Fungicide

FRAC  3; DMI: triazole

NOMENCLATURE

Common name triadimenol (BSI, E-ISO, (m) F-ISO)

IUPAC name (1RS,2RS;1RS,2SR)-1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol 

Chemical Abstracts name b-(4-chlorophenoxy)-a-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol 

CAS RN [55219-65-3] unstated stereochemistry; [89482-17-7] diastereoisomer A; [82200-72-4] diastereoisomer B  EEC no. 259-537-6  Development codes BAY KWG 0519 (Bayer) 

PHYSICAL CHEMISTRY

Composition (1RS,2SR) is referred to here as diastereoisomer A; (1RS,2RS) is referred to here as diastereoisomer B. The ratio of A:B is c. 7:3.  Mol. wt. 295.8  M.f. C14H18ClN3O2  Form Colourless crystals, with a weak characteristic odour.  M.p. A: 138.2 ºC; B: 133.5 ºC; eutectic A+B: 110 ºC; (tech., 103-120 ºC)  V.p. A: 6 ´ 10-4 mPa; B: 4 ´ 10-4 mPa (20 °C)  KOW A: logP = 3.08; B: logP = 3.28 (25 °C)  Henry A: 3 ´ 10-6; B: 4 ´ 10-6 (Pa m3 mol-1, 20 °C)  S.g./density A: 1.237; B: 1.299 (22 °C)  Solubility In water A: 62; B: 33 mg/l (20 ºC). In dichloromethane 200-500, isopropanol 50-100, hexane 0.1-1.0, toluene 20-50 (all in g/l, 20 °C).  Stability Both diastereoisomers are stable to hydrolysis; DT50 (20 ºC) >1 y (pH 4, 7 or 9). 

COMMERCIALISATION

History Fungicide reported by P. E. Frohberger (Pflanzenschutz-Nachr. (Engl. Ed.), 1978, 31, 11). Introduced by Bayer AG and first marketed in 1978.  Patents DE 2324010  Manufacturers Bayer; Makhteshim-Agan

APPLICATIONS

Biochemistry Inhibits gibberellin and ergosterol biosynthesis and hence the rate of cell division.  Mode of action Systemic fungicide with protective, curative and eradicant action. Absorbed by the roots and leaves, with ready translocation in young growing tissues, but less ready translocation in older, woody tissues.  Uses Control of powdery mildews, rusts and Rhynchosporium in cereals, and, when applied as a seed treatment, control of bunt, smuts, Typhula spp., seedling blight, leaf stripe, net blotch and other cereal diseases. Also used on vegetables, ornamentals, coffee, hops, vines, fruit, tobacco, sugar cane, bananas and other crops, mainly against powdery mildews, rusts and various leaf spot diseases. Application rates as a spray are in the range 100-250 g/ha for bananas and cereals, 125-250 g/ha protective and 250-500 g/ha eradicative for coffee, 0.0025-0.0125% for grapes, pome and stone fruit and vegetables; application rates as a seed treatment are in the range 20-60 g/100 kg seed for cereals, 30-60 g/100 kg seed for cotton.  Formulation types DP; DS; EC; EW; FS; GR; SC; WG; WP; WS.  Selected tradenames: 'Bayfidan' (spray application) (Bayer); 'Noidio' (Agrimix); mixtures: 'Baytan Secur' (+ fuberidazole+ imidacloprid) (seed treatment) (Bayer); 'Baytan Spezial' (+ fuberidazole) (seed treatment) (Bayer); 'Baytan Universal' (+ fuberidazole+ imazalil) (seed treatment) (Bayer); 'Cereline Secur' (+ bitertanol+ fuberidazole+ imidacloprid) (UK) (Bayer); 'Cereline Secur' (+ fuberidazole+ imidacloprid) (seed treatment) (Bayer); 'Matador' (+ tebuconazole) (spray) (Bayer)

OTHER TRADENAMES

'Repulse' (Bayer); 'Summit' (Bayer); 'Euro' (Rocca); 'Prodimenol' (Probelte); 'Shavit' (Makhteshim-Agan); 'Vydan' (Vapco) mixtures: 'Abilis' (+ tebuconazole) (spray, France) (Bayer); 'Baysiston' (+ disulfoton) (Bayer); 'Baytan  flowable' (+ fuberidazole) (Bayer); 'Cereline' (+ bitertanol+ fuberidazole) (Bayer); 'Coloso' (+ tebuconazole) (spray, Argentina) (Bayer); 'Domestin' (+ bitertanol+ fuberidazole) (Bayer); 'Falcon' (+ spiroxamine+ tebuconazole) (spray) (Bayer); 'Folicur Plus' (+ tebuconazole) (spray, E. Europe) (Bayer); 'Garnet' (+ tebuconazole) (spray, UK) (Bayer); 'Manta Plus' (+ fuberidazole+ imazalil+ imidacloprid) (Germany) (Bayer); 'Ruby' (+ tebuconazole) (spray, UK) (Bayer); 'Silvacur Combi' (+ tebuconazole) (spray, Central America) (Bayer); 'Silvacur' (+ tebuconazole) (spray, UK) (Bayer); 'Veto F' (+ tebuconazole) (spray, UK) (Bayer); 'Shavit F' (+ folpet) (Makhteshim-Agan) Discontinued names: 'Spinnaker' * (Cyanamid) mixtures: 'Baytan TA' * (+ anthraquinone+ triazoxide) (France) (Bayer); 'Brio Flo' * (+ anthraquinone+ triazoxide) (France) (Bayer); 'Brio' * (+ anthraquinone+ triazoxide) (France) (Bayer); 'Colt' * (+ tridemorph) (Bayer); 'Dorin' * (+ tridemorph) (Bayer); 'Folicur Bayfidan' * (+ tebuconazole) (spray, Switzerland) (Bayer)

ANALYSIS

Product analysis by gc with FID (CIPAC Handbook, 1992, E, 224-229). Residues determined by glc (W. Specht & M. Tillkes, Pflanzenschutz-Nachr. (Engl. Ed.), 1980, 33, 61; R. Brennecke, ibid., 1984, 37, 68; A. Allmendinger, ibid., 1991, 44, 5). Methods for the determination of residues are available from Bayer. 

MAMMALIAN TOXICOLOGY

Reviews FAO/WHO 56, 58 (see part 2 of the Bibliography).  Oral Acute oral LD50 for rats c. 700, mice c. 1300 mg/kg.  Skin and eye Acute percutaneous LD50 for rats >5000 mg/kg. Non-irritating to eyes and skin (rabbits).  Inhalation LC50 (4 h) for rats >0.9 mg/l air (aerosol).  NOEL (2 y) for rats and mice 125, for dogs 600 mg/kg diet.  ADI (JMPR) 0.05 mg/kg b.w. [1989].  Toxicity class WHO (a.i.) III; EPA (formulation) III  EC hazard (Xn; R22) 

ECOTOXICOLOGY

Birds Acute oral LD50 for bobwhite quail >2000 mg/kg.  Fish LC50 (96 h) for golden orfe 17.4-27.3, rainbow trout 14-23.5, bluegill sunfish 15 mg/l.  Daphnia LC50 (48 h) 51 mg/l.  Algae ErC50 for Scenedesmus subspicatus 3.7 mg/l.  Bees Non-toxic to honeybees.  Worms LC50 for Eisenia foetida 772 mg/kg dry soil. 

ENVIRONMENTAL FATE