Effect of substrates on the yield, yield attribute and dietary values of oyster mushroom (<i>pleurotus ostreatus</i>) in the pastoral regions of Northern Ethiopia

Abstract

Dry areas are vulnerable to climate change and are commonly hit by drought, which makes the inhabitants to rely on food aid. Mushroom cultivation is a profitable agribusiness that can improve the economic and food status of farmers in dry areas as an alternative technology. Research on the effect of substrates on the yield, yield attributes and dietary values of oyster mushroom (Pleurotus ostreatus) was conducted to identify the best substrates. The experiment included 23 treatments with three replications. The substrates were sawdust, rice straw, cottonseed hull & maize cob with 100%, 75%, 50% and 25% combination ratios. The substrates were chopped, moisturized and filled into 40 cm X 60 cm polyethylene bags and sterilized for one hour at 100 oC. The substrates were cooled and inoculated with 75g mushroom spawn, and were kept in a dark place to enhance mycelium growth. The substrates were transferred to a growing room, with full light, lower temperature and higher relative humidity for fructification after mycelium growth was completed. Data on yield attributes, fresh yield and dietary values were collected and analyzed. The fruiting bodies were picked after 22 - 35 days of inoculation. The treatments had significant effect on the number of days for mushroom growth, stalk length, pileus diameter and number of fruiting body, fresh yield, biological efficiency and dietary values (P < 0.05). All consumers significantly preferred mushroom grown on 100% maize cob substrate. The 100% cottonseed hull substrate gave the highest profit (133.25US$ 100kg^-1 substrate). The study concluded that 100% cottonseed hull substrate was the best substrate for oyster mushroom production at small-scale level. It was also the best nutritive source of substrate for oyster mushroom growth. Mushroom grown on a 100% maize cob substrate was a tasty and protein rich mushroom. Therefore, producers should be encouraged to use this substrate for maximizing the yield, for changing the agricultural wastes into food in the form of mushroom and for improving their livelihood. Oyster mushroom could play a pivotal role in supporting the food self-sufficiency, hence it should be included as a component of food security assurance strategy for the country.

Key words: mushroom, substrates, yield, pastoral, dietary value, agricultural waste, livelihood