Mushroom Cultivation | Mycology

In this article we will discuss about mushroom cultivation

Mushroom Cultivation

• Mushrooms are the fruiting body of edible fungi, commonly belonging to Basidiomycotina and rarely to Ascomycotina.
• The mushrooms is rich in proteins, fibres, vitamins and minerals.
• In the early years of mushroom culture in the Netherlands, compost was scooped into the mushroom trays and then inoculated with spores. A nine week wait followed, until the mycelium spawned sufficiently, flushing started and the grown mushrooms could be harvested by hand.
• The mushroom cultivation process hasn’t changed that much, but the way the successive steps are performed differ immensely.
• Mushroom cultivation can be divided into five phases: Composting, Spawning, Casing, Pinning and Harvesting

Steps of Mushroom Cultivation

Phase 1: Composting

• The growing cycle of mushroom cultivation starts with compost.
• Compost preparation starts with horse manure, get it from large horse breeding companies.
• Straw, gypsum, chicken manure and water are added to the horse manure.
• Commonly 100 kg of dung is mixed with 33 kg of straw.
• Gypsum is added @ 25 kg/tonne (1,000 kg) dung.
• The straw improves the structure, gypsum ensures the proper acidity and the two manures are the nutrients.
• The compost is produced in tunnels in order to prevent the smell.
• Air purification with ammonia wash prevents gas emissions from manure.
• It is kept at about 50^oC for one week.

Phase 2: Spawning

• Fresh compost is pasteurized in a tunnel at 57-60°C to kill bacteria.
• The compost is mixed with spawn (mycelium) that produces mushrooms.
• Compost is moved to another tunnel for mycelium to spread.
• Mycelium fully permeates the compost in two weeks, making it ready for growers.
• Spawn production is a sophisticated process managed by dedicated companies:
• Grain is sterilized to prevent infection.
• Spores are inoculated into the grain.
• Grain is incubated for two weeks at 25°C, then transferred to refrigerator at 2°C to harden it.
• The spawn gets a shelf life of 6 months without the mycelium losing its vitality

Phase 3: Casing

• The matured compost is spread onto long stainless steel boxes, the mushroom beds.
• The beds are inside special dark rooms called cells.
• The temperature in the cells is kept warm, at about 23 degrees Celsius.
• A layer of peat casing material is added on top of the compost to keep the compost moist.
• Over a period of six days, 20 to 25 litres of water is sprinkled on each cell because more moisture is needed.
• After this, the fungus has two days to grow through the covering layer of casing soil.

Phase 4: Pinning

• Mushrooms grow naturally in autumn but can be cultivated year-round by simulating autumn conditions.
• Temperature in the cell is gradually lowered from 23°C to 17°C over four days.
• The temperature drop signals the mycelium to start sprouting mushrooms, similar to nature’s process.
• Once mycelium fully grows, it begins forming small buds called pins, which develop into mushrooms.
• Air temperature and humidity affect mushroom growth:
  • Low temperature and humidity: More buds, smaller mushrooms.
  • High temperature and humidity: Fewer buds, larger mushrooms.

Phase 5: Harvesting

• The temperature is kept steady at 18 degrees Celsius. Mushrooms grow best at this temperature.
• Mushrooms will grow 3 cm (1 inch) in a week, In week 3 the first flush is harvested.
• The selling fresh mushrooms are still harvested by hand.
• Hand-picking ensures mushrooms are removed undamaged.
• On average, a picker can harvest between 18 and 30 kilos of mushrooms an hour
• Nine days after the first flush, the second flush will be harvested.
• The second flush often consists of larger, but fewer mushrooms than the first flush.

Preservation of Mushrooms

• Discolouration, weight, and flavourloss are the main problems of harvesting stage of mushrooms.
• The following methods are used to Preservation of Mushrooms.
  • Canning: Mushrooms are washed, blanched in hot water and citric acid (3-5 minutes)
  • Drying: Preservation by reducing the moisture Content.
  • Freezing: Subjecting to low temperature (-60°C)
  • Chemical Preservation : such as SO₂, sorbic acid, sodium benzoate, ascorbic acid, acetic acid, citric acid.
  • Pickling: with salt, oil, spices and vinegar
  • Steeping preservation: With salt solution