Spawn Production Technology V.P. Sharma and Satish Kumar Spawn is the vegetative mycelium from a selected mushroom grown on a convenient medium like wheat, pearl millet, sorghum, etc for raising mushroom crop. It essentially involves preparation of pure culture of mushroom from tissues/ spores that is generally maintained on any agar medium, followed by culturing on sterilized grains and further multiplied on grains. The spawn thus comprises of mycelium of the mushroom and a supporting medium which provides nutrition to the fungus during its growth. From 1652 to 1894 A.D. spawn was gathered from the wild rather than made. Before the advent of grain spawn, different kinds of spawn used were natural or Virgin spawn (from the pastures & meadows), Flake spawn (breaking of beds through which mushroom mycelium has run), Mill- track spawn (bricks dried and made from mixture of horse dung, cow dung and loan soil) and manure spawn (on sterilized horse manure or compost manure). The first pure culture spawn was produced in France in 1894 on horse manure compost. Costanin and Matruchot (1894) -the two Frenchmen from Pasteur Institute, France germinated spores, made culture and used it for making spawn after sterilizing horse manure (Manure Spawn). In 1902 Fergusan - an American, published about method of spore germination to make pure culture and the technique was no more a secret. In 1905 Duggar, an American made mycelial culture from tissue of mushroom caps. By 1907 Lambert’s American spawn company was marketing seven pure strains of button mushroom. In 1926 a single cluster of white mushroom in a bed of brown mushroom observed by Mr. Downing from which culture was made by Mr. L.F. Lambert. The process of making spawn on grain was introduced by the Pennsylvania State University which held two patents on it. These patents were assigned to the university by the inventor, Professor J.W. Sinden in 1932. Grain spawn had an advantage over manure spawn as it could be mixed easily and provided many inoculum points. Licenses under the patent were available to any laboratory qualified to make the grain spawn. The grain spawn was further perfected by Stoller in 1962. Since then the fundamentals have not changed. Today most of the traditional spawn laboratories world over are using wheat, rye and millet grains as substrate for spawn making and are following the standard techniques of mother spawn from pure culture mycelium grown on synthetic medium. There have been minor changes in container and mechanization over time. The spawn production technology is divided into following steps (Fig.1). 5