Agronomy

18 pages, 737 KB

Open AccessArticle

Enhancing Olive Oil Functional Properties by Pre-Harvest Foliar Application of Chitosan and Harpin Elicitors on ‘Megaritiki’ Olive Cultivar Grown Under Rainfed Conditions in Greece

by Asimina-Georgia Karyda, Georgios Roubis, Stefania Komninou, Aikaterini Belibasaki, Maria Zoti and Petros Anargyrou Roussos

Agronomy 2026, 16(8), 788; https://doi.org/10.3390/agronomy16080788 (registering DOI) - 11 Apr 2026

Abstract

Climate change-induced abiotic stress, particularly heat and drought during olive oil accumulation, significantly threatens the productivity and oil quality of olive trees (Olea europaea L.). This study investigated the efficacy of pre-harvest elicitation using the biostimulants harpin and chitosan (both as commercially [...] Read more.

Climate change-induced abiotic stress, particularly heat and drought during olive oil accumulation, significantly threatens the productivity and oil quality of olive trees (Olea europaea L.). This study investigated the efficacy of pre-harvest elicitation using the biostimulants harpin and chitosan (both as commercially available products) under summer conditions in Greece, in commercially productive rainfed groves of cv. ‘Megaritiki’. Multivariate analysis (PCA and factor analysis) revealed that pre-harvest application of these elicitors successfully balanced the trade-off between oil yield and quality. Both harpin and chitosan maintained hydrolytic (free acidity—0.25 and 0.29 g oleic acid 100 g⁻¹, respectively, compared to 0.56 g oleic acid 100 g⁻¹ in the control) and primary oxidative markers (peroxides—4.16 and 4.16 meq O₂ kg⁻¹, respectively, compared to 5.20 meq O₂ kg⁻¹ in the control) at exceptionally low levels compared to untreated trees. The treatments induced a distinctive metabolic shift regarding volatile compounds governed by the lipoxygenase (LOX) pathway. Harpin application was strongly associated with complex floral and fruity volatile compounds (2-hexen-1-ol and trans-2-hexenal) and a high α-tocopherol concentration (38.58 mg kg⁻¹ compared to 23.12 mg kg⁻¹ in the control), suggesting an enhanced physiological response in favor of oil quality attributes. Conversely, chitosan elevated the oxidative stability of the oil by increasing total phenol concentration (by almost 97% compared to the control) and prioritizing the accumulation of the stable monounsaturated fatty acids (oleic acid—increased by 12.5% compared to the control) over polyunsaturated ones (linoleic acid), while endowing the oil with desirable “green freshness” aromas (cis-3-hexenal). These results demonstrate that elicitation with harpin and chitosan is a potent tool for sustainably enhancing extra virgin olive oil quality under rainfed conditions in Greece, steering fruit metabolism toward a premium nutraceutical and sensory profile and enhancing the functional properties of the oil (phenol content, antioxidant capacity, monounsaturated fatty acids, α-tocopherol and squalene). Full article

(This article belongs to the Special Issue Improving Nutritional and Functional Quality of Horticultural Crops Through Biofortification Approaches)

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15 pages, 760 KB

Open AccessArticle

Sex-Specific Effects of Protein Limitation and Mating on Longevity in Bactrocera oleae

by Evangelia I. Balampekou, Thomas M. Koutsos, Dimitrios S. Koveos and Nikos A. Kouloussis

Agronomy 2026, 16(8), 787; https://doi.org/10.3390/agronomy16080787 (registering DOI) - 11 Apr 2026

Abstract

Longevity in the olive fruit fly, Bactrocera oleae, is a plastic trait shaped by the synergistic interaction between reproductive effort, sex, and protein availability. This study investigated how the survival of 800 individuals is affected by protein limitation and mating status. Results [...] Read more.

Longevity in the olive fruit fly, Bactrocera oleae, is a plastic trait shaped by the synergistic interaction between reproductive effort, sex, and protein availability. This study investigated how the survival of 800 individuals is affected by protein limitation and mating status. Results from Cox proportional hazards analysis demonstrate that mating and protein deprivation significantly increase mortality risk. Under protein-deprived conditions, mating increased the mortality hazard by 146.5% for males and 121.5% for females compared to virgins. Notably, a significant Sex × Diet interaction (p = 0.022) confirmed that among virgin individuals, the relative mortality hazard increase under protein scarcity was nearly double for males (97.5%) compared to females (51.1%), indicating a higher statistical tolerance for nutritional stress in females. Furthermore, statistical validation confirmed that diet exhibited a significant time-dependent effect (p = 0.029), indicating that nutritional deficits act cumulatively over the fly’s lifespan. These findings suggest that B. oleae longevity is governed by dynamic, synergistic pressures, with females exhibiting a lower hazard of death under resource-limited conditions, an insight essential for refining demographic models in integrated pest management (IPM) strategies. Full article

(This article belongs to the Section Pest and Disease Management)

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13 pages, 2438 KB

Open AccessArticle

Genome-Wide Association Studies Reveal the Complex Genetic Architecture of Grain Number per Spike in Wheat

by Ying Chen, Yiyi Xia, Chaojun Peng, Haibin Dong, Yuanming Zhang and Lin Hu

Agronomy 2026, 16(8), 786; https://doi.org/10.3390/agronomy16080786 (registering DOI) - 11 Apr 2026

Abstract

Grain number per spike (GNS) is a key component of wheat yield, yet its genetic architecture remains incompletely understood. This study phenotyped 610 wheat accessions for GNS in four environments and genotyped them using 429,721 single nucleotide polymorphisms (SNPs). The phenotypes were associated [...] Read more.

