Optimization of appropriate boron fertilization application range for cotton (Gossypium hirsutum L.) based on two varieties in boron-deficient soils

Optimization of appropriate boron fertilization application range for cotton (Gossypium hirsutum L.) based on two varieties in boron-deficient soils | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Optimization of appropriate boron fertilization application range for cotton (Gossypium hirsutum L.) based on two varieties in boron-deficient soils Shanshan Wang, Cheng Wang, Yutian Zhang, Xingjia Liang, Zhiguo Zhou, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6896139/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 01 Apr, 2026 Read the published version in Journal of Cotton Research → Version 1 posted 4 You are reading this latest preprint version Abstract Boron (B) deficiency critically constrains cotton productivity in China’s major cotton-growing regions, where soil available B levels widely fall below the sufficiency threshold (< 0.5 mg kg − 1 ). This multi-site study (2020–2021) quantified the optimal B application ranges for two regionally adapted cultivars (CCRI 425 and Siza 3) through field trials and column experiments across three B-deficient sites in Jiangsu Province. Quadratic regression modeling of seed cotton yield responses identified distinct optima: 1.90–2.36 kg B ha − 1 for CCRI 425 and 2.05–2.36 kg B ha − 1 for Siza 3, achieving yield increases of 14.7–25.9% compared to B-free controls. Within these ranges, key agronomic traits demonstrated peak performance: boll shedding rates decreased by 11.3–42.0%, boll number increased by 12.4–22.0%, and boll size expanded by 16.9–30.8%. The coefficient of variation for boll number (4.2–6.6%) substantially exceeded that of boll weight (0.9–2.2%), identifying boll number as the primary yield determinant. Vertical canopy analysis revealed that middle strata (FB5–8) accounted for 48.2% of the total yield and was more sensitive in response to B fertilizer, likely attributable to restricted B phloem mobility. These findings provide a scientific framework for precision B management, balancing yield maximization with nutrient stewardship in B-deficient cotton systems. Cotton (Gossypium hirsutum L.) Boron deficiency Optimal boron fertilization rate Yield components Quadratic regression Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Cotton ( Gossypium hirsutum L.) constitutes a vital global source of textile fibers, edible oils, industrial feedstocks, and livestock feed protein (Li et al., 2023 ). In China, cotton production is geographically concentrated within three major agroecological zones: the Northwest Inland Cotton Belt, the Yangtze River Valley Cotton Zone, and the Yellow River Basin Cotton Region (Li et al., 2016 ; Xu & Wang, 2017 ). Following nationwide agricultural restructuring initiatives, cotton cultivation areas have demonstrated a consistent annual decline (Feng et al., 2024 ; Wang et al., 2022 ). Remarkably, aggregate production has remained stable through compensatory yield intensification, achieving 3.6% annual productivity gains per unit area (Feng et al., 2022 ). The current national average yield of 1,933 kg ha − 1 masks significant regional disparities, with suboptimal productivity levels persisting in both the Yellow River and Yangtze River basins (Tang et al., 2024 ; Wang et al., 2022 ), indicating significant potential for yield optimization through improved agronomic practices (Zhang et al., 2024 ). Boron (B), an essential micronutrient for vascular plants, plays pivotal roles in numerous physiological and biochemical processes (Riaz et al., 2018 ). Its multifunctional characteristics include: regulation of meristematic cell division and elongation, mediation of phenolic compound metabolism and lignin biosynthesis (Dong et al., 2022 ), maintenance of plasma membrane integrity and cell wall architecture (Voxeur & Fry, 2014 ), and modulation of auxin and cytokinin signaling pathways (Chen et al., 2022 ). These fundamental processes directly influence reproductive development, particularly pollen tube growth, floral organogenesis, and ultimately, yield formation (Gimeno et al., 2012 ; Garcia-Sanchez et al., 2020 ). Since its identification as an essential element in 1923, B deficiency has been documented in over 300 crop species across over 80 nations (Shorrocks, 1997 ). China contains the world’s largest B-deficient arable area, with with > 33 million hectares