Agronomy, Volume 13, Issue 7 (July 2023) – 292 articles

Spring durum wheat occupies over 0.5 M ha in Kazakhstan and represents an important domestic and export commodity. This study aimed to characterize 151 durum wheat cultivars and advanced lines originating from eight breeding programs of the Kazakhstan–Siberia Spring Wheat Improvement Network (KASIB) between 2003 and 2018. The phenotypic characterization was performed in two contracting evaluation sites more than 1000 km apart (Almaty in the Southeast and Shortandy in the North) for two years and a total of 11 agronomic traits were recorded. Field trials at both locations followed regional agronomy practices, including sowing, harvesting, and genotype evaluation using a randomized complete block design (RCBD). The growing season was longer in Almaty, resulting in a higher number of grains per spike. Though grains are smaller in size with an overall higher yield, 243 g/m² versus 170 g/m², there was no correlation between germplasm performance at the two sites. Molecular characterization was performed with 10 iPBS-retrotransposons primers that resulted in a total of 345 bands and showed a mean polymorphism of 91.9%. Mean values of gene diversity (0.251), Shannon’s information index (0.388), and expected heterozygosity (0.233) revealed a relatively high level of genetic diversity in the KASIB set. AMOVA revealed higher genetic variations due to differences within the populations. Marker-based cluster analysis, including STRUCTURE and neighbor-joining algorithms, divided the material into two populations with clear differences in geographic origin. Superiors and diverse germplasm identified in the study are recommended for marker assisted selection and breeding. Full article

This study developed an unattended electric weeder (UEW) to control floor weeds in an orchard greenhouse. The UEW was a motor-driven dolly equipped with a spark exposer. The spark exposer was constructed by applying an alternating voltage (10 kV) to a conductor net (expanded metal net). The charged conductor net (C-CN) discharged into the surrounding space. Wild oat and white clover were used as test weed species. Weed seedlings growing on the floor were grounded by the biological conductor and were subjected to a spark from the C-CN when they reached the discharge space. The spark-exposed seedlings were singed and shrunk instantaneously. In the present experiment, the UEW was remotely controlled to move on the soil-cover metal nets, which were laid on the floor to make a flat surface, in a stop-and-go manner, and to eject a spark to the weed seedlings that emerged from the floor. All of the mono- and dicotyledonous weed seedlings, which had been artificially sown on the floor, were completely eradicated using this method. Thus, this study provides an experimental basis for developing an unattended technique for controlling floor weeds in an orchard greenhouse. Full article

A three-year field experiment was carried out to assess the efficacy of various tillage and residue management practices, as well as weed management approaches, in a rice–wheat–green gram rotation. The treatments included: conventional till transplanted rice–conventional till wheat–fallow (T₁); conventional till transplanted rice–zero-till wheat–zero-till green gram (T₂); conventional till direct-seeded rice—conventional-till wheat—zero-till green gram (T₃); zero-till direct-seeded rice—zero-till wheat—zero-till green gram (T₄); zero-till direct-seeded rice + residue zero-till wheat + residue zero-till green gram (T₅). In weed management, three treatments are as follows: recommended herbicides (W₁); integrated weed management (W₂); and unweeded (W₃). The integrated weed management treatment had the lowest weed biomass, which was 44.3, 45.3, and 33.7% lower than the treatment W₃ at 30 and 60 days after sowing and harvest, respectively. T₁ grain and straw yielded more than T₂ in the early years than in subsequent years. The conventional till transplanted rice–zero-till wheat–zero-till green gram system produced 33.6, 37.6, and 27.7% greater net returns than the zero-till direct-seeded rice—zero-till wheat—zero-till greengram system, respectively. Conventional till transplanted rice–conventional till wheat–fallow had the biggest reduction (0.41%) in soil organic carbon from the initial value. The findings of the study demonstrated that adopting the transplanting method for rice, followed by zero tillage for wheat and green gram, enhanced productivity and profitability, while simultaneously preserving soil health. Full article

Concerns about atmospheric ammonia have been expressed recently by some on the Lower Eastern Shore (LES) of Maryland, which lies between the Chesapeake Bay and the Atlantic Ocean on the Delmarva peninsula. Agriculture, seafood and tourism are responsible for a significant fraction of the economic activity on the LES. The USDA 2017 census reported there were ~100 Concentrated Animal Feeding Operations (CAFOs) raising nearly 63 M chickens per year across Somerset and Worcester Counties. We report air quality data collected from sites near Princess Anne, Somerset County, and near Pocomoke City, Worcester County, to address air quality concerns by examining the influence of chicken farms on ammonia in ambient air on the LES. Within a two-mile radius of the Worcester County site, CAFO operations house ~1.6 million birds. The Princess Anne site is comparable to the Pocomoke City site in agricultural use and population demographics but has only a few chicken houses within two miles. The first 33 months of LES ammonia data are presented, and their significance is discussed relative to other ammonia studies. The 33-month average concentration of ammonia in Pocomoke was 10.3 ± 0.08 ppb, more than double that in Princess Anne, which was 4.7 ± 0.04 ppb. Full article