Grain number per spike (GNS) is a key component of wheat yield, yet its genetic architecture remains incompletely understood. This study phenotyped 610 wheat accessions for GNS in four environments and genotyped them using 429,721 single nucleotide polymorphisms (SNPs). The phenotypes were associated with the SNPs using a three-variance multi-locus random-SNP-effect mixed linear model (3VmrMLM) to identify quantitative trait nucleotides (QTNs), as well as QTN-by-environment (QEI) and QTN-by-QTN (QQI) interactions. These genetic components and residual error explained approximately 18%, 31%, 28%, and 23% of the phenotypic variance, respectively. Two and one previously reported genes were found around QTNs and QEIs, respectively. Bioinformatics and haplotype analyses subsequently yielded 25 candidate genes, 22 gene-by-environment interactions (GEIs), and 24 gene-by-gene interactions (GGIs) around the QTNs, QEIs, and QQIs, respectively. Notably, TraesCS1D01G280000, the wheat homolog of OsRopGEF10, was located near a major QTN explaining over 10% of the total phenotypic variation. A gene interaction network constructed from all identified genes highlighted the central role of GGIs in GNS regulation. Environmental variation may reshape the regulatory network through GEIs. Furthermore, superior haplotypes of 12 candidate genes were identified, providing valuable targets for improving wheat yield. Overall, this study dissects the genetic architecture of GNS and offers practical resources for wheat molecular breeding. Full article

(This article belongs to the Special Issue Utilizing Genetic Resources for Agronomic Traits Improvement: 3rd Edition)

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22 pages, 844 KB

Open AccessReview

The Role of Salicylic Acid in Shaping Plant Resistance to Environmental Stresses

by Piotr Kostiw and Mariola Staniak

Agronomy 2026, 16(8), 785; https://doi.org/10.3390/agronomy16080785 - 10 Apr 2026

Abstract

Salicylic acid (SA) is a key endogenous regulator involved in plant defense responses to biotic and abiotic stresses. The increasing resistance of pathogens to chemical plant protection products and growing environmental restrictions have intensified the search for alternative strategies to enhance plant health [...] Read more.

Salicylic acid (SA) is a key endogenous regulator involved in plant defense responses to biotic and abiotic stresses. The increasing resistance of pathogens to chemical plant protection products and growing environmental restrictions have intensified the search for alternative strategies to enhance plant health and stress tolerance. Among these strategies, the induction of natural defense mechanisms, in which SA plays a central signaling role, has gained particular attention. This review summarizes current knowledge on the role of SA in shaping plant resistance to environmental factors. The fundamental mechanisms of plant defense, including innate immunity, induced systemic resistance (ISR), and systemic acquired resistance (SAR), are discussed, with emphasis on the signaling function of SA and its interaction with other phytohormones, especially jasmonic acid and ethylene. The role of SA in regulating physiological processes associated with stress tolerance, such as antioxidant system activity, photosynthesis, plant growth, and senescence, is highlighted. The review of research results indicates that appropriately selected doses and timing of SA treatments can enhance resistance to selected pathogens and improve plant tolerance to adverse environmental conditions. However, treatment effectiveness depends on multiple factors, particularly SA concentration and plant–pathogen interactions. Salicylic acid is a promising component of integrated and sustainable plant protection strategies. Further research, especially under field conditions, is necessary to optimize its practical use and fully determine its potential in modern agriculture. Full article

(This article belongs to the Special Issue Plant Stress Tolerance: From Genetic Mechanism to Cultivation Methods)

14 pages, 959 KB

Open AccessArticle

Cultivar Variation in Growth, Yield, and Nutritional Quality of Pea Sprouts and Fresh Seeds for the Selection of Specialized Cultivars

by Cheng-Na Zhou, Jing Bai, Xiao-Yan Zhang, Feng-Jing Song, Jun-Jie Hao, Shi-Zuo Qiu, Xiao Cui, Wen-Jiao Wang, Kai-Hua Jia, Ru-Mei Tian, Min Liu, Guan Li and Na-Na Li

Agronomy 2026, 16(8), 784; https://doi.org/10.3390/agronomy16080784 - 10 Apr 2026

Abstract

To clarify cultivar differences in growth performance, yield formation, and bioactive characteristics at the sprout and fresh seed stages, twelve pea cultivars were evaluated. Growth traits, yield formation, and changes in phenolic compounds and antioxidant activity during sprouting were assessed, and the nutritional [...] Read more.

