According to the study, pesticides from apple cultivation in South Tyrol also reach the mountains

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Apple orchards in Vinschgau in South Tyrol: Pesticides even in remote mountain valleys

Photo: Carsten Brühl; Rptu/dpa

The Vinschgau in the west of South Tyrol is the largest contiguous apple-growing region in Europe. However, the consequences of the use of pesticides in fruit production go far beyond this, as shown by a study by a team of researchers that has now been published in the journal “Communications Earth & Environment”. Pesticides can therefore be detected throughout the valley, but also at high altitudes and protected areas.

There are more than 7,000 apple farmers in Vinschgau who produce ten percent of all European apples. Conventional cultivation there relies primarily on synthetic pesticides that are distributed using blowers to combat pests such as the codling moth and fungal diseases. This means that a high level of drift into the surrounding area is possible, especially in windy conditions.

The team led by environmental scientist Carsten Brühl from the Rhineland-Palatinate Technical University of Kaiserslautern-Landau (RPTU) examined eleven so-called elevation transects along the valley axis - stretches from the valley floor to the mountain peaks. Along these routes, samples were taken every 300 meters at altitudes on four days in May 2022 - plant material and soil samples from a total of 53 locations. "From an ecotoxicological point of view, the Vinschgau Valley is particularly interesting because there is highly intensive cultivation in the valley with a lot of pesticides and in the mountains there are sensitive alpine ecosystems, some of which are strictly protected," said Brühl.

Blown by the wind

The amounts of pesticides found decrease at higher altitudes and with distance from the apple orchards, but even in the upper Vinschgau where there is hardly any apple cultivation, several substances can still be detected in the soil and vegetation. »We found the resources in remote mountain valleys, on the peaks and in national parks. They have no business there,” said Brühl. The reason for the widespread distribution is probably the sometimes strong valley winds and the thermals in Vinschgau.

Even at the low concentrations measured, pesticides can lead to so-called sublethal, i.e. not directly fatal, effects on organisms, the researchers explain. For butterflies, a reduction in egg laying is conceivable. So far, however, it is largely unclear what effect chronic exposure to pesticides in low concentrations and mixtures of different pesticides have. What is clear, however, is that there are sometimes alternatives. Instead of relying on pesticides, other pomologists are breeding varieties that are more resistant to disease.

Pesticide researchers have identified a total of 27 substances in South Tyrol, including ten insecticides, eleven fungicides and six herbicides. "The concentrations we found were not high, but it has been proven that pesticides affect soil life even at very low concentrations," said co-author Johann Zaller from the University of Natural Resources and Life Sciences in Vienna (BOKU).

Proven substance banned in Germany

According to the analysis, valley meadows near apple orchards were particularly contaminated, but residues were even found in remote mountain meadows at an altitude of more than 2,000 meters. One of the substances detected was the insecticide methoxyfenozide. It was found in almost half of the soil and plant samples, they said. In Germany, the use of methoxyfenozide has been banned since 2018 due to its environmental damage.

The team concludes from the results that the technology for applying pesticides in apple cultivation obviously needs to be improved. A drastic reduction in the use of pesticides is also necessary.

apr/dpa