General principles of mushroom cultivation

Mushroom cultivation relies on a supply of mushroom spawn. In similar fashion to seed production by seedsmen, specialist producers grow specific mushroom mycelia using aseptic microbiological techniques.

A new strain may start out on a single agar culture plate and then be enlarged by further growth on agar. For final use on the farm the most popular preparation is to grow the mycelium on autoclaved cereal grains. This eventually produces the "spawn" of easily distributed granules that the farmer will use to start his crop.

The first step in mushroom farming is compost production. We illustrate this and the later stages in the picture gallery below. Click on any of the thumbnail images to see a larger picture.

Compost Production This is an important part of mushroom cultivation, as spawns require a rich substrate that is moist and full of nutrients. It also has to be free of harmful microorganisms. Composting is a multi-stage process, taking about 14 days, although before 1964, this process would take many weeks of hard labour:
The main ingredients of compost are straw and horse manure, but the straw has to be pretreated before the two are mixed.		This involves mixing with chicken manure and sprinkling with liquid manure, followed by heating.
The horse manure and bedding straw is then mixed in and fermented.	More chicken manure may be added to provide extra nitrogen and nutrients, and gypsum is included to obtain the correct structure and acidity.
The compost is then split into long narrow piles and periodically turned. During this period its internal temperature can reach 80ºC. At the end of the process the compost is ready to be shipped to a mushroom farm.
The Cultivation process
Most farms now grow their mushrooms on trays in stacks of two or three. The compost shown here is being machine-loaded on sliding sheets.
This is then inoculated with the spawn (grain colonised by mycelium).		Mycelium soon covers the compost.
After two weeks the compost is covered with a mixture of peat and chalk called casing, this shows a machine carrying out this process.	This picture shows the control panel for the climate control system. This is an important part of the process, as the environment has to be changed to induce fruiting.	The mycelium near the surface is then broken up by a machine called a ruffler. This induces fruit body formation. This picture show the blades of a ruffler...
...and this is a ruffling machine in action.	The fuiting bodies start to appear.	They grow tightly packed together ...
and are soon ready for harvesting...	either by hand (for top quality) ...
or by machine (for canning etc).	The mushrooms are then graded by quality, size and colour, and packaged for sale fresh ...	or sent for canning or bottling..
Photography by Prof. S. W. Chiu, Department of Biological Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.

Now you've got your mushrooms......time for a feast!

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