Agricultural Science and Practice

National Features of the Nitrate Directive Implementation in Agricultural Practice

M.M. Miroshnychenko — 2026-04-23

Aim. To substantiate the approach towards the identification of zones, vulnerable to nitrate accumulation, based on the data of mineral nitrogen content in soil according to the requirements of the Nitrate Directive. Methods. The study was conducted on arable soils of humus-accumulative genesis on six land plots in the Forest-Steppe of Ukraine with the rate of applying nitrogen-containing fertilizers from 0 to 170 kg/ha. The content of mineral nitrogen (Nmin), nitrates and productive moisture reserves was determined layer-wise down to the depth of 120 cm, in dynamics during the vegetative periods of 2021, 2024, and 2025. Crops: grain corn, winter wheat, spring barley, oil flax. Results. A considerable variability in the content of Nmin and nitrates proper was determined in soil depending on terms, ways, and norms of applying nitrogen-containing fertilizers. The maximal concentrations were observed in the arable soil layer immediately after the application of nitrogen fertilizers, but these parameters gradually decreased with time and depth. In June–July, the highest accumulation of nitrates in deep soil layers was noted when, at the norm of the application of fertilizers of over N100, the content of nitric nitrogen at the depth from 80 to 120 cm was from 15.6 to 35.8 mg/kg. The accumulation of nitrates in deep layers of soil decreases in the course of the vegetation period, and at the time of harvesting, the content of nitric nitrogen at the depth of 80–120 cm did not exceed 10 mg/kg in a year with normal moisturization conditions and 4 mg/kg in a dry year. At the norm of applying fertilizers up to 100 kg/ha, the accumulation of Nmin and nitrates in deep soil layers is minimal. Conclusions. The use of Nmin as an indicator corresponds to the requirements of the Nitrate Directive regarding the identification of zones, vulnerable to the accumulation of nitrates. It is reasonable to take measurements after harvesting the crops. The application of nitrogen-containing fertilizers for the crops of rotations on arable soils of the humus-accumulative genesis in the plains of Ukraine with non-flushing or periodically flushing type of the water regime at the norm, not exceeding 100 kg/ha, does not pose any threat of leaching mineral nitrogen and its nitrate forms from soil and further pollution of the underground waters.

Seroprevalence and Risk Factors Associated with Bovine Brucellosis and Abortion in Holstein Heifers

J. Mellado — 2026-04-23

Aim: To estimate the seroprevalence of bovine brucellosis (bBR) and identify risk factors associated with seropositivity to this disease. An additional aim was to evaluate heifer-related risk factors for abortion. Methods: A total of 3,848 Holstein heifers with a single lactation from a large commercial dairy herd in northern Mexico (25°N) participated in this study. Multiple regression models were employed to analyze risk factors for brucellosis seropositivity rate and to calculate odds ratios, quantifying the strength of the risks. Results: The seroprevalence of bBR was 30% (95% CI=29–32%) for lactating heifers (card test). Heifers weighing more than 680 kg at calving had half the risk of testing positive for bBR compared to those weighing less than 680 kg (22.7% vs. 36.1%). The risk of being seropositive for bBR increased in heifers with retained placenta compared to those without this reproductive disorder (OR=2.46; 47.5% vs. 26.3%). Heifers vaccinated with two doses of a commercial brucellosis vaccine had 2.2 times higher odds of being seropositive for bBR compared with those vaccinated only once (P<0.01). Seropositive heifers for bBR were 3.1 times more likely to abort than seronegative heifers (38.5% vs. 16.2%; P<0.01). Heifers with a body condition score (BCS) of 3.5 or higher at calving were less likely to abort than heifers with BCS<3.5. Conclusions: Brucellosis control programs should prioritize age at first calving, placenta retention, and the number of RB51 vaccinations administered to Holstein heifers.

