Agaricus Bisporus- Button mushrooms (A. bisporus; syn; A. brunnescens) are grown on decomposed horse manure or (most commonly in India) on paddy or wheat straw compost. Wheat straw compost is prepared from the following ingredients: wheat straw, 300 kg; wheat bran, 25 kg; ammonium sulphate, 9 kg, superphosphate, 3 kg; urea, 3 kg; muriate of potash, 3.5 kg; gypsum, 30 kg; saw dust, 30 kg; zinc sulphate, 109; lindane or gamma- BHC, 1 kg; and malathion, 200 ml.

The straw is wetted for 48 hr; the remaining components (except gypsum, and the insecticides) are also wetted for 24 hr in a separate heap; the two are then mixed into a heap and kept preferably on a clean cemented floor. Adequate watering and turning of the heap at specified intervals is continued; the compost is ready for use after about 22-30 days.

The compost beds are now covered with a 1.5-2 cm thick layer of sterilized mixture of soil and sand (3: 1) with some peat, if available, having pH of about 7; this is called casing. Casing is essential for fruiting bodies to be produced.

The trays are watered regularly and maintained at about 15°C and 70-80% humidity; fruiting bodies appear after about one month of casing. The mushrooms are harvested in the button stage. Button mushrooms are the most liked and prized of them all.