Agronomy

25 pages, 11007 KB

Open AccessReview

Population-Based Threshold Models for Predicting Weed Emergence: A Synthesis as a Conceptual Framework for the Development of Tools for Site-Specific Management

by Cristian Malavert, Diego Batlla and Roberto L. Benech-Arnold

Agronomy 2026, 16(10), 948; https://doi.org/10.3390/agronomy16100948 - 8 May 2026

Abstract

Effective weed management is crucial for optimizing agricultural productivity and minimizing environmental impacts. Weeds are most effectively managed during their seedling or early growth stages, which can be achieved with the aid of tools for predicting seedling emergence. However, many persistent weed species [...] Read more.

Effective weed management is crucial for optimizing agricultural productivity and minimizing environmental impacts. Weeds are most effectively managed during their seedling or early growth stages, which can be achieved with the aid of tools for predicting seedling emergence. However, many persistent weed species exhibit dormant seedbanks, thus complicating prediction attempts. The number of seedlings emerging in these species is closely tied to seedbank dormancy levels, which are influenced by seasonal variations. Thus, predictive population-based threshold models incorporate seedbank dormancy regulation to accurately forecast seedling “window” emergence. These models use the functional relationship between environmental cues (i.e., temperature, light, alternating temperatures, and soil water content) and seed dormancy behavior. Considering that these environmental signals vary among microsites in the field, these tools can be adapted to predict weed emergence in both temporal and spatial dimensions, thus making them suitable for site-specific weed management. The aim of this review is to synthesize existing modeling approaches and present a conceptual framework for dynamic, site-specific weed emergence predictions, supported by case-study-based applications. The illustrative application shows that incorporating soil water content into dormancy dynamics modifies emergence timing and magnitude, restricting emergence to specific topographic zones and potentially reducing herbicide use by up to 60–70%. This approach can improve the efficiency of herbicide applications and other control measures, reducing costs and environmental impact while enhancing crop yields. This work underscores the potential of integrating environmental cues into sophisticated modeling approaches to address the complexities of weed emergence in diverse agricultural landscapes. Full article

(This article belongs to the Special Issue State-of-the-Art Research on Weed Populations and Community Dynamics)

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25 pages, 1054 KB

Open AccessArticle

DNA Barcoding and Allele-Specific PCR Discrimination of Glasswort Ecotypes from Apulia Region (Southern Italy)

by Angelica Giancaspro, Giulia Conversa, Luigi Giuseppe Duri, Gaetana Ricatti, Antonio Elia, Stefano Pavan and Concetta Lotti

Agronomy 2026, 16(10), 947; https://doi.org/10.3390/agronomy16100947 - 8 May 2026

Abstract

In the scenario of ongoing climate changes, the selection of plant genotypes with high salt tolerance is emerging as the most sustainable strategy to safeguard crop yield and quality and make productive use of salinized soils. Glassworts are annual and perennial halophytes found [...] Read more.

In the scenario of ongoing climate changes, the selection of plant genotypes with high salt tolerance is emerging as the most sustainable strategy to safeguard crop yield and quality and make productive use of salinized soils. Glassworts are annual and perennial halophytes found in inner and coastal wastelands, indistinctly consumed as high-nutritional green vegetables. Traditional taxonomic classification based on morphological traits can be very challenging in glasswort, due to phenotypic plasticity, reduced plant morphology, and inbreeding. In this work, we used DNA-based molecular tools to overcome such constraints and assess inter-generic and inter-specific genetic diversity in a collection of ecotypes from different Apulian areas. A fast and reliable Allele-Specific PCR assay was optimized to enable molecular detection of annual and perennial genera. Species-level classification was obtained through a similarity- and phylogeny-based approach relying on matK and rbcL DNA barcoding. Combined DNA tools identified perennial samples as Sarcocornia fruticosa and Arthrocaulon macrostachyum, along with annual Salicornia europaea, and phylogenetic trees unveiled genetic distances between glassworts, which clustered according to life cycle. The relationship between genotypes and nutritional profiles was finally investigated, suggesting that environmental factors may play a predominant role over taxonomic relatedness in shaping interspecific differences in nutrient composition of the analyzed samples. Full article

