NOMENCLATURE       

Common name fosetyl-aluminium    

IUPAC name aluminium tris-O-ethylphosphonate    

Other names efosite-Al* (rejected common name proposal); 

CAS RN [39148–24–8] 

EC no 254–320–2     

PHYSICAL CHEMISTRY        

Mol. wt. 354.1 M.f. C₆H₁₈AlO₉P₃ Form Colourless powder. M.p. 215 °C Kow logP = –2.1 to –2.7 (23 °C) S.g./density 1.529 (99.1%), 1.54 (97.6%) (both 20 °C) Solubility In water 111.3 g/l (pH 6, 20 °C). In methanol 807, acetone 6, ethyl acetate <1 (all in mg/l, 20 °C). Stability Hydrolysis of fosetyl-aluminium occurs under extreme acid or alkaline conditions. DT₅₀ 5 d (pH 3), 13.4 d (pH 13). Decomposes above 276 °C. Photostability DT50 23 daylight hours. pKa 4.7 (20 °C)     

APPLICATIONS       

Biochemistry Possibly acts by inhibiting germination of spores or by blocking development of mycelium and sporulation. 

Mode of action Systemic fungicide, rapidly absorbed through the plant leaves or roots, with translocation both acropetally and basipetally.    

Uses Control of diseases caused by e.g. Phytophthora, Pythium, Plasmopara, Bremia spp., etc. on a variety of crops, including vines, fruit (citrus, pineapples, avocados, stone fruit and pome fruit), berries, vegetables, hops, ornamentals and turf. Also useful activity against several bacterial plant pathogens.    

Formulation types WG; WP. 

Compatibility Incompatible with foliar fertilisers.