The Influence of Green, Corn, and Rice Seed Media Composition on Mycelium Growth of F2 Main Seeds (Pleurotus ostreatus (Jacq. Ex Fr) Kummer)

White oyster mushroom (Pleurotus ostreatus) is a type of fungus wood that has a high nutritional content. White oyster mushroom cultivation begins with the provision of good quality seeds which include 4 stages, namely F1 seeds, F2, F3 and baglog. This study aims to influence the composition of the green bean, maize and rice grain media composition on the growth of mycelium F2 parent white oyster mushroom. This research was conducted at the Microbiology Laboratory, Department of Biology. The research design used a randomized block design (RBD), with the parameters of observing the propagation length, color and thickness of the mycelium. The results showed that the composition of different media had a significant effect on the propagation of mycelium in P2, P9, P10, P18, P19, P20 with the highest length of 14 cm, compact white color and evenly thick on combination media. Environmental conditions suitable for the growth of mycelium seeds F2 white oyster mushroom include temperature 27-28 ̊C, humidity 60-62%, and light intensity 24-54 Lux.