Volume 13 Part 2 Article 12
Title: Cultivation of Shiitake on Straw Based Pasteurised Substrates
Authors: F. Delpech and J.M.Olivier
In INRA, we have developped cultivation techniques using pasteurised substrates more economical than those adopting a sterilised substrate. Two different compositions of substrate have been experimented during two years ; one based on wheat staw enriched with chicken feather meal and the other based on a mixture of oak bark and saw dust. The “pasteurisation” phase carried out in bulk lasts 24 hours at 60-62°C. A small addition of benomyl (75 ppm a.c.) is mixed with the substrate before pasteurisation to enhance the efficiency of the partial disinfection. The spawn rate is high : 7% (w/w). A very severe control of the substrate temperature during spawn run is a condition to avoid moulds development. Substrate temperature is now regulated from sensors placed inside the substrate and acting on the air temperature. This way, substrate temperature never exceeds 28°C and is generally around 25°C. Fruiting occurs whithout “chock” or “stress” other than an increase of air circulation, light, and a serious drop in air temperature. A few strains only are able to give good commercial yields on these substrates; from 150 to 250 kg of fruitbodies per ton of substrate. With certain strains total yield is obtained quickly, within 60 days after spawning. The rate of benomyl residues in the fruitbodies is always below the minimal accepted level. Despite the low genetical ressources available in our collection, a breeding work is now under way to obtain strains better adapted to pasteurised substrates.