Duckweed is a plant with high phytoremediation abilities, which is why it is used in the process of cleaning the aquatic environment. The present study aimed to determine the effect of various concentrations of pig slurry added to the growth media used to produce duckweed (Lemna minor) (laboratory Warsaw University of Life Sciences—SGGW) (experimental groups 1–9, pig slurry concentration (%): 1—2.00, 2—1.50, 3—1.00, 4—0.75, 5—0.50, 6—0.25, 7—0.12, 8—0.06, 9—0.03, control group 0—0.00). The contents of nutrients in the growth media could be classified as high (gr. 1–3), optimal (gr. 4–6), and deficient (gr. 7–9). Analyses were conducted for duckweed yield and growth medium parameters (pig slurry concentration, pH, salinity, temperature, TDS, and EC) on days 0, 10, 20, and 30 of the experiment. No growth or poor growth of duckweed were noted in groups 1, 6–9, and 0. In turn, satisfactory yields of duckweed green mass were recorded in groups 3–5, which allowed choosing them for further observations and analyses, including proximate composition (including protein content); contents of Ca, Mg, K, Na, Zn, Cu, Cd, Pb, Al, Cr, and α-tocopherol; and carotenoids—β-carotene, α-carotene, violaxanthin, zeaxanthin, lutein, amino acids, fatty acids as well as N-NH₄ and N-NO₃. The plant material had an acceptable proximate composition and nutritionally safe analyzed component contents. Appropriate, stable growth medium conditions allowed the production of satisfactory duckweed yields. The study results allowed us to conclude that it is feasible to obtain feed material meeting basic quality standards by maintaining a closed circuit of duckweed culture, and use in the agricultural environment is possible through harnessing pig slurry for its production and ensuring its optimal growth conditions. Full article

Wheat is a staple crop in China’s arid and semi-arid regions. Drought and low nitrogen (LN) are two major constraints to wheat growth and production. However, the molecular mechanism underlying wheat response to both drought and LN stress remains unknown. Accordingly, we conducted a proteomic study on the roots of two wheat varieties, Chang6878 (drought tolerant) and Shi4185 (drought sensitive) and compared the differences between drought and combined drought and LN stress treatments. In total, 5143 proteins were identified, of which 163 differentially abundant proteins (DAPs) were uniquely upregulated under drought and LN stress in Chang6878. Enrichment analysis showed that DAPs were mainly involved in mitogen-activated protein kinase signaling, phenylpropanoid biosynthesis, glutathione metabolism, ethylene biosynthesis, ethylene signal transduction, and oxidation–reduction reactions. These DAPs were verified via parallel reaction monitoring and quantitative real-time polymerase chain reaction. Chang6878 was treated with the ethylene synthesis precursor 1-aminocyclopropanecarboxylic acid, and its resistance to drought and LN stress improved. After treatment with the ethylene synthesis inhibitor silver nitrate and ethylene signal transduction inhibitor 1-methylcyclopropene, drought and LN stress resistance reduced. These results provide novel insights into the tolerance mechanisms of Chang6878 to drought and LN stress by altering ethylene synthesis and signal transduction. This study provides a reference for breeding drought- and low-nitrogen-tolerant wheat germplasm resources and a theoretical basis for maintaining food security in arid, barren areas. Full article

The hard bottom layer of a paddy field has a great influence on the driving stability and the operation quality and efficiency of intelligent farm machinery. For paddy field machinery, continuous improvements in the accuracy and operation efficiency of unmanned precision operations are needed to realize unmanned rice farming. In the context of unmanned farm machinery operation, the complicated hard bottom layer situation makes it difficult to quantify the local characteristics of paddy fields. In this paper, an unmanned direct rice seeding machine chassis is used to maneuver the operation field and collect the hard bottom layer information simultaneously. This information is used to design a data processing method that automatically calibrates the sensor installation error and performs abnormal value rejection and 3D sample curve denoising of the contour trajectory. A hard bottom layer surface profile evaluation method based on the local sliding surface roughness is also proposed. The local characteristics of the hard bottom layer were quantified, and the results from the test plots showed that the mean value of the local roughness was 0.0065, where 68.27% of the plots were distributed in the variation range of 0.0042~0.0087 and 99.73% were distributed in the variation range of 0~0.0133. Using the test field data, the surface roughness features were verified to describe the variability in representative working conditions, such as the transport, downfield, operation, and trapping of unmanned intelligent farm machinery. When driving intelligent farm machinery, the proposed method for quantifying local features of the hard bottom layer can provide feedback on the local environmental features at any given position of the machinery. The method also provides a reference for the design optimization of unmanned systems, which can help to realize speed adaption and improve the local path tracking control accuracy of smart farming machines. Full article