of arable land exhibiting B deficiency (Liu et al., 2024 ). The Yangtze and Yellow River cotton-growing areas are particularly impacted, where suboptimal soil available B concentration (< 0.5 mg kg − 1 ) constitute a primary constraint on yield potential (Lu et al., 2023 ). Recent field trials demonstrate that boric acid application at 13.5 kg ha − 1 increases cotton yield by 17% in the Yangtze River Valley (Li et al., 2016 ), confirming B deficiency as a critical limiting factor in these production systems. Contemporary physiological research indicates that B exhibits limited phloem mobility in cotton (Landi et al., 2019 ), necessitating continuous soil availability throughout the growing season due to the cotton’s infinite growth habit. While plants primarily absorb B as boric acid and borate ions, the high solubility of these compounds renders them susceptible to leaching through precipitation and irrigation events (Brdar-Jokanovic, 2020 ; Garcia-Sanchez et al., 2020 ), thereby exacerbating soil B depletion under intensive cultivation regimes (Dhassi et al., 2019 ). Although B supplementation effectively addresses deficiency, the therapeutic-to-toxic threshold is remarkably narrow (Dridi et al., 2018 ; Lopes et al., 2023 ). Excessive B application or irrigation with B-rich water induces phytotoxicity manifestations (Pennisi et al., 2006 ) including: growth inhibition, morphological aberrations (Simón-Grao et al., 2018 ), and marginal leaf chlorosis/necrosis (Sarafi et al., 2017 ). Comprehensive soil analysis across China’s cotton belt have established four distinct B availability zones, high-response zone ( 20% increases with B supplementation, significant-response zone (0.2–0.5 mg kg-1): Exhibiting petiolar annular formations, yielding 10–20% improvements, moderate-response zone (0.5–0.8 mg kg − 1 ): Occasional petiolar rings, 0.8 mg kg − 1 ): Yield response dependent on fertilizer formulation and application timing (Xu & Wang, 2017 ). Notably, substantial genotypic variation exists in B utilization efficiency among cotton cultivars, with nutrient-efficient genotypes demonstrating superior adaptation to low-B environments (Pommerrenig et al., 2018 ; Liu et al., 2024 ). The optimization of B management strategies with the objective of enhancing cotton yield represents a significant research focus within the domain of crop nutrition research. However, the considerable heterogeneity in soil B availability across geographic regions and soil texture classes poses significant challenges for B management in cotton production systems. Cotton is a crop that has been cultivated across a wide range of ecological zones on a global scale. It is notable that the conditions under which cotton is cultivated vary considerably, with significant differences in the application B fertilizer. Given the polygenic inheritance of yield-related traits and the critical influence of B management, this investigation aimed to: (1) determine the yield potential of two conventional varieties for two conventional cultivars across different soil conditions in B-deficient regions, (2) establish yield-maximizing B application ranges through nonlinear regression analysis of experimental data, (3) validate the optimal B application range through yield component analysis (boll density, boll mass, biomass allocation, and abscission rates) of column planting trials. The ultimate objective was to develop soil-specific B management protocols for maximizing seed production, thereby providing scientific basis for precision nutrient management in B-deficient agroecosystems. 1. Materials and methods 1.1 Experimental design The study utilized two cotton cultivars: early-maturing CCRI 425 (98-day growth cycle) and medium-early maturing Siza 3 (130-day growth cycle). Filed trials were conducted during the 2020 growing season at two locations in Jiangsu Province, China: Dafeng Original Seed Farm (33°20'N, 120°46'E), Yancheng, and Old Agricultural Technology Grain Growing Family Farm, Laowei Village (32°92'N, 119°85'E), Xinghua. A split-plot design was implemented with main plots as cultivar treatments (CCRI 425 vs. Siza 3), and subplots as seven B application rates (0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 kg B ha -1 ). Borax (sodium tetraborate decahydrate, Na₂B₄O₇·10H₂O; 11.3% B content) was homogenized with dry topsoil (0–20 cm depth) and applied as basal fertilizer. Plot dimensions and planting densities differed between