(This article belongs to the Special Issue Agro-Environmental Sustainable Exploitation of Halophyte, Medicinal and Aromatic Species from Marginal Areas—2nd Edition)

23 pages, 866 KB

Open AccessReview

Biological Nitrogen Fixation in Soybean: Mechanisms, Benefits, Sustainability, and Future Prospects

by Manish Pandit, Surekha Panthi and Anuj Chiluwal

Agronomy 2026, 16(10), 946; https://doi.org/10.3390/agronomy16100946 - 8 May 2026

Abstract

Soybean is a globally important legume crop which fulfills most of its nitrogen (N) requirement through Biological Nitrogen Fixation (BNF) in symbiosis with Bradyrhizobium species, thereby reducing dependence on synthetic fertilizers and supporting more sustainable production systems. This review synthesizes current knowledge on [...] Read more.

Soybean is a globally important legume crop which fulfills most of its nitrogen (N) requirement through Biological Nitrogen Fixation (BNF) in symbiosis with Bradyrhizobium species, thereby reducing dependence on synthetic fertilizers and supporting more sustainable production systems. This review synthesizes current knowledge on the mechanism, capacity, and regulation of BNF in soybean, including nodule formation, nitrogenase activity and response to soil and environmental conditions. The evidence shows that BNF can provide a substantial share of the crop’s N uptake, although high-yielding systems frequently experience the “N gap”, which is a difference between a higher crop demand and a lower N supplied from BNF and existing soil reserves. This can be partially managed with strategies like inoculation, co-inoculation, re-inoculation or judicial application of N. This review further highlights the advances in microbial inoculant technologies, plant growth-promoting rhizobacteria (PGPR), soybean breeding and genetic engineering aimed at improving BNF stability, efficiency and capacity across different soil environments. Overall, the maximization of soybean BNF has strong potential to reduce synthetic fertilizer use, improve yield and seed quality, and enhance the economic and environmental sustainability of soybean-based systems. Full article

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

19 pages, 8835 KB

Open AccessArticle

Mitigative Effects of Superabsorbent Polymers on the Growth of Pakchoi (Brassica rapa subsp. Chinensis) Under Drought Stress

by Haodong Zhang, Jinrui Zhou, Yinhua Wang, Bingqin Teng, Runqi Quan and Jun Wu

Agronomy 2026, 16(10), 945; https://doi.org/10.3390/agronomy16100945 - 8 May 2026

Abstract

This study systematically investigated the regulatory effects of different types of superabsorbent polymers (SAPs) on the growth and physiological characteristics of pakchoi (Brassica rapa subsp. chinensis) under drought stress. A pot-controlled experiment was conducted with two stress levels (severe drought and mild [...] Read more.

This study systematically investigated the regulatory effects of different types of superabsorbent polymers (SAPs) on the growth and physiological characteristics of pakchoi (Brassica rapa subsp. chinensis) under drought stress. A pot-controlled experiment was conducted with two stress levels (severe drought and mild drought) and four SAP application ratios (0%, 0.25%, 0.5%, 0.75%). The acrylamide-based SAPs included a self-developed attapulgite clay hydrogel (ACH) and two commercially available mainstream SAPs. The results indicated that: (1) All SAP treatments mitigated the inhibitory effects of drought stress on pakchoi growth to varying degrees, with the 0.5% ACH application showing the most significant effect. Under severe drought, this treatment significantly increased leaf area, shoot fresh weight, and root fresh weight by 184.6%, 127.8%, and 24.6%, respectively, compared to the drought-stressed control without SAP. (2) At the physiological response level, ACH significantly optimized the osmotic adjustment system of pakchoi, manifesting as a significant 53.2% decrease in proline content and a significant 60.1% increase in soluble sugar content. Concurrently, it effectively maintained cell membrane stability, reducing malondialdehyde (MDA) content by a significant 51.6%, and effectively regulated the antioxidant defense system, modulating the activities of key antioxidant enzymes (SOD, CAT, and POD) to prevent oxidative damage. This study reveals that SAPs can effectively alleviate drought stress in pakchoi. Even under severe drought stress, leaf fresh weight reached approximately 67.99% of the normal level. An application rate of 0.5% ACH is identified as an efficient and recommended dose, offering a promising technological option for water-saving and sustainable vegetable production in arid and semi-arid regions. Full article