To clarify cultivar differences in growth performance, yield formation, and bioactive characteristics at the sprout and fresh seed stages, twelve pea cultivars were evaluated. Growth traits, yield formation, and changes in phenolic compounds and antioxidant activity during sprouting were assessed, and the nutritional quality and mineral element composition of fresh seeds were also determined. The results showed that cultivars 24-164 and 24-510 exhibited low germination rates and severe cotyledon decay, making them unsuitable for sprout production. Significant differences were observed among the remaining cultivars in growth traits, edible ratio, and yield efficiency, with cultivars 24-724 and 24-486 showing superior processing efficiency and utilization value. During sprouting, total phenolic and total flavonoid contents, as well as 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and ferric reducing antioxidant power (FRAP), were significantly influenced by both cultivar and light exposure stage. Root length and root diameter were significantly and positively correlated with phenolic accumulation and antioxidant activity. Analysis of fresh seed quality revealed marked inter-cultivar variation in nutritional and health-related traits. Cultivar 24-486 exhibited the highest values for phenolic content, antioxidant capacity, vitamin C, vitamin E, and Fe and Se accumulation, whereas cultivar 24-013 showed advantages in calcium and potassium contents. These results identify cultivars 24-724 and 24-486 as promising candidates for sprout production and highlight cultivar 24-486 as a dual-purpose genotype for both sprout and fresh seed utilization. Full article

(This article belongs to the Special Issue Cultivar Development of Pulses Crop—2nd Edition)

18 pages, 2016 KB

Open AccessArticle

Crop Diversification Enhances Peanut Productivity Through Soil Fertility Improvement and Key Taxa Enrichment in Red Soil

by Zixuan Wang, Yankun He, Jiuyu Li, Kailou Liu, Qin Zhang, Yan Chen and Xinhua Peng

Agronomy 2026, 16(8), 783; https://doi.org/10.3390/agronomy16080783 - 10 Apr 2026

Abstract

Continuous monocropping and inappropriate fertilization have contributed to nutrient depletion and soil degradation, limiting peanut productivity in subtropical red soil agroecosystems. Although diversified cropping may help alleviate these constraints, the reasons why it improves peanut productivity remain unclear. In this study, we conducted [...] Read more.

Continuous monocropping and inappropriate fertilization have contributed to nutrient depletion and soil degradation, limiting peanut productivity in subtropical red soil agroecosystems. Although diversified cropping may help alleviate these constraints, the reasons why it improves peanut productivity remain unclear. In this study, we conducted a long-term field experiment in Jiangxi, China, to compare four cropping systems, assess soil nutrients, peanut productivity, and bacterial communities, and further evaluate the role of key taxa through inoculation assays and structural equation modeling. Results showed that diversified cropping improved peanut growth and yield, with the green manure integrated system performing best overall. Diversified cropping also increased soil organic carbon, total nitrogen, and available phosphorus, while reshaping bacterial communities. Several taxa, including Bradyrhizobium, Mycobacterium, Dormibacter, and Ardenticatena, were positively associated with soil nutrients. Inoculation assays further showed that a synthetic consortium assembled from representative strains affiliated with key taxa produced stronger effects on plant growth than a single-strain inoculation. Structural equation modeling identified key taxa as the factor most strongly associated with crop productivity. These findings suggest that higher peanut productivity under diversified cropping was closely associated with concurrent improvements in soil fertility and the enrichment of key taxa. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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22 pages, 849 KB

Open AccessArticle

The Effect of Arbuscular Mycorrhizal Fungi on Plant Development and Accumulation of Phenolics in the Flower Heads of Meadow Arnica (Arnica chamissonis Less.)

by Zenon Węglarz, Sylwia Styczyńska, Agata Jędrzejuk, Marzena Sujkowska-Rybkowska, Jarosław Leon Przybył, Olga Kosakowska, Kh Altantsetseg and Katarzyna Bączek

Agronomy 2026, 16(8), 782; https://doi.org/10.3390/agronomy16080782 - 10 Apr 2026

Abstract

Meadow arnica is a valuable medicinal plant, used in both the pharmaceutical and cosmetic industries. The aim of the study was to determine the influence of arbuscular mycorrhizal fungi (AMF) on the development, yield, and quality of flower heads (raw material) of meadow [...] Read more.

Meadow arnica is a valuable medicinal plant, used in both the pharmaceutical and cosmetic industries. The aim of the study was to determine the influence of arbuscular mycorrhizal fungi (AMF) on the development, yield, and quality of flower heads (raw material) of meadow arnica grown in an organic farming system. The inoculation of plants with AMF improved the mass of above- and underground organs, including the mass of raw material, as well as the content of chlorophylls and general sugar in the leaves, followed by enhanced starch storage in the roots. The content of phenolics in the raw material was determined using high-performance liquid chromatography (HPLC). The following flavonoids were assessed here: cynaroside, rutin, hyperoside, cosmosiin, astragalin, and diosmetin, as well as the phenolic acids: neochlorogenic, chlorogenic, caffeic, ferulic, rosmarinic, cichoric, 3,4-di-O-caffeoylquinic, and 1,5-dicaffeoylquinic acids. The contents of these substances were higher in non-inoculated plants than in inoculated ones, which contradicts most studies conducted to date on medicinal and aromatic plants. Nevertheless, the results are interesting primarily because of the beneficial developmental changes in inoculated plants, as evidenced by a significantly higher mass of arnica flower heads, more efficient uptake of mineral nutrients from the soil, and lower nitrogen levels in aboveground organs. Full article

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19 pages, 11440 KB

Open AccessArticle

Cross-Sensor Evaluation of ZY1-02E and ZY1-02D Hyperspectral Satellites for Mapping Soil Organic Matter and Texture in the Black Soil Region

by Kun Shang, He Gu, Hongzhao Tang and Chenchao Xiao

Agronomy 2026, 16(8), 781; https://doi.org/10.3390/agronomy16080781 - 10 Apr 2026

Abstract

Soil health monitoring is critical for the sustainable management of the black soil region, a key resource for global food security. However, traditional field surveys are constrained by high operational costs, limited spatial coverage, and low temporal frequency, making them inadequate for high-resolution [...] Read more.

Soil health monitoring is critical for the sustainable management of the black soil region, a key resource for global food security. However, traditional field surveys are constrained by high operational costs, limited spatial coverage, and low temporal frequency, making them inadequate for high-resolution and time-sensitive soil monitoring. The recently launched ZY1-02E satellite, equipped with an advanced hyperspectral imager, offers a new potential data source, yet its capability for quantitative soil modelling requires rigorous cross-sensor validation. This study conducts a cross-sensor evaluation of ZY1-02E and its predecessor, ZY1-02D, for mapping soil organic matter (SOM) and soil texture (sand, silt, and clay) in Northeast China. Optimal spectral indices were constructed through exhaustive band combination and correlation screening, and quantitative inversion models were established using a hybrid framework integrating Random Frog feature selection with Gaussian Process Regression (GPR) and Boosting Trees, based on synchronous ground observations. Results demonstrate strong cross-sensor consistency, with spectral indices showing significant linear correlations (

R^{2} > 0.65

) between ZY1-02E and ZY1-02D. Furthermore, the quantitative retrieval models applied to ZY1-02E imagery achieved robust performance, with cross-sensor retrieval consistency exceeding

R^{2} = 0.60

for all parameters and SOM exhibiting the highest agreement (

R^{2} = 0.74

). These findings confirm the radiometric stability and algorithm transferability of ZY1-02E, demonstrating its capability to generate soil parameter products comparable to ZY1-02D without extensive model recalibration. The validated interoperability of the twin-satellite constellation substantially enhances temporal observation capacity during the narrow bare-soil window, effectively mitigating cloud-induced data gaps in high-latitude agricultural regions. Importantly, the enhanced monitoring framework provides a scalable technical paradigm for high-frequency hyperspectral soil mapping, offering critical spatial decision support for precision fertilization, soil degradation mitigation, and conservation tillage management in the Mollisol belt. Full article

(This article belongs to the Special Issue Advances in Remote Sensing Agronomic Application for Mapping and Modeling Soil Properties)

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18 pages, 3548 KB

Open AccessArticle

Characterization of Alternaria Species Causing Leaf Spot on Drunken Horse Grass (Achnatherum inebrians) in Northwestern China

by Zheng Liang, Wanning Yang, Tingting Ding, Jiaqi Liu, Jiahui Long, Hao Chen, Xuekai Wei and Chunjie Li

Agronomy 2026, 16(8), 780; https://doi.org/10.3390/agronomy16080780 - 10 Apr 2026

Abstract

Drunken horse grass (Achnatherum inebrians) plays a vital role in ecological restoration and grassland sustainability in Northwest China, but its ecological functions are increasingly threatened by emerging fungal diseases. In 2024, a leaf spot disease characterized by brown lesions with yellow [...] Read more.

Drunken horse grass (Achnatherum inebrians) plays a vital role in ecological restoration and grassland sustainability in Northwest China, but its ecological functions are increasingly threatened by emerging fungal diseases. In 2024, a leaf spot disease characterized by brown lesions with yellow halos was observed on drunken horse grass in Gansu Province, China. The causal pathogens were identified as Alternaria alternata and Alternaria infectoria based on morphological characterization, pathogenicity tests, and multi-locus phylogenetic analysis (ITS, TEF, GPD, RPB2, Alt a 1, endoPG, and OPA10-2). Preliminary fungicide sensitivity assays revealed that tetramycin and difenoconazole had the strongest inhibitory effects against mycelial growth in vitro. The EC₅₀ values for tetramycin were 0.0755 mg/L (A. alternata) and 0.2175 mg/L (A. infectoria), while for difenoconazole, they were 0.1023 mg/L (A. alternata) and 0.0599 mg/L (A. infectoria). To our knowledge, this is the first report of Alternaria species infecting the host plant, drunken horse grass, providing an essential basis for the effective management of this disease and the protection of grassland ecosystems. Full article

(This article belongs to the Section Grassland and Pasture Science)

14 pages, 1248 KB

Open AccessArticle

Physiological and Biochemical Responses of Pearl Millet and Mustard to Cut-Soiler-Based Shallow Subsurface Drainage Under Saline Irrigation

by Gajender Yadav, Neha, Ashwani Kumar, Bhawna Babal, Arvind Kumar Rai, Junya Onishi, Keisuke Omori and Rajender Kumar Yadav

Agronomy 2026, 16(8), 779; https://doi.org/10.3390/agronomy16080779 - 10 Apr 2026

Abstract

Inadequate drainage and the application of salty irrigation waterinduced salinity stress, poses a major constraint to agricultural productivity, especially in saline–arid regions. Shallow subsurface drainage has emerged as a potential technique for salinity management; however, its implications for crop physiological and biochemical responses [...] Read more.

Inadequate drainage and the application of salty irrigation waterinduced salinity stress, poses a major constraint to agricultural productivity, especially in saline–arid regions. Shallow subsurface drainage has emerged as a potential technique for salinity management; however, its implications for crop physiological and biochemical responses remain unclear. Therefore, a two-year lysimetric study was undertaken in a split-split plot design investigating cut-soiler-based preferential shallow subsurface drainage (PSSD), soil type (saline sandy loam and normal silty clay loam), and irrigation water salinity levels (4, 8 and 12 dS m⁻¹) to evaluate the effectiveness of rice-residue-filled cut-soiler PSSD in mitigating salinity stress in pearl millet and mustard crops. The cut-soiler PSSD reduced root-zone salinity to around 60.0% by the end of experimentation. Lower root-zone salinity under cut-soiler PSSD alleviated osmotic and ionic stress by reducing hydrogen peroxide (11.0–14.6%), membrane injury (22.7–40.8%), lipid peroxidation (20.0–25.0%), proline accumulation (26.0–37.0%) and improving the Na⁺/K⁺ ratio (44.0%). Antioxidant enzyme activities were also significantly moderated under the cut-soiler PSSD. These physiological and biochemical improvements resulted in significant increases in grain and seed yield of pearl millet (23.5%) and mustard (31.4%), respectively. The findings of this study indicate that cut-soiler PSSD is an effective strategy to mitigate salinity stress at the physiological and biochemical level and offers sustainable management strategies for salt-affected agro-ecosystems. Full article

(This article belongs to the Special Issue Abiotic Stress Resilience: Mechanisms, Management, and Yield Stability)

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16 pages, 1401 KB

Open AccessArticle

Stem Electrical Conductivity of Broccoli (Brassica oleracea L. var. italica Plenk) Under Nitrogen and Phosphorus Fertilizer Deficiency

by Jeong Yeon Kim, Su Kyeong Shin, Ye Eun Lee and Jin Hee Park

Agronomy 2026, 16(8), 778; https://doi.org/10.3390/agronomy16080778 - 9 Apr 2026

Abstract

Nitrogen (N) and phosphorus (P) are essential nutrients that play critical roles in plant physiological processes and the accumulation of N and P in broccoli head was significantly correlated with yield. Therefore, there is a need for a rapid, non-destructive diagnosis of crop [...] Read more.

Nitrogen (N) and phosphorus (P) are essential nutrients that play critical roles in plant physiological processes and the accumulation of N and P in broccoli head was significantly correlated with yield. Therefore, there is a need for a rapid, non-destructive diagnosis of crop status by detecting deficiencies in essential nutrients. This study evaluated the effects of N and P deficiency on field grown broccoli (Brassica oleracea L. var. italica Plenk) using a plant-induced electrical signal (PIES) sensor, in which needle electrodes are inserted into the stem to measure electrical conductivity reflecting plant water and ion status. Four treatments were established, including the control (N100P100) with sufficient N and P supply, N deficiency (N0P100), P deficiency (N100P0), and combined N–P deficiency (N0P0). For sufficient supply, urea and fused phosphate (FP) were applied at rates of 122 kg N ha⁻¹ and 71 kg P ha⁻¹, respectively. Soil, stem, and leaf nutrient contents, growth parameters, and stress related indicators were analyzed and their relationship with PIES values were evaluated. PIES was highest in control (N100P100) and lowest under N–P deficiency (N0P0). Higher PIES values were observed during the vegetative stage, whereas values declined during the reproductive stage, reflecting changes in physiological activity. Growth parameters such as shoot and root weight and stem diameter were generally superior in the control (N100P100) treatment, while leaf calcium (Ca), magnesium (Mg), and potassium (K) concentrations showed no significant differences among treatments. Total N content in leaves was higher in N fertilized treatments (control and P deficiency). Photosynthesis-related parameters, including soil plant analysis development (SPAD), Fv/Fm, and chlorophyll content, were lowest under N–P deficiency, which was reflected in the PIES. Principal component analysis (PCA) showed that the PIES was closely associated with growth and photosynthetic parameters and clearly distinguished N sufficient treatments (control and P deficiency) from N deficient treatments (N0P100, N0P0). Overall, these findings suggest that PIES monitoring can serve as a sensitive physiological indicator of nutrient stress and may be applied as an early diagnostic tool before visible growth inhibition occurs in broccoli cultivation. Full article

(This article belongs to the Special Issue Smart Sensing and Sustainable Crop Management Strategies for Agriculture in Arid and Semiarid Regions)

23 pages, 2826 KB

Open AccessArticle

Impacts of Micro-Polluted River Water on Soil Nitrogen and Microbial Diversity in Paddy Fields Under Different Irrigation Modes

by Lina Chen, Yiqi Zhou, Jiang Li, Yanyu Wang and Siying Lian

Agronomy 2026, 16(8), 777; https://doi.org/10.3390/agronomy16080777 - 9 Apr 2026

Abstract

This study aims to explore the effects of micro-polluted river water on nitrogen and microbial communities of paddy field soil under different irrigation modes. The experiment was conducted in a water-saving park in Nanjing. By establishing three water quality conditions—clean water, micro-polluted river [...] Read more.

