Influence of substrate formulation on some morphometric characters and biological efficiency of Pleurotus ostreatus EM‐1 (Ex. Fr) Kummer grown on rice wastes and “wawa” (Triplochiton scleroxylon) sawdust in Ghana

A study was conducted to correlate the stipe length, cap diameter, and growth yield (fresh weight) of the fruiting body of Pleurotus ostreatus strain EM‐1 using different rice lignocellulosic wastes and “wawa” (Triplochiton scleroxylon) compost: raw unamended rice straw; rice straw amended with 1% CaCO(3) and 10% CaCO(3); rice straw amended with 1% CaCO(3) and 10% CaCO(3) supplemented with 5, 10, and 15% rice bran prior to bagging; rice straw and rice husk mixture (1:1 w/w) amended with 1% CaCO(3) and 10% CaCO(3) supplemented with 5%–15% rice bran prior to bagging; and wawa sawdust amended with 1% CaCO(3) and 10% rice bran. The experiment was laid out in a completely randomized design in a well‐ventilated semi‐dark room at 26–28°C and 60%–65% ERH. The fresh weight, length of the stipe, and cap diameter increased differentially in each treatment with an increasing period of composting in the substrates. There was a good coefficient of determination (R (2)) among stipe length, cap diameter, and biological efficiency (%). The R (2) among stipe length, cap diameter, and biological efficiency for the different formulated substrates ranged between R (2) = 0.6346–0.9454 and R (2) = 0.570–0.9624, respectively. The highest R (2) was obtained on raw unamended rice straw substrates (stipe length and cap diameter were R (2) = 0.9454 and R (2) = 0.9444, respectively), whereas the lowest correlation coefficient among stipe length, cap diameter, and biological efficiency (%) (R (2) = 0.6346; R (2) = 0.0570), respectively, was recorded on the rice straw and rice husk mixture substrates. The results show a positive correlation in morphometric growth parameters studied on the different formulated substrates.