Archives

The influence of ten rootstock selections grafted with the apricot variety Luizet, clone Ctifl, has been analyzed during twelve years in central Valais (Switzerland). The different selections belonging to plum species are: Myrobolan (standard), GF 43, Torinel, Julior, Pixy, GF 655-2, W 61, Jaspi; Rubira is a peach selection and Citation a plum x peach hybrid.
Citation, a low vigour rootstock, gives satisfactory overall performances: no tree decline, good fruit size, high productivity, advanced and better ripeness homogeneity than the standard Myrobolan. With a slightly higher level of vigour, Torinel shows similar qualities. Myrobolan is the most vigorous among the three recommended rootstock types. Excepting the slightly reduced fruit size and longer harvest period, its behaviour is considered acceptable.
Because of its very high vigour, Julior could give satisfactory results in poor soils. Its affinity with Luizet variety is very good and fruit size is close to the best tested rootstocks.
Key words: apricot, rootstocks, vigour, crop-yield, fruit size, yield efficiency, fruit crops.

Keywords:

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

Adress: Agroscope, 1260 Changins/Nyon

The combination of several cultural control methods to control root rot caused by Phytophthora fragariae var. rubi was tested in a naturally contaminated field. The use of raised bed planting, compost amendment and plastic mulch in different combinations was studied from 2000 to 2004. The number of fruiting canes and the cumulative yield were significantly higher when raspberries were planted on raised beds. Adding compost to raised beds or covering them with plastic mulch gave a second protecting effect. Nonetheless, all these cultural control methods did not allow to maintain the optimal number of ten fruiting canes per linear meter at harvest because the mortality caused by P. fragariae var. rubi continued after pruning in spring. Root growth probably caused this ongoing mortality. Even when most of the roots were located in the raised bed, a part of them were growing into the soil below contaminated with the pathogen.
Key words: compost, plastic mulch, raised beds.

Keywords:

E-Mail: andre.ançay@agroscope.admin.ch

Adress: Agora

Between 1997 and 2003, experimental trials on training and pruning systems of Merlot vines were made on the Gudo experimental estate of Agroscope RAC Changins in Ticino, Switzerland. Four different systems of training and pruning were compared: permanent cordon; single Guyot-trained hedgerow with one fruit cane; double Guyot with two fruit canes and double Guyot arch with partial fastening of branches. In the first two systems, vine plants distance was 95 cm and in the double Guyot systems 135 cm. Agronomic, analytical and organoleptic parameters were monitored. Comparative vinifications were carried out during the last four years of experiments. The cordon pruning system improved budbreak rates and favoured a regular growth of shoots. Plant vigor, a phenomenon appreciated by the weight of toppings and pruned branches, was noticeably strengthened. Conversely, bud fertility and, consequently, levels of yield were lower in the cordon pruning system. This decrease in production prevented any improvement in must sugar content and wine quality, certainly due to the induced plant vigor. Plant spacing distances had no obvious effects. The double arched Guyot-trained system with open vegetation facing down slopes tended to bring about improved yield and wine quality, with regard to both tannin content and global impression.
Key words: system of training, vine spacing, pruning, yield, quality.

Keywords:

E-Mail: francois.murisier@acw.admin.ch

Adress: Agroscope, 1009 Pully

To test the behaviour of four Aligoté clones, a trial was set up on the experimental vineyard of Agroscope RAC Changins in Nyon (VD). Four clones of the French Catalogue (263, 264, 651 and 920) were tested. The study showed that clones 651 and 920 had a slightly higher production potential than clones 263 and 264. Under our experimental conditions which included yield regulation, no important difference could be highlighted between the wines, whether from the analytical or the organoleptic point of view.
Key words: grapevine, Aligoté, clones.

Keywords:

E-Mail: dominique.maigre@bluewin.ch

Adress: Agora

To test the behavior of six Syrah clones, a trial was set up on the experimental vineyard of Agroscope RAC Changins in Leytron (VS). Six clones of the French Catalogue (100, 174, 300, 383, 470 and 525) were tested and compared with a RAC selection. Clone 470 and the RAC selection obtained the lowest yield potentials (light coulure, weight of the bunches). For a yield close to 1 kg/m2, the analytical values of the musts were generally very close. However some differences were observed in the sugar rates. The compactness of the bunches influenced the sensitivity to the bunch rot. The analysis of the wines did not highlight important differences between the clones. At the wine tasting, some differences appeared in the quality of the tannins; they were less important with the ageing of the wines.
Key words: grapevine, Syrah, clones.

Keywords:

E-Mail: e.mehinagic@groupe-esa.com

Adress: Agora

Infestation of the Tomato Russet Mite (TRM) Aculops lycopersici is in Switzerland as in the entire continental Europe an increasing problem. The article presents an overview of the biology and impact of TRM, as well as studies on biological control, involving 3 species of Phytoseiidae predatory mites (Neoseiulus cucumeris, N. californicus and Amblyseius andersoni). In laboratory tests conducted on tomato stem pieces at 25 °C, A. andersoni gave the best daily predation rate (aver. 15 preys/day), as well as a rather good fecundity (aver. 2.18 eggs/day). Both N. cucumeris and N. californicus showed a poorer predation rate and had a very strong escaping behaviour, probably because of high trichoma density on tomato stem. Therefore, fecundity tests could not be achieved with these 2 species. A preliminary experiment in the greenhouse was conducted with a single release of 100 A. andersoni per tomato plant, either curatively, simultaneously or preventively to artificial TRM introduction. The preventive release gave the best pest control in term of TRM density on stems after eight weeks. Perspectives for further experiments on practical use of A. andersoni in protected tomato crops are discussed.
Key words: Aculops lycopersici, Tomato Russet Mite, Phytoseiidae, IPM, Biological control.

Keywords:

E-Mail: serge.fischer@agroscope.admin.ch

Adress: Agroscope, 1260 Changins/Nyon

Sage is one of the most important medicinal and aromatic plants in Switzerland. To evaluate the cultivar Regula, created by Agroscope RAC Changins, we compared it with Extrakta, the main cultivar in central Europe. The tests were set up at Arbaz (VS) and Bützberg (BE).
Regula showed at both sites a higher essential oil content of the leaves, an excellent leaf/stem ratio, a clearly higher essential oil yield and a lower amount of flower stems in spring. Concerning dry matter yield, the composition of essential oil and winter hardiness, both cultivars showed similar results. Further, the seasonal variation of the essential oil content of the leaves and the most important compounds such as α and β-thujon, camphor and 1,8 cineol was similar for both cultivars.
In conclusion, Regula is a very interesting cultivar mainly due to its quality traits and can be recommended for Switzerland and central Europe.
Key words: chemical composition, essential oil, leaves, sage, yield.

Keywords:

E-Mail: serge.fischer@agroscope.admin.ch

Adress: Agroscope, 1260 Changins/Nyon

The Engineering School of Changins, the Perroy Fruit Centre and the Cantonal Station of Arboriculture (Vaud) have set up for several years a network of apple orchards in the Lake of Geneva region. Repeated harvests of three varieties (Golden delicious, Gala and Braeburn) are analyzed according to several complementary criterions: physico-chemical measurements, visual and sensory appreciations according to a tasting panel and to consumers tests. The synthesis of these various aspects makes it possible to determine the optimal date of harvest. The results of 2004 campaign, presented in this paper before the final report of the entire project since 2000, show a preference for the latest harvestscharacterized by the good maturity of the fruits: high sugar rates, large fruits and well-coloured skin.
Key words: apple, maturity, sensory panel, optimal harvesting date.

Keywords:

E-Mail:

Adress: