Fate of the dicarboximide fungicide procymidone in alkaline greenhouse soils from Almeria (Spain) and Albenga (Italy)

The fungicide procymidone is currently used in greenhouses and open fields in Southern Europe for the control of plant diseases in vegetables, ornamental crops and grapevine. Procymidone has been reported to be persistent in soil and resistant to microbial degradation after repeated application. However, little is known about its fate in alkaline south European soils where it is extensively used and where it may potentially leach and contaminate the highly used ground water system. The typical soils chosen from a greenhouse in Almeria (Southern Spain) and a greenhouse in Albenga (Italy) are very alkaline and of low organic carbon content. Procymidone is unstable under alkaline aqueous conditions, and hydrolyses at high pHs. The fate of procymidone in soils from the greenhouse in Almeria was studied at various temperatures, under sterilized and non-sterilized conditions and compared to its dissipation in soils from a greenhouse in Albenga. The dissipation of procymidone was also determined at several pHs under aqueous conditions. Procymidone was not persistent in Almeria and Albenga soils, with estimated half-lives of 6 and 5 days, respectively. Due to its high reported sorption and short half-life, procymidone is not expected to leach and contaminate groundwater.