Paddy-straw mushroom (Volvariella volvacea)
Volvariella volvacea Sing., the paddy straw mushroom, or straw mushroom is the most popular mushroom in Southeast Asia. V.diplasia is white while V. volvacea is blackish. V. bombycina differs from the cultivated V. volvacea in terms of habitat as well as colour.
Cultivation of this mushroom started in China almost three hundred years ago. Several species of Volvariella have been grown for food. V. bombycina Sing. and V.diplasia (Berk & Br.) Sing, have been cultivated in India. Volvariella volvacea thrives in a temperature range of 28 to 380 C and relative humidity of 75-85% is required.
In a modified method of cultivation, bundled substrates (rice straw, banana leaves or water hyacinth), prepared in the same way as those used for beds, are soaked in water, drained, then packed (layered) in the wooden frames. Spawn is mixed in with each layer as the frame is packed or filled. The spawned substrate in the boxes may be placed in a specially built incubation room with a high temperature (35 to 380 C) and high relative humidity (at least 75%), or it may be covered with plastic sheets and placed under shade outdoors. For spawning, the air temperature is cooled to 350C and the bed temperature to about 28 to 320 C The amount of spawn to be used is calculated at 1.5% of wet weight basis.