Sticker stain is a material defect that results from moisture migration during wood drying, often spoiling the appearance of the surface of wood products. The effect of drying temperatures on the occurrence of surface sticker stain was investigated using Japanese cedar (Cryptomeria japonica D. Don) and three types of stickers (air-dried Japanese cedar, aluminum, and stainless steel) under four drying temperatures (20°C, 50°C, 75°C, and 100°C). At lower drying temperatures, the air-dried wood sticker tended to suppress the occurrence of surface sticker stains, whereas higher temperature or metal stickers produced sticker stains with deep color. However, no definitive relation was shown between the initial moisture content and the extent of sticker stain with deep color regardless of drying temperatures. It was considered that the partial delay of drying happened around the contact area with stickers, especially in cases of metal stickers. It was also found that the use of metal stickers at higher drying temperatures induced depressions in Fourier transform infrared spectra related to the occurrence of hygrothermal conditions.

No abstract

No abstract

Abscission layer formation and development and abscission process of cut lily perianth were investigated anatomically and histochemically by applications of ethephon. At three days after application with ethephon, cell walls of the juncture tissue between the perianth and receptacle were disintegrated. Histochemical study showed that the pectic materials were dissoluted from the middle-lamella of the abscission region. The results indicate that the cell degrading enzymes such as pectinase may play a role in perianth abscission.