This study aims to explore the effects of micro-polluted river water on nitrogen and microbial communities of paddy field soil under different irrigation modes. The experiment was conducted in a water-saving park in Nanjing. By establishing three water quality conditions—clean water, micro-polluted river water, and alternating irrigation—and two moisture conditions—flood irrigation and controlled irrigation—this study investigates the effects of different irrigation patterns on soil nitrogen and microbial communities. The results indicate that, under flood irrigation, the input of micro-polluted river water can effectively alleviate NH₄⁺-N loss during the heading stages of rice growth by 49.3%. Moisture conditions are the primary factor influencing microbial community structure. Although the input of micro-polluted river water reduces community stability, rotation irrigation can increase microbial abundance and enhance network complexity, thereby enhancing the system’s resilience. Redundancy analysis shows that soil moisture, pH, and ion content are the key environmental factors driving microbial distribution. The clean and polluted water rotation irrigation model performs best in maintaining soil nitrogen and microbial health. Rotation irrigation promotes the enrichment of key functional groups, such as Actinobacteria, effectively increasing rice yield. This study provides a theoretical basis for promoting sustainable agricultural production through water resource management. Full article

(This article belongs to the Special Issue Enhancing Nitrogen Use Efficiency in Major Crops: Mechanisms, Management, and Synergies with Yield Formation)

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13 pages, 1901 KB

Open AccessArticle

Establishment of an Efficient Protoplast-Based Base Editing Platform in Lettuce

by Yu Jia, Guo Peng and Qiang Zhou

Agronomy 2026, 16(8), 776; https://doi.org/10.3390/agronomy16080776 - 9 Apr 2026

Abstract

Lettuce (Lactuca sativa L.) is an important leafy vegetable crop, yet the efficiency and reliability of genome editing platforms in lettuce remain limited, particularly for precision base editing applications. In this study, we established an optimized PEG-mediated protoplast transformation system for lettuce [...] Read more.

Lettuce (Lactuca sativa L.) is an important leafy vegetable crop, yet the efficiency and reliability of genome editing platforms in lettuce remain limited, particularly for precision base editing applications. In this study, we established an optimized PEG-mediated protoplast transformation system for lettuce through systematic evaluation of key parameters, including protoplast density, incubation time, plasmid size, and transformation method. Under optimized conditions, a maximum transient transformation efficiency of up to 81% was achieved. Using this optimized protoplast platform, we comparatively evaluated the performance of three single-base editing systems—adenosine base editor (ABE), glycosylase-based guanine base editor (gGBE), and rice alkylpurine DNA glycosylase-mediated A-to-K base editor (rAKBE)—targeting the LsALS gene, encoding acetolactate synthetase as a herbicide target with great value in weed control. Among the tested editors, ABE exhibited the highest A-to-G editing efficiency, reaching 9.3%. In contrast, gGBE and rAKBE showed lower editing efficiencies. Together, this study established a robust and reproducible protoplast-based platform for transient genome editing in lettuce and provides a practical framework for the rapid evaluation of base editing tools and target sites, firstly for gGBE and rAKBE evaluation in lettuce. The optimized system facilitates functional genomics studies and supports the development of precision breeding strategies in lettuce. Full article

(This article belongs to the Special Issue Advances in Crop Molecular Breeding and Genetics—2nd Edition)

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22 pages, 16716 KB

Open AccessArticle

Comparative Transcriptomic and Metabolic Analyses Reveal Temperature Intensity-Dependent Changes in Phenolic Compound Concentrations in Three Wine Grape Cultivars

by Huawei Chen, Xinyu Ren, Bowei Yang, Yang Yi, Miaomiao Wang, Ruihua Ren, Maosheng Ge and Sha Xie

Agronomy 2026, 16(8), 775; https://doi.org/10.3390/agronomy16080775 - 9 Apr 2026

Abstract

Global climate change poses a significant threat to viticulture, primarily due to high temperatures. This study examined temperature-induced changes in phenolic profiles in berries of three wine grape cultivars under 25, 35, and 45 °C for 0–48 h using HPLC-ESI-MS/MS. To investigate the [...] Read more.

Global climate change poses a significant threat to viticulture, primarily due to high temperatures. This study examined temperature-induced changes in phenolic profiles in berries of three wine grape cultivars under 25, 35, and 45 °C for 0–48 h using HPLC-ESI-MS/MS. To investigate the molecular response to severe heat stress, transcriptomic analysis was conducted in Cabernet Sauvignon berries subjected to a 45 °C treatment. Results showed that the 45 °C treatment decreased the levels of anthocyanins (particularly delphinidin-3-O-glucoside and cyanidin-3-O-glucoside) in grape berries. Acylated anthocyanins, such as malvidin-3-O-(6-acetyl)-glucoside, exhibited enhanced stability at elevated temperatures. Additionally, high temperatures increased the levels of protocatechuic and gentisic acids and decreased those of rutin, ferulic acid, and p-coumaric acid. Transcriptomic and qRT-PCR analyses revealed that the expression of OMT, LDOX, GST, F3′5′H, and 3AT was positively correlated with changes in anthocyanin levels under high temperatures, suggesting their roles in the observed phenolic alterations. These findings highlight the molecular responses of winegrapes to heat stress, providing a foundation for future viticulture strategies under changing climatic conditions. Full article

(This article belongs to the Special Issue Precision Breeding and Cultivation of Grapevine for Trait Improvement)

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19 pages, 2209 KB

Open AccessArticle

Aquatic Ecotoxicity Risk Assessment of Difenoconazole and Its Transformation Residues Using Experimental–In Silico Integrated Approach

by Constantina-Bianca Vulpe, Cosmina-Alecsia Cosma, Andrijana Pujicic, Bianca-Vanesa Agachi, Adriana Isvoran and Adina-Daniela Iachimov-Datcu

Agronomy 2026, 16(8), 774; https://doi.org/10.3390/agronomy16080774 - 9 Apr 2026

Abstract

Difenoconazole is a triazole fungicide used to ensure sustainable agricultural, although it may also affect the aquatic environment. This study assessed the effects of this fungicide by both an experimental and a computational approach. The experimental assessment involved the acute exposure of Lemna [...] Read more.

