Abstract:
Preparation of saw dust as the growing media and filling it into poly bags are the most laborious
operations of mushroom cultivation in Sri Lanka. Saw dust is used as the main substrate; it should be
sieved well to get fine particles and mixed properly with the other essential nutrient ingredients and
water. The purpose of this research was to find an appropriate mechanical solution to prepare the saw
dust based growing media and filling of growing medium into transparent poly bags for artificial
cultivation of Oyster mushrooms. A power operated machine with three separate units; saw dust sieving
unit, ingredient mixing unit and mixture filling unit were designed and, fabricated. An electric motor was
used as the power source for all three units. The integrated filing and compaction of the mixture filling
unit is the most salient feature of this machine. The performance of the machine was evaluated compared
against the manual preparation by a skilled laborer using well dried mango saw dust and other
recommended ingredients. Machine capacity of the sieving unit and sieving efficiency were 212 kg/hr and
84%, respectively while the corresponding figures of manual sieving were 145 kg/hr, and 76%
respectively. The capacity of the mixing unit and the mixing efficiency were 323 kg/hr and 67%. In manual
mixing, the corresponding values were 162 kg/hr and 70 %. The capacities of the mixture filling unit and
filling efficiency were / 81 bags/hr and 83%, respectively compared to the manual filling where those
corresponding values were 32 bags/hr and 72 % respectively. According to the results, this machine can
effectively replace the manual sieving, mixing and filling of mushroom growing medium in oyster
mushroom cultivation.
