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• Epidemiological survey of Xanthomonas arboricola pv. juglandis and Gnomonia leptostyla on natural population of walnut (Juglans regia) in eastern Transylvania

  7-9.

  R. Thiesz

  A. Bandi

  M. Tóth

  A. Balog

  Views:

  2140

  In Romania, walnut Juglans regia L. is an important fruit crop, although most of the fruit production comes from non-grafted walnut trees, which are natural hybrids. Breeding programs have been launched during last 30 years to develop new cultivars with uniform fruit quality. In addition, foreign cultivars have been introduced and tested to establish a valuable walnut genepool. To improve the present assortment of generative rootstocks in walnut and to examine the infestation level, a long term survey was carried out in Eastern Transylvania. The main physical characteristics of fruits and its variation to the infestation level were considered. The cumulative distribution of Xanthomonas arboricola pv. juglandis and Gnomonia leptostyla were relatively low and the maximum value was around 15%. The highest infestation of husk with X. arboricola pv. juglandis was observed for roundish forms and differences were statistically significant comparing with other phenotypes. Infestation with G. leptostyla was similar for roundish, elliptic and thwarting egg-shaped phenotypes, while the husk infestation for egg-shaped phenotypes was not observed. The walnut population studied in our experiment can be considered as a genetically valuable population. More than 20% of them have upper class quality fruits with at least or more than 50% of nutmeat. Do to the large scale climate variation in Eastern Transylvania and the high humidity favourable for pathogen infestations, these population can be considered resistant and well adapted to abiotic and biotic factors.

• Influence of abiotic factors on the green mass and seed productivity of the raw material of Levisticum оfficinalе c. Koch in the conditions of Transcarpathia

  46-51.

  S. M. Kormosh

  G. Simon

  I. E. Povlin

  Views:

  281

  For the wide implementation of Levisticum officinalе C. Koch in Transcarpathia into production it is necessary to widen its sort composition, as it is rather poor in Ukraine. Solving this problem is possible by enriching the source material with the samples of different ecological and/or geographical origin, by studying the influence of abiotic factors on the formation of green mass and seed productivity, separating the specimens best adapted to the conditions of growing, involving them into the selection process and creating new, highly productive sorts on this basis. The scientists of the Transcarpathian State Agricultural Experimental Station (TSAES) conducted researches (during 2011-2016) on the adaptive potential of the source material of the type of Levisticum officinalе C. Koch, which counts seven samples (Ukraine – 5 samples, Poland – 1, and Romania – 1), the selection work on creating new varieties for the given region is being done. The investigations were made on soddy podzolic gleyed low-humus soils with low content of nutrients. The results were obtained on the basis of generally accepted methods of investigation, i.e.: laboratory, field, visual, measuring-weighing, biochemical, mathematically statistic, and comparative-calculating. In the conditions of Transcarpathia the spicy greens of the high quality L. officinalе C. Koch are being gathered on days 25-30, the output of the essential oil makes up from 0.72 tо 1.89% on c.d.s., depending on the climate conditions of growing. The plants pass through all the stages of development, the bush is 55.4 to 92.7 сm in height, the plants form a big amount of rosette-shaped stems (11-34 pieces), the productivity of spicy greens is between 9.9 and 42.1 t hа¹. The scientists of TSAES created the following sorts – Mriya (А. с. 06131 Ukraine, first registered in the State register of plant varieties of Ukraine) and Coral (Pat. on the variety № 140830). Economic effect from growing of the Coral variety in the conditions of Transcarpathia is 10230 UAH/ha and the level of profitability is 28.4%. The geographic position and agroclimatic conditions of Transcarpathia, as well as the unpretentiousness of L. officinalе C. Koch. tо the conditions of growing contribute to the enrichment of the local flora with useful plants; and the rich chemical composition contributes to the spread of this culture in the given region.

• The increasing importance of grapevine trunk diseases

  21-30.

  Cs. Kovács

  E. Sándor

  Views:

  363

  Grapevine trunk diseases (GTDs) are destroying the woody parts of the plants, resulting decline or dieback of the grapevine. More detailed research of the GTD began in 1950s, when Hewitt et al. (1957) observed that specific symptoms cannot be detected on the diseased trunks every year. Latest results have also proved that abiotic factors affect the appearance and the severity of the disease. Moreover several pathogenic fungi may play role as causative agents (Bertsch et al., 2013). Eutypa, Botryosphaeria, Phomopsis dieback, esca disease complex, and Petri disease are considered the major GTDs, where a variety of pathogens attack the woody perennial organs of the vine and ultimately lead to the death of the plant (Lehoczky, 1974; Larignon & Dubos, 1997; Rolshausen et al. 2010; Kotze et al., 2011; Bertsch et al., 2013; Fontaine et al., 2015).
  The GTD incidence has been reported to be increased during the last decades (Úrbez-Torres et al., 2014). The esca incidence has reached 60% to 80% in some old vineyards in southern Italy (Pollastro et al., 2000; Surico et al., 2000; Calzarano & Di Marco, 2007). The disease incidence of the esca was reported to be increased from 1.83% to almost 13%, between 2003 and 2007 in Hungary (Dula, 2011). There was detected a five times increase in the GTD disease incidence in the Tokaj Wine Region, Hungary between 2014 and 2016 (Bihari et al,
  2016).