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The apricot supply chain in Valais (Switzerland) has known a strong development in the last years. The public authorities provided support for an orchard renewal and the production has increased with the planting of new varieties. However, the market conditions are more and more competitive for the producers who need to be flexible and innovative to guarantee their margins. The profitability of an orchard is directly influenced by the variety and its intrinsic characteristics. The aim of this work is to assess the importance of the different intrinsic characteristics. Logically, the putative yield is the most influencing factor with a 174 % increase of the profit compared to the profit of a variety having standard values. Following characteristics, like tree mortality, regularity of the production and proportion of the first class fruits are also important, with an increase of 119 %, 87 % and 88 % respectively. On the contrary, the proportion of big size fruits and manual thinning time have a weak influence, with both an increase of only 53 % of the profit. These economic results are complementary information to the usual technical variety recommendations.

Keywords: apricot, cultivar characteristics, profitability, decision support system

E-Mail: danilo.christen@agroscope.admin.ch

Adress: Agroscope, 1964 Conthey

An essay of partial drying on the vine, with pruning of the fruit cane before harvest, was made on the cultivar Carminoir in the Agroscope research vineyard in Gudo (TI), from 2007 to 2014. The partial grape drying was linked to yield loss of 24 % in average. Sugar content was improved with the technique of grape drying in the vine. The total acidity and the malic acid of the must were also higher in the dried grape, as welle as the wine color intensity, the anthocyanin content and the polyphenols index. At the testing, the wines resulting from the dried grape were slightly preferred to those issued from the control. The main differences were noticed in the intensity and the quality of the tannins.

Keywords: partial grape drying, red wine quality

E-Mail: vivian.zufferey@agroscope.admin.ch

Adress: Agroscope, 1009 Pully

The yeast assimilable nitrogen (YAN) in the must is a major component of the quality of the wine. Agroscope set up a vineyard network for three years, with the aim of monitoring the variations of YAN in the must of the cv. Gamaret (Gamay x Reichensteiner) in the climatic conditions of the Leman region (Switzerland). For each of the five plots, a control treatment with no N fertilisation and a treatment with 20 kg N/ha of foliar urea applied around veraison allowed to evaluate the efficiency of foliar-N fertilisation to enhance the YAN concentration and its consequences on wine characteristics. The YAN concentration mainly depended on the vintage weather conditions and on the soil type. Few plots regularly had a better YAN gain. 66 % of the wines gave a better impression after urea supply in the vineyard, among them 33 % were significantly preferred to their associated control wine.

Keywords: foliar-N fertilization, yeast assimilable nitrogen, wine quality

E-Mail: thibaut.verdenal@agroscope.admin.ch

Adress: Agroscope, 1009 Pully

The interest of a ground cover between rows of vineyards is now well known and so are its failings: competition, management and risks of frost. Selecting plant species for ground covers could mitigate the negative impacts while keeping their advantages. The main goal is to obtain a mix of species which, on the long term and with minimal management, offer good soil protection and weed control, while contributing to promote biodiversity. From 2011 to 2016, the botanical evolution of six seeds mixtures was observed in an experimental vineyard in Geneva. Based on those observations, a «pilot mixture» of 13 species was elaborated. Its validation and optimisation are discussed.

Keywords: ground cover, vineyards, weed management, biodiversity

E-Mail: nicolas.delabays@hesge.ch

Adress: Hepia, 1254 Jussy