Difenoconazole is a triazole fungicide used to ensure sustainable agricultural, although it may also affect the aquatic environment. This study assessed the effects of this fungicide by both an experimental and a computational approach. The experimental assessment involved the acute exposure of Lemna minor to different concentrations of difenoconazole and the determination of main endpoints such as number of fronds and colony, as well as secondary endpoints represented by gravimetric, morphometrical and biochemical parameters. The in silico analysis consisted of the testing of difenoconazole and 14 of its transformation residues (TRs), using three computational tools (admetSAR, ADMETlab and T.E.S.T.) to assess either their toxicological endpoints (EC₅₀, IGC₅₀) or their probability of affecting a range of model aquatic organisms. The results highlighted a concentration-dependent effect of difenoconazole on both main and secondary endpoints. The calculated EC₅₀ value was 2.47 mg/L (data validated by EC₅₀ on Lemna gibba from Pesticides Properties DataBase), which categorizes difenoconazole as moderately toxic in the aquatic environment. The in silico assessment showed that two of the TRs showed lower toxicity, with these having only one aromatic ring compared to the others analyzed. Full article

(This article belongs to the Special Issue Pesticide Residues Abatement: A Central to Regenerative Agriculture)

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22 pages, 6188 KB

Open AccessArticle

Assessing Dispenser-Based Control on Mealybug (Hemiptera: Pseudococcidae) and Ant (Hymenoptera: Formicidae) Populations in Virginia Vineyards

by Pragya Chalise, Douglas G. Pfeiffer, Thomas P. Kuhar, Mizuho Nita, Timothy A. Jordan, Carlyle C. Brewster and Ryan Mays

Agronomy 2026, 16(8), 773; https://doi.org/10.3390/agronomy16080773 - 9 Apr 2026

Abstract

Mealybugs (Hemiptera: Pseudococcidae) are one of the prevalent pests infesting wine grapes in the eastern United States. Their close association with ants (Hymenoptera: Formicidae) provides them with protection against natural enemies. Although sugar-based dispensers have been proposed as a strategy to disrupt this [...] Read more.

Mealybugs (Hemiptera: Pseudococcidae) are one of the prevalent pests infesting wine grapes in the eastern United States. Their close association with ants (Hymenoptera: Formicidae) provides them with protection against natural enemies. Although sugar-based dispensers have been proposed as a strategy to disrupt this trophobiotic interaction, their field performance and indirect effects on mealybug infestation remain poorly understood. This study addresses this gap by identifying mealybug species present in Virginia vineyards, characterizing dominant ant genera associated with mealybugs, and evaluating the impact of sugar dispensers (with and without insecticide) on ant activity, mealybug density, and fruit cluster infestation. Field trials were conducted in two commercial vineyards in Virginia, USA, both with a history of mealybug infestations. Sampling plots with or without sugar dispensers were compared to assess differences in mealybug and ant population densities and fruit cluster infestation levels. Two mealybug species, Pseudococcus maritimus (Ehrhorn) and Ferrisia gilli Gullan, were detected at both sites. Some dominant ant genera, including Tetramorium Mayr, Lasius Fabricius, Solenopsis molesta (Say), Crematogaster Lund, and Pheidole Westwood, were found in close association with mealybugs. Ant activity remained low in untreated plots, whereas insecticide-treated dispensers initially attracted high ant numbers, which declined over time. Fruit cluster infestation was highest in plots lacking dispensers, indicating that dispenser deployment reduced mealybug impact. These findings demonstrate that sugar dispensers, particularly those containing insecticide, can suppress ant activity and reduce mealybug-related fruit damage, offering a practical non-disruptive tool for integrated pest management in small- and medium-sized vineyards. Full article

(This article belongs to the Section Pest and Disease Management)

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23 pages, 4041 KB

Open AccessArticle

Detection of Phosphorus Deficiency Using Hyperspectral Imaging for Early Characterization of Asymptomatic Growth and Photosynthetic Symptoms in Maize

by Sutee Kiddee, Chalongrat Daengngam, Surachet Wongarrayapanich, Jing Yi Lau, Acga Cheng and Lompong Klinnawee

Agronomy 2026, 16(8), 772; https://doi.org/10.3390/agronomy16080772 - 8 Apr 2026

Abstract

Phosphorus (P) deficiency severely limits maize growth and yield, yet early detection remains challenging, as visible symptoms appear only after prolonged starvation. This study evaluated the capability of hyperspectral imaging (HSI) combined with machine learning to detect P deficiency in maize seedlings at [...] Read more.

