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The increasing temperatures observed during the latter years did influence the vegetative development of grapevine. Since 1958, different development stages of Chasselas vine have been observed at Agroscope ACW Changins site and related to the climate change and its incidence on the vegetation period. The early stages, from budbreak (BBCH 09) to initiation of flowering (BBCH 51) do not show any precocity tendency related to the temperature increase, while flowering (BBCH 65), fruit maturation and grape harvest (BBCH 89), were in average about ten days earlier during the last years, reducing thus considerably the vegetation period.When considering a longer period of time, such phenomena proved to be happening already in the past.

Keywords: phenology, climatology, vine, temperature, harvest, growth stage

E-Mail: bernard.bloesch@acw.admin.ch

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The principle growth stages of grapevine have been observed during the last 84 years on the cultivar Chasselas at the research station Agroscope Changins-Wädenswil ACW in Pully (Vaud, Switzerland). These observations enhance a cyclic development of grapevine. The current global warming of the last twenty years has significantly reduced the time for bloom and «véraison». Such conditions have already been observed during the ten years between 1940 and 1950, with precocity records for these two growth stages. Before the forties and after the fifties, slower development periods have been registered.

Keywords: grapevine, growth stages, climate change, Chasselas, Switzerland

E-Mail: jean-laurent.spring@acw.admin.ch

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Four training systems (V-trellised multiple leader, Palmette, Solaxe and Y-trellised), with the variety Summit on semi dwarfing rootstock P-HL A and dwarfing rootstock Gisela 5 were compared during nine years. P-HL A revealed too vigourous for planting densities between 570 and 890 trees/ha. V-trellised multiple leader produced the highest cumulated yields. Despite its training method supposed to increase early production, Solaxe did not perform significantly better than the three other systems during the first production years. Rootstock and training did not significantly influence fruit commercial quality. Nevertheless, by equivalent fruit load (number of fruit/trunk cross section area) Gisela 5 showed an obvious tendency to better fruit size, although it was often affected by to high productivity. V-trellised multiple leader and Solaxe obtained the best cumulated yields/ha, proved to be easy in tree formation and showed well balanced crowns. Both were analysed for profitability under Swiss conditions on the basis of trial datas. Simulations with different crop yields and commercial quality levels showed that very high fruit size objective (60% fruits > 28 mm) causing a decrease of about 35% in production would not improve orchard profitability, considering prices and quality standards in Switzerland. In contrast, slightly better fruit load control applied in order to obtain 45% of fruits > 28 mm instead of 35% doesn’t influence the production too much (-9% to -14%) and finally improves the profitability through better commercial crop value and harvest efficiency.

Keywords: cherry, training systems, rootstocks, Gisela 5, orchard profitability

E-Mail: philippe.monney@acw.admin.ch

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The erineum mite Colomerus vitis is widespread in Swiss vineyards, but its pest status is still unclear. Damages of C. vitis are rarely serious. Nonetheless acaricides are occasionally applied, although these products are moderately toxic to predatory mites. For a better understanding of erineum mites impact on vine, harmfulness of C. vitis was studied from 2005 to 2007 on the variety Muscat. At the time of the most severe mite infestation, about 3% of leaves had more than 60% of the leaf area damaged. Nevertheless, mites had almost no effect on transpiration rates measured. Photosynthesis and stomatal conductance rates slightly decreased on heavily infested leaves while chlorophyll index was unaffected. The presence of mites had also no effect on shoot growth and foliation. Overall, individual plant damage was neither correlated with overwintering mite population nor with plant damage in the previous year. In conclusion, C. vitis impact on photosynthesis is negligible and acaricide treatment can be abandoned at moderate pest infestations.

Keywords: Vitis vinifera, pest control, threshold levels, Muscat, gas exchanges, erineum mite, Colomerus vitis

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

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In food technology, sensory characterisation is more and more used. To obtain a characterisation of the products, the sensory analyst generally uses the competences of a trained panel to obtain conventional profiling. This method requires a long training period for the judges, generally over several months. In the particular case of wine, professionals are not trained together and their performance is not checked. They are however used to taste and describe wines. Spontaneous methods such as Free choice profiling or Napping® do not require common preliminary training of judges and give a great freedom to the taster, particularly in the choice of descriptors. These methods thus appear more adapted to juries of professionals. This study compares the interest of Free profiling and Napping® carried out by professionals (winemakers, winegrowers, and technicians) with a conventional profiling obtained from a trained panel, applied to ten white wines of the Loire Valley. Results show that free and conventional profiling are very close in terms of characterisation. Data from conventional profiling are easier to interpret but free profiling fits more to professionals. The Napping® method is also adapted to professionals but it provides a slightly different representation of the wines because of its decisional character: only the most important criteria for the judges arise.

Keywords: sensorial analysis, free choice profile, Napping®, conventional profiling, trained jury

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Adress: Agora

Today, the evaluation of fruit maturity in orchard only rely on the expert eye of the producer. At harvest time, optimal maturity is estimated according to fruit calibre or background coloration of the skin. The obtention of a new and objective method able to follow fruit maturity until harvest would be advantageous. The aim of the presented trial was to evaluate the near infrared spectroscopy (NIR) ability to follow fruit development in orchard and to measure the physico-chemical quality of fruit during growing (soluble solids content and firmness). The obtained results showed that NIR was able to classify correctly about 99% of fruit according to several picking dates during fruit development. NIR measurement allowed also determinating flesh firmness with an error lower than 6.2%. Concerning soluble solids content, the level of prediction was correct for the Bergarouge variety (error = 0.85 °Brix) but unsatisfactory for the Harostar variety (error = 1.47 °Brix).

Keywords: NIR, AFD, PLS, apricot, preharvest, maturity

E-Mail: cedric.camps@acw.admin.ch

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