Polymorphism of SCD1 Gene and Its Associations with Dairy Performance in Ukrainian Red-and-Motley Cattle and Their Crossbreeds

V.V. Dzitsiuk — 2026-04-23

Aim. To investigate the genetic structure of populations of the Ukrainian Red-and-White Dairy cattle (URW) and its crossbreeds based on SNP g.10153G>A at SCD1 locus and to evaluate the association of this polymorphism with traits of dairy performance and the fat and protein content in milk. Methods. The genetic structure of two groups of cows (purebred URW, n=43; URM × M crossbreeds, n=41) was studied by g.10153G>A polymorphism of SCD1 gene using the PCR-RFLP method. The performance was assessed using the indicators from the first completed lactation. The correspondence of the distribution of quantitative traits to the normal law was tested using the Shapiro-Wilk test. For normally distributed traits (milk yield), one-way analysis of variance (ANOVA) with Tukey's post-hoc test was used; for non-normally distributed traits (fat and protein content), the Kruskal-Wallis test with Dunn's post-hoc test adjusted for Bonferroni correction was used. Results. Certain intergroup differences in allele distribution were observed: in purebred animals, a slight predominance of allele G was observed (0.535 versus 0.465 for allele A), whereas in crossbreeds, a relative increase in the frequency of allele A was noted (0.524 versus 0.476 for allele G). In the crossbreed group, an increased frequency of the heterozygous AG genotype (0.512) was also observed. For milk yield indicators, opposite genotype-associated trends were identified between groups: in purebred animals, the highest mean values were observed in homozygous AA individuals, whereas in crossbreed animals, they were observed in heterozygous AG individuals; however, within individual groups, no statistically significant differences between genotypes were found (p > 0.05). No statistically significant associations with genotype were found for fat and protein content (p > 0.05). Conclusions. The results obtained indicate the presence of certain genetic differentiation between the study groups at the SCD1 locus and a possible dependence of the manifestations of the associations on the genetic background of the population. At the same time, no statistically confirmed effects of polymorphism on milk yield, fat content, or protein content were found. Further studies using larger sample sizes are needed to clarify the nature of the identified trends.

Antifungal Activity of Four Trichoderma Species against Phytophthora megakarya, the Causal Agent of Cocoa Pod Brown Rot in Côte d'Ivoire

C. N'Guessan Adou Bedel — 2026-04-23

Aim. In Côte d'Ivoire, cocoa pod brown rot caused by Phytophthora megakarya represents a major constraint to sustainable cocoa production due to the severe yield losses it induces. This study aimed to evaluate the antifungal activity of four Trichoderma species (T. harzianum, T. asperellum, T. virens and T. hamatum) against P. megakarya under in vitro and in vivo conditions using detached cocoa pods. Methods. In vitro assays were conducted using a dual culture technique on PDA medium to assess the inhibition of mycelial growth of the pathogen. In vivo tests consisted of preventive treatments followed by aggressive and non-aggressive inoculations on healthy cocoa pods. Results. The in vitro results showed a significant inhibition of P. megakarya mycelial growth by all Trichoderma species, with inhibition rates ranging from 77.27% to 89.27%. Trichoderma virens exhibited the highest antagonistic activity. Under in vivo conditions, T. virens and T. harzianum significantly reduced the severity and spread of cocoa pod brown rot, with inhibition rates exceeding 80% depending on the inoculation method. Conclusions. The in vitro and in vivo assays showed that all tested species exert a significant inhibitory effect on the development of the pathogen, although the efficacy varies according to the Trichoderma species. Among the evaluated species, Trichoderma virens stood out for its strongest ability to inhibit the mycelial growth of P. megakarya and for a marked reduction in disease severity on cocoa pods under both aggressive and mild inoculation conditions. These results confirm the strong potential of Trichoderma species, particularly T. virens, as effective biocontrol agents against P. megakarya and support their integration into sustainable management strategies for cocoa pod brown rot, however, further field studies are necessary. ```

Endogenous Antioxidant Defense Responses in Grapevine Plants to the Infection of GLRaV-3

