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Presently, ground management in vineyards relies mainly on the use of herbicides. These are very efficient but they raise growing concerns about problems such as water contamination, development of herbicide resistant biotypes and reduction of biodiversity in cultivated fields. Obviously, a better management of the spontaneous vegetation in vineyard is now needed. Yet, the flora of Swiss vineyards is still not well known, as it has not been widely studied. This paper presents a synthesis of a botanical inventory carried out in the different vineyard areas of the French-speaking part of Switzerland. Globally, 211 species have been observed but the majority of them are not very frequent. On the contrary relatively few species are really frequent: only 25 species have been found in more than half of the fields studied. The inventory also distinguished between different soil managements: cover cropping, mechanical management, herbicide applications. Species richness is higher in field with ground cover than in weeded plots and it tends to decrease with intensification.

Keywords: spontaneous flora, vineyards, weed management

E-Mail: nicolas.delabays@acw.admin.ch

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Cover cropping in vineyards offers numerous well described benefits, especially for soil protection and weed management. Nevertheless, the competition for water and nitrogen induced by the cover crop can prejudice the harvest, as well as the must and the vine. In order to keep the advantages of cover cropping while limiting its negative effects, it is proposed to use species with low competitive ability. This paper presents the results gathered in a trial carried out in a vineyard between 2000 and 2005, in which 8 different ground covers have been compared: 2 controls (the spontaneous flora and a mixture of perennial grasses) and 6 potentially weakly competitive species: Creeping Bent, Dutch Clover, Subterranean Clover, Drooping Brome, Wall Barley, and a mixture of Small-flowered Cranesbill and Small Burnet. In this experiment, it took several months to the spontaneous flora to provide a complete covering of the soil, but, it is composed of species potentially highly competitive. The perennial grasses mixture offered a quick and complete soil protection, but its species are highly competitive too. Results obtained with the low competitive species emphasize the difficulty to install such cover cropping and to maintain it for several years. In our trial, only Wall Barley, and to a lesser extent Dutch Clover and Subterranean Clover, offered a satisfying ground cover during all the time of the experiment. To improve the installation of such weakly competitive cover cropping, progresses must still be made on three aspects: adequacy between the species and the soil and climatic conditions, selection of adapted biotypes and optimisation of the management techniques.

Keywords: cover cropping, vineyards, Agrostis stolonifera, Bromus tectorum, Geranium pusillum, Hordeum murinum, Sanguisorba minor, Trifolium repens, Trifolium subterraneum

E-Mail: nicolas.delabays@acw.admin.ch

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A research experiment was conducted at the research station Agroscope Changins- Wädenswil in Nyon (VD) in order to find cover crops with low competitive ability against grapevine. Compared to perennial grasses used as control, the installation of annual grasses such as Bromus tectorum or Hordeum murinum allowed a clear reduction of the competition for water. Nevertheless these two species could not improve the nitrogen status of the vine. The annual legume Trifolium subterraneum and the perennial one Trifolium repens induced a positive effect on the nitrogen level of the vine. White clover (Trifolium repens) and the perennial grasses are the two types of cover crop inducing the highest competition for water. Compared to the control plots, all the tested species increased the vigour and the production potential of the vine, without negative impacts on the most composition. The use of certain of these cover crops will need further experiments and improvements selection of adapted biotypes, optimal management techniques and seed production.

Keywords: grapevine, nitrogen concurrency, water stress, cover crop, Hordeum murinum, Bromus tectorum, Trifolium subterraneum, Trifolium repens

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

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Presently, cover cropping is widening in raspberry fields in Switzerland, as it offers numerous benefits in soil protection and weed management. A mixture of grasses is generally used to that purpose. Nevertheless, such cover cropping may compete with the crop for water and nutriments supply and impact negatively its productivity. In order to keep the advantages of cover cropping while limiting its negative effects, it is proposed to use species with low competitive ability. This paper presents the results of a trial carried out in a raspberry field between 2001 and 2005, in which 5 different ground managements have been compared: 2 controls (regular weeding and cover cropping with a mixture of perennial grasses) and 3 cover croppings with potentially weakly competitive species: Creeping Bent, Dutch Clover and a mixture of Drooping Brome and Small-flowered Cranesbill. The best results have been obtained with the Creeping Bent. This species offered a complete covering of the ground during the four years, while allowing the best yields, even higher than in the weed free plots. Good results have also been obtained with Dutch Clover, but this species is quite vigorous and needs to be cut several times during the season. As expected, the mixture of perennial grasses reduced significantly the yield.

Keywords: cover cropping, raspberry, Agrostis stolonifera, Bromus tectorum, Sanguisorba minor, Trifolium repens

E-Mail: andre.ancay@acw.admin.ch

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Tests were carried out to determine the efficacy and the persistence of some insecticides applied against summer fruit tortrix moth A.orana. Leaves were collected after the application of the treatments for rearing of 12-days old larvae in blooming period or newborn larvae in summer. The products lufenuron, tebufenozide and methoxyfenozide had a very high efficacy and an excellent persistence. Emamectin, indoxacarb and spinosad had a very good initial efficacy but a shorter persistence, independently of the tested concentration; tested on the young leaves, the efficacy declined quickly, due to growth that diluted the residues. The short persistence of chlorpyrifos-methyl, practically identical on the old and the young leaves, let suppose that this product has a systemic activity. Methoxyfenozide and spinosad had an excellent rain fastness.

Keywords: summer-fruit tortrix moth, insecticides, larvicidal activity, persistence, Adoxophyes orana

E-Mail: pierre-joseph.charmillot@acw.admin.ch

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Using barrels made of oakwood of known botanical species and geographical origin to grow wines is justified only if specific organoleptic traits, collectively depicted as «Oak Terroirs», are transferred to wines by these woods. The Changins School of engineering attempted to show that such «Oak Terroirs» exist and to characterize them by chemical analysis of (semi)volatile compounds in sessile and pedunculate oak staves, and by sensory analysis of Chardonnay and Pinot noir wines raised in these woods. Principal component analysis of raw data enables to discriminate oak woods at regional level (Jura versus Plateau) and even at smaller scale (forest), and between species as well. Wines can be differentiated too according to the same criteria. Although wine matrix (red or white) and growth duration in barrel modulate the woody scent attributable to oak species and origin, «Oak Terroirs» do exist, to the winemaker’s benefit.

Keywords: oak terroirs, oak species, barreled wines, origin discrimination

E-Mail: judith.auer@eic.vd.ch

Adress: Station cantonale d'arboriculture, Marcelin, 1110 Morges