03323naa a2200193 a 450000100080000000500110000800800410001910000250006024501050008526000090019052027940019965000120299365000160300565000100302165300090303170000200304070000190306077300500307912796412025-02-14       1968    bl uuuu     u00u1 u    #d1 aBUIJTENEN, J. P. van  aMicropulping loblolly pine grafts selected for extreme wood specific gravity.h[electronic resource]  c1968  aLoblolly pine possessing high wood specific (gravity is desirable as pulpwood because of its potentially high yiel¿l per volume, leading to a higher cellulose production per acre for the Same growth rate. It aliso results in a more efficient use of machinery in the pulp mills. Loblolly pine of low woold specific gravity is desirable for its more favorable pulp and papermaking properties. The relationship of wood specific gravity to pulp and papermaking properties is quite complex. Wood specific gravity is the average result of a great variety of properties such as specific gravity of the cell wall material, microporosity of the cell walls, proportions of springwood and summerwood, wall thickness and fi~ber dimensions within springwood and summerwood, and amount of extractives in the wood. To gain a complete undrrstanlding it is necessary to accumulate information on the relationship between each of these factors contrilbuting to wood specific gravity and the various pulp and papermaking properties. Considerable evidence has accumulated that wood specific gravity is strongly inherited. Et is, therefore, expected that the associated pulip and papermaking properties are also under strong genetic control. This needts to be verified experimentally. In addition, quantitative information about the relationshilps is needed. Thus the objectives of the study described in this paper are: 1. To compare the pulp and papermaking properties 01 several clones selected for high wood specific gravity with several clones selected for low wood specific gravity. I) J. P. VAN BUIJTENEN, Silviculturist I, Texas Forest Service, College Station, Texas, at present Research Geneticist, Northeastern Forest Experiment Station, +Durham, New Hampshir?. D. W. EINSPAHR, Chief, Genetics and Physiology Group, Biology Section, The Institute of Palper Chemistry. JOHN R. PECKHAM, PrOject Supervisor, The Institute of Paper Chemistry. 2. To determine the relative importance of the various anatomical faotors inifluencing wood specific gravity. 3. To ~determine the influence of these factors on pulp and papermaking properties. 4. To get sorne indication of the inheritance of these wood and pulp praperties. For a literature review of the variation and inheritance of wood properties, one is referrod to GOGGANS (1961). Excellent literature reviews on the influence of wood properties on pulp and papermaking properties were made by DADSWELL, et al. (1959), BESLEY (1959), and DINWOODIE (1965). In general, an increase in woad specific gravity has been associ~ated with a decrease in bursting strength and an increase in tear strength. More recently, studies by BAREFOOT (1966) and WANGAARD (1966) indicated strong influence of some of the fiber dimensions on pulp and papermaking properties.  aMadeira  aPinus Taeda  aPolpa  aPine1 aEINSPAHR, D. W.1 aPECKHAM, J. R.  tSilvae Geneticagv. 17, n. 1, p .15-19, 1968.