locations, at the Yancheng site, subplots measured 15 × 3 m with planting densities of 37,050 plants ha -1 for Siza 3 and 90,000 plants ha -1 for CCRI 425, while at the Xinghua location, subplots of 15 × 2.4 m were planted with both cultivars at a uniform density of 49,500 plants ha -1 . All treatments were replicated three times. Conventional agronomic practices except B management were applied consistently. In 2021, follow-up experiments with CCRI 425 were conducted in controlled conditions using polyvinyl chloride (PVC) columns (49 cm height × 23 cm diameter) within a rainout shelter at Nanjing Agricultural University’s Pailou Experimental Station (118°50'E, 32°02'N). Seven B treatments replicated three times. Irrigation protocols were modified while maintaining other field-derived parameters. The nutrient status of the topsoil (0–20 cm) layer before the experimenting is shown in Table S1. The soil available B content at the Yancheng, Xinghua, and Nanjing trial sites was 0.36, 0.31, and 0.24 mg kg -1 , respectively. All sites were classified as mildly B-deficient (0.2-0.5 mg kg -1 ) with distinct soil textures: loam (Yancheng), sandy loam (Xinghua), and clay (Nanjing). Meteorological data are presented in Fig. S1. 1. 2 Measurements Yield and yield component: For field trials, seed cotton yield was quantified at physiological maturity through complete boll harvest from 4 m 2 (2 × 2m) quadrats per plot. For column trials, ten uniformly growing plants per treatment were sampled at boll maturation, with air-dried bolls counted and weighed. Phenological monitoring: Ten representative plants per block were tagged for longitudinal assessment of floral development (total flower count, pigmentation stages at 1 st –3 rd fruiting nodes), boll formation dynamics (total boll count, nodal distribution), and boll shedding rate (%). Measurements were recorded at 15-day intervals from first flowering. Biometric analysis: At 10, 17, 24, 31, and 38 days post-anthesis (DPA), 4–6 bolls from 4 th –6 th fruiting branches were sampled per treatment for dimensional analysis (length × width) and biomass accumulation. 1.3 Statistical analysis Data processing utilized: Microsoft Excel 2022 for preliminary calculations, SPSS 20.0 for ANOVA with LSD post-hoc testing (α= 0.05), and Origin 2025 for graphical representation and nonlinear regression modeling. Optimal B application rates were determined through quadratic regression analysis of yield response curves. 2. Results 2.1 Response of seed cotton yield and yield components to B fertilizer in field trials Seed cotton yields for both cultivars across field experimental sites exhibited a consistent single-peak response to increasing B application rate (0–3.5 kg B ha -1 ), characterized by initial increases followed by subsequent declines. At the Yancheng trial site, maximum yields for CCRI 425 and Siza 3 were observed at 2.5 kg B ha -1 , which represented increases of 25.89% and 17.34%, respectively, compared to the no B application. Similarly, at the Xinghua site, peak yields occurred at 2.0 kg B ha -1 , corresponding to yield enhancements of 14.74% and 20.58% relative to the control. Notably, cultivar CCRI 425 achieved its highest yield (4,065 kg ha -1 ) at the Yancheng site with 2.5 kg B ha -1 (Table 1). Among yield components, the coefficient of variation (CV) for boll number (4.2%–6.6%) considerably exceeded that for seed cotton weight per boll (0.9%–2.2%). Analysis of variance (ANOVA) revealed that cultivar had a significant effect (p < 0.05) on both yield and yield components, whereas B application significantly influenced only yield and boll number. 2.2 Optimal B application rates for two cotton varieties in field trials Seed cotton yield exhibited an initial increase followed by a subsequent decrease with elevated B application rates. A quadratic regression model was employed to characterize the relationship between B application rates (independent variable) and seed cotton yield (response variable) for both cultivars across two experimental sites. The downward-opening parabolic relationships yielded coefficients of determination (R 2 ) exceeding 0.82 (p < 0.05), revealing a critical agronomic threshold beyond which yield returns to B application diminished. CCRI 425 achieved maximum yields of 3,115.8 and 3,982.1 kg ha -1 at B application thresholds of 1.90 and 2.35 kg B ha -1 in Xinghua and Yancheng, respectively (Fig. 1a). Similarly, Siza 3 reached peak yields of 3,557.0 and 3,298.3 kg ha -1 at 2.05 and 2.36 kg B ha -1 in Xinghua and Yancheng, respectively (Fig. 1b). These results indicate optimal B application ranges of 1.90–2.35 kg B ha -1 for CCRI 425 and 2.05–2.36 kg B ha -1 for Siza 3. 