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Common NameFenamidone
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中文通用名咪唑菌酮
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IUPAC(S)-1-anilino-4-methyl-2-methylthio-4-phenylimidazolin-5-one
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CAS(5S)-3,5-dihydro-5-methyl-2-(methylthio)-5-phenyl-3-(phenylamino)-4H-imidazol-4-one
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CAS No.161326-34-7
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Molecular FormulaC17H17N3OS
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Molecular Structure
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Category
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ActivityFenamidone has protectant and curative activity against oomycete diseases, some Ascomycetes and Alternaria spp. It is systemic and can be applied to foliage, to the soil and as a seed treatment (particularly for the control of Pythium spp). The product acts at several different stages of the fungal life cycle to inhibit zoospore liberation and cyst and sporangial germination. Although it is not systemic, the translaminar effect enables fenamidone to migrate from the point of application to protect new growth. The exact mode of action has not yet been elucidated but it is known that fenamidone inhibits mitochondrial respiration at a single site - the cytochrome b site on Complex III.
The biochemical mode of action of fenamidone is similar to that of the strobilurins and famoxadone; all three families are classed ‘QoI-STAR’ by FRAC. Erysiphe graminis tritici and Sphaerotheca fuliginea have developed a resistance to this group due to a point mutation (G143A) in the cytochrome b gene, and are found to be as fit as sensitive wild-type under growth room environment conditions. However, resistant populations of Plasmopora viticola (carrying the G143A mutation) are found to be less fit than sensitive wild-type.
Fenamidone has activity against sensitive and resistant strains of Plasmopara viticola and Phytophthora infestans. Trials have shown no cross-resistance with phenylamide-resistant strains of P infestans. Use in combination products with systemic fungicides is recommended both to extend its use spectrum and to avoid/delay the onset of resistance.
In field trials, fenamidone gave similar levels of control to mancozeb but at a fraction of the application rate. Mixtures of fenamidone and mancozeb provided a high level of control of late blight on potato foliage and stems while the mixture gave superior control of tuber blight to mancozeb alone. In trials in Brazil, fenamidone provided control of potato early blight at the level of the references (mancozeb, chlorothalonil).
Field trials carried out in the US, Hungary, Argentina and Canada (see Tektran 2001) compared fenamidone with a number of other fungicides for the control of sunflower downy mildew (Plasmopara halstedii). No treatment provided 100% disease control but fenamidone was the most effective product; the 200 g ai / 100 kg treated seed rate resulted in 8% infection compared to 60% with seed treated with Apron-XL. A project is underway (October 2003 - March 2004) with the UK Horticultural Development Council to evaluate the potential for fenamidone and other products in the control of sudden oak death (Phytophthora ramorum) in nursery stock. -
CropUseCropUses:
aubergines, brassicas, citrus, cotton, cucurbits, fruiting vegetables, leafy vegetables, lettuces, onions, peppers, potatoes, rice, roses, sunflowers, tobacco, tomatoes, turf, vines, wheat
75-300g ai/ha
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PremixFenamidone+Mancozeb
Premix Parters:
carbendazim prochloraz;
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Physical PropertiesMolecular weight:311.4; Physical form:White woolly powder. Density:1.285; Melting point:137 °C; Vapour pressure:3.4 × 10-4 mPa (25 °C); Partition coefficient(n-octanol and water):logP = 2.8 (20 °C); Solubility:In water 7.8 mg/l (20 °C).;
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ToxicologyOral:Acute oral LD50 for female rats 2028, male rats >5000 mg/ kg. Percutaneous:Acute percutaneous LD50 for rats <2000 mg/kg. Non-irritating to skin and eyes (rabbits); not a skin sensitiser (guinea pigs).
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Environmental ProfileEcotoxicology:
Bobwhite quail LD50 >2,000 mg/kg；Earthworm LC50 = 25 mg/kg soil；Rainbow trout[96 hrs] LC50 =0.74 ppm ；Bee[96 hrs, contact] LD50 = 74.8 μg/bee；Daphnia magna[48hrs] LC50 =0.19 ppm；Mallard duck LC50 >5,200 ppm
Environmental fate:
Fate in :
Based on the PRZM / EXAM and SCI-GROW models, the Estimated Environmental Concentrations (EECs) for fenamidone and its metabolites of concern are 49.7 ppb for surface water and 45.4 ppb for groundwater for acute exposure. The EECs are 8.92 ppb for surface water and 45.4 ppb for ground water for chronic exposure. These values are less than the lowest drinking water level of concern (DWLOC) value of 14000 ppb for the acute scenario and 320 ppb for the chronic. Therefore it appears that exposure to fenamidone in drinking water should not pose a risk to human healthFate in aquatic systems:
Fenamidone is sensitive to hydrolysis under acidic and basic conditions, with half-lives of 42 and 28 days at pH 4 and 9 respectively, but it is stable at pH 5 to 7. Aqueous photolysis is likely to play a role in fenamidone's degradation, as the product degrades rapidly under aqueous photolytic conditions (DT50 < 30 hrs). In aquatic systems, fenamidone is rapidly removed from the water and partitioned to sediments, where fenamidone is observed to be persistent, especially under anaerobic conditionsFate in soil:
Fenamidone shows moderate to high mobility in the soil depending on environmental conditions but little potential to accumulate or move into ground water. Photolysis and hydrolysis on soil are not significant. Biotransformation of fenamidone is rapid in aerobic sandy loam (DT50 = 7 days) and loam soils (DT50 = 8 days). Fenamidone is classified as moderately mobile in soil and not persistent under field conditions. -
Transport InformationHazard Class:O (Obsolete as pesticide, not classified)
Porduct NewsMore
Gowan Company announces acquisition of fenamidone and pencycuron from Bayer
Fungicide fenamidone not renewed in EU