Lodging Resistance Research Articles

Variation and interrelationships in the growth, yield, and lodging of oat under different planting densities.

Oat is a dual-purpose cereal used for grain and forage. The demand of oat has been increasing as the understanding of the nutritional, ecological, and economic values of oat increased. However, the frequent lodging during the growing period severely affect the high yielding potential and the quality of the grain and forage of oat. Therefore, we used the lodging-resistant variety LENA and the lodging-sensitive variety QY2 as materials, implementing four different planting densities: 2.25×106 plants/ha (D1), 4.5×106 plants/ha (D2), 6.75×106 plants/ha (D3), and 9×106 plants/ha (D4). At the appropriate growth and development stages, we assessed agronomic traits, mechanical characteristics, biochemical compositions, yield and its components. The study investigated the impact of planting density on the growth, lodging, and yield of oat, as well as their interrelationships. Additionally, we identified the optimal planting density to establish a robust crop structure. The research aims to contribute to the high-yield and high-quality cultivation of oat. We observed that with increasing planting density, plant height, grass and grain yields of both varieties first increased and then decreased; root fresh weight, stem diameter, stem wall thickness, stem puncture strength, breaking strength, compressive strength, lignin and crude fiber contents, and yield components decreased; whereas the lodging rate and lodging coefficient increased. Planting density affects lodging by regulating plant height, height of center of gravity, stem wall thickness, internode length, and root fresh weight of oat. Additionally, it can impact stem mechanical strength by modulating the synthesis of lignin and crude fiber, which in turn affecting lodging resistance. Plant height, height of center of gravity, stem wall thickness, internode length, root fresh weight, breaking strength, compressive strength, lignin and crude fiber content, single-plant weight, grain yield and 1,000-grain weight can serve as important indicators for evaluating oat stem lodging resistance. We also noted that planting density affected grain yield both directly and indirectly (by affecting lodging); high density increased lodging rate and decreased grain yield, mainly by reducing 1,000-grain weight. Nonetheless, there was no significant relationship between lodging and grass yield. As appropriate planting density can increase the yield while maintaining good lodging resistance, in this study, 4.5×106 plants/ha (D2) was found to be the best planting density for oat in terms of lodging resistance and grass and grain yield. These findings can be used as a reference for oat planting.

Alginate Oligosaccharides Alleviate Salt Stress in Rice Seedlings by Regulating Cell Wall Metabolism to Maintain Cell Wall Structure and Improve Lodging Resistance.

Salt stress is one of the major abiotic stresses that damage the structure and composition of cell walls. Alginate oligosaccharides (AOS) have been advocated to significantly improve plant stress tolerance. The metabolic mechanism by which AOS induces salt tolerance in rice cell walls remains unclear. Here, we report the impact of AOS foliar application on the cell wall composition of rice seedlings using the salt-tolerant rice variety FL478 and the salt-sensitive variety IR29. Data revealed that salt stress decreased biomass, stem basal width, stem breaking strength, and lodging resistance; however, it increased cell wall thickness. In leaves, exogenous AOS up-regulated the expression level of OSCESA8, increased abscisic acid (ABA) and brassinosteroids (BR) content, and increased β-galacturonic activity, polygalacturonase activity, xylanase activity, laccase activity, biomass, and cellulose content. Moreover, AOS down-regulated the expression levels of OSMYB46 and OSIRX10 and decreased cell wall hemicellulose, pectin, and lignin content to maintain cell wall stability under salt stress. In stems, AOS increased phenylalamine ammonia-lyase and tyrosine ammonia-lyase activities, while decreasing cellulase, laccase, and β-glucanase activities. Furthermore, AOS improved the biomass and stem basal width and also enhanced the cellulose, pectin, and lignin content of the stem, As a result, increased resistance to stem breakage strength and alleviated salt stress-induced damage, thus enhancing the lodging resistance. Under salt stress, AOS regulates phytohormones and modifies cellulose, hemicellulose, lignin, and pectin metabolism to maintain cell wall structure and improve stem resistance to lodging. This study aims to alleviate salt stress damage to rice cell walls, enhance resistance to lodging, and improve salt tolerance in rice by exogenous application of AOS.

