Forst- und Lebensmittelwissenschaften HAFL, 3052 Zollikofen

Use of economic damage thresholds, forecasting systems and warning services in Switzerland

According to Direct Payment regulations, Swiss farmers are obliged to take into account economic damage thresholds and the recommendations of forecasting and warning services before taking phytosanitary measures. In order to assess how well these requirements were being fulfilled in arable farming, farmers and agricultural contractors were anonymously surveyed in 2013-2014. Out of 477 returned questionnaires, 456 were evaluated. The results showed that control thresholds for weeds and grasses were only considered to a limited extent. Lack of time and a known weed infestation were given as reasons for this. Control thresholds were better respected in the treatment of disease. Most commonly, the control threshold was applied in treating leaf spot in sugar beets. Eighty-one per cent of farmers stated that they always or often used the control threshold for leaf spot. Least attention was paid to the control threshold in the treatment of Rhizoctonia in potatoes: 47% of respondents never or rarely used the threshold. The control thresholds were most often used when treating pests, especially pests with a high potential for causing damage, and for which the control threshold could be monitored easily and precisely, with little time expenditure. This was the case with pollen beetle: 92.6% of respondents stated that they always or often applied the threshold. The existing forecasting systems such as Phytopre and Fusaprog were unknown to many farmers and therefore not used. The warning services, on the other hand, were used by many farmers: 87% said that they always or often used the warning services in the trade press. The cantonal advisory services were also valued as a source of information. The study shows the areas in which there is still additional potential for reducing risks caused by the use of pesticides.

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