Search Results (211)

During ultrasonic detection of buried seeds after sowing, variations in soil conditions can strongly affect ultrasonic signals and make seed identification difficult. In this study, soil moisture content, particle size, and compaction pressure were investigated to evaluate their effects on ultrasonic frequency-domain responses and seed-presence discrimination. The first-wave dominant frequency (F_g) and dominant-frequency amplitude ratio (k) were extracted from the received signals. Seed presence altered the spectral peak position and amplitude distribution, whereas the direction of the F_g shift varied with soil conditions, limiting its use as a standalone discrimination feature. In sieved soil, k showed the best discrimination at 10% moisture content, with an AUC of 0.951. Using the predefined threshold k = 1, the sensitivity, specificity, and overall accuracy were 94.7%, 81.3%, and 88.0%, respectively. In non-sieved field soil, the highest AUC was 0.923 at 15% moisture content, with an accuracy of 90.0% using k = 1. An additional 40 independent tests conducted at 15% moisture content and 0.50 MPa yielded a sensitivity of 95.0%, a specificity of 90.0%, and an overall accuracy of 92.5%. These results demonstrate the potential of ultrasonic frequency-domain features for identifying buried seeds under controlled soil conditions. Full article

The uniformity of maize plant spacing serves as a critical indicator for assessing sowing quality, seed vigor, and field seedling emergence stability. However, manual measurement is inefficient, and complex field conditions make automatic seedling detection and plant spacing measurement challenging. Aiming at the challenges of missed detection, insufficient accuracy for small targets, and large errors in plant spacing calculation under complex field conditions, this study constructs a high-quality dataset containing 693 maize seedling images and implements preprocessing enhancement for images degraded by haze or dust. An intelligent maize seedling detection and plant spacing measurement method based on improved YOLOv8 is proposed. The Global Attention Mechanism (GAM) is embedded into the backbone network to strengthen cross-dimension information interaction between channels and spaces, suppress background interference, and reduce the missed detection rate. The Bi-directional Feature Pyramid Network (BiFPN) is adopted to replace the original PAFPN for enhanced multi-scale feature fusion and deep semantic representation. A new 160 × 160 high-resolution small-object detection layer is added to significantly improve the detection performance of weak and small seedlings. Experimental results demonstrate that the improved model achieves a precision, recall, mAP50, and mAP50-95 of 89.4%, 90.3%, 94.4%, and 49.4%, respectively, which are 2.6, 0.5, 1.5, and 2.7 percentage points higher than those of the original YOLOv8 model. These results indicate that the proposed model improved maize seedling detection performance under complex field conditions. Automatic plant spacing calculation is realized based on detection outputs; the average plant spacing of the dataset is 30.42 cm, with a relative error of only 4.93% compared with the preset sowing spacing of 32 cm. The proposed method can efficiently accomplish field seedling identification, plant spacing quantification, and sowing quality evaluation, providing reliable technical support for precision maize sowing, seeder parameter optimization, and intelligent field management, which is of great significance for promoting the intelligent upgrading of grain crop production. Full article

Reliable establishment of direct-seeded onion requires coordinated control of sowing geometry, nutrient supply, crop protection, and resource use. This study combined Hartley-4 optimization of a four-section, multi-row ridge seeder with a two-year randomized complete block experiment comprising ten fertilization × crop-protection treatments. Engineering tests at 5.2, 6.4, and 7.6 km h⁻¹ identified a central operating setting at 6.4 km h⁻¹ that maintained a sowing depth of 1.5–2.0 cm and depth variability below 0.5 cm. In field plots, chemical protection with vermicompost produced the highest mean total yield (25.54 t ha⁻¹), whereas chemical split NPK maximized marketable and standard yields. Biological split NPK showed the greatest two-season yield retention (0.780), although biological protection was associated with higher downy mildew severity. The biological biocomplex treatment ranked highest under the author-defined EIQ-adjusted resource-efficiency screening index, but sensitivity analysis showed that intermediate rankings depended on aggregation assumptions. The optimized design provides manufacturers with validated parameter ranges and gives users a constant-speed platform for comparing crop-management programs. Future research should test the seeder across contrasting soil textures and speeds and directly measure field capacity, fuel use, and long-term agronomic performance. Full article

