Mushroom Culture

White Button Mushroom

1. WHITE BUTTON MUSHROOM ( Agaricus brunnescens Peck.)

White variety -------A. brunnescens var. albidus
Brown variety ------ A. brunnescens var. bisporus
Cream variety ------A. brunnescens var. avellaneous

This mushroom is commonly found growing in soil enriched with cow dung, horse dung or forest litters in temperate climate. A most widely cultivated mushroom in the world. The name Agaricus originated from the greek word Agaricon—with a Scythian people called Agari who were knowing the use of medicinal plants and employed a fungus called “ agaricum ”, probably a polypore in the genus Fomes . Brunnescens means brown in latin, as the colour changes to brownish after bruising . It is also called as A. bisporus because of the two spored basidium.

Description:
White button mushroom (A . brunnescens) is thick fleshed , robust with thin gills on the underside of the cap that are pinkish white in early age and darkening to chocolate brown at maturity. Cap is whitish, cream coloured or brown. Cap surface smooth to appressed and dry. The stem is short, thick adorned with a persistent membranous annulus from a well developed partial veil. Spores chocolate brown in mass, basidia bipolar ( two spored ) forming diploid spores, secondarily homothallic, clamp connection absent. Mating of compatible dikaryons typically results in development of strain which is more vigorous and high yielding. Mycelium is dingy white, moderately rhizomorphic.

White button mushroom (A. bisporus) cultivation

Nutritional Value : Button mushrooms contain 90-92 % water and only 8-9% dry matter. Also contains 3.92 % protein, 1.09 % crude fibre, 1.25 % ash, 0.19 % fat and 56 mg. niacin / 100 g weight.

Spawn production : The Master culture and spawn are produced on wheat or rye grains buffered with Calcium carbonate and Calcium sulphate.

Cultivation : Button mushrooms, including the high temperature species A. bitorquis ( 20 – 25° C ) require well decomposed manure for its cultivation which is prepared by long method or the pasteurization method of composting by mixing wheat or rye straw with supplements like chicken manure, cotton seed cake, wheat bran, urea, gypsum etc. The prepared compost is filled in polythene bags or wooden trays, spawned by through or layer spawning method and incubated in a closed room at 25 ± 1ºC and 90 % relative humidity with high concentration of carbon dioxide (5,000 to 10,000 ppm ) in the absence of light . After 10 -15 days of incubation, when mycelium of spawn completely impregnates the compost, it is covered with 1-1.5 inch layer of sterilized wet casing mixture containing FYM alone or FYM + spent compost or FYM + forest soil or soil + sand + coco coir or sand + soil + paddy ash or peat soil . The mycelium of button mushroom will not fructify unless it is covered on the surface with a layer of fine casing mixture.