Effects of narrow-wide row planting patterns on canopy photosynthetic characteristics, bending resistance and yield of soybean in maize‒soybean intercropping systems

With the improvements in mechanization levels, it is difficult for the traditional intercropping planting patterns to meet the needs of mechanization. In the traditional maize‒soybean intercropping, maize has a shading effect on soybean, which leads to a decrease in soybean photosynthetic capacity and stem bend resistance, resulting in severe lodging, which greatly affects soybean yield. In this study, we investigated the effects of three intercropping ratios (four rows of maize and four rows of soybean; four rows of maize and six rows of soybean; six rows of maize and six rows of soybean) and two planting patterns (narrow-wide row planting pattern of 80–50 cm and uniform-ridges planting pattern of 65 cm) on soybean canopy photosynthesis, stem bending resistance, cellulose, hemicellulose, lignin and related enzyme activities. Compared with the uniform-ridge planting pattern, the narrow-wide row planting pattern significantly increased the LAI, PAR, light transmittance and compound yield by 6.06%, 2.49%, 5.68% and 5.95%, respectively. The stem bending resistance and cellulose, hemicellulose, lignin and PAL, TAL and CAD activities were also significantly increased. Compared with those under the uniform-ridge planting pattern, these values increased by 7.74%, 3.04%, 8.42%, 9.76%, 7.39%, 10.54% and 8.73% respectively. Under the three intercropping ratios, the stem bending resistance, cellulose, hemicellulose, lignin content and PAL, TAL, and CAD activities in the M4S6 treatment were significantly greater than those in the M4S4 and M6S6 treatments. Compared with the M4S4 treatment, these variables increased by 12.05%, 11.09%, 21.56%, 11.91%, 18.46%, 16.1%, and 16.84%, respectively, and compared with the M6S6 treatment, they increased by 2.06%, 2.53%, 2.78%, 2.98%, 8.81%, 4.59%, and 4.36%, respectively. The D-M4S6 treatment significantly improved the lodging resistance of soybean and weakened the negative impact of intercropping on soybean yield. Therefore, based on the planting pattern of narrow-wide row maize‒soybean intercropping planting pattern, four rows of maize and six rows of soybean were more effective at improving the lodging resistance of soybean in the semiarid region of western China.

Detection of maize stem diameter by using RGB-D cameras' depth information under selected field condition.

Stem diameter is a critical phenotypic parameter for maize, integral to yield prediction and lodging resistance assessment. Traditionally, the quantification of this parameter through manual measurement has been the norm, notwithstanding its tedious and laborious nature. To address these challenges, this study introduces a non-invasive field-based system utilizing depth information from RGB-D cameras to measure maize stem diameter. This technology offers a practical solution for conducting rapid and non-destructive phenotyping. Firstly, RGB images, depth images, and 3D point clouds of maize stems were captured using an RGB-D camera, and precise alignment between the RGB and depth images was achieved. Subsequently, the contours of maize stems were delineated using 2D image processing techniques, followed by the extraction of the stem's skeletal structure employing a thinning-based skeletonization algorithm. Furthermore, within the areas of interest on the maize stems, horizontal lines were constructed using points on the skeletal structure, resulting in 2D pixel coordinates at the intersections of these horizontal lines with the maize stem contours. Subsequently, a back-projection transformation from 2D pixel coordinates to 3D world coordinates was achieved by combining the depth data with the camera's intrinsic parameters. The 3D world coordinates were then precisely mapped onto the 3D point cloud using rigid transformation techniques. Finally, the maize stem diameter was sensed and determined by calculating the Euclidean distance between pairs of 3D world coordinate points. The method demonstrated a Mean Absolute Percentage Error (MAPE) of 3.01%, a Mean Absolute Error (MAE) of 0.75mm, a Root Mean Square Error (RMSE) of 1.07mm, and a coefficient of determination (R²) of 0.96, ensuring accurate measurement of maize stem diameter. This research not only provides a new method of precise and efficient crop phenotypic analysis but also offers theoretical knowledge for the advancement of precision agriculture.

Transcriptional Regulation and Gene Mapping of Internode Elongation and Late Budding in the Chinese Cabbage Mutant lcc.

