Growth Influence of Some Additives on the Mycelial Growth and Fruit Body Development of Pleurotus Ostreatus (Jacq. Et. Fr.) Kummer

Studies were conducted to establish the response of a wood – rotting fungus, Pleurotus ostreatus to different growth substrates (sawdust (SD), dry banana leaves (BL) and a combination of both) and additives [groundnut cake (GC) and palm kernel cake (PKC)]. Spawning (Mycelia running rate) and fruit body development (area of pileus, length of stipe and fresh weight) were assessed. Initiation of mycelial growth took place in both treated and untreated substrate samples within 7 days post inoculation (dpi). Spawn run was delayed in SD substrates treated to PKC beyond 2% and in BL substrates treated with 4% PKC and above. In BL+SD, spawn run was delayed at all levels of PKC treatments. Spawn run in the BL, BL+SD and SD controls were completed in 21, 28 and 35 days respectively, following inoculation. Primordia production occurred in all the samples within 7 days of transfer of bags to the cropping room. Treatment of substrates with additives (GC and PKC) negatively affected the performance of the substrates. Addition of 4% of the additives on BL and BL+SD substrates produced mushrooms with smaller pileus size with the smallest (13.08cm2) observed on 4% PKC-treated BL substrates. Similar trends were observed in length of stipe, fresh weight and biological efficiency of the mushroom. All substrates evaluated supported production of fruit bodies for 70 days making a total of 14 flushes from the inception of cropping. Key words: Additives, Mycelial growth, fruit body production, Pleurotus ostreatus