2.3 Agronomic trait responses to B application within optimal threshold ranges Boll shedding rates displayed a parabolic response to increasing B application levels, initially decreasing before rising at higher concentrations. Quadratic regression analysis identified the B application rates for minimum boll shedding rates: CCRI 425 exhibited minimum shedding (31.7% and 37.5%) at 1.90 and 1.99 kg B ha -1 in Xinghua and Yancheng, respectively (Fig. 2a). Similarly, Siza 3 showed minimal shedding 25.8% and 46.6% at 2.01 and 2.32 kg B ha -1 in the respective locations (Fig. 2b). Cotton boll numbers exhibited significant variation (p < 0.05) across developmental stages in response to B fertilizer. Quadratic regression models indicated a non-linear relationship, with boll numbers initially increasing then decreasing under elevated B application rates, and peaking within the optimal B ranges for both cultivars. CCRI 425 attained maximum boll counts of 13.8 and 10.7 per plant in Xinghua (2.06 kg B ha -1 ) and Yancheng (2.24 kg B ha -1 ), respectively (Fig. 3a). Siza 3 achieved peak boll production of 15.2 and 13.0 per plant at 1.99 kg B ha -1 in both locations (Fig. 3b). Boll dimensions displayed significant developmental-stage-dependent responses to B application. At 38 DPA, maximum boll size of CCRI 425 and Siza 3 varieties was significantly increased by 16.9%–17.7% and 30.0%–30.8%, respectively, under B application treatment compared to no B application. With the exception of Siza 3 in Yancheng, quadratic models demonstrated maximum boll size attainment within optimal B ranges. CCRI 425 exhibited peak boll sizes of 19.3 cm 2 (Xinghua: 2.11 kg B ha -1 ) and 18.1 cm 2 (Yancheng: 1.98 kg B ha -1 ) (Fig. 3c), while Siza 3 reached maxima of 15.1 cm 2 (Xinghua: 2.03 kg B ha -1 ) and 14.8 cm 2 (Yancheng: 1.65 kg B ha -1 ) (Fig. 3d). 2.4 Validation of optimal B application rate in column planting trials conducted in Nanjing Vertical distribution analysis of fruiting branches revealed distinct canopy-layer responses to B application in Nanjing. The lower canopy (FB1–4) contributed 22.81% of total yield, achieved maximum productivity (22.90% increase) at 2.5 kg B ha -1 . Similarly, the middle canopy (FB5–8), accounting for 48.22% of total yield, peaked at 17.40% higher productivity under this rate. The upper canopy (FB9+), representing 28.96% of yield, was optimized at a 22.57% increase with 2.5 kg B ha -1 . B application exerted significant influences (p < 0.05) on both boll number and seed cotton weight per boll across canopy layers. The CV for boll number substantially exceeded that of seed cotton weight, with lower canopy branches exhibiting higher boll densities compared to central and upper strata. Relative to the no B application, the maximum increases in boll number (14.7%) and seed cotton weight per boll (4.6%) were observed predominantly at 2.5 kg B ha -1 (Table 2). For CCRI 425, seed cotton yield per plant in Nanjing exhibited a parabolic response characterized by an initial increase followed by a decline with escalating B application. Quadratic regression analysis identified a peak yield of 57.6 g plant -1 at 2.25 kg B ha -1 , aligning with the previously determined optimal range (Fig. 4a). Quadratic models for CCRI 425 further demonstrated critical agronomic optima within the validated B application range: Minimum boll abscission rate (56.40%) at 2.17 kg B ha -1 (Fig. 4b), Maximum boll number (11.9 per plant) at 2.15 kg B ha -1 (Fig. 4c), peak boll size (21.3 cm 2 ) at 1.97 kg B ha -1 (Fig. 4d). 3. Discussion Since B was first identified as an essential micronutrient for plant growth, B deficiency has emerged as a critical global production constraint, currently affecting hundreds of crop species across more than 80 countries (de Bang et al., 2021 ; Lilay et al., 2024 ). Field trials of B application to cotton in China demonstrated seed cotton yield increase of 17% (Li et al., 2016 ), confirming that B deficiency is still a key limiting factor in China’s cotton production system. Although supplemental B fertilizer is considered an important strategy to mitigate the decline in cotton yield in B-deficient areas, the unusually narrow range of adequacy between B deficiency and toxicity