Shiitake (lentinula edodes) cultivation dates back to at least 800 years ago. Farmer in China and Japn imitated the natural process of shitake fruiting from falling barachens of the Shii tree after heavy rain. It is now a well known edible mushroom here in the UK. Fresh, it has a good shelf life but this, as well as favour and nutritional value, can be increased through drying.
Shiitake can be easily grown on lignin based substrates. The proposed cropping scheme here describes the application Log Culture. Shiitake can be grown on particular species of hardwood, with some species performing better than others, we reccomend participants try to source Alder as this is readily available in Cymru but Oak or Beech are ideal. It is possible to use chestnut, sycamore and birch but they do not perform as well.
Logs are inoculated one week after of having been cut and before 4 weeks. This is to allow natural anti-fungal compounds to degrade and to introduce the shiitake mycelium before ambient fungi naturally colonise the wood. The process of inoculation involves drilling 12mm drill holes, filing these holes with sawdust spawn then sealing the holes with wax. One person can inoculate around 10 logs per hour using this technique. Once inoculated the logs are left in a sheltered area for 12-18 months before they can be fruited.
Shiitake logs can be “shocked” into fruiting giving the grow er much greataer control compared to other “natural methods” of cultivation. Traditionally the method involved soaking in cold water then striking the log. This method does require a significant amount of labour which is a limiting factor of scalability. However, recent studies have shown the high voltage electric shock can induce fruiting in mushroom substrates. We are thus proposing an “in-situ” method of shocking usings simple sprinklers and a hand held cattle prod. The logs are cross stacked on raised support above the ground, a sprinkler system soaks the logs for 12-24hrs before they are literally shocked with the cattle prod. Obviously this does assume an availability of water.
We are proposing inoculating 100 logs per year in order to achieve a 400 log cropping cycle by year 5. Allowing for a growing season from April to September and a rest period of 6 weeks, each log could be initiated 3 times during the season. Over an 8 week cycle this would mean 50 logs would be initiated each week yielding a minimum of 5 kg.
Fresh mushrooms are easily picked from logs and can be transported in trays for wholesale or retail with a good shelf life. If drying they can be dried whole or sliced. It is best to remove the stems if selling as a dried product. The vitamin D content of the fruitbodies can be enhanced with exposure to sunlight. This is best achieved by placing the fruitbodies gill side up in sunlight.
Sawdust spawn has to be made at least 4 weeks prior to innoculation. This requires the ability to use grain spawn to inoculate sterilised sawdust.