Mushrooms are a source of high quality proteins, essential minerals and vitamins. Being low in starch content, they are good for diabetic patients. Mushroom is grown on agriculture residues like straw, leaves, and sticks which (after use) can be recycled back as organic manure. Mushroom cultivation demands no land but closed structure, which can even be a thatch-hut. it can be a remunerative cottage industry for rural women.
Tissue Culture Method
Select fresh mature mushrooms (straight from the bed), wash them gently under running water to remove surface dirt. Blot it dry. Wipe the surface gently with 70 per cent alcohol. Using a sterile knife, cut a small slit at the bottom of the mushroom. Tear it into two halves and avoid touching the inner surface. Transfer a few pieces of tissue (Pseudoparenchyama) from the centre of the mushroom to the media in plants.
Spore Culture Method
The surface of a mature (open) mushroom should be disinfected by wiping gently with 70 percent alcohol. Remove the spore and place the cap with gills downwards on a piece of sterile white paper. Cut tiny piece of spore print and soak it in a few mi. of sterile tap water. Dip a sterile inoculating loop into this spore suspension and streak gently across the surface of an agar plate. Incubate the plate for a few days and a white mycelial (white thread like structure) mass resulting form the growth of germinated spores becomes evident.
Preparation of Spawn
Cook the grains (rye/sorghum/maize/wheat) in water until they are ready to burst. Drain off excess water. Mix in 2 percent (w/w) lime (calcium carbonate), fill loosely into glass bottles and plug with cotton. Sterilize them in an autoclave for 30 minutes at 1210C and allow it to cool. Inoculate the bottles with the prepared pure culture and incubate at 250 C for 10-15 days. When the whitish mycelium has spread over the Surface, the spawn is ready for use.
For 100 kg Mushroom production - Dry paddy straw (not more than one year old) -100 kg; gram powder-2 kg; spawn bottles-l0; polythene bag-i kg; water and a shady structure.
Preparation of Substrate
Use Dried paddy straw, 500 gms per bed (Hulled maizecob, sugarcane bagasse, cotton waste, paper waste, etc, can also be used instead of paddy straw). Cut the paddy straw into small bits of 3 to 5 cm. and soak it in cold water for 6-8 hours. Take it out and then immerse in boiling water for 15-30 minutes and drain off excess water. Dry the straw in the shade for 2 hours and then use. Remove the spawn from the bottle using a small iron rod with hook on one side. Dip the iron rod in antiseptic solution before use. Separate the spawn into four lots. Fill the first layer with straw bits upto 5 cm height in the bottom of the polythene bag. Sprinkle spawn over the entire surface of the straw layer. Add second layer with the straw bits upto 10 cm height and sprinkle spawn as before. Similarly, repeat the spawning for third and fourth layers of straw bits. Then, fill the final layer with straw bits upto 5 cm height.
After spawning the beds keep the beds in the growing room for spawn running. Keep bags in the dark for a period of twenty days. White mycelial growth appears throughout the bed.
Cropping & Harvesting
After the spawn running period (nearly 15 days), remove the polythene cover and keep in the rack. The relative humidity is maintained above 75% by spraying water on the floor and gunny screens, but watering the beds is avoided for first two days.
After two days, sprinkle beds with water twice daily. Allow aeration and light for 20-30 minutes in morning and evening by opening windows of the growing room.
First harvest can be made 24 to 26 days after spawning. Harvest fully-opened mushroom before the edge of the top rolls downward. Two to three harvests can be taken at 7-10 days interval. The yield is about 35 to 85 percent of the substrate (w/w).