On the mode of action of triadimefon

Abstract

Besides its known systemic activity, triadimefon acts in the vapour phase.This vapour phase activity of triadimefon was shown for powdery mildew on cucumbers and barley in greenhouse experiments at concentrations recommended for use in the field (I00 and 250 pg/ml) and also at substantially lower concentrations.The degree of vapour phase activity is dependent on the distance from the spray deposit.In experiments with radiolabelled triadimefon, it was observed that gaseous material was deposited on untreated barley plants, thus either keeping them free from attack or reducing infection.

Vapour Phase Activity of Imazalil

“…In plant disease control, a few com pounds have been reported to show fungici dal activity after redistribution in the va pour phase [1,3,4,6,7,[12][13][14]17]. In most cases the test organisms were different species of powdery mildew.…”

Residual effects of triadimefon in soil on powdery mildew and yield of spring barley

“…Significant or complete control of mildew on seedling barley has been obtained for 10 days by spraying leaves or feeding roots with 1-5 ppm triadimefon 1 or 2 days before inoculation (Buchenauer, 1976). Scheinpflug & Paul (1977) reported that triadimefon also has unusually powerful activity in the vapour phase at concentrations above 10 /ig/ml; plants distant from those sprayed with 277 /ig received 0-1 jug/g fresh weight of plant by contact with the vapour and were protected from mildew. This high vapour activity of triadimefon seems anomalous in view of its low vapour pressure (1 X 10~* mbar at 20°C).…”

Photodegradation of Azole Fungicide Triadimefon

“…It has been claimed to move systematically after application to roots or leaves of cereals (Kasper et al, 1975) and basipetally in cucumber and barley (Scheinpflug and Paul, 1977). Its activity is probably enhanced as a result of considerable redistribution in the vapor phase.…”