Effect of Manganese, Iron and Growth Promoting Bacteria on Some Quantitative and Qualitative Characteristics of Button Mushroom (Agaricus bisporus)

Mushroom (Agaricus bisporus) cultivation is strongly dependent on biological (type and activity of microorganisms) and non-biological supplements in the culture medium. This study was performance to investigate the effects of Manganese and Iron as chemical and Azotobacter chroococcum, Pseudomonas putida, Azospirillum lipoferum, Bacillus subtilis, Enterobacter cloacae, mixed cyanobacteria as biological supplements on the growth and yield of button mushrooms. Two separate experiments were conducted based on a completely randomized design with three replications. Results showed that addition of Azotobacter chroococcum (18.9%) and Pseudomonas putida (8.2%) into substrate had a positive effect on yield compared to the control (p≤0.05). Among the bacteria, Azotobacter chroococcum and Pseudomonas putida showed more effect than other bacteria. Although the addition of chemical supplements (Mn+Fe) affected the time of harvesting and the weight of the harvested mushrooms in the first flash, no significant difference was observed in the total weight and yield of the produced mushrooms compared to the control. However, the mushroom yield increased by 11.2% compared to the control. The amount of microbial respiration in the compost of the casing run stage and spent mushroom compost in the biological treatment was greater than the control treatment, which indicated the more microbial activity and more decomposition of organic carbon compounds during the growth period of edible mushroom.