk powder 15%, bran 16%, lime 0.5%, sugar 0.5%, appropriate amount of water.

(3) Mixed wood sawdust 65%, cottonseed hulls 24%, bran 15.5%, lime 0.5%, appropriate amount of water.

II. Production Process Flow

The water content when mixing materials for bag-cultivated black fungus is slightly drier than for bag-cultivated shiitake mushrooms, with 50%-55% being suitable. Because black fungus mycelium is fine and slow to colonize, the culture substrate being slightly dry provides large gaps and sufficient oxygen content, which can significantly accelerate the fungus mycelium and is beneficial for the later stage (field management). Bagging and sterilization are similar to bag-cultivated shiitake mushrooms (15×15 log material). Inoculation should be carried out with an inoculation box under sterile conditions, with four inoculation points per bag, appropriately increasing the inoculation amount, and using whole blocks of spawn for inoculation, so that the black fungus mycelium can quickly resume growth and occupy the inoculation openings. After inoculation, tie the bag openings with overbagging and transfer to the culture room for cultivation. The culture room should be cleaned in advance, fumigated and disinfected with sulfur or sprayed with 5% phenol or peracetic acid on the walls, space and floor. After the chemical odor has dissipated, move in the inoculated fungus bags and stack them in parallel piles or in a "well" pattern.

Suitable temperature cultivation: Temperature has an enormous influence on the growth of black fungus mycelium. In order for the black fungus mycelium to grow normally, the room temperature must be controlled differently according to different growth stages. The mycelium growth stage is divided into:

Germination stage: That is, within 15 days after inoculation. For the first 10 days, the indoor temperature should preferably be 26-28°C, so that the mycelium can accelerate nutrient absorption in the most suitable environment, colonize and spread, occupy the culture substrate, become dominant, and reduce contamination by competing microorganisms. However, it should not exceed 30°C. After 10 days, as the mycelium grows and develops, the temperature inside the bag gradually rises. Generally, the bag temperature is 2-3°C higher than the room temperature, so the room temperature should be adjusted to 22-24°C.

Vigorous stage: After 20 days, the mycelium reaches the stage with the strongest ability to decompose and absorb nutrients. The mycelium is vigorous and strong, metabolism accelerates, and the bag temperature continues to rise. The room temperature should preferably be around 22°C. At this time, special attention should be paid to turning the piles to prevent abnormal temperature fluctuations and increase ventilation frequency.

Maturation stage: That is, after 40 days, the mycelium enters the physiological maturation stage and is about to transition from vegetative growth to reproductive growth. The bag temperature gradually decreases and should be maintained at around 20°C. Temperature changes should be observed, and the timing of opening and closing doors and windows should be controlled well. When closing doors to raise temperature, be sure to ventilate in time according to the temperature. After closing the doors, the temperature can still rise, so attention should be paid to timely spreading out the fungus logs to avoid "burning the fungus." When the mycelium has fully covered the bag, it can be moved to the cultivation site for fruiting management.

III. Selection of Fruiting Site

Choose a field plot or lawn with good ventilation, sufficient sunlight, convenient water source, no pollution sources, and flood prevention as the fruiting site. Prepare it into a turtle-back-shaped raised bed, 120 cm wide, with unlimited length, and the side ditches serving as walkways. Set up with small wooden poles or wire, with rows slightly sparser than shiitake mushroom logs. Cover the raised bed with dry grass to help retain moisture (or cover with perforated plastic film) to prevent mud and sand from eroding the fungus logs, so that the fungus slices are clean, free of impurities and contamination, and of top quality after drying. The fungus logs do not need film covering, do not require a shade shed, and are arranged in the open air to allow smooth air flow. IV. Log Arrangement and Fruiting Management

In early February, transfer the well-colonized fungus logs to the fruiting site. Choose a sunny or cloudy day for arrangement. Punch about 180 fruiting holes in each fungus log (using a hole-punching tool made from a 0.5 mm thick nail head). Use the method of not removing the bag. One week after punching holes in the fungus logs, only after seeing the mycelium at the holes recover, can fine water spraying management begin, spraying once in the morning and once in the evening, half an hour each time, and increasing the amount of water sprayed according to the growth of the fruiting bodies. Spray when the temperature is low, do not spray when the temperature is high (during the day), and spray more on sunny and windy days (morning and evening). Water management is the key in the black fungus cultivation process. When primordia form, the relative air humidity of the cultivation site should be 90%-95%. In an environment of alternating dry and wet conditions, when the temperature is high, spray water in the morning and evening; when the air is dry, increase the frequency of water spraying. Stop spraying water 1 day before harvesting. After harvesting, rest the fungus for 7 days, then spray fine water once every 8 days to moisten the culture substrate. After new fungus buds form, continue spraying water. The fungus slices can be picked when they are 80%-90% mature. Harvest two batches of fungus, then turn the fungus logs once, so that both ends produce fungus evenly, promote the mycelium to form fruiting bodies, and harvest 4 to 5 batches in total. The processing and drying of black fungus is relatively simple; simply air-dry in the sunlight. Storage is also very simple; just put them into plastic film bags or woven bags and stack them in a dry, dark place. V. Points to Note

The main existing problem in sawdust bag cultivation of black fungus is mold contamination. This is because the fungus logs lack a protective layer like the bark of log-cultivated trees or the mycelial skin layer of shiitake mushroom logs, which is why pathogen infection occurs. In addition, black fungus mycelium is fine and lacks the strength and stress resistance of shiitake mushroom mycelium. Also, because black fungus is a gelatinous fungus, during the bud emergence and fruiting stages, if temperature and humidity management is poor and ventilation is insufficient, it is easy to attract disease-causing pests and diseases. Therefore, we adopt the open-field cultivation method without building a shade shed and without film covering, which is an effective measure to solve ventilation and reduce humidity, and can also avoid the breeding of contaminating microorganisms and pests.

Properly arranging the fruiting time, the superior conditions of early spring temperature, humidity, air, etc. are all beneficial to the growth of black fungus, ensuring high yield and high quality of the fungus, enabling breakthrough progress in bag-cultivated black fungus cultivation and stabilizing the yield; using a scientific method to punch fruiting holes causes the fungus logs to be stimulated without being damaged, producing uniform and neat fruiting, and harvested fungus is free of impurities. With well-distributed early spring rain, fruiting is early, flush turnover is fast, there are no pests or diseases, no pesticide spraying is needed, and management is simple and easy. The fungus quality is good, with dark color and thick flesh, and the fruit body shape is comparable to log-cultivated fungus, meeting foreign trade export standards. Lei Shoubin