SURFACTANTS AS FUNGICIDES

Abstract

The cationic (Hyamine 3500, Cyprex, or dodine, and Triton X-400), anionic (Atlox G-3300 and Santomerse), and non-ionic (Tritons X-100, X-114, and B-1956 as well as Tween 81) surfactants were compared as inhibitors of respiration, as agents promoting the passage of amino acids out of spores into the surrounding medium, and as inhibitors of germination of the spores of one or more of the test organisms Monilinia fructicola, Alternaria solani, Puccinia recondita, and Puccinia coronata. The loss of cell constituents by leakage caused by the various surfactants paralleled their efficacy as fungicides against A. solani. Although the surfactants do cause reduction in respiration rates paralleling their fungicidal activity, the effect of the compounds on respiratory or other enzyme systems is considered to be secondary to the irreparable damage caused to the semipermeable outer membrane of the cytoplasm. The cations Ni++ and Cu++ were compared with the surfactants as inhibitors of respiration and as stimulators of cell leakage.