Environmental-benign methods for the color protection of stripe long-shoot bamboo (Bambusa dolichoclada) culms

Fresh stripe long-shoot bamboo (Bambusa dolichoclada   Hayata) culm is attractive for its yellow and green stripes. The stripes, however, discolor quickly after harvest, and currently there is no method to preserve the colors. The objective of this study was to find methods to preserve the colorful yellow–green stripes. Results indicated that excellent color preservation was achieved by treating the bamboo culms with 1% copper nitrate in alcohol at 60∘C for 2 h. Such treatment could be shortened to 30 min by the aid of ultrasonic vibration during the treatment. Immersing bamboo culms in 1% copper nitrate alcohol solution at the ambient temperature for 4 h also achieved the same result. Treated specimens exhibited outstanding colorfastness and mildew resistance after 18 months of indoor exposure.