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27 pages, 2382 KB

Open AccessArticle

Evaluating Photochemical Efficiency and Recovery Potential in Wheat Varieties with Divergent Drought Tolerance

by Vladimir Aleksandrov, Dilyana Doneva, Svetlana Misheva, Katelina Prokopova, Alexander Angelov and Violeta Peeva

Agronomy 2026, 16(10), 944; https://doi.org/10.3390/agronomy16100944 - 8 May 2026

Abstract

Drought stress during early growth stages severely limits wheat productivity globally. Understanding varietal physiological responses to drought stress is critical for breeding climate-resilient cultivars. Two-week-old plants from two winter wheat (Triticum aestivum L.) cultivars—Katya (drought-tolerant) and Zora (drought-sensitive)—were subjected to drought for [...] Read more.

Drought stress during early growth stages severely limits wheat productivity globally. Understanding varietal physiological responses to drought stress is critical for breeding climate-resilient cultivars. Two-week-old plants from two winter wheat (Triticum aestivum L.) cultivars—Katya (drought-tolerant) and Zora (drought-sensitive)—were subjected to drought for seven days, followed by rehydration. The experiments were conducted in pots in controlled conditions. The photosystem II (PSII) function was evaluated using chlorophyll a fluorescence (OJIP transients), thermoluminescence emissions and pigment content analysis. Under drought, Katya maintained functional PSII integrity with stable quantum efficiency and increased chlorophyll content, while Zora exhibited chlorophyll degradation. Fresh and dry weight declined in both genotypes but significantly only in Zora; recovery occurred after rehydration. Chlorophyll fluorescence revealed that varietal divergence was localized to the O–J phase of PSII photochemistry, indicating differences in reaction-center behavior confirmed by thermoluminescence. Katya demonstrated preserved PSII reaction-center density, balanced energy partitioning, homogeneous PSII populations, and superior recovery capacity. Conversely, Zora showed reaction-center depletion, elevated energy dissipation, impaired electron transport beyond Q_A, and persistent PSII heterogeneity even after rehydration. Drought tolerance in the studied genotypes was associated with the maintenance of PSII structural integrity, efficient photochemical function, and rapid recovery mechanisms. These physiological markers—particularly early PSII photochemistry kinetics and reaction-center stability—provide valuable selection criteria for breeding programs, targeting drought resilience under changing climate conditions. Full article

(This article belongs to the Section Plant-Crop Biology and Biochemistry)

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18 pages, 1958 KB

Open AccessArticle

Determination of the Physiological Maturity Point and Establishment of Physical Dormancy in Hymenaea martiana Seeds

by Joyce Naiara da Silva, Eduardo Luã Fernandes da Silva, Guilherme Vinícius Gonçalves de Pádua, Caroline Marques Rodrigues, João Henrique Constantino Sales Silva, Maria Karoline Ferreira Bernardo, Aline das Graças Souza and Edna Ursulino Alves

Agronomy 2026, 16(10), 943; https://doi.org/10.3390/agronomy16100943 - 7 May 2026

Abstract

In forest species with physical dormancy, defining the ideal harvest point is challenging because of the limited understanding of the relationships among maturation, physiological quality, and seed dormancy. Hymenaea martiana Hayne, a native species of the Caatinga (Brazil) biome with ecological and economic [...] Read more.

