SELECTION METNODS AND CRITERIA FORPLUS TREES 0F EUCOMMIALI
HUOGENG,WANG ZHANG RONG,and SHEN XIUWENNanjing Forestry University, Nanjing, Jiangsu 210037
Based on their investigation in four 35-year-old eucommiastands, the authors argue that the five check tree system is applicableto the selection of plus trees of that plant. They have also formed thecriteria for plus tree selection, According to them, the criteria ofabsolute growth is 0.6 0.8 cm/yr for d.b.h.and 0.3 0.4m/yr for heightrespectively; the criteria of relative growth is no less than the meanincrement of dominant trees for height and more than 15 percent of domin-ance ford.b.h. respectively.