Two important traits of Chinese cabbage, internode length and budding time, destroy the maintenance of rosette leaves in the vegetative growth stage and affect flowering in the reproductive growth stage. Internodes have received much attention and research in rice due to their effect on lodging resistance, but they are rarely studied in Chinese cabbage. In Chinese cabbage, internode elongation affects not only the maintenance of rosette leaves but also bolting and yield. Budding is also an important characteristic of Chinese cabbage entering reproductive growth. Although many studies have reported on flowering and bolting, studies on bud emergence and the timing of budding are scarce. In this study, the mutant lcc induced by EMS (Ethyl Methane Sulfonate) was used to study internode elongation in the seedling stage and late budding in the budding stage. By comparing the gene expression patterns of mutant lcc and wild-type A03, 2280 differentially expressed genes were identified in the seedling stage, 714 differentially expressed genes were identified in the early budding stage, and 1052 differentially expressed genes were identified in the budding stage. Here, the transcript expression patterns of genes in the plant hormone signaling and clock rhythm pathways were investigated in relation to the regulation of internode elongation and budding in Chinese cabbage. In addition, an F2 population was constructed with the mutants lcc and R500. A high-density genetic map with 1602 marker loci was created, and QTLs for internode length and budding time were identified. Specifically, five QTLs for internode length and five QTLs for budding time were obtained. According to transcriptome data analysis, the internode length candidate gene BraA02g005840.3C (PIN8) and budding time candidate genes BraA02g003870.3C (HY5-1) and BraA02g005190.3C (CHS-1) were identified. These findings provide insight into the regulation of internode length and budding time in Chinese cabbage.

System of wheat intensification (SWI): Effects on lodging resistance, photosynthetic efficiency, soil biomes, and water productivity.

Intense cultivation with narrow row spacing in wheat, a common practice in the Indo-Gangetic plains of South Asia, renders the crop more susceptible to lodging during physiological maturity. This susceptibility, compounded by the use of traditional crop cultivars, has led to a substantial decline in overall crop productivity. In response to these challenges, a two-year field study on the system of wheat intensification (SWI) was conducted. The study involved three different cultivation methods in horizontal plots and four wheat genotypes in vertical plots, organized in a strip plot design. Our results exhibited that adoption of SWI at 20 cm × 20 cm resulted in significantly higher intercellular CO2 concentration (5.9-6.3%), transpiration rate (13.2-15.8%), stomatal conductance (55-59%), net photosynthetic rate (126-160%), and photosynthetically active radiation (PAR) interception (1.6-25.2%) over the existing conventional method (plant geometry 22.5 cm × continuous plant to plant spacing) of wheat cultivation. The lodging resistance capacity of both the lower and upper 3rd nodes was significantly higher in the SWI compared to other cultivation methods. Among different genotypes, HD 2967 demonstrated the highest recorded value for lodging resistance capacity, followed by HD 2851, HD 3086, and HD 2894. In addition, adoption of the SWI at 20 cm × 20 cm enhanced crop grain yield by 36.9-41.6%, and biological yield by 27.5-29.8%. Significantly higher soil dehydrogenase activity (12.06 μg TPF g-1 soil hr-1), arylsulfatase activity (82.8 μg p-nitro phenol g-1 soil hr-1), alkaline phosphatase activity (3.11 n moles ethylene g-1 soil hr-1), total polysaccharides, soil microbial biomass carbon, and soil chlorophyll content were also noted under SWI over conventional method of the production. Further, increased root volumes, surface root density and higher NPK uptake were recorded under SWI at 20×20 cm in comparison to rest of the treatments. Among the tested wheat genotypes, HD-2967 and HD-3086 had demonstrated notable increases in grain and biological yields, as well as improvements in the photosynthetically active radiation (PAR) and chlorophyll content. Therefore, adoption of SWI at 20 cm ×20 cm (square planting) with cultivars HD 2967 might be the best strategy for enhancing crop productivity and resource-use efficiency under the similar wheat growing conditions of India and similar agro-ecotypes of the globe.

