Volume 17 Part 1 Article 25: Chemical and Physical Properties of Alternative Casing Media in Commercial Production of Button Mushrooms [Agaricus bisporus (Lange)]

Volume 17 Part 1 Article 25
Year 2008
Title: Chemical and Physical Properties of Alternative Casing Media in Commercial Production of Button Mushrooms [Agaricus bisporus (Lange)]
Authors: L.P. van Jaarsveld and L. Korsten

Abstract:

Limited local peat supplies and new restrictive legislation to protect wetlands has forced the South African mushroom industry to search for alternative casing media. It would be advantageous and time saving if new materials could be screened beforehand, for physico-chemical and biological properties that support mushroom growth. Materials including composted wattle bark, coir, and sugarcane bagasse and filter cake were screened for use to expand local peat supplies. However, certain materials, such as composted wattle bark, favour the prolific growth of Chromelosporium fulvum (Cinnamon Brown Mould), a weed mould known to delay mushroom growth, lower yields and cause respiratory allergies. It is a common mould on South African mushroom farms, partly because casing material is steam pasteurised before use. The objective of this study was to determine the physical and chemical parameters, as well as the effect of heat treatment on the casing media and growth of C. fulvum. The parameters included total soluble phenolics, pH, electrical conductivity, water and water release ability, and isolation and identification of prevalent micro-organisms and growth and sporulation curves of C. fulvum on various casing materials. It was found that the sporulation of C. fulvum differs on the various growing media. Heat treatment of casing material influenced the phenolic content, as well as some physical characteristics. The information obtained from this study provides some insight into factors inhibiting the growth of C. fulvum and thereby enhances the option of materials such as composted wattle bark and sugarcane bagasse as potential casing.

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