Biodegradation and mildew resistance of naturally colored cottons

Naturally colored cottons contain significantly higher amounts of wax and have a different wax constitution and connectivity with cellulose than conventional cotton. Researchers have proposed that this wax content, together with the natural pigmentation, may serve as a defense against soil-borne pathogens. The purpose of this research is to study the biodegradation and mildew resistance characteristics of naturally colored cotton compared to conventional white and dyed cotton under field soil burial and laboratory mildew culture conditions. Laboratory culture results show that naturally brown and green colored cotton fabrics resist the growth of Aspergillius niger. However, after soil burial, both naturally brown and green cotton specimens showed severe degradation, manifested by significant loss of fabric strength as well as fiber structural damage. This suggests that naturally colored cottons are biodegradable. However, the rate of biodegradation of naturally colored cottons, especially green cotton, is much lower than that of white cotton or conventional dyed cotton.