Microscopic Characterization of Nonmicrobial Gray Sapstain in Southern Hardwood Lumber

Authors

  • Paul G. Forsyth
  • Terry L. Amburgey

Keywords:

Hardwoods, sapstain, microscopy

Abstract

Southern red oak, ash, and hackberry sapwood containing nonmicrobial discolorations was examined by both light and scanning electron microscopy to determine the causes of these discolorations. Ray parenchyma cells in discolored sapwood of all three species contained globose to amorphous pigmented globules of starch. Ray parenchyma cells in nondiscolored sapwood occasionally contained a few globules. Results indicate that the formation of pigmented starch compounds occurs during normal air-drying operations and is intensified by slow-drying conditions. This results in the macroscopic sapwood discoloration commonly called gray stain.

References

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Published

2007-06-28

Issue

Number 3 / July 1991

Section

Research Contributions

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