Preparation of high quality oyster mushroom seed (Pleurotus ostreatus.L) from locally sourced mushrooms

Abstract

Mushroom cultivation has gained increased attention especially in the recent 10 years (Mayanja, 2018). In Uganda, poor spawn quality and availability has led to difficulty in selecting suitable inoculum for any level of production of oyster mushrooms. Spawn production is an agronomic process which consists of tissue culturing fresh mushrooms and inoculating prepared grains to obtain the spawn. In this study, three sources of mushroom seed were used with a substantial impact on mushroom yield and quality. Fresh mushrooms from the first three flushes (harvests; sample A, B, and C respectively) were used to prepare spawn. Cultivation trials on cotton husks supplemented with maize bran and lime were used to evaluate its quality, yield and biological efficiency. Results from Analysis of variance of data from cultures of A, B and C showed that the mycelial extension rates were not significantly different (P= 0.076) among the samples. Prepared pure cultures from Sample C were least contaminated, and samples A and B had greater contamination during the two weeks period of incubation. During spawn run, inoculated gardens with Sample B spawn exhibited a greater percentage contamination, followed by the control, C and finally A with the least percentage contamination. Mean weight of the best mushroom from each garden per sample was not significantly different (P= 0.581, P= 0.088, P= 0.227 for May, June and July respectively). Total yield from the samples was not significantly different in May and June (P= 0.474 and P= 0.301), but a significant difference was observed in July (P= 0.0376). No significant difference in biological efficiency was observed among the samples (P= 0.474). Sample A maintained its fruiting potential during an examined period of 3-months. The study has shown the possibility to use locally sourced mushrooms to produce high quality spawn that is of low cost compared to the imported cultures. The conclusion is that spawn developed from Flush A has the potential to give better yields and therefore an excellent inoculum for mushroom cultivation.