Strips of cotton duck were treated with low concentrations of fourteen commercial and experimental fungicides and subjected to a soil burial test. Comparative effectiveness of the compounds was determined in terms of dosage required to yield 50per thousand loss in breaking strength (ED₅₀) at ten days burial. The effectiveness of the several compounds used ranged from 0. 01per thousand to 1.5per thousand based on concentration of the treating solution. The most commonly used compounds were all effective at 0.5per thousand or less. The effective soil burial life was found to be a function of the concentration within the limits of time and concentration studied. Several compounds were investigated in factorial combinations at concentrations known to result in partial effectiveness at ten days when used singly. No significant synergism was observed. The significance of minimal concentrations in relation to the breakdown process is discussed.