Production of indigenous mushrooms spawn using crop residues as substrates

Indigenous oyster mushrooms occur naturally when conditions are favourable. Achieving good quality spawn is a major challenge to small-scale farmers in Kenya, who strive to domesticate indigenous mushrooms. The use of wheat grain in mushroom growing industries for spawn production poses a threat to food security. The objective of this study was to evaluate crop residues as alternative substrates for indigenous mushrooms spawn production in Kenya. Different crop residues, including straws of wheat, barley and beans, maize cobs and sawdust were sterilised and tested for spawn production. Colonisation, pinning and mushroom yields were evaluated on bean and wheat straw substrates. There was a significant difference (P<0.05) in mycelia colonisation period when different spawn types were inoculated on bean and wheat straw substrates. Bean straw spawn had the shortest colonisation period (23 days) and was the best agricultural waste spawn. There was no significant difference (P<0.05) on pinning days and 2nd flush yields for the different types of spawn. There was a significant difference (P<0.05) between maize cob and wheat grain spawn in 1st flush yields. Bean straw spawn had a flush 1 yield of 125.2 g which, was not significant (P>0.05) compared to the wheat grain spawn (control) that gave a yield of 126.1 g. Results of this study indicate the suitability of various agricultural crop residues as alternative substrates for indigenous spawn production.