The propagation of native plants that support pollinators is a relevant strategy for strengthening seed banks, pollinator gardens, and local restoration efforts. This study evaluated whether pre-sowing magnetic exposure modifies germination, early survival, and initial seedling growth in two Salvia species with ecological and biocultural value from Michoacán, Mexico. A total of 1000 seeds, equally distributed between both species, were analyzed. The seeds were assigned to a non-exposed control group and magnetic field exposure treatments at 83.94, 166.94, 292.30, 305.40, 350.70, or 375.10 mT for 5, 10, 15, or 20 min. Germination, survival, time to radicle emergence, and seedling height on day 13 were recorded. Although magnetic exposure did not significantly increase germination, seedlings from exposed seeds were taller on day 13 than those in the control group. Furthermore, higher seed mass increased germination probability. These results suggest that magnetic exposure cannot be considered a direct strategy to increase germination in these species but could be explored as a complementary tool to promote early seedling growth in native plants intended for conservation, environmental education, and restoration. Full article

This study investigated alternative pathways involving adaptive traits associated with drought tolerance in popcorn cultivated under soil water restriction through path analysis. Direct and indirect effects were estimated for morpho-agronomic variables, including ear height (EH), grain number per ear (GNE), grain number per row (GNR), 100-grain weight, grain yield (GY), and popping expansion (PE); physiological variables, such as relative chlorophyll content, anthocyanin and flavonoid indices, and maximum quantum efficiency of photosystem II; and root-related traits, including brace- and crown-root number and root angle. Fifty popcorn inbred lines were assessed under contrasting water conditions (WC), namely well-watered and water-stressed environments, during two crop seasons (CS). Water restriction was imposed before male anthesis, and the permanent wilting point was reached at 63 days after sowing in CS-2020 and at 100 days in CS-2021. Significant genotype × WC × CS interactions were identified for all evaluated traits. The effects of drought varied according to the developmental stage at which stress occurred. Under both water regimes, indirect selection through EH and GNR favored gains in GY, whereas EH and GNE showed the strongest indirect contributions to PE. Among the evaluated variables, EH emerged as a promising trait for indirect selection in popcorn breeding under water-limited conditions. Full article

The quality and productivity of tomato (Solanum lycopersicum L.) crops largely depend on the quality of the seedlings used for cultivation. Several factors, including cultivation strategy, fertilization practices, and abiotic and biotic stressors during early plant development, influence seedling quality. Recently, anaerobic digestate has attracted attention as a potential organic fertilizer and substrate component; however, information about its effects on tomato seedling quality remains limited, particularly when comparing different seedling establishment methods such as direct sowing and transplanting. Therefore, this study aimed to evaluate the effects of different concentrations of solid grain waste digestate (further digestate) in the peat substrate on the growth and physiological characteristics of tomato seedlings grown by means of direct sowing and transplanting. The experiment was conducted at the Institute of Horticulture of the Lithuanian Research Centre for Agriculture and Forestry in unheated greenhouses covered with double polymer film. Two cultivation strategies were applied (factor A): transplanting and direct sowing into pots. To evaluate the influence of digestate (factor B), different substrate compositions were used: peat (control) and peat mixed with 10%, 20%, 30%, 40%, and 50% digestate. The strong decline in growth parameters with increasing digestate concentration indicates that higher proportions of digestate created unfavorable conditions for seedling development in both cultivation stategies. A 10% digestate addition improved certain plant characteristics, while 20% improved some physiological indices but was associated with reduced growth. However, higher digestate concentrations (≥30%) negatively affected plant growth and physiological activity. Seedlings grown in substrates with higher digestate levels exhibited reduced transpiration rates and lower gas exchange indices, suggesting impaired water relations and stomatal regulation. These effects were more pronounced in transplanted plants compared with direct-sown seedlings, indicating greater sensitivity to changes in substrate composition after transplanting. Overall, the results demonstrate that digestate can be used as a substrate component for tomato seedling production. Still, its concentration must be carefully optimized to avoid negative effects on plant growth and physiological performance. Full article