Phosphorus (P) deficiency severely limits maize growth and yield, yet early detection remains challenging, as visible symptoms appear only after prolonged starvation. This study evaluated the capability of hyperspectral imaging (HSI) combined with machine learning to detect P deficiency in maize seedlings at both symptomatic and pre-symptomatic stages. Two greenhouse experiments were conducted: a long-term pot system under high and low P conditions and a short-term hydroponic experiment with three P concentrations of 500, 100, and 0 μmol/L phosphate (Pi). After long-term P deficiency, significant reductions in shoot biomass and Pi content were observed, while root biomass increased and nutrient profiles were altered. Hyperspectral signatures revealed distinct wavelength-specific differences across visible, red-edge, and near-infrared (NIR) regions, with P-deficient leaves showing lower reflectance in green and NIR regions but higher reflectance in the red band. A multilayer perceptron machine learning model achieved 99.65% accuracy in discriminating between P treatments. In the short-term experiment, P deficiency significantly reduced tissue Pi content within one week without affecting pigment composition or photosynthetic parameters. Despite the absence of visible symptoms, hyperspectral measurements detected subtle spectral changes, particularly in older leaves, enabling classification accuracies of 80.71–84.56% in the first week and 85.88–90.98% in the second week of P treatment. Conventional vegetation indices showed weak correlations with Pi content and failed to detect early P deficiency. These findings demonstrate that HSI combined with machine learning can effectively detect P deficiency before visible symptoms emerge, offering a non-destructive, rapid diagnostic tool for precision nutrient management in maize production systems. Full article

(This article belongs to the Special Issue Nutrient Enrichment and Crop Quality in Sustainable Agriculture)

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25 pages, 4466 KB

Open AccessArticle

Integrated Multi-Omics Profiling Elucidates the Molecular Mechanisms of Salt Stress Adaptation in Tartary Buckwheat (Fagopyrum tataricum)

by Yi Yuan, Zilong Liu, Yunzhe He, Liming Men, Zhihui Chen, Guoqing Dong and Dengxiang Du

Agronomy 2026, 16(8), 771; https://doi.org/10.3390/agronomy16080771 - 8 Apr 2026

Abstract

Soil salinization is a major threat to global crop production. Tartary buckwheat (Fagopyrum tataricum), valued for its hardiness in marginal environments, provides an excellent system for studying plant salt tolerance. Using an integrated multi-omics approach, we deciphered the physiological, metabolic, and [...] Read more.

Soil salinization is a major threat to global crop production. Tartary buckwheat (Fagopyrum tataricum), valued for its hardiness in marginal environments, provides an excellent system for studying plant salt tolerance. Using an integrated multi-omics approach, we deciphered the physiological, metabolic, and transcriptional responses of Tartary buckwheat to prolonged NaCl stress. Physiological profiling confirmed membrane damage alongside osmotic adjustment via proline accumulation and a phased antioxidant response. Metabolomics revealed extensive reprogramming, with dynamic enrichment in pathways of flavonoid biosynthesis, lipid metabolism, and the TCA cycle. Transcriptomics delineated a time-specific cascade from early signaling to late defense activation. Critical regulators within ABA and MAPK signaling pathways showed fine-tuned, divergent expression; for instance, SnRK2.3 was suppressed while specific PP2Cs were induced, and FtMAPK10 was dramatically up-regulated. Integrated analysis demonstrated coordinated induction of osmoprotectant synthesis (e.g., galactinol and betaine pathways) and a rewiring of central carbon metabolism. Our findings reveal a sophisticated, multi-layered adaptation strategy in Tartary buckwheat, integrating enhanced osmolyte production, antioxidant defense, membrane remodeling, and metabolic reprogramming, orchestrated by key signaling networks. This study provides a comprehensive molecular framework for salt tolerance and identifies valuable genetic targets for improving crop resilience. Full article

(This article belongs to the Special Issue Germplasm Conservation and Genetic Improvement in Tropical and Subtropical Crops)

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26 pages, 5629 KB

Open AccessArticle

Effect of Red–Blue Light Ratios on Leaf Development and Steviol Glycoside Production at Different Growth Stages in Hydroponic Stevia

by Cheng Tai Chou, Vivian Christabel, Mai Anh Le, Min-Lang Tsai and Shang-Ta Wang

Agronomy 2026, 16(8), 770; https://doi.org/10.3390/agronomy16080770 - 8 Apr 2026

Abstract

Stevia is a natural source of high-intensity sweeteners, collectively known as steviol glycosides (SG), which are approximately 300 times sweeter than sucrose and widely used as sugar substitutes. This study examines the impact of five different red-to-blue (R:B) light ratios on SG content [...] Read more.

Stevia is a natural source of high-intensity sweeteners, collectively known as steviol glycosides (SG), which are approximately 300 times sweeter than sucrose and widely used as sugar substitutes. This study examines the impact of five different red-to-blue (R:B) light ratios on SG content and yield in hydroponic Stevia across four growth stages. Results indicate that the highest and lowest leaf dry weights were recorded in the R1B0 (R:B = 1:0) and R0B1 (R:B = 0:1) groups, at 2.88 and 1.98 g/plant, respectively, reflecting a 45.45% difference. The total SG content in dried leaves was highest in R0B1 (196.32 mg/g) and lowest in R1B0 (115.16 mg/g), with a 70.48% variation. The highest and lowest total SG yields (YSG) per square meter were observed in R0B1 (46.56 g/m²) and R50B37 (35.70 g/m²), differing by 30.42%. Stage-specific optimal YSG values were identified, with designated growth stages P1 (early vegetative growth phase), P2 (early leaf development phase), and P3 (late leaf development phase) favoring R4B1 and P4 (leaf senescence phase) favoring R0B1. These findings suggest an optimized lighting strategy for the four growth stages of hydroponic Stevia, sequentially applying R4B1, R4B1, R4B1 and R0B1 to enhance biomass accumulation and SG production at different developmental stages. Full article

(This article belongs to the Special Issue Advancement in Controlled Environment Agriculture (CEA) Automation and Crop Management—2nd Edition)

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