In forest species with physical dormancy, defining the ideal harvest point is challenging because of the limited understanding of the relationships among maturation, physiological quality, and seed dormancy. Hymenaea martiana Hayne, a native species of the Caatinga (Brazil) biome with ecological and economic relevance and potential for use in restoration, still requires integrated information on these processes. This study aimed to identify the point of physiological maturity and the moment of establishment of physical dormancy in H. martiana seeds on the basis of the associations between fruit color and indicators of physiological quality. The experiment was conducted in a completely randomized design with a 6 × 2 factorial scheme (maturation stages × with and without scarification), and the physical characteristics and physiological quality of the seeds were evaluated. The data were analyzed using univariate and multivariate approaches, with inflection point analysis applied as a complementary method to identify structural changes throughout maturation. Maturation is characterized by a reduction in water content, accumulation of dry matter, and the progressive establishment of physical dormancy. Seed coat dormancy is the main limiting factor for germination, and it is efficiently overcome by mechanical scarification, which confirms the role of seed coat impermeability in controlling imbibition and seedling emergence. Stage V represents the most suitable harvest point under the conditions evaluated, at which point the seeds exhibit physiological maturity associated with the greatest expression of vigor and the best germination performance when subjected to scarification. Defining this interval as the ideal harvest point contributes to improving seed collection and handling strategies, particularly for seedling production. Full article

(This article belongs to the Special Issue Seed Dormancy and Germination: Ecological, Physiological and Applied Perspectives)

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40 pages, 3393 KB

Open AccessArticle

Multi-Environment Genome-Wide Association Analysis Reveals Stable Genetic Loci for Soybean Yield Component Traits

by Ruonan Du, Qiang Gao, Hui Jin, Jumei Zhang, Yordan Dimitrov, Haibin Zhao, Yu-E Wu, Danna Chang, Chunwei Zhou, Zhuo Li, Xue Yang and Rui Zhang

Agronomy 2026, 16(10), 942; https://doi.org/10.3390/agronomy16100942 - 7 May 2026

Abstract

Soybean yield is governed by key agronomic traits such as main stem node number, lowest pod height, and branch number. These polygenic traits exhibit substantial environmental variation, and the instability of associated genetic loci identified in single-environment studies constrains their application in molecular [...] Read more.

Soybean yield is governed by key agronomic traits such as main stem node number, lowest pod height, and branch number. These polygenic traits exhibit substantial environmental variation, and the instability of associated genetic loci identified in single-environment studies constrains their application in molecular breeding. To uncover their stable genetic basis, we conducted multi-environment phenotyping over three years and six locations using a panel of 320 soybean accessions. The Best Linear Unbiased Prediction (BLUP) model was employed to integrate phenotypic data and control for genotype-by-environment interactions. Subsequently, genome-wide association studies (GWAS) were performed using BLUP-integrated phenotypic values to capture stable genetic effects, with optimal model using the Mixed Linear Model (MLM). As a result, a total of 22 significant single-nucleotide polymorphism (SNP) loci were identified. Among these, 10, 7, and 5 significant loci were associated with main stem node number, lowest pod height, and branch number, respectively, representing stable genetic signals across multiple environments. These loci primarily clustered on chromosomes 19, 8, and 18. Within these associated regions, we predicted eight high-confidence candidate genes. Functional annotation revealed that these genes are significantly enriched in pathways related to cell wall biosynthesis, energy metabolism, and stress response. This study provides effective genomic resources derived from a multi-environment GWAS framework. These stable loci and candidate genes directly facilitate the molecular breeding of soybean varieties with improved yield-related traits and environmental adaptability. Full article

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

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Agronomy, Volume 16, Issue 10 (May-2 2026) – 7 articles

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