Plant N concentration (PNC) has been commonly used to guide farmers in assessing maize (Zea mays L.) N status and making in-season N fertilization decisions. However, PNC varies based on the development stage. Therefore, a relationship between biomass and N concentration is needed (i.e., critical N dilution curve; CNDC) to better understand when plants are N deficient. A few CNDCs have been developed and used for plant N status diagnoses but have not been tested in the US Midwest. The objective of this study was to evaluate under highly diverse soil and weather conditions in the US Midwest the performance of CNDCs developed in France and China for assessing maize N status. Maize N rate response trials were conducted across eight US Midwest states over three years. This analysis utilized plant and soil measurements at V9 and VT development stages and final grain yield. Results showed that the French CNDC (y = 34.0x^−0.37, where y is critical PNC, and x is aboveground biomass) was better with a 91% N status classification accuracy compared to only 62% with the Chinese CNDC (y = 36.5x^−0.48). The N nutrition index (NNI), which is the quotient of the measured PNC and the calculated critical N concentration (Nc) based on the French CNDC was significantly related to soil nitrate-N content (R² = 0.38–0.56). Relative grain yield on average reached a plateau at NNI values of 1.36 at V9 and 1.21 at VT but for individual sites ranging from 0.80 to 1.41 at V9 and from 0.62 to 1.75 at VT. The NNI threshold values or ranges optimal for crop biomass production may not be optimal for grain yield production. It is concluded that the CNDC developed in France is suitable as a general diagnostic tool for assessing maize N status in US Midwest. However, the threshold values of NNI for diagnosing maize N status and guiding N applications vary significantly across the region, making it challenging to guide specific on-farm N management. More studies are needed to determine how to effectively use CNDC to make in-season N recommendations in the US Midwest. Full article

Castanea sativa Mill. is a valuable species with historical and economic importance in Europe, particularly in the Mediterranean area. In Italy, chestnut cultivation has been developed for centuries, leading to the recognition of more than 300 varieties. Nevertheless, a profusion of local names has been assigned by growers, causing the occurrence of synonyms and homonyms across the country. This research focused on genetic characterization and identification using 21 single sequence repeats (SSRs) for four chestnut varieties (i.e., Pastinese, Nerattino, Carpinese, and Rossola) commonly used for flour production in the Tuscan Apennine Mountains (Pistoia Province). A comprehensive number of 55 accessions identified by local growers as belonging to the four varieties were analyzed, in addition to a few “Marrone” accessions as outgroups. The 21 microsatellites were highly informative, detecting 98 alleles and displaying an average polymorphism information content (PIC) equal to 0.582. In addition, a considerable amount of genetic diversity was revealed, as shown by the heterozygosity levels (He = 0.634 and Ho = 0.475). The STRUCTURE analysis provided clear distinctions among the different varieties, splitting them into four separate groups. This result was also confirmed by UPGMA dendrogram and principal co-ordinates analysis (PCoA). However, one accession (Carp_5), previously identified as Carpinese, showed an allelic profile attributable to Pastinese, suggesting that farmers might have performed mislabeling or grafting propagation errors. Thus, our results confirm the use of SSRs to allocate the accessions of different varieties, uncovering possible synonyms and homonyms. Specifically, in the context of the Pistoiese mountain region, this tool can favor the traceability of processed products, such as flour, enhancing the quality and economic value of the local market. Lastly, our findings have revealed a considerable genetic variability within the Tuscan chestnut varieties whose preservation is mandatory to face climate change challenges through sustainable forest management practices. Full article

Kenaf is one of the most important natural cannabis plants. Molecular marker-assisted breeding is vital for accelerating the breeding process of kenaf. However, the number of kenaf markers is insufficient for molecular marker-assisted breeding. Using transcriptome sequencing data for salt-stressed kenaf plants, the number and distribution of simple sequence repeats (SSRs) and single nucleotide variations (SNVs) in the expressed sequences were determined. The objectives of this study were to elucidate the sequence variations in kenaf genes expressed in response to salt stress and to identify stable and dependable molecular markers. Primers were designed for SSR loci and then EST-SSR molecular markers were generated. The subsequent analyses revealed that 30.50% of the unigenes contained SSR motifs, most of which were single nucleotides followed by trinucleotides and dinucleotides. The unigenes containing SSRs were mostly associated with kenaf salt tolerance. Additionally, 10,483 SNVs were detected in contig sequences. Of the 3995 differentially expressed genes encoding interacting proteins, 1297 contained SSRs. Most of these genes were associated with metabolic pathways (e.g., 03000 transcription factors, B09132 signal transduction, and 04122 sulfur relay system). We designed 20 pairs of EST-SSR primers to genotype 30 kenaf varieties (lines), of which 9 primer pairs were ideal for genotyping (e.g., 1 highly polymorphic marker and 2 moderately polymorphic markers). The primer pairs designed for the EST-SSR markers in the kenaf genome may be useful SSR molecular markers for future research on kenaf. The verified polymorphic markers may be applicable to the molecular marker-assisted breeding of salt-tolerant kenaf varieties. Full article

