Fungitoxic properties of a N-3-pyridylimidodithiocarbonate derivative.

Abstract

Fungitoxic properties of a new compound, S-n-butyl S'-p-tert-butylbenzyl N-3-pyridylimidodithiocarbonate (S-1358), were examined. Some genera in Ascomycetes and Fungi Imperfecti were highly sensitive to S-1358 in vitro. Powdery mildews of cucumber and barley were controlled at extremely low concentrations of the fungicide, whether it was applied preventively or curatively. Microscopic observation showed that S-1358 did not inhibit conidial germination of Sphaerotheca fuliginea but suppressed further extension of germ tubes, causing swelling of their tips. Moreover, the same morphological effect was observed at any concentration ranging from 1ppm to 1000ppm. These facts suggest that S-1358 has influence on cell membrane or cell wall in fungi. Another important feature of S-1358 was that it prevented powdery mildew beyond the edge of fungicidal deposits on cucumber leaves, liberating fungitoxic vapor which may contribute to controlling diseases in field conditions.