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Lovage (Levisticum officinale) is an Apiaceae cultivated for the production of essential oil. As a perennial crop, lovage can locally suffer from important outbreaks of the Celery fly (Euleia heraclei), whose larvae live as leafminers in its foliage. The biology and phenology of the pest were studied in the laboratory as well as in the field and control trials were conducted using insecticides. The insect overwinters as a pupae in the soil and develops two generations the year. Depending the altitude, the first flight starts between mid-March to mid-April. The development from the egg to the adult took 51 days at 15 °C and 21 days at 25 °C. Adults survived more than 45 days at 20 °C and 25 °C and total fecundity was 570 eggs/female. Insecticide trials showed that the organic products spinosad and azadirachtin have a low efficacy, while the pyrethroid -cyhalothrin kills adults by contact and the neonicotinoid thiacloprid acts systemically against larvae. A sustainable chemical control based on the monitoring of E. heraclei with yellow sticky traps should allow to reduce pest pressure within a field and thus avoid systematic interventions every year.

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

Adress: Agroscope, 1260 Changins/Nyon

An irrigation trial was conducted from 2009 to 2016 at the Agroscope experimental station in Leytron in order to study the effect of vine water regime on grape ripening and the quality of Chasselas wines. Progressive, moderate water stress over the growing season resulted in less vigorous shoot growth and favoured grape ripening compared to vines without water stress. The nitrogen content of the must decreased along with the increase in water stress. Neither bud fertility nor berry and cluster weight at harvest was affected by the moderate water restriction. By contrast, more-severe water stress resulted in a decrease in both photosynthesis and transpiration, and triggered the phenomenon of embolism in the petioles. During hot, dry vintages, wines from vines subject to drought were judged more bitter at tastings than those from irrigated vines.

Keywords: Irrigation, water stress, grapevine physiology, berry composition, wine quality.

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

Adress: Agroscope, 1009 Pully

Apple breeding at Agroscope contributes to finding and using alternatives to the application of plant protection agents. However, apple varieties that are cultivated nowadays carry a narrow genetic basis. This is also true for disease resistant varieties. To ensure a sustainable resistance against apple scab, crosses were made with varieties carrying polygenetic resistance. Enhanced scab defense reaction was visible in the progeny of ‘ACW 17314’ x “Seemer”. Resistances originating from wild apples have been used to breed fire blight resistant varieties. Low fruit quality of wild apples was outcrossed using the “Fast track” method during several generations to achieve high quality resistant apples. Promising plants carrying resistance QTL’s were screened in shoot inoculation and flower tests, repectively. Currently, progeny plants of the 3rd and the 4th backcross generation are undergoing shoot inoculation tests and plants of the 3rd generation are investigated in the flower test. The first results are promising. In the shoot inoculation test an infestation of less than 1% compared to “Gala Galaxy” was observed in the fast track number ‘1421_03’ (4th generation FB_MR5 QTL). Likewise, fast track numbers of the 3rd generation FB_MR5 (’1124_26’) and “Evereste” (‘1420_78’) showed less infestation than “Gala Galaxy” and were classified as “low susceptible”. The existing variety “Ladina” with a fire blight QTL FB_F7 satisfied with an average infestation of 17.1% versus “Gala Galaxy”. In the flower test, “Ladina” and ‘1124_26’ both showed solid robustness against fire blight.

Keywords: Apple breeding, Venturia inaequalis, Erwinia amylovora, resistance, genetic resources, polygenic resistance

E-Mail: markus.kellerhals@agroscope.admin.ch

Adress: Agroscope, 8820 Wädenswil

Most studies show that the production system has few effects on tomato quality. For now, the main factor dictating the quality differences of tomatoes is the genetic heritage, in other words the variety. Today, the production of quality tomatoes is a key issue for Switzerland as consumers expect the product to be in line with their expectations and preferences. A trial considering the diversification of the round-type tomato was carried out in the greenhouses of Agroscope Conthey. A range of twelve varieties of round tomatoes of various breeders was chosen. These so-called old, current and future varieties were cultivated in soil under greenhouse according to the guidelines of organic farming. The 12 tomato varieties were submitted to a panel of more than 500 consumers attending the “Tomato and Terroir Festival” (Geneva, CH, 2016). Consumers were asked to express their preferences after tasting the tomatoes. The 12 varieties could thus be classified according to their degree of appreciation. Among the most appreciated: Paronset, Estiva, Cindel and Pilu, among the least appreciated: Fiorentino and especially Natyssa. The tomatoes were analyzed to determine the SSC, TA, background color but also the texture of the skin and flesh. The preferred varieties had the highest SSC and TA values and at the same time the lowest skin and flesh texture values. The low color index of Natyssa, Admiro and Octydia appears to have been detrimental to consumer judgments.

Keywords: Tomato varieties, skin texture, flesh texture, chemometric modelling

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

Adress: Agroscope, 1964 Conthey