Seed treatment with micronutrients is a crucial strategy for providing early seedling supply during development, and is commonly employed in soybean cultivation. However, responses to micronutrient treatment may vary based on seed vigor levels. Therefore, this study aimed to assess the potential of hyperspectral imaging combined with preprocessing and machine learning, compared to X-ray fluorescence spectroscopy, in evaluating the dynamics of micronutrient uptake during the germination of soybean seeds with varying levels of vigor. Two seed lots with differing levels of vigor were utilized for the analysis. The absorption of micronutrients by the seeds was evaluated using X-ray fluorescence spectroscopy (XRF), microprobe X-ray fluorescence spectroscopy (μ-XRF) and hyperspectral imaging (HSI) in two regions of interest (cotyledons and the embryonic axis). Artificial neural network (ANN), decision tree (DT) and partial least squares–discriminant analysis (PLS-DA) classification models, along with the Savitzky–Golay (SG), standard normal variation (SNV) and multiplicative scatter correction (MSC) methods, were employed to determine seed vigor based on the impact of micronutrient treatment. XRF identified higher concentrations of micronutrients in the treated seeds, with zinc being the predominant element. μ-XRF analysis revealed that a significant proportion of the micronutrients remained adhered to the hilum and seed coat, irrespective of seed vigor. The PLS-DA classification model using spectral data exhibited higher accuracy in classifying soybean seeds with high and low vigor, regardless of seed treatment with micronutrients and the analyzed region. Full article

Tobacco brown spot caused by Alternaria alternata is a devastating fungal disease endangering plant production. To effectively control brown spot disease, an antagonistic Actinomyces strain, Streptomyces hygroscopicus JY-22, was isolated from rhizospheric soil, which remarkably restrains the growth of phytopathogenic fungus Alternaria alternata. This antagonistic strain and its culture filtrate showed significant antifungal activity against Alternaria alternata. Firstly, the confrontation culture method of strains JY-22 and Alternaria alternata showed that Streptomyces hygroscopicus JY-22 had noticeable antifungal activity against Alternaria alternata, including inhibition of mycelial growth and mycelial morphological changes, compared with the control group. Furthermore, the culture filtrate of Streptomyces hygroscopicus JY-22 showed substantial inhibition of the mycelial growth and spore germination of Alternaria alternata in a dose-dependent manner. Additional studies revealed that these antifungal actions were mainly related to membrane-active mechanisms that increased membrane permeability and damaged the cell membrane, leading to changes in certain cytoplasmic properties, such as extracellular conductivity and ergosterol, MDA and soluble protein content. In detached-leaf and field experiments, foliar spraying with culture filtrate resulted in smaller lesions and a lower disease index than the control group. Taken together, these results suggest that Streptomyces hygroscopicus JY-22 and its culture filtrate have the potential to be a safe biopesticide for the bio-control of tobacco brown spot. Full article

Smart agriculture relies on accurate yield maps as a crucial tool for decision-making. Many yield maps, however, suffer from spatial errors that can compromise the quality of their data, while several approaches have been proposed to address some of these errors, detecting voids or holes in the maps remains challenging. Additionally, the quality of yield datasets is typically evaluated based on root mean squared errors after interpolation. This evaluation method relies on weighbridge data, which can occasionally be inaccurate, impacting the quality of decisions made using the datasets. This paper introduces a novel algorithm designed to identify voids in yield maps. Furthermore, it maps three types of spatial errors (GPS errors, yield surges, and voids) to two standard data quality dimensions (accuracy and completeness). Doing so provides a quality score that can be utilized to assess the quality of yield datasets, eliminating the need for weighbridge data. The paper carries out three types of evaluations: (1) evaluating the algorithm’s efficacy by applying it to a dataset containing fields with and without voids; (2) assessing the benefits of integrating void detection and other spatial error identification techniques into the yield data processing chain; and (3) examining the correlation between root mean squared error and the proposed quality score before and after filtering out spatial errors. The results of the evaluations demonstrate that the proposed algorithm achieves a 100% sensitivity, 91% specificity, and 82% accuracy in identifying yield maps with voids. Additionally, there is a decrease in the root mean squared error when various spatial errors, including voids after applying the proposed data pre-processing chain. The inverse correlation observed between the root mean squared error and the proposed quality score (−0.577 and −0.793, before and after filtering spatial errors, respectively) indicates that the quality score can effectively assess the quality of yield datasets. This assessment enables seamless integration into real-time big data quality assessment solutions based on various data quality dimensions. Full article

As the global population continues to increase, projected to reach an estimated 9.7 billion people by 2050, there will be a growing demand for food production and agricultural resources. Transition toward Agriculture 4.0 is expected to enhance agricultural productivity through the integration of advanced technologies, increase resource efficiency, ensure long-term food security by applying more sustainable farming practices, and enhance resilience and climate change adaptation. By integrating technologies such as ground IoT sensing and remote sensing, via both satellite and Unmanned Aerial Vehicles (UAVs), and exploiting data fusion and data analytics, farming can make the transition to a more efficient, productive, and sustainable paradigm. The present work performs a systematic literature review (SLR), identifying the challenges associated with UAV, Satellite, and Ground Sensing in their application in agriculture, comparing them and discussing their complementary use to facilitate Precision Agriculture (PA) and transition to Agriculture 4.0. Full article

