Institute of Field and Vegetable Crops

Accurate wheat yield prediction is essential for ensuring food security and sustainable resource management under the increasing challenges of climate change. This study investigates the integration of unmanned aerial vehicle (UAV)-based multispectral imaging and machine learning (ML) techniques to improve yield forecasting in European wheat cultivars. Field experiments were conducted on 400 sub-plots with varying NPK fertilization regimes and five wheat varieties, monitored across six phenological stages during the 2023 growing season in Vojvodina, Serbia. A DJI Phantom 4 Multispectral UAV collected high-resolution imagery, from which 65 vegetation indices were computed. Using PyCaret’s automated ML framework, 25 regression algorithms were evaluated for yield prediction. Ensemble models, particularly Random Forest, Extra Trees, Gradient Boosting, and LightGBM, consistently outperformed linear and kernel-based approaches. The highest prediction accuracy was achieved with the Random Forest Regressor during full flowering (BBCH 65–69), yielding an R2 of 0.952 and an RMSE of 0.44 t/ha. Results highlight the temporal dynamics of model performance, with optimal predictions occurring during reproductive stages. The findings confirm that UAV-derived multispectral data, coupled with ensemble machine learning, provide a non-invasive, accurate, and computationally efficient method for yield forecasting. This framework has significant potential for supporting precision agriculture, enabling real-time decision-making, and enhancing the resilience of wheat production systems.

In recent years, iron oxide nanoparticles (Fe3O4 NP) have emerged as a promising eco-friendly approach to mitigate various abiotic stresses. However, the role of surface-coated Fe3O4 NP with bio-derived organic compounds, particularly fulvic acid, in mitigating saline-alkali stress in Chinese kale plants has not yet been explored. In this study, we investigated for the first time the effects of green-synthesized Fe3O4 NP, both uncoated (UFe) and fulvic acid-coated (FFA), on mitigating saline-alkali stress in Chinese kale, with a specific focus on modulating physiological responses and biochemical parameters. Both UFe and FFA alleviated growth inhibition caused by saline-alkali stress; however, FFA consistently outperformed UFe across all measured parameters. UFe and FFA treatments restored shoot and root biomass, improved relative water content, and stabilized the membrane integrity by reducing electrolyte leakage and lipid peroxidation. Photosynthetic capacity was strongly enhanced, as reflected by higher net photosynthetic rate, stomatal conductance, Rubisco activity, chlorophyll index, and PSII efficiency. Oxidative stress was alleviated through significant reductions in H2O2 and MDA, supported by activation of SOD, CAT, and APX enzymes and strong recovery of the ascorbate-glutathione cycle, particularly under FFA treatment. At the transcriptional level, both treatments upregulated genes associated with antioxidant defense (SOD, CAT, APX, GR, DHAR), osmolyte biosynthesis (P5CS1), stress tolerance (LEA), photosynthesis (RBCS, LHCB1), and secondary metabolism (PAL, CYP79F1); however, this response was more pronounced in FFA-treated plants. These transcriptional changes were consistent with enhanced accumulation of osmolytes, including soluble sugars, free amino acids, and proline. Untargeted LC-MS/MS metabolomics identified 46 differentially regulated metabolites spanning sugars, amino acids, organic acids, glucosinolates, and phenolics. Multivariate analyses (PLS-DA and VIP scores) further highlighted proline, glucobrassicin, sinigrin, tryptophan, citric acid, and caffeoylquinic derivatives as key discriminators, enriched in both treatments but more substantially in stress + FFA, reflecting enhanced osmoprotection, redox stability, and secondary metabolism. Fulvic acid functionalization substantially enhanced the stress-mitigation potential of Fe3O4 NP, with FFA conferring significant improvements in growth, photosynthesis, antioxidant defense, gene regulation, and metabolic reprogramming, suggesting its potential as a nano-biofertilizer for saline-alkali soils.