Legume cultivation offers a chance for agricultural development on lands that have been abandoned over the years. In this study, simple agronomic indicators on the growth and yield of faba bean (Vicia faba L.), pea (Pisum sativum L.), and white lupin (Lupinus albus L.) were assessed on the abandoned agricultural lands of Foloi Plateau in Western Greece. Field trials were conducted from October 2023 to July 2025, and the legumes were grown either according to the false seedbed concept or with conventional seedbed preparation practices (direct sowing). The false seedbed involves pre-sowing weed control following initial seedbed preparation, and in these trials, it suppressed weed density by 62–77%. The Normalized Difference Vegetation Index (NDVI) of faba bean and pea increased by 13% on the false seedbed plots, while white lupin NDVI was not affected by treatments (p ≥ 0.05). Destructive crop biomass measurements were in accordance with NDVI assessments. Faba bean and pea seed yield demonstrated an increase of 17% and 23%, respectively, in the false seedbed plots compared to direct sowing plots. White lupin seed yield was not significantly affected by false seedbed (p ≥ 0.05). This study provides preliminary evidence supporting the use of legume crops as a component of sustainable agricultural revitalization in the Foloi region. However, further research is required to optimize legume cultivation on the abandoned lands of the wider region as a first step towards the agricultural revitalization in the Plateau. Full article

The present study was conducted to evaluate recently developed pungent and unpungent red pepper varieties for paprika production with respect to carotenoid and tocopherol composition and content. Varieties with outstanding traits were cultivated using various methods to determine the optimal conditions for maximizing bioactive component levels. The biologically ripe fruits of these varieties were stored under ambient conditions to initiate postharvest overripening. Carotenoids and tocopherols were analyzed using recent HPLC methods. The different varieties of pungent pepper differed significantly in the levels of carotenoid groups and tocopherols. Among pungent breeds, Hetényi Triász (HET-T), CF5, and Uniring (UNIR) showed the highest levels of total carotenoids (1967.39 ± 260.35, 1642.72 ± 67.41, and 1609.07 ± 524.52 µg g⁻¹, respectively). The highest amounts of provitamin A (187.60 ± 8.19 µg g⁻¹) were recorded in the CF5 variety. As regards tocopherols, the highest concentration (547.09 ± 44.20 µg g⁻¹) was recorded for CF5, with no significant differences among the studied varieties. However, the content of vitamin E was significantly higher in CF1 and CF5 than in HET-T and UNIR. Notably, under organic farming conditions, the carotenoid content in UNIR was significantly lower than in the direct-sowing and seedling-transplantation modes. Organic farming of UNIR resulted in lower levels of all carotenoid groups compared with other cultivation modes, particularly conventional seedling transplantation. The indoor cultivation of the unpungent Borbási genotype did not significantly improve the carotenoid content, particularly the total red xanthophylls. Ambient postharvest overripening led to a substantial increase, up to 3-fold, in carotenoid group content in both pungent and non-pungent genotypes. The average value for the total carotenoid content increased from 5005.7 to 8208.3 µg g⁻¹ in unpungent varieties and from 1896.4 to 3426.8 µg g⁻¹ in pungent varieties. For tocopherols, overripening had a slightly positive effect on total tocopherol (from 1375.3 to 1594.7 µg g⁻¹) and esterified forms of vitamin E in pungent breeds with a significantly high increase from 532.0 to 823.7 µg g⁻¹. In conclusion, postharvest overripening is indispensable for obtaining paprika products with an outstanding content of bioactive compounds, particularly red carotenoid diesters. Based on carotenoid content and response to overripening of red and total carotenoids, the UNIR and Borbási varieties are superior to other pungent and unpungent genotypes, respectively. The positive impact of postharvest overripening on carotenoid and tocopherol levels depended mainly on genetic factors. Full article

