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

Document Type : Full Paper

Authors

• Saheb Soodaee Mashaee ¹
• Golnoosh Banitalebi ²

¹ Department of Soil Science and engineering Department, Faculty of Agricultural,, Shahr-e-kord University, Shahrekord , Iran

² PhD in Soil Science and Engineering, Director of Research and Development, Negin Fasle Mushroom Company, Shahrekord, Chaharmahal Bakhtiari

Abstract

Keywords

• Spawn-run
• Pseudomonas putida
• Yield
• Mushroom
• Plant growth promoter

Main Subjects

• vegetable plant science

Extended Abstract

Introduction

  The most important edible mushroom is the button mushroom (Agaricus bisporus), which is an excellent example of sustainable food production that grows on a substrate with a layer of casing soil and is produced in large quantities for human consumption. Wheat stubble is one of the main traditional materials for button mushroom cultivation. Microorganisms have a remarkable ability to convert and degrade organic residues. Furthermore, addition of manganese dioxide to the compost has a stimulatory effect on mushroom yields. It is worth mentioning that manganese dioxide can enhance the extracellular electron transfer among bacteria. The aim of this study was to optimize the mushroom production process by adding chemical and biological supplements to the casing soil and study their effects on the quality and yield of edible mushrooms in growing room.

Materials and Methods

The effects of manganese and Iron as chemical and Azotobacter chroococcum, Pseudomonas putida, Azospirillum lipoferum, Bacillus subtilis, Enterobacter cloacae and a mixture of cyanobacteria, as biological supplements on the growth and yield of button mushrooms were investigated in two separate experiments based on a completely randomized design with three replications. Manganese and iron sources were manganese oxide (25% manganese dioxide) and iron sulfate (20% iron), respectively, which were added to the compost pile in the amount of 0.05% (w/w) in phase III of composting along with the casing soil. A certain volume (500 ml) of bacterial inoculum (about 1×10⁸ cells/ml population) was sprayed on the compost surface (2.8 m²) at the casing run stage, this step was repeated on the casing soil on the same day.

Results

The results obtained from the analysis of variance showed that there were statistically significant differences in the weight of mushrooms harvested in the first, second and third flashes and the average weight of each mushroom, among biological treatments (p≤0.01). Meanwhile, significant differences observed in the weight of mushrooms harvested in the second flash (p≤0.01) and the average weight of each mushroom (p≤0.05), between chemical treatments. The results showed that the addition of Azotobacter chroococcum and Pseudomonas putida had a positive effect on yield (18.9% and 8.2%, respectively) compared to the control (p≤0.05). Among the bacteria used in biological treatment, Azotobacter chroococcum and Pseudomonas putida showed more effect than other bacteria on yield and quality of mushroom. 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 treatments was greater than the control treatment.

Conclusion

    The results of the present research showed that it is possible to obtain reasonably high yields of A. bisporus by using biological and chemical supplements at casing run or at casing stage. Supplements types and the potential of using suitable casing soil and compost affect the biological efficiency of mushroom production. The use of microorganisms associated with casing soil in mushroom cultivation can be monitored and used for efficient management in mushrooms production. Among the bacteria used in this research, Azotobacter crococcum and Pseudomonas putida had a greater effect on mushroom yield, also the highest mushroom size was pbtained, by using Pseudomonas putida and Enterobacter cloacae. The organic carbon content in biological treatment was higher than chemical treatments during the experiments, which indicates the significant effects of microorganisms compared to chemical supplement. Additional research is needed to determine if the addition of bio-chemical supplements at casing or later, or the addition of both organic and inorganic supplements simultaneously, would further enhance mushroom productivity.