The Effect of Casing Material and Thickness

The casing layer material and thickness are so important operational steps in button mushroom production potentially leading to the variation in yields and nutritional characteristics of mushroom. Four casing layers comprising commercial casing soil (CCS), spent compost (SC), coco peat (CP) and vermicompost in three thicknesses (2, 4 and 6 cm) were evaluated in this study for production of Agaricus bisporus. The CCS treatment had the most mushroom yield (27.03 Kg m-2) whereas CP casing layer showed the minimum yield (4.43 Kg m-2). The same results were obtained in total yield of compost and biological efficiency. The CCS treatment induced the first flush to be in advance, however, the CP procrastinated the first flush. Overall, the highest average weight of mushroom and the mushroom cap diameter were observed in 4 cm depth casing. No significant deference was observed in the phosphorus and potassium concentration of treated mushrooms but nitrogen concentration was affected by casing layer soil materials and thickness. The lowest nitrogen concentration was in 4 cm depth of CP casing layer that was not significantly different with 2 cm depth of CP casing layer. As a general conclusion, CCS in depth of 4 cm can be the best choice for casing but in case that using SC for its double advantages of reducing initial costs and waste disposal is preferable, some amount of yield decrease can be ignored