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Vplyv odlistenia viniča hroznorodého na reguláciu cukornatosti a kyselín v hrozne
Soós, Tomáš
The aim of this study was to summarize findings on the effect of partial defoliation on quality characteristics of Vitis vinefera and to compare them with own experiment's results. An experimental vineyard in Malokarpatská vinohradnícká oblasť in The Slovak republic was chosen where Vetlínske zelené cultivar is grown. Here a partial defoliation of the same intensity was done at different time (before flowering / right after flowering / twice during grapes ripening) at the different grapevines. Quality characteristics of the grapes (total soluble sugar, total titratable acid, pH value ...) from the experimental vineyard were measured and compared with the quality characteristics of grapes from non-defoliated vines. The results of the experiment are in line with existing findings. Sugar content in berries of partially defoliated vines, where the defoliation was done right after flowering, was significantly higher than in berries of vines defoliated at other time or non-defoliated vines. Defoliation had no significant effect on total titratable acid in grapes and pH value. The level of yeast assimilable nitrogen was higher in berries of partially defoliated vines. In conclusion, defoliation soon after flowering had positive effect on grapes quality. Defoliation increased sugar content and yeast assimilable nitrogen in berries and improved the quality of grapes.
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Vliv intenzity odlistění na kvalitu hroznů
Zugárková, Petra
The aim of this thesis was to establish experiment with different dates of defoliation in the zone of grapes, evaluate the infestation by Botrytis cinerea putrefaction, monitor the development of qualitative and quantitave parametres and the content of phenolic compounds. The experiment was conducted at white wine grapes variety Ryzlink rýnský a blue wine grapes variety Carmenere. The literary section describes leaf and its area, microclimate of leaf walls, qualitative parametres, balance of the vineyard, green works, Botrytis cinerea and partial defoliation. Within the experiment were evaluated and controled at the defoliated variation: quality parameters (sugar content, titratable acid pH, assimilable nitrogen, amount of glucose and fructose, tartaric acid and malic acid), infestation by Botrytis cinerea putrefaction, content of phenolic compounds. Measurements were performed at the Department of viticulture and viniculture in faculty of Horticulture in Lednice. Used instruments: TitroLine - pH, titratable acid, assimilable nitrogen; HPLC - tartaric acid, malic acid, glucose and fructose; Spectrophotometer - the content of phenolic compounds; Digital Scale - weight of the grapes. As the most appropriate option in terms of measured parameters was selected the option before the flowering and during the flowering of Ryzlink rýnský and Carmenere.
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