Light can regulate leaf stomatal development and movement, but the effects of different red-to-blue light mass ratios on leaf stomatal morphology and openness are not fully understood. In this trial, five different red-to-blue light (R:B) ratio treatments were used to study the changes in morphology, photosynthesis, and stomatal-related indexes of cucumber seedlings under fixed light intensity (200 μmol·m⁻²·s⁻¹). The results showed that the thickness of spongy tissue and stomatal size (SZ) of cucumber seedling leaves decreased, and the photosynthetic potential, stomatal density (SD), maximum stomatal conductance and stomatal responsiveness increased with decreasing R:B content. The experimental results showed that when R:B = is 1:9, cucumber seedlings had the greatest stomatal density and the fastest response rate, and the stomatal opening rate was accelerated with the increase in the proportion of blue light; when R:B = is 3:7, the stomatal conductance was the greatest and the net photosynthetic rate was the highest. This trial provides some implications for changing plant light quality and thus affecting stomatal development and movement. Full article

Accurately estimating aboveground dry biomass (ADB) is crucial. The ADB of rice has primarily been estimated using vegetation indices with several discrete bands; nevertheless, these indices cannot take advantage of continuous bands available with hyperspectral remote sensing. This study analyzed the quantitative relationship between canopy hyperspectral characteristic parameters (HCPs) and the ADB of rice. Twenty HCPs were used, including red edge area (SDr), blue edge area (SDb), and others. The variable-screening methods involved stepwise regression (SR), a regression coefficient (RC), variable importance in projection (vip), and random forest (RF). Stepwise and partial least squares regression methods were employed with traditional linear regression as well as machine learning methods including random forest (RF), a support vector machine (SVM), a BP artificial neural network (BPNN), and an extreme learning machine. Whole- and screening-variable models were constructed to estimate rice ADB at jointing, booting, heading, and maturing stages and across growth stages. Screening-variable models include SVM models based on SR (SVM-sr), RF models based on vip (RF-vip), and others. The results show that the HCPs had a significant correlation with ADB containing elements in the red edge region, namely SDr, SDr/SDb, and (SDr − SDb)/(SDr + SDb) at each growth stage. In addition, the screening performance of vip and SR was better than that of RC and RF, and fewer variables were screened. Moreover, the HCPs of the red edge region were screened using different screening methods at each growth stage. Among them, SDr/SDb and (SDr − SDb)/(SDr + SDb) appeared frequently, indicating they are important. Furthermore, at each growth stage, ADB could be well-estimated using diverse models with the RF modeling method based on vip screening variables found to be the best modeling method for ADB estimation; the independent variables of the RF-vip model involved the (SDr − SDb)/(SDr + SDb) at each growth stage. Full article

The concentration of selenium (Se) in agricultural products primarily depends on the concentration of Se in soil and the ability of plants to accumulate Se. Selenium deficiency not only leads to decreased body resistance, but also increases the risk of cancer. The form and concentration of bioavailable Se is important for diet. The present study was carried out via field experiment with wheat and broad beans in soil of different Se concentrations (0, 1.12, and 11.2 kg·ha⁻¹), which was determined based on the national standard and the team’s previous experience. Results indicated that the concentration of Se in the edible organs of wheat was higher than in broad bean, while the enriched Se concentration in the root of broad bean was more than twice and three times higher than that of wheat at medium and high levels of Se, respectively. Selenomethionine, which accounted for over half of the total Se speciations, was the dominant species in the edible parts of the two crops, followed by Selenocystine and methylselenocysteine. Through the analysis of the rhizosphere soil, it was found that Fe-Mn oxide-bound Se exceeded 80% of the total Se. Additionally, there was a significant linear correlation between the Se content in the edible parts of the two crops and the Se content in the soil. Findings suggested that wheat was more favorable than broad beans as Se supplement crops in a Se-supplied field. Full article

To improve water use efficiency and productivity, particularly in irrigated areas, reliable water accounting methodologies are essential, as they provide information on the status and trends in irrigation water availability/supply and consumption/demand. At the collective irrigation system level, irrigation water accounting (IWA) relies on the quantification of water fluxes from the diversion point to the plants, at both the conveyance and distribution network and the irrigated field level. Direct measurement is the most accurate method for IWA, but in most cases, there is limited metering of irrigation water despite the increasing pressure on both groundwater and surface water resources, hindering the water accounting procedures. However, various methodologies, tools, and indicators have been developed to estimate the IWA components, depending on the scale and the level of detail being considered. Another setback for the wide implementation of IWA is the vast terminology used in the literature for different scales and levels of application. Thus, the main objectives of this review, which focuses on IWA for collective irrigation services, are to (i) demonstrate the importance of IWA by showing its relationship with water productivity and water use efficiency; (ii) clarify the concepts and terminology related to IWA; and (iii) provide an overview of various approaches to obtain reliable data for the IWA, on the demand side, both at the distribution network and on-farm systems. From the review, it can be concluded that there is a need for reliable IWA, which provides a common information base for all stakeholders. Future work could include the development of user-friendly tools and methodologies to reduce the bridge between the technology available to collect and process the information on the various water accounting components and its effective use by stakeholders. Full article

