The influence of leaf area and various variants of manual defoliation on the phenolic profile of the Prokupac variety grape berry were investigated in the agroecological conditions of southern Serbia. The following four trial variants of manual defoliation were assessed: Early defoliation—variant I (flowering stage, 50% open flowers); early defoliation—variant II (grape size 3–5 mm); late defoliation—variant III (onset of grape ripening, veraison); and control (no defoliation). The first six leaves of each primary shoot were removed from all defoliated vines. The greatest assimilation area of primary and lateral shoots during the study was observed in the control, i.e., the trial variant with no defoliation. Defoliation significantly decreased the grape yield of the all three defoliated variants in regard to the control. The phenolic profile of the three variants and control was established by analyzing the grape seeds and skin. Based on the collected results for the Prokupac variety, significant differences between the trial variants were established regarding the content of phenols and total polyphenols, as well as radical scavenging activity. Defoliation variants showed a significant effect on the total phenols content of grape skin. In all defoliation variants, as well as in the control, high amounts of ellagic acid were measured. Resveratrol was identified only in grape skin samples of the control variant. The removal of leaves increased the concentration of phenolic compounds in variants where early defoliation was applied. The highest total anthocyanins content was found in 2015 in variant I, where leaves were removed during the full flowering stage.

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.

Research and practice experience have shown that in the Republic of Serbia, vine pruning residues (VPRs) from vineyard production are mostly partially ploughed or uncontrollably burned in fields. Uncontrolled burning of VPRs in fields can destroy flora and fauna and cause uncontrolled fires. On the other hand, on an annual basis, the resulting VPRs can completely replace the fossil fuels used for thermal energy production on these estates and significantly reduce the emission of pollutants from fossil fuels. The novelty of this study lies in the fact that the research was conducted on a very young vineyard, four years old, and the results show that the agricultural property is fully sustainable in terms of thermal energy needs. The research aimed to investigate the energy potential of VPRs at the vineyard located in the Mrčić settlement in Western Serbia. The research results include the following grape varieties: Tamjanika, Morava, Cabernet Sauvignon, and Cabernet Franc. The average yield of VPR biomass for all tested varieties was 0.387 kg/vine or 1741.50 kg/ha. The lower calorific values for the tested biomass samples at 15% moisture content ranged from 14,668 kJ/kg to 14,258 kJ/kg, while the upper values ranged from 16,099 kJ/kg to 15,721 kJ/kg. The total energy potential of biomass obtained from a vineyard, expressed in final energy, was 41.90 MWh/year. In the observed vineyard, for the same equivalent value, biomass from VPRs was 3.57 times cheaper compared to brown coal and 8.26 times cheaper compared to diesel fuel.

In the modern global environment, there is a trend of increasing and changing the structure of demand for agricultural sector products. This situation requires a market-oriented approach from agricultural producers, ranging from economic entities to individual farms. Serbia’s agricultural policy is characterized by short-term, ad hoc measures, which prevent predictions and timely adjustments by producers, leaving participants in the market chain uncertain about their long-term orientation. In the total value of agricultural production in 2023, crop production accounted for 69.8%, while livestock production accounted for 30.2%, whereas in developed EU countries, the ratio of crop to livestock production is reversed. This indicates a significant share of low-value-added production, or production with a low level of processing. This paper analyzes the state of Serbia’s agricultural sector, which is under pressure from poor agricultural policies, numerous internal weaknesses, and insufficient financial resources in an unstable geopolitical environment.

Wheat yields in production often fall below the genetic potential of varieties, creating a persistent challenge in improving productivity. This study investigated the effects of genotype, sowing date, sowing density, and fertilization model on wheat yield, as well as their interactions, to identify optimal management strategies. Field trials were conducted during two successive growing seasons in the Semberija region, Republic of Srpska, Bosnia and Herzegovina, using three wheat varieties. The experiment followed a randomized split-plot design with three replications, including three varieties, three sowing dates, five sowing densities, and three fertilization models. Data were analyzed with four-factor ANOVA, and significant differences were tested using Fisher’s LSD at the 0.05 and 0.01 probability levels. The results showed that average yields exceeded 8,000 kg ha⁻¹ in the first year, but decreased with delayed sowing. Yield losses due to late sowing could not be offset by increasing seed density, although 400-500 seeds m⁻² proved optimal. Fertilization effects varied across conditions, with the second fertilization model producing the highest yields under favorable circumstances. Overall, both individual treatments and their interactions significantly affected yield, underscoring the importance of tailoring sowing and fertilization practices to specific varieties and environments.

This study examined the morphogenesis of male inflorescences (catkins), staminate flowers, and pollen development in five walnut cultivars over two years. Differentiation of catkins began in spring with the formation of axillary meristems, followed by the successive development of bracts, floral meristems, the perianth, and stamens. Clear genotypic differences were observed in developmental dynamics: the cultivars ‘Sheynovo’ and ‘Champion’ entered the key stages of organogenesis earliest, whereas ‘Elit’ showed the latest differentiation and flowering. During the summer, catkins grew intensively until August, after which their growth slowed considerably. In the following spring, reproductive organ development resumed, with temperature conditions having a marked influence on growth rate. Histological analysis showed that the walnut anther develops through the differentiation of the epidermis, endothecium, middle layers, and tapetum, while microsporogenesis proceeds synchronously within the same microsporangium. Meiosis lasted 6-8 days, the tetrad stage 2-3 days, and the microspore and two-celled pollen stages 7-10 days each. Mature pollen grains were pantopororate, with a spinulate exine. The study was supported by photographic documentation of characteristic stages in the development of catkins, flowers, and anthers, as well as histological and cytological changes in the microsporangia. Strong correlations (r = 0.90-0.98**) were found between developmental stages and the morphometric parameters of catkins and anthers. These results contribute to a better understanding of walnut reproductive biology and may be significant for breeding and cultivar selection according to male flowering phenology.