LAUSR

ABSTRACT This study is to find out an appropriate log cutting period for saprotropic Lentinula edodes log cultivation. Seasonal changes in nutrients in sapwood and cell activities in the inner bark from logs of Quercus acutissima cut during September to February were analyzed. Total carbon content in the sapwood was higher in September (76.5%) than in other months (67.8–69.2%). Total nitrogen content was higher in November and December (0.21–0.22%) than in other months (0.14–0.15%). Inorganic nutrients such as phosphate, potassium and magnesium, and heavy metals like cadmium were higher in November and December than in other months. Over 90% of axially vertical and radial parenchymatous cells contained starch granules in November and December while only 20–30% of these cells did in February. The cell activities in the inner bark of logs cut in October to November, measured with formazan absorbance values during mid March, were 0.013–0.018, which were lower than those cut in December (0.027–0.045). Therefore, our results support that it is better to cut logs for L. edodes cultivation in November when nutrients accumulate in the wood but wood cells are less active.