thresholds for B fertilizer management in cotton (Brdar-Jokanovic, 2020 ). Under-application limits yield potential, while cumulative effects of over-application or long-term application may lead to phytotoxicity in subsequent crops (Bogiani et al., 2014 ). Given this precision-dependent balance, where B deficiency ( 2.0 kg B ha − 1 ) thresholds differ by only a few ppm, precise optimization of B fertilization is required to maximize yields while promoting efficient use of B fertilizer resources. Furthermore, substantial heterogeneity in soil B availability across geographic regions and soil texture classes poses a major challenge for B management in cotton production systems. As a globally grown crop spanning numerous ecological zones, cotton is grown under markedly different environment conditions, each with different climatic regimes, soil properties and fertilizer application rates (Garcia-Sanchez et al., 2020 ). This study investigated two conventional cotton cultivars extensively cultivated in Jiangsu Province, planted across two geographically distinct long-term intensively cultivated fields with contrasting soil types. Pre-experimental soil analyses confirmed deficient soil available B levels (Table 1 ), in the range of soil available B in regions demonstrating significant B fertilization responsiveness (Xu & Wang, 2017 ). Both cultivars exhibited marked yield responses to B supplementation, with seed cotton yields increasing by 25.89% (CCRI 425) and 17.34% (Siza 3) in Yancheng, and 14.74% (CCRI 425) and 20.58% (Siza 3) in Xinghua relative to B-free controls. These results establish B as the key yield-limiting factor under these edaphic conditions. This is related to the primary physiological function of B in maintaining cell wall structural integrity through the formation of the boronic acid dimeric rhamnogalacturonanⅡ-B (RG-Ⅱ-B) complex, which stabilizes the pectin network and regulates cell wall porosity, and whose main functions are cell wall formation and cell division (Gimeno et al., 2012 ). Previous studies have characterized the anatomical disruption caused by B deficiency, particularly the formation of brown petiole rings, as leading to impairment of phloem transport and photosynthetic efficiency, ultimately affecting reproductive organ development and seed cotton productivity (Li et al., 2017 ; Lilay et al., 2024 ). In addition, B is involved in multiple metabolic pathways, including nucleic acid and carbohydrate metabolism, protein synthesis, phosphorus cycling, phenolic compound metabolism, and phytohormone regulation (Papadakis et al., 2018 ), which results in enhanced plant defense against abiotic stresses such as such as salt stress, drought, and heavy metal overload, providing yield stability in cotton. The critical role of B in facilitating photoassimilate translocation from source leaves to reproductive sinks (Panter et al., 2023 ) ensures proper boll development and biomass accumulation (Wahid et al., 2020 ), aligning with the observed yield enhancements. In this study, the CV for boll number significantly exceeded that of boll weight across B treatment (Table 2 ), which is because boll number is more responsive to environmental fluctuations due to its sensitivity as a real-time indicator of plant physiological status. This differential response underscores boll number as the principal determinant of seed cotton yield. Boll shedding, a natural adaptive mechanism in cotton, typically accounts for 70% of the total number of nodes (Ertek & Kanber, 2003 ). In response to biotic and abiotic stresses, the internal development of plants and external stimuli will affect the expression of genes, leading to changes in hormones and enzymes and other endogenous substances, resulting in a significant increase in the rate of abscission (Zhao et al., 2024 ), so the growth and development of bolls have a direct impact on the cotton yield. Mechanistically, B enhances reproductive structure development and assimilate partitioning to fruiting organs (Padbhushan & Kumar, 2015 ; Wahid et al., 2020 ), directly correlating with the reduced boll abscission rates observed in this study. Prior research on sandy loam soils demonstrated that foliar B application (1.0 kg B ha − 1 ) maximized boll numbers, achieving 63–75% increases over controls (Mehran et al., 2023 ; Wahid et al., 2020 ), corroborating our findings. Fertilizer efficiency models provide a robust framework for optimizing the relationship