Positive Correlation of Lodging Resistance and Soybean Yield under the Influence of Uniconazole

Increasing planting density is one of the most effective ways to increase soybean yield, but supra-optimum density leads to an increase in the risk of lodged soybean. In this study, two varieties were selected. Heinong84 (lodging-susceptible variety, HN84) had planting densities of 200,000 plants/hm2, 300,000 plants/hm2, and 400,000 plants/hm2. Henong60 (lodging-resistant, HN60) had planting densities of 300,000 plants/hm2, 400,000 plants/hm2, and 500,000 plants/hm2. When the foliar application of uniconazole (50 mg/L) occurred at the beginning of the flowering stage (R1), the plant morphology, fiber composition, and mechanical properties of soybean internodes were determined at the podding and seed filling stages, and the yield was measured at the harvest stage. The results showed that spraying uniconazole at the R1 stage changed the morphology structure of soybean plants (i.e., plant height and petiole length reduction; stem diameter and leafstalk angle increase), improved the internode quality (i.e., increased breaking force, lignin content, cellulose content, hemicellulose content, and stem dry weight per unit length), and increased the number of grains per plant at the harvest stage. Thus, it is concluded that the application of uniconazole improved the plant population structure by changing the morphology of soybean plants, which was conducive to good light transmission and ventilation, improved the internode quality and lodging resistance, and increased the yield.

Strong culm: a crucial trait for developing next-generation climate-resilient rice lines.

Lodging, a phenomenon characterized by the bending or breaking of rice plants, poses substantial constraints on productivity, particularly during the harvesting phase in regions susceptible to strong winds. The rice strong culm trait is influenced by the intricate interplay of genetic, physiological, epigenetic, and environmental factors. Stem architecture, encompassing morphological and anatomical attributes, alongside the composition of both structural and non-structural carbohydrates, emerges as a critical determinant of lodging resistance. The adaptive response of the rice culm to various biotic and abiotic environmental factors further modulates the propensity for lodging. Advancements in next-generation sequencing technologies have expedited the genetic dissection of lodging resistance, enabling the identification of pertinent genes, quantitative trait loci, and novel alleles. Concurrently, contemporary breeding strategies, ranging from biparental approaches to more sophisticated methods such as multi-parent-based breeding, gene pyramiding, genomic selection, genome-wide association studies, and haplotype-based breeding, offer perspectives on the genetic underpinnings of culm strength. This review comprehensively delves into physiological attributes, culm histology, epigenetic determinants, and gene expression profiles associated with lodging resistance, with a specialized focus on leveraging next-generation sequencing for candidate gene discovery.

Registration of ‘FL12034‐10’ oat: A new dual‐purpose disease resistant cultivar for Florida and southern United States

Abstract‘FL12034‐10’ (Reg. no. CV‐389, PI 704483), a facultative oat (Avena sativa L.) cultivar, co‐developed by the University of Florida and Louisiana State University Agricultural Center, was released in October 2022. FL12034‐10 was derived from a three‐way cross LA06055SBSBSB‐79/FL11048 F1. It is well adapted across the southern United States and provides producers with a medium‐tall, mid‐season, awnless, white‐glumed, dual‐purpose oat that has high yield potential, good straw strength, and good forage yield. FL12034‐10 was observed to be uniform and stable across environments in the southern United States from 2017 to present. The line possesses a semi‐prostrate growth habit, vigorous growth, and high tillering capacity, and has large leaves that are dark green in color. It expresses moderate‐to‐high levels of resistance to most oat diseases prevalent in the southern United States. The crown and stem rust and Barley yellow dwarf virus ratings (0–9 scale) of FL12034‐10 were 1.7, 0.7, and 1.5, respectively, across different environments. The disease ratings were better than most of the checks. The grain yield average of FL12034‐10 from 41 environments during 2018–2021 was 6437 kg ha−1, which is competitive with check cultivars that are widely used in the southern part of the United States. The forage yield of FL12034‐10 ranged from 2358 to 6617 kg ha−1 (20 environments), which was higher than most of the checks. FL12034‐10 demonstrated better lodging and disease resistance, higher grain yield potential, and higher mid‐winter to late spring season forage yield potential than Horizon 720 and Legend 567 oats released by University of Florida.

Evaluation of lodging resistance in pepper (<i>Capsicum annuum</i> L.) using different cultivation practices in the preparation of seedlings and transplanting

Evaluation of lodging resistance in pepper (<i>Capsicum annuum</i> L.) using different cultivation practices in the preparation of seedlings and transplanting

How do novel plant growth regulators and cultivation models strategies affect mechanical strength, lodging resistance and maize productivity in semi-arid regions?

