The variety Prokupac is the dominant variety in the vineyards of Southern Serbia, which produces quality wines of characteristic and unique tastes. In the agroecological conditions of the Prokuplje vine district, the influence of manual defoliation on the phenolic profile of the wine produced from the variety Prokupac was examined. Four experimental treatments with different timings of manual defoliation were applied: early defoliation—treatment I, early defoliation—treatment II, late defoliation—treatment III and the control. The phenolic profile of the wine was determined for the three treatments of defoliation and the control treatment. Additionally, a multivariate analysis was applied on the obtained results, together with already published data (grape seeds and skins phenolic profiles). Identification and quantification of the phenolic compounds was performed using ultra-high-performance liquid chromatography (UHPLC) with an ultraviolet multi-diode detector (DAD) and mass detector with three analyzers—triple quadrupole (QQQ). Based on the obtained results, it was determined that there are significant differences between the experimental treatments in the content of individual polyphenols, total polyphenols and the antioxidant capacity. Twenty (20) phenolic compounds were identified in the wine samples of the experimental treatments. Defoliation significantly affected the variations of the contents of phenolic acids and flavonoids. In treatment III, the highest content of gallic acid was obtained, while the treatments with early defoliation did not differ in relation to the control sample. Early defoliation in treatments I and II had an effect on the phenolic composition of the wine by favoring the accumulation of flavonol, while the content of hydroxycinnamic acid and total anthocyanins (TAC) was higher in treatment III. The TAC increases with later defoliation. The wines obtained by the defoliation treatments did not show higher antioxidant activity compared to the control sample. A principal component analysis resulted in clustering of the samples based on the phenolic components characteristic for each group of samples.

The variability and mode of inheritance of young shoot tip, leaf, grape and berry morphological characteristics were investigated in F1 generation obtained by crossing of Drenak crveni and Afuz-ali. Based on seedlings description, considering investigated characteristics, grouping was done by applying O.I.V. method. The conclusions about inheritance of characteristics were obtained based on results of Hi2 test. The consider able variability was expressed in hybrid population. For properties of leaf characteristics (largeness, shape, dividity, and incisions), exception from typical monogenic ratio was determined. The monohybrid inheritance was determined in density of leaf hairs and downs. The monohybrid mode of inheritance was not confirmed in grape characteristics (largeness, compactness and stem length) and berry characteristics (largeness, shape and taste), while skin color is monogenic property.

This paper evaluates the application of a statistical model to estimate leaf surface area in grapevines, expressed as leaf area of an individual leaf as well as total leaf area per shoot, including any lateral shoots. Estimating the area of an individual leaf was based on a formula obtained by regression analysis that uses the sum of the lengths of two inferior leaf veins as an independent variable. To estimate the leaf area per main shoot and per lateral shoot we used the model derived from multiple regression analysis that has the following independent variables: the number of leaves, and surface area of the largest and of the smallest leaf on the shoot. High values of the coefficient of determination (r²), as well as satisfactory levels of mean absolute error (MAE), suggest that the applied models appear valid. These results have shown a good fit of observed and predicted values of shoot and lateral leaf areas.

The effect of pruning severity on quercetin and catechin content in berry skins of cv. Blaufränkisch (Vitis vinifera L.) was studied over 3 years. Different crop levels and canopy structures were obtained by retaining 8, 16, and 24 nodes per vine at pruning. Canopy density, which is proportionate to the shoot number per canopy volume, directly affects the intensity of photosynthetically active radiation (PAR). The quercetin content has been shown to be highly dependent on the light exposure of the berries in which it accumulates. An increase in node number linearly decreased skin catechin, and it is suggested that the decrease was caused by increased yield per vine.

The purpose of this paper was to characterize the clones obtained from Kreaca, autochthonous grapevine cultivar of Banat. Based on examination of 6 important biological and technological properties, phenotypic and genetic divergence of 28 selected clones was established. The divergence was determined using ANOVA and hierarchical cluster analysis. Using variance analysis, for grape weight, yield, total acid content, sugar content and sugar/acid ratio very significant or significant differences were obtained between clones. The UPGA method was used and the Euclidean distance in order to determine the difference between the groups. Two clone groups were obtained on the dendrogram. The objective of clone differentiation was primarily cluster weight, although other properties were taken into account as well. As the most perspective clones for further investigation and production, that can be recommended, were clones 12/5/5, 56/11/7 and 69/11/7.

The research was carried out at University of Belgrade Faculty of Agriculture experimental station “Radmilovac” on table grape Victoria cv with aim to improve grape quality and with consideration the introduction of these ampelographic measures in regular grapevine growing. The research included two treatments of berry thinning (thinning bunch tip - BtT and first lateral wink -BtW), girdling (G) and control (C). Combined effect of berry thinning and girdling were not examined. The following features were examined: fertility and yield, bunch and berry dimensions, bunch and berry structure, sugar content and total acidity. The thinning treatments did not have significant effect on uvometric parameters and grape quality, but they improved the yield by 41.7% (BtW) and 51.4% (BtT) in comparison to the control. It can be explained by bad fruit set influenced by unfavourable meteorological conditions during flowering in control treatment. Berry thinning achieves a better fruit set. Berry thinning should be applied as a regular ampelographic measure according to weather conditions during flowering phonological stage. Results confirm the positive influence of girdling. The yield was increased by 88,34% compared to control, berries had a higher diameter (for about 1mm with respect to control), fruit set and bunch mass were in higher level against other treatments, sugar content (17,00%), total acidity (5,75 g/L) were improved too. Girdling can be introduced as a regular ampelographic measure in the table cultivars vineyards, in order to obtain higher yields and better quality of table grape.