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The presence of the vector Scaphoideus titanus was in Switzerland already known in all of Tessin and in parts of the canton of Geneva. A national monitoring program revealed the presence of the vector in the lake of Geneva area (cantons of Geneva and Vaud). Recommendations for prevention and control are proposed to wine growers.

Keywords: grapevine flavescence dorée, vector, Scaphoideus titanus, monitoring, Switzerland

E-Mail: lukas.schaub@acw.admin.ch

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This paper presents a comparative synthesis of observations carried out for the last years in the cantons of Ticino and Geneva (Switzerland) on the biology of the leafhopper Scaphoideus titanus Ball. Distribution and spread of the insect in vineyards and their effects on monitoring techniques are also discussed.

Keywords: grapevine flavescence dorée, vector, Scaphoideus titanus, biology, Switzerland

E-Mail: christian.linder@acw.admin.ch

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Scaphoideus titanus, vector of the grapevine flavescence dorée, has for several years been present in Ticino (Swiss canton in the South of the Alps). The first outbreaks in 2004 of this disease triggered mandatory insecticide treatments against the vector in 350 ha in 2005 and 366 ha in 2006. The control strategy is based on two applications of buprofezine. Efficacy results of the strategy are presented.

Keywords: grapevine flavescence dorée, vector, Scaphoideus titanus, control,efficacy,Switzerland

E-Mail: mauro.jermini@acw.admin.ch

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The two grapevine yellows diseases flavescence dorée and bois noir are present in Switzerland. Both spread through contaminated plants (they are graft-transmissible) and/or infectious insect vectors. Whereas bois noir is present in Eastern, as in Western Switzerland, flavescence dorée is confined, so far, in the canton of Ticino. This article presents the situation of the flavescence dorée disease in Switzerland, particularly in regard to bois noir, with which it is often confused. Relevant aspects related to the diagnosis, the control measures and the fight against the disease are also presented.

Keywords: grapevine flavescence dorée, bois noir, yellows, phytoplasma, monitoring,Ticino, Switzerland

E-Mail: santiago.schaerer@acw.admin.ch

Adress: INRAE, UMR LAE, 68000 Colmar

Hot water treatment is considered to be efficient against the grapevine flavescence dorée phytoplasma. Preliminary experiments made in Switzerland confirm international experiences: the treatment does not harmpropagationmaterial if several rules are respected.

Keywords: grapevine flavescence dorée, hot water treatment, Switzerland

E-Mail: philippe.dupraz@eic.vd.ch

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Biological control of two-spotted spider mite is interesting in everbearing strawberry culture, because its harvesting period stretching over more than four months makes it difficult to apply a classical acaricide treatment schedule. In strawberry cultures on substrate, three years of two-spotted spidermite control with the predator Phytoseiulus persimilis showed that a satisfactory control could be obtained under certain conditions. The auxiliary has to be ordered as soon as the leaves occupation rate by the pests reaches 10%.With a concentration of tenmobile predators per m2, it takes two weeks until the pest population decreases. After four weeks, the spider mites were controlled. In the event of a strong attack of mites, it is recommended to combine the auxiliaries release with an acaricide treatment with fatty acid. With such a biological pest control, the fruit quality is not reduced and the cost is affordable for the producer.

Keywords: biological control, strawberry, two-spotted spider mite, Tetranychus urticae, Phytoseiulus persimilis

E-Mail: catherine.baroffio@acw.admin.ch

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In order to answer the request of producers and industry for a homogeneous, highquality and characteristic edelweiss variety, Agroscope Changins-Wädenswil ACW started a selection programme in 1999. The observation of floral biology put into evidence the natural dioecy of the plants issued from the basic population Fotsch. The selection programme chosen was the creation of hybrids’ clones from female plants (sterile males) and hermaphrodite plants (fertile males). The comparison of 19 hybrids issued from various combinations of female and hermaphrodite plants lead to the choice of a productive, homogeneous and phytochemically characterised variety baptised Helvetia. The seeds production was tested at a large scale and organised to fulfil the requirements of the aromatic and medicinal plants branch.

Keywords: edelweiss, hybrid, dioecy, hermaphrodite, sterile male

E-Mail: claude-alain.carron@acw.admin.ch

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Since 1996, Agroscope Changins-Wädenswil runs a breeding program for resistant grapevine cultivars. Selection aims are: high downy mildew resistance, low sensitivity to powdery mildew, good agronomical characteristics and high oenological potential. Seedlings obtained after hybridisation were screened according to four criteria, including histological and biochemical analyses, based on different mechanisms of resistance to grapevine downy mildew. 24 hours post-inoculation (hpi), the production of callose in the stomata was analysed by fluorescent microscopy. 48 hpi the synthesis of _- and _-viniferin was analysed by chromatography (HLC) and 5 days later sporangia density was determined with a spectrophotometer. This approach allowed a rapid selection based on objective criteria. Only the most resistant plantlets were retained for further agronomical and oenological evaluation. The selection procedure can thus be significantly reduced compared to the evaluation of resistance in the field. 22 known grapevine cultivars and 80 new hybrids were tested and classified in five resistance groups. This paper presents the results obtained with a selection of 48 cultivars. The whole data set for the 102 cultivars is available at the authors address.

Keywords: Plasmopara viticola, resistance, grapevine, stilbens, callose

E-Mail: katia.gindro@acw.admin.ch

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The biofumigation is a biological method that aims the reduction of the number of pathogens, pests, and weed seeds in the soil. It is based on the use of plants with a high glucosinolate content, mainly cruciferous species. During the decomposition of these plants, glucosinolates are transformed in isothio- and thiocyanates. Latter substances are volatile and toxic to a number of soil organisms. The effect of the biofumigation on verticillium wilt, a soil-borne disease, was tested in a series of field and pot trials. The number of microsclerotia, organs of survival of verticillium wilt in the soil, was reduced between 19 and 74%. The factors influencing the efficacy of the biofumigation are discussed.

Keywords: biofumigation, glucosinolates, isothio- and thiocyanates, soilborne diseases, verticillium wilt

E-Mail: vincent.michel@acw.admin.ch

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