Plant growth regulators are synthetic compounds that have become a significant and technical guarantee for agricultural productivity. In China, "Jindeli", which contains active elements of ethephon and cycocel (EC), has been proven to prevent maize stem elongation, improve maize stem thickness, stem morphology and mechanical strength, root growth, lodging resistance, and yield under various cultivation models. Diethyl aminoethyl hexanoate (DA-6) can promote cell division and growth. From 2020–2021, four growth regulators sprays were used to conduct a field experiment; G1: water spraying; G2: EC spraying; G3: DA-6 spraying; G4: EC+DA-6 spraying under two cultivation models; R: ridge covered with plastic film mulching and T: traditional flat planting without plastic mulching. The results indicated that RG4 treatment considerably decreased plant height, internode length, ear height, lodging rate, and center of gravity height, while improved the internode bending strength, cross-sectional area, cortical thickness, and stem vascular bundles as compared with rest of all other treatments. RG4 treatment considerably improved internode diameter, stem mechanical strength, filling degree, root growth, mean tilt angle, and lignin content, while significantly reducing LAI. In addition, RG4 considerably enhanced the quality of corn stems, such as increasing mechanical properties and enhancing the compressive strength of corn stalks that content of hemicellulose, cellulose, and lignin has been increased. Furthermore, RG4 treatment significantly improved grain yield by optimizing leaf layer structure and increasing bleeding saps levels, increasing the grains per row and ear. Thus, under the RG4 treatment maize lodging rate was decreased 72.1%, and increased WUE (52.8%), and grain yield (46.6%). In conclusion, the results clearly demonstrate that in the semi-arid regions risk of lodging can be avoided by spraying EC+DA-6 with ridge covered plastic film mulching to the enriched stalk quality, shaping plant morphological characteristics, and proving a stable cultivation model to improving maize productivity.

Effect of a novel dwarfing mutant site on chromosome 4B on agronomic traits in common wheat.

The introduction of dwarfing genes triggered a wave of "green revolution". A number of wheats dwarfing genes have been reported in previous studies, and only a small fraction of these have been applied to production practices. Therefore, the development of novel dwarfing genes for wheat is of great value. In this study, a novel dwarfing site, Rht-yz, identified in the Yanzhan mutation, is located on chromosome 4B (30-33MB) and its mechanism of action is different from that of Rht-B1b (C-T mutation), but whether it affects the Rht-B1a (TraesCS4B02G043100) or other genes is unclear. Exogenously applied GA3 experiments showed that Rht-yz is one of the gibberellin-insensitive dwarf genes. The effects of the dwarf gene Rht-yz on agronomic traits in wheat were evaluated in the field using Yanzhan, Yanzhan mutations, F2:3 and F3:4 lines. The results showed that Rht-yz improved lodging resistance by reducing plant height, increasing diameter, wall thickness and mechanical strength of the basal stem. In terms of yield traits, Rht-yz had negative effects on tiller number plant-1, biomass plant-1 and yield plant-1, but had no significant effect on harvest index, 1000-kernel weight and spike traits. In addition, Rht-yz significantly increased crude protein, wet gluten and starch content. Therefore, the rational use of the new dwarfing site Rht-yz has potential and value in dwarf wheat breeding.

Optimal N fertilizer management method for improving maize lodging resistance and yields by combining controlled-release urea and normal urea

Despite being an efficient nitrogen (N) management method, the effects of controlled-release urea combined with normal urea (CRUNU) on stem and root lodging and yield in maize have been rarely reported. Therefore, we conducted a field trial for three years between 2020 and 2022 using two N fertilizer types (CRUNU and normal urea (NU)) and three N application levels (low: 135 kg N ha–1; medium: 180 kg N ha–1; and high: 225 kg N ha–1) to evaluate their effects on stem and root lodging and the yield in maize, and the factors involved. The results showed that, compared with NU, CRUNU reduced the stem and root lodging rate under the three N application rates, and all were lowest under the medium N application rate. The decreased stem and root lodging rate was mainly attributed to the improved the synchronization of nitrogen supply and demand, reduced population traits (plant height, ear height, and center of gravity height), improved morphological traits (length and mass density) for the basal second, third, and fourth internodes (I2, I3, and I4), increased mechanical properties (stem breaking strength and rind penetration strength), greater stem lodging resistance index (SLRI), enhanced chemical compositions (lignin and its related synthetase activities, cellulose, and hemicellulose) in I2, I3, and I4, and increases in the stem bending strength, root average diameter, and vertical root-pulling resistance under CRUNU. In addition, the SLRI values for different internodes followed the order of: I2 > I3 > I4, thereby indicating that I2 and I3 played important roles in stem lodging resistance. Furthermore, compared with NU, the maize grain yield increased by 1.27–44.83% under CRUNU with the three N application rates. In particular, there was no significant difference in the grain yield between the high and medium N application rates under CRUNU. In conclusion, CRUNU combined with N application at a rate of 180 kg ha–1 may be a superior N fertilizer management method.