N. Sultanova — 2026-04-23

Aim. The aim of this study was to investigate how viral infections, which severely impair plant growth and productivity, affect reactive oxygen species (ROS) accumulation, and to evaluate the roles of both enzymatic antioxidant defenses and non-enzymatic low-molecular weight antioxidants, including ascorbate (ASA), glutathione (-L-glutamyl-L-cysteinyl-glycine = GSH), and tocopherols (TOCs), in mitigating virus-induced oxidative stress in plants. Methods. In the present study, a total of 45 leaf samples were collected from mature 10-year-old vines of the cultivars 'Gara Shani' (red) and 'Ag Shani' (white). Sampling was conducted in three vineyards, where five vines were selected per vineyard, and three physiologically mature leaves were collected from each vine, resulting in 15 leaves per vineyard and 45 leaves in total (3 vineyards × 5 vines × 3 leaves). In each vineyard, one vine without visible symptoms was designated as a healthy control, while the remaining vines exhibited typical viral symptoms such as reddening of leaf margins and petioles, reduced vigor, leaf rolling, yellowing, and curling. Consequently, 36 leaves were obtained from symptomatic vines and 9 leaves from asymptomatic (healthy) vines. Grapevine leafroll-associated virus 3 (GLRaV-3) infection was confirmed in grapevine samples using AgriStrip rapid assay, double-antibody sandwich ELISA (DAS-ELISA), and reverse transcription-polymerase chain reaction (RT-PCR). Subsequently, virus-induced changes in non-enzymatic antioxidants were quantified by spectrophotometric determination of ascorbate and glutathione, tocopherols via the Emmerie-Engel reaction, and lipid peroxidation through MDA content using the thiobarbituric acid reactive substances (TBARS) assay. Enzymatic antioxidant activities, including ascorbate peroxidase and catalase, were measured spectrophotometrically, and soluble protein content was determined by the Sedmak method. Results. Viral screening using AgriStrip assays and DAS-ELISA, followed by RT-PCR targeting the coat protein gene, confirmed GLRaV-3 infection in 13 samples (approximately 36.1%), while symptomless vines tested negative, demonstrating consistency between visual assessment and molecular diagnostics. GLRaV-3 infection resulted in significant increases in non-enzymatic antioxidant levels compared with healthy controls. Tocopherol (TOC) content increased by 18-73% across infected samples 2-6, whereas sample 1 showed no significant change. Glutathione (GSH) levels were elevated by 20-60% in infected samples 1, 2, 4, 5, and 6, while sample 3 showing no significant difference. Ascorbic acid (ASA) content increased by 10-23% in infected samples 1, 3, 5, and 6, with sample 2 and 4 showing no significant difference. Lipid peroxidation, as indicated by malondialdehyde (MDA) content, was also significantly enhanced in infected leaves. MDA levels increased approximately 1.5-2.6-fold in samples 1, 2, 4, 5, and 6 compared with healthy controls, reaching absolute values of 0.85-1.75 µmol g-1 FW versus 0.45-0.9 µmol g-1 FW in controls. In parallel, the activities of key antioxidant enzymes were elevated: catalase (CAT) activity increased by 25-48%, and ascorbate peroxidase (APX) activity increased by 30-55% in infected leaves compared with corresponding controls. Conclusions. Surveys conducted in Salyan vineyards confirmed GLRaV-3 infection supporting the link between observed symptoms and biochemical oxidative stress responses. These biochemical changes demonstrate that GLRaV-3 infection triggers oxidative stress and concurrently activates both enzymatic and non-enzymatic antioxidant defense mechanisms in grapevine leaves. The coordinated increase in ASA, GSH, TOC, CAT, and APX, alongside elevated MDA, indicates a complex redox adjustment aimed at mitigating virus-induced oxidative damage. ```

Biological Properties of Spelt Wheat and Prospects of Its Use in Breeding

O.M. Radchenko — 2026-04-23

Spelt wheat (Triticum aestivum ssp. spelta (L.) Thell.) is a type of hulled wheat whose genome is the same as that of hexaploid common wheat (T. aestivum L.) and is characterized by many valuable properties, including plant resistance to pathogens, better adaptability to adverse environmental factors, increased protein content in the grain, and nutritional value of the grain. In recent years, the popularity and use of spelt in the world, and in Ukraine in particular, has been steadily growing, which is associated with the development of organic farming, as well as the need for high-quality food products provided by this crop. In this regard, the purpose of this review was to present the current state of research into the biological properties of spelt wheat, as well as the prospects for its use in breeding. The current hypotheses of the origin of this crop, its distribution in the world and Ukraine, as well as the biological characteristics of this cereal are briefly considered. The genetic features of spelt are highlighted in detail, in particular the genes of morphological traits, vernalization and photoperiod, the variability of waxy genes. The polymorphism in the genes of storage proteins and the prevalence of their alleles, which can be used as marker systems and a source of enriching the common wheat gene pool, are described. The modern data on the quality of spelt grain, including its physical properties, chemical composition, functional-technological and baking properties of flour are presented. The physiological effect of spelt consumption is highlighted. This cereal is considered as a source of useful genes for common wheat breeding. The information on modern strategies and new scientific directions of genetic improvement of this crop is presented.