|Chemical Abstract Number (CAS #)||
||EPA Method 633|
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| Active against mildews and rusts of grains, fruits, vegetables and ornamentals.
Experimental systemic fungicide used for control of wheat leaf rust.
Control of powdery mildews in cereals, pome fruit, stone fruit, berry fruit, vines, hops, cucurbits,
tomatoes, vegetables, sugar beet, mangoes, ornamentals, turf, flowers, shrubs, and trees; rusts in
cereals, pines, coffee, seed grasses, turf, flowers, shrubs, and trees; Monilinia species in stone
fruit; black rot of grapes; leaf blotch, leaf spot, and snow mould in cereals; pineapple disease butt
rot in pineapples and sugar cane; leaf spots and flower blights in flowers, shrubs, and trees; and
many diseases of turf.
Triadimefon with carbendazim and sodium alginate is used to protect pruning wounds on apple
and pear trees.
|Apparent Color|| Colorless crystals; Colorless solid; White to tan crystals
|Melting Point|| 82 deg C
|Molecular Weight|| 293.75
|Density|| 1.22 at 20 deg C
|Environmental Impact|| Triadimefon's use as a systemic fungicide releases the compound directly to the
environment through applications in dusts, emulsifiable concentrates, sprays and other routes of
application. If released to the atmosphere, triadimefon will degrade rapidly in the vapor-phase by
reaction with photochemically produced hydroxyl radicals (estimated half-life of about 14 hr).
Particulate phase triadimefon and aerosols released to air during applications of triadimefon
fungicides will be removed from air physically by dry and wet deposition. If released to soil or
water, triadimefon may undergo biodegradation. Soil fungi have been shown to metabolize
triadimefon to triadimenol; however, the relative importance of biodegradation as a fate process in
the environment is uncertain. Field and soil-water partitioning studies indicate that triadimefon has
low mobility in soil. The US Dept of Agric's Pesticide Properties Database lists a soil half-life of
26 days. Field studies have found soil half-lives ranging from 10 days to 7 months. In water, some
hydrolysis may occur through a catalytic action involving divalent cations. Occupational exposure
occurs through dermal contact, especially to workers using the compound as a fungicide. Since
triadimefon has been detected in U.S. foods, exposure to the general population may occur
through consumption of foods containing triadimefon residues.
|Environmental Fate|| TERRESTRIAL FATE: In soil, the carbonyl group is reduced to a hydroxyl group, with
the formation of triadimenol.
TERRESTRIAL FATE: Although soil fungi have been shown to metabolize triadimefon to
triadimenol(1-2), the relative importance of biodegradation as a fate process in soil is
uncertain. An experimentally determined Koc value of 520 and field studies indicate that
triadimefon has low mobility in soil . The US Dept of Agric's Pesticide Properties Database lists
a soil half-life of 26 days for triadimefon . Laboratory persistence studies using a silty clay loam
soil with no prior exposure to triadimefon found a soil half-life of 15 days . West German field
tests in various soils and conditions found half-lives ranging from 10 days to 7 months .
AQUATIC FATE: The exact fate of triadimefon in the aquatic environment is not clear.
Although fungi have been shown to metabolize triadimefon to triadimenol(1-2), the relative
importance of biodegradation as a fate process in water is uncertain. In the absence of
catalytic action, hydrolysis is not important ; hydrolysis can occur via a catalytic action by water
salts, mainly divalent cations ; degradation in tap water at 70 deg C has been reported to reach
90% in 8 weeks . Based upon an experimentally determined Koc value of 520(4,SRC), some
partitioning from the water column to sediment and suspended material may occur. Aquatic
volatilization and bioconcentration are not expected to be important fate processes.
ATMOSPHERIC FATE: Based upon a reported vapor pressure of 1.5X10-8 mm Hg at 25 deg
C , triadimefon can exist in both the vapor and particulate phases in the ambient
atmosphere(2,SRC). It will degrade rapidly in the vapor phase by reaction with photochemically
produced hydroxyl radicals with an estimated half-life of about 14 hr(3,SRC). Particulate phase
triadimefon released to air during applications of triadimefon fungicides will be removed from air
physically by dry and wet deposition.
|Drinking Water Impact|| GROUNDWATER: During various sampling periods in 1984, water samples were
collected from 206 waterworks wells in German and analyzed from 35 different pesticides ;
triadimefon was not detected above a detection limit of 0.05 ug/l .