Effect of planting density on yield and architecture suitability of groundnut (Arachis hypogaea) varieties

A field experiment was conducted during rainy (kharif) seasons of 2018 and 2019 at the research farm of Sri Venkateswara Agricultural College (Acharya N. G. Ranga Agricultural University), Tirupati, Andhra Pradesh, to study the effect of planting density on yield and architecture suitability of groundnut (Arachis hypogaea L.) varieties. The experiment included 4 sowing densities (D1, 33.3 plants/m2; D2, 50 plants/m2; D3, 66.6 plants/m2 and D4, 100 plants/m2) and 3 genotypes with varying architecture (G1, Kadiri 6-erect; G2, Kadiri 9-decumbent 2; and G3, Dharani-decumbent 3). The results showed that across planting densities, Dharani and Kadiri 9 genotypes showed higher architectural traits, structural carbohydrates and kernel yield compared to the Kadiri 6. A significant positive correlation was detected between the lodging percentage and both plant height (r = 0.88**) and internodal length (r = 0.61*). Significant negative correlations, were identified between lodging percentage and several parameters, including leaf thickness (r = -0.92**), specific leaf weight (r = -0.93**), stem diameter (r = -0.79**), specific stem weight (r = -0.97**), number of branches (r = -0.72**), cellulose content (r = -0.80**), and lignin content (r = -0.79**). These findings indicate that the decumbent architecture is optimal for achieving groundnut lodging resistance and kernel yield in high-density planting systems.

Yield, lodging, and water use efficiency of Tef [Eragrostis tef (zucc) Trotter] in response to carbonized rice husk application under variable moisture condition.

Terminal drought and lodging are among the major yield-limiting factors for tef cultivation in the highly weathered soils of the Ethiopian highlands. Therefore, a study was conducted to assess the yield and lodging responses of tef to varying moisture depletion levels (MDL) and the application of carbonized rice husk (CRH). A two-year 4×4 factorial experiment with 20, 35, 55, and 75% MDL and 0, 291, 582, and 873 kg ha-1 of CRH was laid out in a split-plot design, with each treatment replicated four times. The pooled mean ANOVA showed leaf area index (LAI) and lodging index (LI) were not significantly influenced by the main and interaction effects of MDL and CRH (p > 0.05); however, individual year ANOVA showed that both LI and LAI were influenced by the interaction of MDL and CRH (p<0.05) in 2021 and 2022, respectively. The lowest LI (19.7%) was obtained from the application of 873 kg CRH ha-1, followed by 20.6% from 582 kg CRH ha-1 in 2022. A 20.7% LI reduction was recorded in 2022 compared to 2021. Tef plant height and number of tillers per plant were significantly affected by MDL at p<0.05 and p<0.01, respectively, but not by CRH and its interaction with MDL. The effect of MDL was significant on tef HI (p<0.01) but not on traits including grain yield, straw yield, and water use efficiency. In conclusion, the pooled mean analysis result showed that, though there was no significant difference in yield, tef irrigated at 55% MDL provided a maximum HI of 33.8%, which was 6.21% more than the control, and increased the level of lodging resistance with a LI of 31.9%, which was next to 75% MDL with 582 kg ha-1 CRH. The authors suggested that the research should further be verified across locations for wide application.

Integrated VIS/NIR Spectrum and Genome-Wide Association Study for Genetic Dissection of Cellulose Crystallinity in Wheat Stems.

