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68Several technological applications can be used in order to reduce these negative effects. 69Cluster thinning (Guidoni et al., 2002; Prajitna et al., 2007), girdling (Singh Brar et al., 2008; 70 Koshita et al., 2011) and early defoliation (Poni et al., 2006; Poni et al., 2009; Kemp et al., 2011; variety, fungal infections and yield (Jeandet et al., 1995; Bavaresco 2003; Bavaresco et al., 2007; 75 Prajitna et al., 2007). There are also some paper which are dealing with increasing resveratrol 76 concentration in grapes using elicitors (Vezzulli et al., 2007; Santamaria et al., 2011). accumulation is very fast at the Nagy-Eged-hill, leading too alcoholic, unbalanced wines. 91Besides, the desired level of phenolic maturity cannot be achieved in most of the vintages. The Three one kg samples for each treatment were collected at random from several clusters before 121 vinification. The berries were selected randomly from the upper, middle, and lower parts of the 122 bunches. All the berry samples were prepared and analyzed within 2 hours after the harvest. juices was determined at 20 °C using a hand-held refractometer (Atago MASTER-α, Japan). 137 Assesment of grape phenolic maturity 138The phenolic potential of grapes was calculated according to the method described by with their pedicel were removed from the bunch, they were laid on the plate of the analyzer and 158 then they were punctured in the lateral face (Letaief et al., 2008a). The skin break force (F sk ), 159 skin break energy (W sk ) and Young's modulus of berry skin (E sk ) were calculated from the 160 puncture test data using the software Exponent 6.1.4.0. Berry skin thickness (Sp sk ) was measured 161 using a P/2 probe with 2 mm diameter. For this measurement, approximately 0.25 cm 2 skin was 162 removed from the lateral face of the berry. The skin was carefully and gently cleaned of pulp, and 163 then placed on the platform and the test was conducted as described by other authors previously 164( Letaief et al., 2008a; Letaief et al., 2008b; Río Segade et al., 2008

The Bois noir (BN) disease induced by 'Candidatus Phytoplasma solani' (CPs) is common in European vineyards. Its damage has not been fully investigated, especially with regards to wine attributes. The impact of BN on yield, berry composition and wine characteristics of Vitis vinifera L. cv. 'Chardonnay' was therefore comprehensively characterized in a 3-year field experiment in Hungary, Eger winegrowing region. Additionally, the bindweed-related tuf-b1 genotype was identified to be involved in the BN pathosystem in the experimental vineyard. Infection of CPs tuf-b1 genotype resulted in severe yield loss, the average decrease in number of bunches and total yield per vine was 56.7% and 68.4%, respectively. Analyses of wines produced from grapes of BN infected vines revealed decreased alcohol, epicatechin and iron contents; and increased organic acids, titratable acidity, catechin and calcium contents. Sensory evaluation of these wines confirmed

The effect of moderate and severe water deficit was examined on berry skin phenolic concentration and composition of the Kékfrankos variety (Vitis vinifera L.). Moderate water stress induced higher concentration of anthocyanin derivatives compared to the non-stressed plants with, the exception of Cya-3-g. Concentrations of some anthocyanin derivatives (Mal-3-g and Peo-3-g) were also higher in the severely stressed berry skins than in the control berries. No differences were found between the stressed and the non-stressed plants in the case of Cya-3-g. Similarly, concentration of some flavonol components (ie. protocatechuic acid, gallic acid, vanillic acid, trans-resveratrol etc.) increased as a result of water deficit. On the other hand, others such as quercetin-3-glucuronide decreased as the water deficit increased. In general, water deficit had a great effect on grape phenolic concentration; however it can be modified by the changes in berry skin/flash ratio.

Fungal disease resistant (PIWI) interspecific grape varieties are playing an important role as an alternative for organic wine production. Organic (bio) wines are demanded by numerous conscious consumers around the globe. They choose this kind of wines predominantly because of the absence of synthetic pesticides, fertilisers and sustainable agriculture. Resistant grape growing moreover results in additional environmental and health benefits. Nero and Bianca are among Hungary's most promising interspecific grape cultivars gaining international interest recently, there are, however, limited vitivinicultural knowledge on them. Our aim was to examine the flavonoid and anthocyanin composition for both interspecific varieties during different harvest times in two consecutive vintages. The date of harvest and vintage played a significant effect on grape and wine quality.