between fertilizer inputs and crop productivity. Q modeling has become an established analytical approach in studies examining single-nutrient management (Luo et al., 2024 ). Under controlled fertilization conditions, crop yield response is influenced not only by B application rates but also by the indigenous soil B supply, which represents the baseline plant-available B content prior to fertilization and constitutes a key determinant of crop yield response. While current understanding of indigenous B supply’s role in developing effective management strategies remains preliminary (Ahmed et al., 2018 ). Cotton yield response to B application varied significantly across trial sites, mainly attributed to differences in native B supply levels. While seed cotton yield exhibited a positive quadratic relationship with B application in the results of this study (R 2 > 0.82 across field trials), diminishing yield gains occurred beyond optimal thresholds due to non-linear dynamics. This pattern likely reflects limitations in soil B bioavailability, cultivar-specific uptake saturation, and potential phytotoxicity at supraoptimal concentrations (Simón et al., 2013 ). The Q models effectively quantified regional yield variability by capturing these non-linear dynamics. Maximum yields of CCRI 425 occurring at B application rates of 1.9 and 2.36 kg B ha − 1 in Xinghua and Yancheng and at 2.05 and 2.36 kg B ha − 1 in Siza 3, highlighting the necessity of balancing soil B availability with cultivar-specific demand to optimize yield and resource efficiency. Column-planting trials for CCRI 425 in Nanjing (2.25 kg B ha − 1 ) verified the theoretical optimum application rate, confirming cultivar-specific B requirements while revealing significant intraspecific differences across locations (Fig. 3 ). These variations reflect differential B stress tolerance thresholds. The observed rate discrepancies between Yancheng and Xinghua further demonstrate how edaphic and climatic factors mediate B efficacy. Available B content, organic matter, pH and texture as key determinants of soil properties affecting B fertilizer use efficiency. Yield response was inversely related to soil available B levels, peaking in B-deficient soils, where supplemental B compensated for inherent limitations (Cordeiro et al., 2022 ). Conversely, high natural B levels increased toxicity risk and reduced agricultural efficiency (Niaz et al., 2013 ). Organic matter exhibited parabolically related to efficiency, peaking at moderate concentrations due to its dual role as a B reservoir versus immobilization agents (Atique ur et al., 2018 ). Soil texture significantly moderated B retention, with coarse-textured soils exhibiting lower efficacy due to leaching, while fine-textured soils maintained better nutrient retention (Cordeiro et al., 2024 ). B bioavailability was pH-dependent, with maximal uptake occurring under acidic to weakly alkaline conditions and sharply decreasing at higher soil pH. Thermal and hydrological conditions strongly influenced B utilization (Yeates et al., 2010 ; Dusenge et al., 2019 ). The optimal temperature range (25–30 ℃) enhanced metabolic activity and photosynthetic efficiency and maximized yield response. Suboptimal temperatures ( 30 ℃) may be attributed to B-induced activation of antioxidant enzymes and carbohydrate metabolism, which mitigated heat-induced oxidative stress. Extreme water conditions, either in excess (promoting leaching) or deficiency (reducing bioavailability), emphasize the need for balanced water management. These findings reinforce the imperative for soil-specific B management strategies to maximize cotton productivity (Liu et al., 2024 ). Column-planting trials in Nanjing elucidated vertical canopy partitioning of B responses, with middle (FB5–8) and upper (FB9+) canopy boll production demonstrating greater B sensitivity than lower strata (FB1–4) (Table 3). Given the middle canopy’s disproportionate contribution to total yield (48.22%), B application primarily modulated yield-determining components in these strata. This vertical response gradient constitutes a novel finding, potentially linked to restricted B phloem mobility impeding redistribution to lower canopy organs (Landi et al., 2019 ; Oikonomou et al., 2019 ). Further investigation is warranted to elucidate the physiological mechanisms underlying this stratification. 