Soybean (Glycine max L.) is a globally strategic crop valued for its high-quality protein and oil, yet its yield potential is frequently constrained by inconsistent seed germination and a heavy reliance on chemical treatments that carry environmental and health risks. Physical pre-sowing stimulation has emerged as an eco-friendly alternative, but the comparative efficacy of direct current (DC) versus alternating current (AC) high-voltage electric fields—and the mechanistic basis for their differential effects—has remained poorly understood. Here, we systematically compared DC and AC pre-sowing treatments across a comprehensive matrix of field intensities (0.5, 1.0, and 1.5 kV/cm) and exposure durations (30, 60, and 120 s) at a fixed electrode gap of 10 cm, using soybean seeds of the Volgogradka 1 cultivar. Germination energy (day 3) and total germination (day 7) were assessed under standardized laboratory conditions in triplicate, followed by a replicated field trial to evaluate plant height, bean yield, and disease incidence. DC treatment significantly outperformed both the untreated control and AC treatment: germination energy increased by up to 60%, and total germination reached 100% compared with 85% in the control. The optimal DC window was identified at 0.8–1.5 kV/cm with a 30 s exposure. In stark contrast, AC treatment at industrial frequency not only failed to enhance germination but also frequently suppressed it and markedly increased susceptibility to fungal crown rot. Field results corroborated these findings: DC-treated seeds produced the highest bean mass (85 g per five plants vs. 80 g in the control), while AC-treated seeds yielded the lowest (72 g). Backward elimination regression analysis revealed that field intensity alone was the sole significant predictor of treatment outcomes, whereas exposure time and interaction effects were non-significant. We conclude that short-duration DC pre-sowing stimulation (1.0 kV/cm, 30–60 s) is a robust, chemically safe, and readily scalable technique for enhancing soybean establishment and yield. Conversely, AC treatment at power frequency is not recommended due to its deleterious effects on plant health and productivity. These findings establish a clear, evidence-based framework for the rational design of electrical seed treatment protocols. Full article

Conventional spring sowing of sugar beet in Europe faces increasing constraints from summer drought, high temperatures, and Cercospora beticola pressure due to climate change. This two-year field trial (2021–2022 and 2022–2023) evaluated the feasibility of autumn-sown sugar beet at a northern Mediterranean site in Legnaro (Padua, NE Italy, 45°21′ N). Nine varieties were assessed across four sowing dates in 2021 (late September to early November) and two sowing dates in 2022 (late September and late October). Measurements included overwinter survival, bolting incidence at two reproductive stages, fresh root and above-ground biomass yield at sequential harvest dates, and root soluble solids (°Brix). Post-winter mortality was negligible following September and early-October sowings, moderate after late-October sowings (17.3% in 2021; 13.2% in 2022), and extremely high after early-November sowing (81.5%). These patterns indicated that winter survival was more strongly determined by crop developmental stage before winter than by seasonal minimal temperatures recorded in two seasons (−3.6 °C and −6.3 °C, respectively). Bolting incidence showed the opposite trend, reaching near-complete or complete expression in the earliest sowings regardless of variety choice. In late-October sowings, clear varietal differences emerged. Some varieties combined low bolting incidence with high root yields, reaching 81.1–84.4 t ha⁻¹ at the final harvest (early August 2023). Root juice soluble solids were higher in the drier 2021–2022 season (exceeding 20 °Brix in several cases) than in the wetter 2022–2023 season (consistently below 17.5 °Brix), reflecting dilution effects associated with the different seasonal precipitation. In the sequential harvest series of late-October 2022 sowing, later harvest dates were generally associated with lower soluble solids. These results indicate that, within the autumn sowing window evaluated, late-October sowing combined with appropriate varietal selection provided the best balance between overwinter survival, bolting incidence, and root yield at this northern Mediterranean latitude. Future multi-site studies, including spring-sown controls, could enable direct comparison with conventional sowing practice. Full article

