Oyster mushroom (Pleurotus spp.) cultivation technique using re-usable substrate containers and comparison of mineral contents with common leafy vegetables

Alternative re-usable substrate containers for fructification are required because plastic bags currently used suffocate soil biotic entities. They are a cost for mushroom farmers who purchase plastic bags in every oyster mushroom crop and they are left as non-biodegradable wastes, which are disposed of to the environment after every oyster mushroom cropping. On the other hand, oyster mushroom contains essential nutritional elements comparable to leafy vegetables. Objectives: The objectives of this study were to determine the effects of substrate types and substrate containers on yield, biological efficiency, size and solid content of oyster mushroom Pleurotus ostreatus; and to compare mineral content of mushrooms produced from different types of substrates to common leafy vegetables. Methodology and results: Substrate containers: clear plastic bags, re-usable substrate containers (RSC), coloured plastic bags, shelved clear plastic bags and substrates: banana leaves, rice straws and maize cobs were used to grow oyster mushrooms. The experiment was carried out in complete randomized block design (CRBD) in a factorial arrangement. The mineral content of oyster mushroom grown on rice straws, Leucaena leucocophala, sorghum grains, banana leaves and maize cobs substrates were compared in a CRBD to those of pumpkin leaves (Curcubita spp.), narrow-leaved African night shade (Solanum villosum), broad-leaved African night shade (Solanum scabrum), cowpea leaves (Vigna unguiculata), cabbage (Brassica spp.), sweet potato leaves (Ipomea batatas), amaranth (Amaranthus spp.) and cassava leaves (Manihot esculentus L.). Mushroom yields and BE in RSC were comparable to non-RSC. The highest yields (1,116.25 g/g) and BE (105.75%) were produced from rice straws substrate in coloured bags followed by RSC (yield 694.6 g/g, BE 65.6%). Mushroom solids content (19.4%) was highest from banana leaves substrates. The highest Fe, Zn, Se and Ca were obtained from amaranth, oyster mushrooms produced from rice straws, narrowand broad-leaves African nightshade and pumpkin leaves respectively. Conclusion and application of results: The utilization of RSC to produce oyster mushrooms protects the environment from disposed plastic bags which are non-biodegradable and if burned may cause ill-health effect to the human. Additional research is needed to specify quality of material to be used in the manufacture of RSC and specifications to suit cultivation of oyster mushrooms. In addition, consumption of oyster mushrooms in combination with other vegetables complements availability of various essential dietary elements such as Fe, Zn, Se and Ca.