Poplar Breeding for Superior Papermaking Fibers, 2005 Engineering, Pulping & Environmental Conference

The papermaking properties of twenty-two pure and hybrid poplars are being evaluated in an on-going investigation. Twenty of the poplars were harvested after 7.5 years from three different sites in the Midwestern and North Central US. The other 2 poplars survived at only two of three sites (64 total samples). Although additional results are presented, we focus on only two of the poplars from Year 1 of the study. The Crandon hybrid had the highest growth rate (tonnes ha-1y-1) and wood density (both averaged across the 3 sites). This poplar had a high cellulose content (compared to the average), a low lignin content and produced bleached kraft fibers at a high yield (wt. % on wood chips). Further, this poplar responded very well to kraft pulping and oxygen delignification and bleached to the highest final brightness ever observed in our laboratory (94.5% Elrepho). It also produced an 18 kappa number unbleached pulp with <0.5% rejects="" in="" only="" two-thirds="" the="" time="" required="" for="" sugar="" maple="" (acer="" saccharum).="" the="" second="" poplar="" is="" clone="" 220-5="" that="" had="" the="" highest="" area-weighted="" average="" microfibril="" angle="" (mfa)="" and="" excellent="" tensile="">