Actual crop evapotranspiration (ETa) is measured or estimated using different methods, and its accuracy is critical for water management under precision agriculture. The objective of this study was to compare maize ETa estimated by the two-step approach using a locally developed crop coefficient curve with satellite-retrieved evapotranspiration by six models incorporated in the OpenET to identify the best evapotranspiration estimation alternatives to the two-step approach for water management in northern New Mexico. Maize (Zea mays L.) was planted at the NMSU Agricultural Science Center at Farmington from 2017 to 2022 and uniformly managed across years. Water management in plants was based on maize’s actual evapotranspiration estimated as the product of the reference evapotranspiration and the local crop coefficient, which is described as a third-order polynomial function of the accumulated heat units by maize plants. For the same growing seasons, maize ETa was retrieved from satellite, and was estimated by six models listed within the OpenET from 2017 to 2022. The results show that maize daily ETa was consistently smaller when measured by SIMS and PT-JPL during maize initial and actively growing stages, while ETc(kc), SIMS and eeMETRIC showed similar maize daily ETa during maize full canopy development and mid-season, and which overcome the evapotranspiration estimated by DisALEXI, PT-JPL, geeSEBAL, and SSBop. ETc(kc) drastically dropped and became the lowest value among all ETa estimation models after the first fall snow or the first killing frost. Regarding the seasonal average, all six models included in OpenET showed smaller maize evapotranspiration. Maize seasonal evapotranspiration varied from 589.7 to 683.2 mm. eeMETRIC compares most similarly to the ETc(kc) model, followed by SIMS, with percent errors of 2.58 and 7.74% on a daily basis and 2.43 and 7.88% on a seasonal basis, with the lowest MBE and RMSE values, respectively, and could be used as an alternative for maize actual daily evapotranspiration for water management in northern New Mexico. The results of this study could be used by water managers and crop growers to improve water management in the Four Corners region, using eeMETRIC for crop water use to improve water management and conservation under sustainable agriculture. Full article

Identifying elite stress-tolerant varieties and elucidating the genetic mechanisms mediating stress resistance can help breeders develop and exploit new rice germplasm resources. In this study, we identified five salt-tolerant varieties and five drought-tolerant upland rice varieties by survival rate and drought tolerance grade and constructed variation maps of the resistance using a deep-sequencing approach. Using 116 rice accessions from the 3000 Rice Genomes Project, we characterized the population structure of sequenced varieties. Through comparative genomics and transcriptome analysis, we screened 39 salt-response candidate genes. Natural variation analysis on root length-related drought candidate gene showed that Hap1 and Hap4 were the predominant haplotypes in indica, while Hap5 was the predominant haplotype in japonica. Gene Ontology (GO) analysis showed that carbohydrate metabolic process, defense response, and response to stimulus were the common GO terms associated with salt and drought tolerance. Selective signatures in elite stress-tolerant varieties indicated that multiple important stress tolerance genes, namely OsRac1, Pikp-2, Xa26, OsSIRP4, and wsl1, were selected and utilized in these sequenced rice varieties. These findings may be useful for clarifying the genetic variations among elite stress-tolerant varieties, while also laying the foundation for a more comprehensive investigation of the genetic basis of salt and drought tolerance. Full article

Water loss through surface runoff is a significant constraint for rainfed agricultural lands across the Mediterranean region. Using straw-mulch cover (SMC) as a runoff mitigator has been successfully utilized to negate the impact of raindrop splashing. However, this practice is uncommon due to the high demand for crop residue as feed or fodder for livestock. Therefore, the application of synthetic polyacrylamide (PAM) has become a common practice. Although many studies have shown the positive impact of PAM on runoff control, most were conducted under laboratory conditions, where interactions with crop phenology and runoff dynamics were disregarded. In this study, on-site rainfall simulation was used to determine the efficiency of PAM and SMC to control runoff from foxtail millet (Setaria italica) fields under three seasonal conditions: (1) high-intensity rainfall, characteristic of autumn, on bare soil surfaces; (2) moderate-intensity rainfall, characteristic of winter, following crop tillering; and (3) high-intensity rainfall, characteristic of spring, following the flowering phase. The effect of SMC during the autumn and spring simulations was significantly better than that of the PAM and control treatments. For the winter simulation, runoff rates and runoff ratios were similar for all treatments. The most prominent finding was obtained for the spring simulation, where SMC yielded no runoff, whereas the PAM and control treatments yielded similar runoff rates and runoff ratios. Full article

