The paddy straw mushroom Volvariellavolvaceais a fast growing fungus with a slender fleshy stipe 3-8cm in length and a dark gray cap 6-12 cm in diameter.

Nutritional requirements

This mushroom gives the best yield on waste cotton, mannose and starch also support greater growth. Addition of ammonical nitrogen supports the greatest growth.

Environment Requirements

The optimum temperature for mycelial growth is 30-350C. The moisture content of the substrate should be between 70 to 80%. Light is required for fruiting, there is no fruiting in complete darkness. Well ventilation should be provoded in the cultivation room.

Cultivation

1. Spwan production

The pure culture is obtained from the tissues of the cap of a healthy fruiting body. With a needle, a small portion of tissue from the interior of pileus or stipe is removed and transferred to a semisolid nutrient medium (PDA) in test tubes or petri plates. The spawn is usually prepared on paddy straw or wheat. The milk bottles are filled with chooped and soaked paddy straw or cooked but firm grains of wheat. When grains are used 1-2% calcium carbornate is mixed to prevent clumping. The bottles are then sterilized for 30 min. After inoculation with pure culture aseptically the bottles are incubated at 32-370C. It will be ready within 2-3 weeks.

2. Substrate

The most common substrate is paddy straw but it can also be grown on sugarcane bagasse, banana leaves, sawdust, common waste.

3. Cultivation Method

The paddy straw is made into bundles of 20-25 cm dimater with its full length. The bundles are soaked in water tank for 18-24 hr and taken out. The excess of water is allowed to drain off and they are placed close contact to each other on the beds in a bamboo frame. Second layer is placed lengthwise over the first making the panicles in opposite direction. Similarly third and fourth layers are placed. Grain spwan is scattered 7-10 cm inside from the margin in a row from all sides in each layer. The uppermost layer of spawn is covered with the thin layer of straw and firmly pressed to remove the excess of air from inside. During the hot summer days the beds may to covered with plastic sheet without touching the beds. The mycelium growth will take within a week and the polythene sheet should be removed. The pinhead size mushroom appears in about 10 days and gets ready to harvest after 3-5 days.

Harvesting

This mushroom should be harvested when the cap begins to fold and has attained a diameter of 8-10 cm. Picking is done by twisting the mushroom gently. The base of stipe, deep within the straw, should be removed by cutting with a sharp knife.