4. Conclusion The application of supplemental B fertilizer significantly modulates yield components, particularly boll number, thereby enhancing seed cotton yield. Through integration of quadratic modeling, the optimal B application rates for yield maximization were established as 1.90–2.36 kg B ha − 1 for CCRI 425 (14.74–25.89% yield increase), 2.05–2.36 kg B ha − 1 for Siza 3 (17.34–20.58% yield increase). Within these ranges, critical agronomic traits, including boll number, boll shedding rate and boll size, exhibited optimal performance, aligning with physiological thresholds for reproductive efficiency. Vertical canopy analysis demonstrated that the most substantial response of B fertilization on seed cotton yield was the middle canopy seed cotton yield, and the yield component with the same most significant variance was the number of cotton bolls. These findings underscore the importance of cultivar- and site-specific B management strategies to reconcile yield optimization with nutrient use efficiency in intensive cotton production systems. Declarations Ethics approval and consent to participate ： Not applicable. Consent for publication ： All co-authors have consent for submission of manuscript. Availability of data and materials ： All relevant data are within this article. Competing interests ： The authors declare no conflict of interest. Funding: This work was supported by China Agriculture Research System (CARS-15-14), Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP). Author Contributions: Conceptualization, W.H.; data collection, S.W., C.W., Y.Z. and X.L.; formal analysis, S.W. and W.H.; funding acquisition, W.H.; investigation, S.W., C.W., Y.Z. and X.L.; methodology, S.W. and C.W.; writing—original draft, S.W., C.W. and Y.Z.; writing—review and editing, S.W., C.W. and W.H.; All authors have read and agreed to the published version of the manuscript. Acknowledgements ： Not applicable. References Ahmed N., Masood S., Abid M., Mustafa G., Ali M. A., Ahmad S., Qayyum M. F. 2018. Determination of residual and cumulative boron requirements for cotton and wheat crops grown under calcareous soil conditions. Communications in Soil Science and Plant Analysis , 49(9): 1092-1098. Atique Ur R., Farooq M., Rashid A., Nadeem F., Stuerz S., Asch F., Bell R. W., Siddique K. H. M. 2018. Boron nutrition of rice in different production systems. A review. Agronomy for Sustainable Development , 38(3). Bogiani J. C., Sampaio T. F., Abreu C. H., Rosolem C. A. 2014. Boron uptake and translocation in some cotton cultivars. Plant and Soil , 375(1-2): 241-253. Brdar-Jokanovic M. 2020. Boron Toxicity and Deficiency in Agricultural Plants. International Journal of Molecular Sciences , 21(4). Chen X., Humphreys J. L., Ru Y. Q., He Y. T., Wu F. H., Mai J. W., Li M., Li Y. L., Shabala S., Yu M., Smith S. M. 2022. Jasmonate signaling and remodeling of cell wall metabolism induced by boron deficiency in pea shoots. Environmental and Experimental Botany , 201. Cordeiro L. F. D., Cordeiro C. F. D., Ferrari S. 2022. Cotton yield and boron dynamics affected by cover crops and boron fertilization in a tropical sandy soil. Field Crops Research , 284. Cordeiro L. F. D., Malenowtch J. V. C., Cordeiro C. F. D., Detoni J. A. C., Furlani E., Jr., Ferrari S. 2024. Improving cotton yield and fiber quality in different tropical soils with boron fertilization. Agronomy Journal , 116(3): 1540-1550. De Bang T. C., Husted S., Laursen K. H., Persson D. P., Schjoerring J. K. 2021. The molecular-physiological functions of mineral macronutrients and their consequences for deficiency symptoms in plants. New Phytologist , 229(5): 2446-2469. Dhassi K., Drissi S., Makroum K., Er-Rezza H., Amlal F., Houssa A. A. 2019. Soil Boron Migration as Influenced by Leaching Rate and Soil Characteristics: A Column Study. Communications in Soil Science and Plant Analysis , 50(14): 1663-1670. Dong X. C., Jiang C. C., Wei S. W., Jiao H. J., Ran K., Dong R., Wang S. M. 2022. The regulation of plant lignin biosynthesis under boron deficiency conditions. Physiologia Plantarum, 174(6). Dridi I., Tlili A., Fatnassi S., Hamrouni H., Gueddari M. 2018. Effects of boron distribution on sugar beet crop yield in two Tunisian soils. Arabian Journal of Geosciences , 11(15). Dusenge M. E., Duarte A. G., Way D. A. 2019. Plant carbon metabolism and climate change: elevated CO 2 and temperature impacts on photosynthesis, photorespiration and respiration. New Phytologist , 221(1): 32-49. Ertek A., Kanber R. 2003. Effects of different drip irrigation