Soil amendments with composted organic materials are recommended to increase soil organic matter (SOM) and promote soil fertility. Growing areas of hedged olive groves in the southern Iberia peninsula generate huge amounts of olive leaves, and their potential as an organic soil amendment is not fully studied. An experimental field trial in a hedged olive grove (“Cobrançosa”) was set up near Portalegre, Portugal, to test a compost of olive leaves plus sheep manure (with a ratio of 2:1) when applied in a row at the soil’s surface. Nominal rates of zero, 2.5, and 5.0 kg m⁻² (T0, T1, and T2, respectively) were applied in a complete randomized block setup (three treatments, three replicas, and nine plots), and soil properties of layers between 0–5, 5–15, and 15–30 cm were annually monitored. More expressive results occurred in the soil layer 0–5 cm, and with the dosage T2. After one year, there were significant increases in the total N, carbon of the particulate organic matter, permanganate oxidizable carbon (POX-C), extractable phosphorus, and zinc. After two years, there was 16% more soil organic carbon (SOC), an absolute increase of 0.5 in pHKCl, 1.9 times more extractable phosphorus, and ten times more zinc. The soil’s C-stock in the 0–30 cm layer, after two years of T1 and T2 dosages, was 0.11 and 0.35 kg m⁻² (~3 and ~9%, respectively), which was higher than with T0. POX-C was the most sensitive SOM-related indicator, showing increases of up to 30 cm deep after one year. This compost improved soil fertility but should be monitored over longer periods of time. Full article

The accurate identification of the water layer condition of paddy fields is a prerequisite for precise water management of paddy fields, which is important for the water-saving irrigation of rice. Until now, the study of unmanned aerial vehicle (UAV) remote sensing data to monitor the moisture condition of field crops has mostly focused on dry crops, and research on the water status of paddy fields has been relatively limited. In this study, visible and thermal infrared images of paddy fields at key growth stages were acquired using a UAV remote sensing platform, and three model input variables were constructed by extracting the color features and temperature features of each field, while K-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and logistic regression (LR) analysis methods were applied to establish a model for identifying the water layer presence in paddy fields. The results showed that KNN, SVM, and RF performed well in recognizing the presence of water layers in paddy fields; KNN had the best recognition accuracy (89.29%) via algorithm comparison and parameter preference. In terms of model input variables, using multisource remote sensing data led to better results than using thermal or visible images alone, and thermal data was more effective than visible data for identifying the water layer status of rice fields. This study provides a new paradigm for monitoring the water status of rice fields, which will be key to the precision irrigation of paddy fields in large regions in the future. Full article

Barley is an important feed crop in Iran and is threatened by an increased frequency of drought. Increasing diversity in the form of evolutionary populations (EPs) and mixtures is one strategy to increase the resilience of crops. Four barley EPs, which have evolved in different locations over 7 to 10 years from the same original population, were evaluated for agronomic trait and stability together with two landraces, and one improved variety for three cropping seasons in four locations. Modest but significant differences were found only for plant height with a range of less than 4 cm. Stability, measured with cultivar superiority, as well as environmental variance and reliability measures generally indicated a superior stability of EPs—with two of them ranking first and second for grain yield reliability—but also differences between the EPs. The effect of recurrent droughts on the diversity within EPs is discussed as a possible explanation for the lack of divergent evolution. The seed management of Eps, including seed exchange between farmers, is suggested as a possible strategy to avoid the reduction in diversity within populations. Future research will address the nutritional value of the EPs, which is often quoted by sheep owners as superior to commonly grown varieties. Full article

Ethylene at least partly regulates some aspects during non-climacteric ripening in strawberry. However, the ethylene signaling pathway genes in the strawberry fruit have not been comprehensively and systematically analyzed. In the present study, 15 FaETRs and 14 FaEIN3/EINs were identified in the octoploid strawberry genome. Subcellular localization analysis predicted that FaETRs and FaEIN3/EINs are respectively localized to the endoplasmic reticulum and the nucleus. The phylogenetic trees showed that FaETRs were classified into two subgroups, while FaEIN3/EINs were divided into three clades, which was supported by gene structure and conserved motif analysis. FaETRs and FaEIN3/EINs could interact with several components, such as CTR1, RTE1, EIN2 and ERF1B, in the ethylene signaling pathway by protein–protein interaction network analysis. Transcriptomic data showed that FaETRs were mainly expressed at the early stage of fruit development in three strawberry cultivars. Additionally, a couple of FaETRs (FaETR2 and FaETR13) and FaEINs (FaEIN2 and FaEIN7) could be induced by 1 μM ABA and inhibited by 100 μM nordihydroguaiaretic acid (NDGA, an ABA biosynthesis blocker). These findings suggested that the FaETR- and FaEIN3/EIN-mediated ethylene signaling pathway might play a role in strawberry fruit ripening. Full article

Maize is a valuable raw material for feed and food production. Healthy seed germination is important for improving the yield and quality of maize. However, the molecular mechanisms that regulate maize seed germination remain unclear. In this study, multi-omics was used to reveal the molecular mechanism of seed germination induced by gibberellin (GA) in maize. The results indicated that 25,603 genes were differentially expressed (DEGs) and annotated in the GO database, of which 2515 genes were annotated in the KEGG database. In addition, 791 mature miRNAs with different expression levels were identified, of which 437 were known in the miRbase database and 354 were novel miRNAs. Integrative analysis of DEGs and miRNAs suggested that carbohydrate, lipid, amino acid, and energy metabolisms are the primary metabolic pathways in maize seed germination. Interestingly, a lipid metabolism-related gene named ZmSLP was found to negatively regulate maize germination. We transformed this gene into Arabidopsis thaliana to verify its function. The results showed that the germination rate of transgenic Arabidopsis seeds was obviously decreased, and the growth of seedlings was weaker and slower than that of WT plants, suggesting that this gene plays an important role in promoting seed germination. These findings provide a valuable reference for further research on the mechanisms of maize seed germination. Full article

