Influence of sawdust supplemented with farm and industrial wastes on the growth, yield and mineral composition of Pleurotus ostreatus (Jacq. ex. Fr.) Kummos.

Results from the study showed that rice bran sucrose agar, banana sucrose agar, pineapple sucrose agar and potato sucrose agar supported rapid mycelial growth proving it suitable for pure culture cultivation of Pleurotus ostreatus. Measurement of the mycelial colony of P. ostreatus from the fifteen plated substrates of farm wastes consisting of sawdust [Sd], sugarcane bagasse [SB], coffee hull [CH], spent grain [SG] and rice hull [RH], revealed that SB combined with RH in a ratio of 1:1 had the fastest mycelial growth. The same substrate combination produced the first flush of basidiocarps after opening the bags with a shorter incubation period. There was no significant difference among treatments on the number of flushes. The highest production of basidiocarps was noted in SB + RH (1:1) and the production decreased from the first flush to the third or fourth flush in all treatments. Results on the number of basidiocarp produced during the first three flushes was much higher for the substrate combination of SG + RH (1:1). Heavier basidiocarps were produced by substrates without Sd and SB + RH (1:1) ranked the highest in basidiocarps production both in fresh and dry weight. On productivity period, substrates combination without Sd produced heavier and faster fruit bodies in a shorter period. Those substrates with Sd had a longer productivity period as a result of longer intervals between flushes. SB + RH has the shortest productivity. The same substrate combination scored the highest biological efficiency three times than the control (Sd). In mineral composition of the basidiocarp, laboratory analysis resulted in high composition of N, P, and Zn in Sd + SG (1:3) in the initial substrate before seeding. Ca was the least element in all the substrates. The percentage of N in the basidiocarp was higher than in the initial substrate as well as P and K.