Cellulose crystallinity is a crucial factor influencing stem strength and, consequently, wheat lodging. However, the genetic dissection of cellulose crystallinity is less reported due to the difficulty of its measurement. In this study, VIS/NIR spectra and cellulose crystallinity were measured for a wheat accession panel with diverse genetic backgrounds. We developed a reliable VIS/NIR model for cellulose crystallinity with a high determination coefficient (R2) (0.95) and residual prediction deviation (RPD) (4.04), enabling the rapid screening of wheat samples. A GWAS of the cellulose crystallinity in 326 wheat accessions revealed 14 significant SNPs and 13 QTLs. Two candidate genes, TraesCS4B03G0029800 and TraesCS5B03G1085500, were identified. In summary, this study establishes an efficient method for the measurement of cellulose crystallinity in wheat stems and provides a genetic basis for enhancing lodging resistance in wheat.

Management of Seeding Rate and Nitrogen Fertilization for Lodging Risk Reduction and High Grain Yield of Mechanically Direct-Seeded Rice under a Double-Cropping Regime in South China

Precision hill-drop direct seeding using mechanical drilling is a unique direct seeding technique employed in south China that offers advantages such as excellent grain yield and high lodging resistance. Improving yield and lodging-related traits is essential for efforts to improve mechanically direct-seeded rice (MDSR) production. Seeding rates (SR) and nitrogen (N) fertilization rate are two of the main factors affecting grain yield and lodging resistance under MDSR production. However, little information about double-season MDSR production in south China is available. Here, we evaluated yield and lodging risk for two rice cultivars Huanghuazhan, HHZ, lodging-resistant; Xiangyaxiangzhan, XYXZ, lodging-susceptible across two consecutive growing seasons under two under two seeding rates (LSR, 30 cm × 18 cm; HSR, 30 cm × 12 cm) and three N fertilization rates (N1 = 100 kg ha−1, reduced N; N2 = 150 kg ha−1, normal N; and N3 = 200 kg ha−1, enhanced N). We found that increased SR and N fertilization rate improved grain yield and increased lodging risk. SR and N were consistently and positively related to plant height (PH), gravity center height (GCH), the length from the broken basal internode to the panicle tip (SL), the fresh plant weight of the plant part above the broken point (FW), and the length of the two basal internodes. SR and N decreased breaking force (F) and breaking strength (BM), driving increased lodging risk as reflected by increases in lodging index (LI) values. Culm diameter (CD) and culm wall thickness (CWT) did not respond consistently to SR and N treatments. Correlation analysis revealed that PH, GCH, the length of first and second basal internodes, FW, and bending moment for the whole plant (WP) were positively correlated with LI, while F and BM were negatively associated with LI. These findings suggest that the increased lodging risk resulting from high SR could be mitigated by applying appropriate rates of N; that is, this work suggests that grain yield can be maximized and lodging risk minimized by increasing SR while decreasing N fertilization rate. Seasonal differences in the effects of SR and N fertilization should be considered to achieve a high grain yield and maintain high lodging resistance. Our study suggests that increasing SR and decreasing N fertilization can enhance rice grain yield while improving lodging resistance for both varieties. Optimizing grain yield by increasing SR while reducing lodging risk by lowering N application rates may maintain lodging resistance and improve grain yield.

Biological and economic traits of Yasmina – a new variety of six-row spring barley with high productive potential

Abstract. The Yasmina variety is a new, highly productive spring fodder barley. It was created at the Institute of Agriculture in Karnobat by means of a combinatorial selection method. The biological and economic traits of the variety were tested in the Institute’s competitive variety trials and the IASAS system during 2019-2020. The aim of this study was to present the biological and economic traits of the new recognized spring six-row barley variety Yasmina. In the ecological network regions, it demonstrated high productivity. The mean yield from the new variety obtained in 4 Bulgarian regions was proven higher than the one from the standard variety Venera by 22.0%. During the testing period, the variety realized a yield of up to 6500 kg/a. With high protein content of 13.51%, it is ideally suited for fodder.The variety has good lodging resistance. Yasmina was recognized as an original cultivar with Order No RD-12-4/10 Mar 2021 by the Minister of Agriculture, Food and Forestry and was approved for entry in List A of the Official Variety List of the Republic of Bulgaria.

