Is yellow rust a danger for Swiss wheat production?

In 2008, yellow rust of wheat was observed in two experimental sites in the cantons of Thurgau and Aargau. After isolation and purification, the virulence spectrum was determined based on wheat differentials. By this, both virulences Yr4 and Yr32 were identified for the first time in Switzerland. These virulences have already been described in the 90s in the North of Europe and their migration towards South was detected in 2007 in France and in 2008 in Switzerland, as related in the present work. Infection tests in greenhouses with these new strains showed that today’s wheat varieties present a satisfactory resistance against the new virulences. The reporting of other virulences occurrence in Europe emphasizes the importance to carry on with the pathogens monitoring organized by Agroscope, cantonal phytosanitary offices and the cereal branch.