Production of oyster mushroom using simplified technology

Studies were carried on to evaluate legume waste and/or gypsum as possible additives to rice straw for the cultivation of the oyster mushrooms Pleurotus florida and Pleurotus ostreatus. Cultivation studies were conducted in a greenhouse at Mushroom Res. Farm, Protected Cultivation Center, ARC, Dokki. Soaking in hot water, as a simplified heat treatment, was adapted for the preparation of the different combinations of the waste materials. Both yield and quality of oyster mushroom have been improved by supplementing rice straw with legume waste. The highest beneficial effect on yield was achieved when rice straw was supplemented with 50% legume waste. The biological efficiency, i.e. kg of fresh mushroom harvested from 100 kg of dry substrate, were 121.3 and 116.2 for P. ostreatus and P. florida, respectively. Lower mushroom yields were obtained from the two species when substrates composed of either lower or higher percentages of legume wastes had been used. Both dry matter and protein contents of the two mushroom species continued to increase with higher percentages of legume waste. However, P. ostreatus was more responsive than P. florida when rice straw substrate was enriched with legume waste. The highest mushroom yield was obtained with substrates composed of equal amounts of rice straw and legume waste with 5% gypsum; these yields were, however lower than those obtained without gypsum addition. The same trend of adverse effect was noticed on dry matter and protein contents of mushroom produced from substrates containing gypsum. Clearly the gypsum addition adversely inhibited the favorable effect observed with legume waste on both mushroom yield and quality.