Studies On Properties Of Qinbaiyang Series Varieties Wood

This research refers to the physical and mechanical properties, fiber morphology of new clones of poplar named Qinbaiyang with the comparison group Populus Tomentosa clone 30 which were 10-year-old. It also analyzed the differences between the four varieties and compared to the respective performance advantages, provided scientific data and theoretical support to promote the cultivation and application of the varieties. The results show as follow:(1)The maximum average of air-dry density and wood basic density in Qinbaiyang varieties was Qinbaiyang 1, which was little lower than P. tomentosa clone 30. The minimum density of the two indexes was Qinbaiyang 2. The difference of density among trees was significant.(2) The maximum average of tangential, radial and volume shrinkage from green wood to oven-dry rate and to air-dry rate in Qinbaiyang varieties were Qinbaiyang 1,which were 2.93%,6.79%,9.42%and3.17%,7.06%,9.89%, little higher than P. tomentosa clone 30. The minimum ratio of tangential shrinkage to radial shrinkage at oven-dried condition and air-dried condition were Qinbaiyang 3, which were 2.07 and 2.36. The difference of density among trees was significant.(3)The maximum average of compression strength parallel to the grain of wood and compression strength perpendicular to grain in Qinbaiyang varieties were Qinbaiyang 1, which were 42.33 MPa and 5.33 MPa(radial direction), 4.02 MPa(tangential direction). The compressive strength parallel to grain and compression strength perpendicular to grain(tangential direction) had significant difference. The compression strength perpendicular to grain(radial direction) had significant difference at.(4) The maximum average of bending strength and MOE in Qinbaiyang varieties were Qinbaiyang 1,which was 72.45 MPa and 7344.51 MPa. The bending strength and the modulus of elasticity(MOE) had significant difference.(5) Qinbaiyang 1 and P. tomentosa clone 30 were medium comprehensive strength and high quality. Qinbaiyang 2 and Qinbaiyang 3 were low comprehensive strength and high quality.(6) The mean staple length of Qinbaiyang varieties was intermediate length. Early wood fiber length were less than the late wood. The maximum average of fiber length in Qinbaiyang varieties was Qinbaiyang 3,which was 1197.38μm. The minimum average of fiber width in Qinbaiyang varieties was Qinbaiyang 1, higher than P. tomentosa clone 30. The maximum average of fiber ratio of length to width in Qinbaiyang varieties was Qinbaiyang 1,which was 45.08. The fiber ratio of length to width of Qinbaiyang 3 was high than 43. Outward the pith, the fiber length and fiber ratio of length to width were gradually increasing along the growth of the wheel from the south to north direction, with a slight fluctuations in the overall upward trend.