Popping expansion is the main quality trait determining the commercial value of popcorn maize, yet its evaluation requires destructive grain sampling. We investigated whether multitemporal UAV multispectral and textural features could predict grain yield and popping expansion in a native population of Peruvian popcorn and its five purple-kernel corn hybrids grown in 16 drainage lysimeters (80 subplots) under controlled irrigation in Lima, Peru. Eight UAV flights were conducted between 50 and 117 days after sowing, and 8 vegetation indices plus 5 GLCM texture metrics were extracted from canopy-masked imagery. Six regression algorithms were trained using Sequential Forward Selection (SFS; applied to five of six algorithms) and validated by Leave-One-Lysimeter-Out cross-validation (LOGO). Early grain, grain filling, and maturity were the most informative stages for yield prediction. The best model, obtained at maturity, was SVR-rbf using SCCCI and Homogeneity, reaching R² = 0.66 and RMSE = 1.23 t ha⁻¹. SCCCI was the most consistently selected predictor across models. By contrast, popping expansion was poorly predicted (R² = 0.17), indicating that this post-harvest quality trait is only weakly linked to canopy-level spectral information. Multitemporal UAV phenotyping therefore shows promise for non-destructive yield screening, but not for replacing direct popping expansion measurements. Full article

Early pregnancy diagnosis is a key component of reproductive management in swine production systems. Accurate identification of pregnant and non-pregnant sows within the first 30 days after insemination allows timely reproductive decisions and reduces non-productive days. The present systematic review evaluates the diagnostic efficiency of ultrasonographic and progesterone-based methods used for early detection of pregnancy in sows. A structured literature search was conducted in accordance with the PRISMA Statement guidelines, using major scientific databases. Studies evaluating pregnancy diagnosis in sows within the first 30 days after insemination were included. Diagnostic approaches were analyzed with respect to methodological design, timing of examination, biological sample matrix, and reported indicators of diagnostic accuracy. Ultrasonographic techniques have evolved from early acoustic detection in A-mode to real-time imaging in B-mode and more recently algorithm-assisted interpretation of ultrasound images. Real-time ultrasonography allows direct visualization of gestational structures; in one study, diagnostic accuracy above 95% was reported after approximately 23–24 days of pregnancy under optimal examination conditions. Progesterone-based analyses evaluate luteal endocrine activity and are particularly useful for early identification of non-pregnant animals after luteolysis. The diagnostic efficiency of hormonal assays depends strongly on the timing of sampling and the biological matrix used for analysis, including plasma, serum, dried blood spots, saliva, or feces. The comparative analysis shows that ultrasonography provides morphological confirmation of pregnancy, whereas progesterone analyses serve mainly as functional indicators of luteal activity. These methods play complementary roles in reproductive management. Ultrasonography remains the most reliable method for confirming pregnancy, while progesterone-based analyses are valuable tools for early reproductive screening and identification of non-pregnant sows. Full article

Agronomic practices can modify cereal grain chemical composition and processing performance. Long-term evidence linking agricultural management with functionality-related quality remains limited, especially in terms of combined tillage x crop residue management strategy. We evaluated the effects of long-term tillage simplifications and straw management on productivity and processing-relevant traits of winter wheat and spring barley in a split-plot field experiment (Lithuania). Straw was either removed (S0) or chopped and retained (S1), and six tillage systems were compared (conventional ploughing (CP), shallow ploughing (SP), shallow cultivation (SOW), stubble over winter, no-till with cover crops (NTC), and no-till without cover crops (NT)). The yield and starch content of winter wheat and spring barley groats increased with the addition of straw and the application of SOW, NTC, and NT systems. The hectolitre mass of winter wheat and spring barley grains increased with the addition and removal of straw using SP technology. The protein content and wet gluten content of winter wheat and spring barley grains decreased, while the starch content increased, with the addition and removal of straw using SC technology. In wheat, protein content showed weak separation among treatments, while wet gluten and Zeleny sedimentation displayed mostly directional trends (wet gluten–sedimentation correlation: r = 0.844 under S0 and r = 0.984 under S1). In terms of the tillage systems, it can be stated that in most cases, SP and NT increased grain yield and improved quality indicators, while SC and NTC technologies showed opposite results. Soil-function assessment (CEI, 10–25 cm) indicated substantially higher integrated soil functioning under conservation agriculture (e.g., SOW/NTC/NT: 5.28–5.70) than under conventional systems (CP: 3.23). The results support framing sustainable soil management for cereal functionality as a system package: residue retention enables the productivity benefits of reduced-tillage systems while maintaining key quality proxies. Full article