Silicon Fertilizer Addition Can Improve Rice Yield and Lodging Traits under Reduced Nitrogen and Increased Density Conditions

Reducing nitrogen fertilizer application, selecting a reasonable planting density, and adding silicon fertilizer can be used together to decrease excessive nitrogen fertilizer inputs in rice fields, reduce production costs, and ensure stable rice yield. However, the dynamics of the stem and internodes, as well as the changes in the physical and physiological characteristics of rice under a combination of these three strategies, are still unclear. In this study, we aimed to clarify these effects to improve the efficiency of rice production in northeastern China. A 2-year field experiment was conducted using five treatments: a conventional densification treatment (DM), a densification combined with reduced N input (−20%) treatment (DLM), and three densifications combined with reduced N input (−20%) and basal silicon fertilizer treatments (low fertilizer: DLMS1; medium fertilizer: DLMS2; and high fertilizer: DLMS3). This study revealed that the addition of silicon fertilizer improved rice yield compared to that under reduced nitrogen or increased density treatments alone, prevented excessive ineffective tillering after a density increase, and increased the number of productive panicles. Among the treatments, the DLMS3 treatment had the highest yields of 10.53 t/ha and 10.73 t/ha over the 2 years. Reducing nitrogen and increasing density reduced the weight and length of single panicles, while the addition of silicon fertilizer was beneficial for improving stem toughness, improving the physical and physiological characteristics of the plants and panicles, and enhancing plant bending resistance. Among the treatments, DLMS3 had the highest bending resistance, which increased by 440.1 g and 503.8 g compared to the lowest values in the DM treatment in 2020 and 2021, respectively. Nitrogen reduction resulted in the lowest lodging index values, with DLMS3 having the lowest values in both years, which decreased by 19.6% and 22.5% compared to the highest values in DM (2020) and DLM (2021), respectively. This study indicates that the application of 150.0 kg/ha silicon fertilizer in combination with reduced nitrogen and increased density (DLMS3) reduces the lodging index while ensuring rice yield, preventing a tradeoff between yield reduction and lodging due to a density increase or due to nitrogen reduction combined with a density increase and allowing for a reduction in nitrogen fertilizer input, which could ensure a uniform yield and an increase in lodging resistance. These results provide a scientific basis for rice cultivation measures that lead to high yield and lodging resistance while protecting the environment.

Registration of USDA‐N6006 soybean germplasm combining high yield, flood tolerance, and elevated oil content

AbstractUSDA‐N6006 soybean [Glycine max (L.) Merr.] (Reg. no. GP‐527, PI 704140) is a conventional F4–derived early maturity group (MG) VI germplasm jointly released by USDA‐ARS and North Carolina Agricultural Research Service in 2023. USDA‐N6006 is the first MG VI, publicly released germplasm that combines flood tolerance with high‐yield lodging resistance, and elevated seed oil. Over 19 environments of the MG VI USDA Southern Uniform Soybean Trials (2017–2018), seed yield of USDA‐N6006 (3393 kg ha−1) was similar to high‐yielding lodging‐resistant check cultivars ‘NC‐Dunphy’ (3427 kg ha−1) and ‘NC‐Dilday’ (3475 kg ha−1). It matured 1 day earlier than NC‐Dunphy and exhibited similar lodging scores. Over 5 years of testing in North Carolina (2016–2019), USDA‐N6006 exhibited very robust flood tolerance. Mean flooding scores were numerically or statistically (p &lt; 0.05) superior to the four flood‐tolerant controls at both V4 and R1 growth stages. USDA‐N6006 was not intentionally bred to be flood tolerant and identified as such only through an extensive screening of “in house” USDA breeding lines. USDA‐N6006 and most of its antecedents are unique in that they are derived from unreleased breeding lines developed at the flood prone Tidewater Research station in North Carolina. Inadvertent selection for flood tolerance may have been a part of the USDA's long‐term breeding effort to improve yield. Seed oil content of USDA‐N6006 (237 g kg−1) was similar to that of elevated seed oil cultivar NC‐Dilday, but significantly higher than NC‐Dunphy (228 g kg−1) in the Uniform Trials. Seed protein content and estimated meal protein contents of USDA‐N6006 (389 g kg−1 and 46.4%, respectively) were similar to that of NC‐Dunphy. USDA‐N6006 should be excellent parental stock for applied breeding in the southern United States.