In 2008 and 2009, in field trials at the Changins-Nyon (Vaud canton) and Zurich-Reckenholz sites, respectively, the two research stations of Agroscope Changins-Wädenswil ACW and Agroscope Reckenholz-Tänikon ART investigated the varietyspecific nitrogen (N) requirement of the potato varieties Gourmandine, Jelly, Laura and Lady Jo (the latter at Changins only). The N levels varied from 0 to 200 kg N per hectare. All varieties reacted to the increasing N supply with a higher gross- and marketable yield. From an N-application level of 120 kg/ha onwards, however, no significant surplus yields were demonstrated. The Gourmandine variety produced significantly higher gross- and marketable yields than Jelly and Laura. The higher the N supply, the lower the starch content of the tubers. Tubers from plants fertilised with N tended to exhibit a slightly higher brushing susceptibility than those from the non-fertilised treatment. Crisps made from the tubers of non-fertilised plants were slightly lighter in crisp colour than those of the tubers of the fertilised plants. The Gourmandine, Jelly and Laura varieties produce high marketable yields at average N-application levels of 100 to 120 kg N/ha. These trials confirm the significant influence of the weather over the year as well as the site conditions on potato yields.
Herbicide-resistant weeds are a growing problem throughout the world. Monitoring herbicide resistance in Switzerland allows us to understand the mechanisms behind it and to better manage the use of herbicides.
Agroscope compared crop protection strategies in apple production. Reducing the use of plant-protection products lowered the local ecotoxological risks, but resulted in trade-offs between environmental and economic performance.
Bacillus thuringiensis (Bt) bacterium proteins protect Bt maize from being fed on by specific insects. A new, systematic analysis of international field data confirms that non-target organisms in Bt maize are largely spared.