Determination of fungicide residues in field-grown strawberries following different fungicide strategies against gray mold (Botrytis cinerea).
In a 2 year experiment, residues in field-grown strawberries were investigated from the fungicides fenhexamid, pyrimethanil, tolylfluanid, and kresoxim-methyl resulting from different strategies, as regards the dose, number, and time of fungicide applications. Kresoxim-methyl was only used the first year and in full or no dose to control powdery mildew. In the first year, the highest concentrations analyzed were 0.66 mg kg(-1) for pyrimethanil and 0.63 mg kg(-1) for fenhexamid resulting from the use of recommended dose rates and a preharvest interval (PHI) of 10 days, thus not exceeding the Danish maximum residue limit (MRL) of 1 mg kg(-1). Tolylfluanid was used no later than 21 days before harvest, which left residue contents in the berries of 0.48 mg kg(-1), a value well below the MRL of 5 mg kg(-1). In the second year, fungicide residues found in the samples were generally lower, 0.39 and 0.03 mg kg(-1) for pyrimethanil and fenhexamid, respectively. No residues of kresoxim-methyl were found in any of the samples from the field trials, indicating that kresoxim-methyl residues had declined to a level well below the detection limit within the 28 day period between the last application and the harvest.
Rabølle
Mette
M
Department of Integrated Pest Management, Danish Institute of Agricultural Sciences, Research Centre Flakkebjerg, DK-4200 Slagelse, Denmark.
Spliid
Niels H
NH
Kristensen
Kristian
K
Kudsk
Per
P
D020171:Botrytis / Q000187:drug effects*; D002853:Chromatography, Liquid; D031985:Fragaria / Q000737:chemistry* / Q000382:microbiology*; D005638:Fruit / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000032:analysis*; D013058:Mass Spectrometry; D008689:Methacrylates / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D010648:Phenylacetates / Q000032:analysis; D011743:Pyrimidines / Q000032:analysis*; D000073739:Strobilurins
D005659:Fungicides, Industrial; D008689:Methacrylates; D010573:Pesticide Residues; D010648:Phenylacetates; D011743:Pyrimidines; D000073739:Strobilurins; C469328:kresoxim-methyl; C108337:pyrimethanil