Spawning Methods

Spawning methods, like spawn itself, have evolved over the years. As late as
1950 Agaricus brunnescens growers customarily planted walnut sized pieces
of manure spawn or kernels of grain spawn in holes poked into the compost at
regular intervals. Using this method spawn running was slow, and areas far from
the inoculum were more susceptible to invasion by competitors. The full potential
of grain spawn was not realized until the development of "mixed spawning". The principle of mixed spawning is the complete and thorough
mixing of the grain kernels throughout the substrate. In this manner all parts
of the substrate are equally inoculated, resulting in the most rapid and complete
colonization possible.

The standard spawning rate used by Agaricus growers is seven liters/ton
of compost or one quart/8 sq. ft. If spawn is readily available and cheap, it
is advantageous to use high spawning rates which lead to more rapid colonization.
It is also advantageous to break up the grain spawn into individual kernels
the day before spawning. If the spawn is fresh, the grain should break apart
easily. If the spawn can not be used when fresh, it should be refrigerated at
38?F.

The basic principle of spawn running is the same regardless of the type of mushroom
or substrate. COLONIZATION MUST PROCEED AS RAPIDLY AS POSSIBLE TO PREVENT OTHER
ORGANISMS FROM BECOMING ESTABLISHED. Once the mushroom mycelium becomes dominant,
natural antibiotics secreted into the substrate inhibit competitors. To prevent
invasion by competitors it is important that spawning take place under carefully
controlled hygienic conditions. Fungus gnats in particular must be excluded,
and for this purpose a tight, well sealed working area is best. This area and
all tools should be disinfected one day prior to spawning with a 10% bleach
solution. When using disinfectants be sure your skin is protected and avoid
breathing any fumes.