Investigations on fungicides: The systemic fungicidal activity of certain N‐carboxymethyl dithiocarbamic acid derivatives

SUMMARY The systemic activity of thirty‐three N‐substituted S‐esters derived from dithiocarbamic acid was investigated by assessing their ability to reduce the infection of broad‐bean seedlings by Botrytis fabae and of wheat seedlings by Erysiphe graminis, following application to the roots or cut shoots of the host. Marked systemic activity against mildews was shown by the N‐carboxymethyl dithiocarbamates, by S‐carboxymethyl‐N, N‐dimethyl‐dithiocarbamate (G33) and by procaine and 6‐azauracil. The effect was not very host‐specific since most compounds showing high activity in wheat also showed activity in pea, cucumber and, to a smaller extent, apple. All the materials tested showed a much lower level of systemic activity in broad‐bean seedlings against B. fabae. Measurements were also made of the uptake, translocation, phytotoxicity and the stability within plant tissues of some of these compounds. The degree of systemic activity which they show is discussed in relation to these and other properties of the compounds.