CHEMICALLY PROTECTING CELLULOSIC STRING FROM MICROBIAL ATTACK

The ability of various biocides to protect cellulosic string from deca y was investigated by measuring tensile strength after various periods of soil burial. Copper naphthenate, the biocide currently used for th is purpose, provided little protection. The nature of this failure at high levels of treatment was studied to determine the effect of copper tolerance developed through prior soil treatments. Several other chem icals, including oxine copper, didecyldimethylammonium chloride (Barda c(R)), one formulation of 3-iodo-2-propynylbutylcarbamate (IPBC) or P- 20-T, Isothiazolone(R), and chlorothalonil, provided good protection o ver a 10- to 19-week test period and appear to be useful replacements for copper naphthalenate. Others, including zinc naphthenate, two othe r IPBC formulations, and Propiconazole(R), provide little or no protec tion under the conditions employed.