The importance of tan spot disease of wheat, caused by Pyrenophora tritici-repentis (anamorph: Drechslera tritici-repentis DTR) has increased in many European countries in the last years. In Switzerland the impact of the tan spot disease is low so far. The reason probably is that wheat is usually not grown after wheat. However, changes in farming practices, e.g. increase of conservation and zero tillage systems, could promote the prevalence of tan spot. This hypothesis is supported by results of the seed health test for Swiss wheat seed lots: from 1995 to 1998 the mean incidence of DTR on grains varied between 0.1 % and 0.6 % and from 1999 to 2001 between 3.7 % and 8.5 %. From 1999 to 2001 the tan spot resistance of 18-20 winter wheat varieties was tested in 5 field trials on two locations. Naturally infected wheat straw was used for artificial infection. Arina, a Swiss cultivar with excellent resistance against head blight and septoria diseases, showed the best DTR resistance, followed by Taneda (CH) and Pegassos (D). Terza (CH), Habicht (D) and Greif (D) were highly susceptible and showed yield losses of 30 % to 35 %. The average yield loss of Arina, Camino, Tamaro and Titlis (all CH) was 10 % to 11 %.The efficacy of strobilurin and triazole fungicides against DTR was evaluated in field trials with Galaxie (FR) and Danis (CH). In comparison with the untreated control, yield improvements of 7 % to 12 % were observed with applications between growth stage BBCH 32 and BBCH 45. Although the tested fungicides showed good efficacy, we recommend crop rotation, an adapted straw management and the choice of varieties with good resistance and tolerance to DTR as efficient means to control the risk of yield loss even in reduced tilla
Arbuscular mycorrhizal fungi are important for healthy soils and crops. A pan-European study shows that plant-protection products adversely affect these fungi, reducing their ability to supply plants with phosphorus via their roots.
Birdsfoot trefoil and sainfoin are used in mixtures for perennial hay meadows and for tannin-containing fodder. Agroscope is adding two new cultivars of birdsfoot trefoil to the ‘List of Recommended Varieties of Forage Plants’, whilst there is no change in the case of sainfoin.
Tall oat grass and golden oat grass are typical hay-meadow grasses that are also suitable for forage mixtures. Of the four tall and three golden oat grass varieties tested, only one new variety of tall oat grass is likely to make it onto the List of Recommended Varieties.