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Soil fumigants are used extensively in the protection of crops against parasitic nematodes and other soil borne pests. The active ingredient in Telone II soil fumigant is 1,3-Dichloropropene (1,3-D) which has a wide range of uses in Europe as a pre-plant nematocide. During the use of soil fumigants such as 1,3-D a range of non-target soil dwelling organisms has the potential to be exposed and impacted. We report here the results of a field study conducted in Italy to assess the impact of 1,3-D applications to soil-dwelling non-target organisms. This study was conducted under conditions of commercial tomato growing either without (untreated control) or with an application of 1,3-D at 224 kg a.i./hectare. Samples of arthropods and earthworms were taken before and up to 12 months after application to measure season long effects. A soil sample was taken at 4.5 months and a soil function test performed. By evaluating the effects of 1,3-D both in the Laboratory and under field conditions equivalent to commercial practices it was concluded that applications of 1,3-D would not adversely effect soil arthropods, but may have an effect on earthworms and soil microflora. These effects were, however, transient as full recovery was observed within six months of application for earthworms and 4.5 months for soil microflora. Consequently, the risk to non-target soil micro- and macro-organisms was considered acceptable according to current risk assessment guidelines within the European Union.

Two Large scale field studies have been conducted to the same design in commercial apple orchards in north and south France. Mancozeb (Dithane M-45) was applied at its post-annex I use rate of 1.6 kg a.i./ha on four occasions with a spray interval of 7 days. Reference treatments of a water treated control and toxic reference of dimethoate were also included. Studies were of randomized block design with 4 replicates (4 plots of 6 adjacent rows of 8 trees, on a surface of approximately 16 x 21 m) per treatment. Leaf and canopy dwelling arthropods were sampled before and at regular intervals after application until the end of the season. A diverse range of arthropod taxa was sampled, counted and identified which enabled for an evaluation of key taxa such as predatory mites and other beneficials but also of the whole foliar dwelling arthropod community. This two level analysis allows for a thorough investigation of both direct and indirect effects of the test item on beneficial, pest and non-target arthropods and for a state of the art evaluation at the ecological community Level using ordination techniques. The findings from the two locations were highly consistent in that mancozeb applied four times at 1.6 g a.i./ha with a 7 day spray interval caused significant but short lived reductions in predatory Phytoseiid mites of50% with rapid recovery approximately one month after application. These transient effects did not impact secondary pests such as rust mites (Eriophyoidea) and broad mites (Tarsonemidae). A wide range of arthropod taxa were investigated (229 taxa in the north and 215 taxa in the south) and consistent adverse treatment related effects were not noted for any taxa other than Phytoseiidae. At a lower rate of mancozeb representing potential off-field deposits at 3 m due to drift effects were virtually absent on predatory mites in and to all other taxa present.