This study presents the first integrated analysis of genotype–medium interactions and temporal morphogenesis profiling in sunflower regeneration. It aims to characterize genotype-specific responses, identify predictive morphological markers, and develop a scalable framework for breeding and transformation. Eighteen sunflower genotypes were evaluated to assess organogenic performance. The model genotype Ha-26-PR was used for a complementary experiment, testing varying sucrose concentrations to examine their influence on morphogenic outcomes. Hierarchical Cluster Analysis (HCA), guided by the Elbow method, identified four optimal clusters (K = 4). These aligned with three biologically meaningful categories: High Regenerators (Cluster 1), Moderate/Specific Regenerators (Clusters 2 and 3), and Non-Regenerators (Cluster 4). On S1 medium, NO-SU-12 and AS-1-PR showed superior shoot regeneration, while on R4 medium, HA-26-PR-SU and NO-SU-12 performed best. Genotypes such as NO-SU-12 and AS-1-PR consistently excelled across both media, whereas AB-OR-8 and FE-7 remained non-regenerators. Medium R4 supported superior regeneration, primarily through root formation, while S1 failed to induce roots in any genotype, highlighting the importance of hormonal composition. Although sucrose promoted callus induction, it did not trigger organogenesis. Callus was consistently present across media and time points, but its correlations with shoot and root formation were weak and temporally unstable, limiting its predictive value. Root formation at 14 days (Root 14D) emerged as a robust early predictor of organogenic success. This integration of morphological, temporal, and statistical analyses offers a genotype-tailored regeneration framework with direct applications in molecular breeding and CRISPR/Cas-based genome editing.

Wheat agronomic traits and soil microbial activity were closely shaped by NPK supply. Moderate to high fertilization improved plant height, thousand grain weight and yield, while the number of grains per spike remained relatively stable. Number of Azotobacter spp. and soil dehydrogenase activity increased with nutrient input, ammonifiers increased mainly at higher rates, and actinomycetes did not change significantly. Statistical results confirm the importance of balanced NPK management for enhancing both wheat productivity and soil biology.

Spelt (Triticum spelta L.) is an ancient wheat species that holds an important place among alternative cereals and is increasingly attractive due to its highly favourable agronomic, nutritional and medicinal characteristics. This cereal should play a leading role in organic plant-based food production. The aim of this research was to determine the influence of sowing time and fertiliser type on the yield of the spelt varieties Nirvana and Ostro. The one-year study (2023/24) was conducted at the Experimental Farm of the Research and Development Institute “Tamiš” in Pančevo, on a plot certified for organic production, using a split-plot design with four replications. Sowing time significantly affected the dynamics of phenophase occurrence and duration. The longest vegetation period during the study was achieved with sowing on 16 October (256 days), while the shortest was with sowing on 31 October (241 days). Sowing time had a notable impact on yield in both varieties: later sowing resulted in higher grain yield. This is explained by the milder winter compared to previous years and the later onset of cold periods, which allowed later-sown varieties to be better prepared. Organic fertilizers (Guanito) and microbiological fertilizers (Unimax and Slavol) influenced the number of spikelets: with top-dressing in any combination, the number of fertilized spikelets increased while unfertilized spikelets decreased. Spelt grain possesses high nutritional value and deserves much greater attention in the system of producing safe and healthy food.

The identification of wheat genotypes with balanced grain yield, stability, and antioxidant response to abiotic stress is crucial for creating adaptable varieties in changing climates. The research was conducted as a multi-environment trial (MET) across six environments (three localities over two seasons), and included 15 wheat genotypes (bread wheat lines, standard varieties and two spelt wheat lines). This study integrates AMMI and GGE biplot analyses with antioxidant profiling across growth stages to identify genotypes combining yield stability and stress tolerance. Lines KG-4/1, KG-11/1 and the variety Pobeda were identified as high-yielding and stable genotypes, with KG-11/1 ranked as an “ideal genotype” and KG-4/1 achieving the highest grain yield on MET level (6.48 t ha–1). Specific adaptation of genotypes KG-40/1 and Renesansa indicates their potential for targeted breeding in particular environments. Antioxidant parameters (TPC and DPPH• scavenging activity) at early growth stages were positively correlated with grain yield, indicating that they can serve as suitable biochemical markers for selecting stress-tolerant, high-yielding wheat genotypes. This comprehensive approach, which includes the analysis of grain yield stability/adaptability and antioxidant parameters, is adequate for the evaluation of promising lines that may be suitable genetic resources in climate-resilient wheat breeding programs.

