after inoculation in the control and in samples grown in low concentrations of Se. Higher levels of Se prolonged this incubation time ( Table 1), as harvesting was initiated after 36 days when grown in the substrates with 25.4, 51, 76.4 or 102 mg kg1 of Se. At this time, the second flush was beginning in the control, the substrate without Se addition ( Table 1). Prolonged times for mushroom formation were also observed in L. edodes enriched with sodium selenite in cold water at concentrations of 0.32 and 0.64 mM, while concentrations above 0.96 mM completely inhibited mushroom formation ( Nunes, 2005).