This study has investigated the occurrence characteristics and population damage of weeds in double-cropping direct-seeded rice fields in Hunan, and has identified efficient and safe pre- and post-emergence herbicides to enhance resistance management. Field trials were conducted at two representative sites (Yiyang and Changsha) in Hunan in 2024~2025. Weed community composition and emergence patterns were systematically monitored. The inhibitory effects of weed infestations on rice growth and yield were quantified. The biological activity and field efficacy of various herbicide classes against barnyardgrass (Echinochloa crus-galli) were evaluated via greenhouse bioassays and field trials. Weed emergence lasted 3–48 days after sowing (DAS) with three distinct peaks. Grasses emerged earliest and dominated the community, with barnyardgrass peaking at 13–17 DAS (≈50% of total weeds), followed by broadleaves at 20 DAS (≈40%) and sedges at 25 DAS (<20%). Weed infestation drastically suppressed rice height (max 19% reduction) and tillering (max 50% reduction), with mixed-weed and grass-dominated plots causing the severest yield losses (92.0% and 90.5%, respectively), versus only 18.0% in broadleaf-dominated plots. Greenhouse bioassays showed that oxaziclomefone had the highest intrinsic activity against barnyardgrass (GR₉₀ = 17.70 g ai ha⁻¹). In pre-emergence applications in field trials, pretilachlor (900 g ai ha⁻¹) and mefenacet (147.6 g ai ha⁻¹) provided >96.8% control at 20 and 40 days after treatment (DAT), while oxaziclomefone (66 g ai ha⁻¹) achieved 88.2% control at 20 DAT. For post-emergence herbicides, Profoxydim showed the highest intrinsic activity (GR₉₀ = 33.01 g ai ha⁻¹), followed by feproxydim (GR₉₀ = 33.45 g ai ha⁻¹) and flusulfinam (GR₉₀ = 64.55 g ai ha⁻¹). In field trials, flusulfinam provided 100% control with superior crop safety at 20 and 40 DAT, while Florpyrauxifen-benzyl, feproxydim, and metamifop reached >93% efficacy. In conclusion, weed emergence in Hunan direct-seeded rice follows a three-peak pattern, with barnyardgrass being the most destructive species. An integrated strategy combining pretilachlor (pre-emergence) and flusulfinam (post-emergence), rotated with florpyrauxifen-benzyl and feproxydim, is recommended for effective barnyardgrass management and resistance mitigation. Full article

Durum wheat production in the Mediterranean basin faces increasing climate variability and thus the need for computationally efficient tools to support agronomic decision-making at regional scale. Process-based crop models such as AquaCrop provide mechanistically sound yield estimates but require substantial computation time when screening large numbers of soil–climate–management combinations. The present study addresses this constraint by developing and evaluating five machine learning (ML) surrogate models—Linear Regression (LR), Multilayer Perceptron (MLP), Support Vector Machine for regression (SMOreg), RandomTree, and Reduced Error Pruning Tree (REPTree)—trained to emulate the AquaCrop-GIS response surface for durum wheat (Triticum durum Desf.) grain yield across the Capitanata plain (Southern Italy). A dataset of 342 instances was constructed by crossing 25 soil profiles, three sowing dates, and two irrigation regimes across 15 climatic grid cells (2014–2023), evaluated by stratified 10-fold cross-validation. The MLP achieved the highest accuracy (R = 0.983; R² = 0.966; RMSE = 0.083 t ha⁻¹); the four interpretable models were clustered at R = 0.891–0.907 (RMSE = 0.192–0.203 t ha⁻¹). All models converged on consistent agronomic signals: standard sowing (1 November) yielded +0.53 t ha⁻¹ over late sowing (15 November), supplemental irrigation added +0.17 t ha⁻¹, and fine-textured soils produced superior yields. The convergence of directional signals across linear, kernel-based, and tree-based architectures confirms that ML surrogates trained on process-model outputs can efficiently emulate AquaCrop response surfaces and deliver actionable management guidance for durum wheat producers and agricultural planners in Mediterranean dryland farming systems. Full article