Abstract Wheat straw, as a lignocellulosic residue, can be effectively converted into compost, representing a sustainable approach to agro-industrial waste management. This study investigates the effect of inoculating wheat straw with Bacillus strains on composting dynamics and organic matter degradation efficiency, with implications for soil quality improvement and environmental sustainability. Compost maturity and quality were evaluated through chemical and biological parameters over a 40-day period. Results showed that Bacillus -inoculated compost exhibited traits of a stable and mature product: the NH 4 ⁺-N/NO 3 ⁻-N ratio was 0.625, the C/N ratio was 25.88, and the pH was 7.26. The mineral composition of the inoculated compost was significantly increased compared to the control compost, namely: Ca (36%), Mg (58%), Cu (62%), and Zn (75%), with the greatest increase observed in Mn concentration (threefold). Phosphorus content in the treated compost increased eightfold compared to the initial value and exceeded that of the control. The germination index of white mustard seeds ( Sinapis alba L. ) was 30% higher in the inoculated sample. Bacillus strains accelerated the degradation of lignocellulosic material derived from wheat straw, yielding a mineral-rich, phytotoxin-free compost suitable for agricultural application and with enhanced biofertilization potential.

Roman chamomile is a perennial herbaceous plant that has been widely cultivated for its medicinal and ornamental properties. This study investigated the chemical composition, sensory properties, and antimicrobial potential of essential oils (EOs) and hydrolates (HYs) extracted through steam distillation (SD) and hydro-distillation (HD) from Roman chamomile grown in Serbia. GC-MS analysis showed that EOs were rich in esters such as isoamyl tiglate (21.1-32.5%) and isobutyl angelate (28.5-35.7%), while HYs contained trans-pinocarveol (20.9-22.7%) and pinocarvone (14.8-19.5%) as dominant compounds, with concentrations varying depending on the extraction method. These differences influenced sensory properties and were clearly distinguished in a PCA biplot. In general, the EOs exhibited a strong herbal and spicy aroma with floral, fruity, and minty undertones, while the HYs displayed a herbal scent with minty, ethereal, and green notes. Additionally, the antimicrobial, antibiofilm, and antiadhesion activities of the samples were evaluated against pathogens, including Salmonella enterica serovar Typhimurium, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, E. hirae, Staphylococcus aureus, and S. epidermidis. Results showed that EOs exhibited strong antimicrobial activity, with inhibition zones up to 40 mm and MIC values using diluted EOs, while HYs had no significant effects. Multivariate and in silico analyses indicated that the antimicrobial activity of EOs is likely due to the synergistic effects of fatty acid esters, which also contribute to their pleasant aroma and potential for cosmetic use. In contrast, the aroma compounds in HYs were not associated with antimicrobial properties. Since HYs are largely by-products of EO extraction, further research is needed to explore their biological activities and potential applications.

ABSTRACT Wheat yield in Pakistan is constrained by improper seed rates and weed interference. A two-year field trial (2020–2021) was conducted to determine the optimal seed rate and critical weed competition period for wheat. Treatments included three seed rates (37, 74, and 111 kg ha−1) with weed competition and weed-free periods up to 45, 60, and 75 days after sowing (DAS), along with full-season competition. The treatments were arranged in an RCBD in three replications. Results showed that a seed rate of 111 kg ha−1 with a weed-free period up to 75 DAS significantly reduced weed cover, density, and dry weight. It also enhanced plant height, productive tillers, grains per spike, 1000-grain weight, grain yield, biological yield, crop vigor, growth rate, leaf area index, test weight, and grain protein content of wheat. Weed-free up to 45 DAS resulted in better performance than the same duration of weed competition, showing that early-season weed control is important. The study confirms that the critical period for weed management may begin before 45 DAS and extend to around 75 DAS and recommends a seed rate of 111 kg ha−1 with at least 60 DAS weed-free period to maximize growth, yield, and quality of wheat.