and pectins (Micheli, 2001 and Wang et al., 2010) which may be important in determining fibre strength by joining cellulose fibrils.
Although these polysaccharides have a higher metabolic cost (Amthor, 2010),
it seems unlikely that a higher metabolic cost for such small fractions of the fibre would be a yield drain unless transport of complex polysaccharides was an issue.
More research should be done on these fundamental reasons for negative association between yield and fibre strength.