Dendrobium loddigesii has long been used in traditional folk medicine. The purpose of this study was to optimize the culture conditions for its protocorm-like bodies (PLBs) and explore their biological activities. The use of an air-lift bioreactor demonstrated superior PLB proliferation compared to agitated and solid culture methods. The optimal inoculum quantity of 30 g/vessel, cultured for 28 days in the bioreactor, yielded the highest PLB biomass production. Analysis of PLB extracts revealed that the ethyl acetate (EtOAc) extract exhibited the highest levels of flavonoids and alkaloids, as well as potent antioxidant activity demonstrated by DPPH free radical scavenging assay and reducing power. Furthermore, the antiproliferative effects of the PLB extracts were assessed using MTT assays, and the EtOAc extract showed significant efficacy by reducing cell viability by over 60% in the human colon carcinoma cell line SW620 at the highest tested concentration (200 μg/mL). Mechanistic analysis revealed the downregulation of key regulatory apoptosis genes, including survivin, p53, caspase-3, and caspase-9. These results demonstrate the potential of the bioreactor culture method for the efficient production of D. loddigesii PLBs and the biological activities of the EtOAc extract, suggesting its therapeutic potential. Full article

The continuous input, slow decomposition, and retention of straw can impede tillage and crop growth, and the decomposition process of the straw in soil is affected by its composition and the method of application. Experimental Station of Jilin Agricultural University, Changchun City, Jilin Province. The soil type was Argiudolls, the experimental field area was 30 m², and the maize was planted continuously for 12 years without returning the straw to the field. There were four treatments: (1) control (CK), 10 g of straw was placed on the surface of a nylon mesh bag, and the nylon mesh bag was separated from the soil by polyethylene film without contacting with the soil; (2) straw mulching (CM), a nylon mesh bag with 10 g of straw was placed on the soil surface; (3) straw burying (CD), a nylon mesh bag with 10 g of straw was buried at a depth of 40 cm from the soil surface; (4) straw burying (CE), a nylon mesh bag with 40 cm of soil depth. Fifteen micro-zones were set up with a micro-zone area of 1 m² and each micro-zone consisted of four treatments randomly grouped in three replicates per treatment. The on-site nylon bag burying trial started on 20 April 2021 and ended on 15 April 2022. Nylon bag and soil samples were collected on days 0, 30, 90, 180, 270, and 360. SOC, TN, straw component decomposition, and water droplet-soil contact angle were determined. Our results showed that the CE treatment increased soil organic carbon (SOC) and total nitrogen (TN) content compared to the CM and CD treatments. Compared with CK, straw decomposition rates increased by 13.3%, 30.8%, and 22.3% in the CM, CD, and CE treatments, respectively. Lignin decomposition rates increased by 7.8%, 27.3%, and 16.2%; cellulose decomposition rates increased by 14.6%, 35.4%, and 27.3%; and hemicellulose decomposition rates increased by 17.2%, 31.7% and 23.7% in the CD treatment, respectively. Compared with CK, the contact angle of droplets in the CD treatment was statistically significantly increased by 91.5% when the droplets remained on the soil surface for 5 s. The rate of decrease of droplet contact angle with time was statistically significantly decreased by 11.8%, and the penetration rate of droplets on the soil surface was slower. Overall, the CD treatment promoted straw decomposition and increased SWR compared to the CM and CE treatments. which are important attributes to enhance soil quality and improve soil structural stability. Full article

Wolfberry (Lycium barbarum L.) is a small Solanaceae shrub with medicinal and edible homology, and widely used as ethnobotanical medicine and nutraceutical food. The wolfberry fruits mainly have red, purple, and yellow phenotypes. Wolfberries are rich in flavonoids, which are natural water-soluble pigments that endow a variety of colors in plants There are very few investigations on mechanism of flavonoids biosynthesis and fruit coloring reported about wolfberry. The widely targeted metabolome and transcriptome analysis were performed to obtain metabolite and gene expression profiles of red, yellow, and purple wolfberries and to explain the underlying molecular mechanism of the color differences in wolfberry. As result, metabolomics analysis revealed that the bluish anthocyanins Malvidin and petunidin trended to accumulate in purple wolf-berry, while red and yellow wolfberries trended to accumulate more yellowish flavonoids. And transcriptome analysis showed that flavonoid synthesis-related genes, such as CHS, F3H, ANS and DFR, and several MYB and bHLH genes were differentially expressed among wolfberries in different colors: most of them were more highly expressed in purple wolfberries than in red and yellow ones. In conclusion, the different flavonoids’ accumulation patterns may result in the different fruit colors of wolfberry, and the MYB or bHLH transcription factors could regulate the expression of flavonoids biosynthesis related genes to change the composition of flavonoids or anthocyanins in wolfberry fruits and result in varied fruit colors. These findings provide new insights into the underlying molecular mechanism of the fruit color differences in wolfberry and provide new ideas for molecular breeding of wolfberry. Full article