Persistence of Diflubenzuron on Conifer Forest Foliage in a Mediterranean-Climate Ecosystem Following Aerial Application

Variability of Pesticide Dissipation Half-Lives in Plants

“…Increasing temperature is known to accelerate numerous processes involved in pesticide dissipation 10,27,159 by, for example, increasing a substance's solubility. 10 Effects of temperature on the dissipation of pesticides in plants have been assessed by four studies qualitatively (mainly discussing seasonal aspects with respect to growing seasons) 134,163,175,176 and by 18 studies quantitatively, 69−71,73,74,119,137,157,174,177−185 of which 14 studies explicitly investigated the influence of cold storage conditions. 70,71,73,74,119,137,157,177−183 The effect of reduced temperatures in cold storage rooms varies significantly ranging from reduced dissipation of carbendazim in mango fruits by a factor 2 during storage at 15 °C (the corresponding average temperature in the field study was 25 °C) 179 to reduced dissipation of pyriproxyfen in bell pepper fruits by a factor 24 during storage at 4 °C (the corresponding average temperature in the field study was 24 °C).…”

“…Photodecomposition comprises processes where molecular excitation by absorption of sunlight energy results in organic reactions like hydroxylation or decarboxylation (direct photolysis) and where reactive oxygen species oxidize a pesticide’s functional groups (indirect photolysis or photosensitization). , Photodecomposition mainly depends on meteorological conditions (irradiation intensity, shading effects), on plant surface affinity to the pesticide formulation, but also on surface wax composition, ,− since pesticides applied via oil-based spray droplets dissolve in the epicuticular waxes and are thus protected from photodecomposition . Hence, the large lipid-covered plant surface forms an ideal sink for accumulating hydrophobic pesticides .…”

“…Hence, the large lipid-covered plant surface forms an ideal sink for accumulating hydrophobic pesticides . Despite the importance of photodecomposition as a dissipation pathway, effects have been explicitly reported as influencing pesticide dissipation in plants by 1 study qualitatively and by 17 studies quantitatively, ,,,,,− together summing up to only 2.2% of all considered studies. Reported contributions of photodecomposition to pesticide dissipation range from less than 6% for pendimethalin in turf foliage to 99% for rotenone in olive fruits. , The influence of pesticide formulation type and epiculticular waxes has been addressed in 3 and 8 studies, respectively.…”

Efficient use of Dimilin insecticide in forestry of the region

“…Described characteristics of the product, as well as its high resistance to sunlight and temperature, predetermine the length of the protection period of the insecticide, which is at least 3-4 weeks. In soil, the half-life of Dimilin is ranging from 2 to7 days, in water, its half-life is about 24 hours, unlike most organophosphorus pesticides (about a month) and pyrethroids (from 17-29 days to 13 weeks) [22,23].…”

Combination of photoinduced fluorescence and GC–MS for elucidating the photodegradation mechanisms of diflubenzuron and fenuron pesticides

“…Literature results showed that some of these DFB photoproducts were metabolites, and were found in plants, animals, especially fish, and in the marine environment . For example, 4‐chloroaniline‐2‐sulfate and N ‐(4‐chlorophenyl)oxamic acid were detected in rat urine, whereas PCPU, DFBA and DFBAc were generally found in groundwater, surface water, soils, and sediments…”