Cultivation Trial of Pleurotus eous and Pleurotus ostreatus Mushrooms on Rice Straw (Oryza sativa L.) in Daloa, Côte d'Ivoire

In Côte d'Ivoire, rice growing plays an important nutritional and economic role. However, rice fields also produce huge quantities of waste (rice straw) which is often not used or used very little and in some cases burnt; yet the valorization of this agricultural waste can increase profitability. It is in this context that this study used P. eous and P. ostreatus, two edible mushroom, to bio-delignify rice straw and produce edible carpophores. To this end, the stems and leaves of oryza sp were sun-dried for a fortnight and cut into pieces (2-3cm). Agricultural lime and rice bran were added in varying proportions (1% = agricultural lime; 0-15 % = rice bran) to obtain several formulations. The substrates were moistened and packaged in heat-resistant bags. The various substrates were then sterilized and inoculated with spawn from P. eous and P. ostreatus. The results showed that the mycelial filament of P. eous was observed three (3) days after inoculation. On the other hand, there were three dates (3rd, 9th and 21st day) of appearance of the mycelial front in P. ostreatus. The incubation period for P. ostreatus ranged from 51 to 57 days, while that for P. eous was 52 days. The addition of rice bran in increasing doses reduced the colonization rate of both species of fungus. The lowest values of biological efficiency were obtained by growing P. eous. They ranged from 0 % (F4) to 6 % (F3). In the case of P. eous, the addition of rice bran in increasing doses increased the carpophore yield. But beyond 10 %, the yield became zero. In the case of P. ostreatus, the yield became low when rice bran was added in increasing doses. This study confirms that rice field waste (rice straw) can be a raw material for the production of edible mushrooms. These results should be disseminated to the general public in order to increase the profitability of rice growers.