programs on the boll number and shedding percentage and yield of cotton. Agricultural Water Management , 60(1): 1-11. Feng L., Chi B. J., Dong H. Z. 2022. Cotton cultivation technology with Chinese characteristics has driven the 70-year development of cotton production in China. Journal of Integrative Agriculture , 21(3): 597-609. Feng L., Wan S. M., Zhang Y. L., Dong H. Z. 2024. Xinjiang cotton: Achieving super-high yield through efficient utilization of light, heat, water, and fertilizer by three generations of cultivation technology systems. Field Crops Research , 312. Garcia-Sanchez F., Simon-Grao S., Martinez-Nicolas J. J., Alfosea-Simon M., Liu C., Chatzissavvidis C., Perez-Perez J. G., Camara-Zapata J. M. 2020. Multiple stresses occurring with boron toxicity and deficiency in plants. Journal of Hazardous Materials , 397. Gimeno V., Simón I., Nieves M., Martínez V., Cámara-Zapata J. M., García A. L., García-Sánchez F. 2012. The physiological and nutritional responses to an excess of boron by Verna lemon trees that were grafted on four contrasting rootstocks. Trees-Structure and Function , 26(5): 1513-1526. Landi M., Margaritopoulou T., Papadakis I. E., Araniti F. 2019. Boron toxicity in higher plants: an update. Planta , 250(4): 1011-1032. Li H. J., Wang J. W., Huang X. L., Zhou Z. G., Wang S. S., Hu W. 2023. Phosphate fertilization promotes fiber elongation by affecting sucrose inversion, K plus accumulation, and malate synthesis in cotton fiber. Field Crops Research , 303. Li M. F., Peng W. Y., Li H. T., Huang X. J., Z.Q. Z. 2016. Effects of the combined application of nitrogen and boron on the yield，petiole annulus and nutrient uptake of cotton. Soil and Fertilizer Sciences in China , 4: 97-102. Li M. F., Zhao Z. Q., Zhang Z. H., Zhang W., Zhou J., Xu F. S., Liu X. W. 2017. Effect of boron deficiency on anatomical structure and chemical composition of petioles and photosynthesis of leaves in cotton ( Gossypium hirsutum L.). Scientific Reports , 7. Lilay G. H., Thiebaut N., Du Mee D., Assuncao A. G. L., Schjoerring J. K., Husted S., Persson D. P. 2024. Linking the key physiological functions of essential micronutrients to their deficiency symptoms in plants. New Phytologist , 242(3): 881-902. Liu S., Song B., Sehar S., Adil M. F., Lin X., Huo J., Zhao X., Riaz M. 2024. Variations in rhizosphere soil dominant and pathogenic flora improve boron-efficient Beta vulgaris L. yield under boron deficit. Journal of Cleaner Production , 444. Lopes P., Campos C. N. S., Teodoro P. E., Costa M. G., De Souza J. P., Jr., Prado R. D. 2023. The synergistic effects of soil-applied boron and foliar-applied silicon on cotton fiber quality and yield. BMC Plant Biology , 23(1). Lu K. S., Yan L., Riaz M., Babar S., Hou J. Y., Zhang Y. L., Jiang C. C. 2023. Exogenous boron alleviates salt stress in cotton by maintaining cell wall structure and ion homeostasis. Plant Physiology and Biochemistry , 201. Luo L. C., Wei P., Peng S. Y., Wang X. X., Chai R. S., Zhang C. C., Kadambot S. H. M., Palta J. A. 2024. Rational phosphorus stewardship for sustainable maize production in China: A meta-analysis. European Journal of Agronomy , 153. Mehran M., Ashraf M., Shahzad S. M., Shakir M. S., Azhar M. T., Ahmad F., Alvi A. 2023. Growth, yield and fiber quality characteristics of Bt and non-Bt cotton cultivars in response to boron nutrition. Journal of Cotton Research , 6(1): 1. Niaz A., Ahmad W., Zia M. H., Malhi S. S. 2013. Relationship of soil extractable and fertilizer boron to some soil properties, crop yield, and total boron in cotton and wheat plants on selected soils of Punjab, Pakistan. Journal of Plant Nutrition , 36(3): 343-356. Oikonomou A., Ladikou E. V., Chatziperou G., Margaritopoulou T., Landi M., Sotiropoulos T., Araniti F., Papadakis I. E. 2019. Boron Excess Imbalances Root/Shoot Allometry, Photosynthetic and Chlorophyll Fluorescence Parameters and Sugar Metabolism in Apple Plants. Agronomy-Basel , 9(11). Padbhushan R., Kumar D. 2015. Yield and Nutrient Uptake of Green Gram ( Vigna radiata L.) as Influenced by Boron Application in Boron-Deficient Calcareous Soils of Punjab. Communications in Soil Science and Plant Analysis , 46(7): 924-939. Panter P. E., Seifert J., Dale M., Pridgeon A. J., Hulme R., Ramsay N., Contera S., Knight H. 2023. Cell wall fucosylation in Arabidopsis influences control of leaf water loss and alters stomatal development and mechanical properties. Journal of Experimental Botany , 74(8): 2680-2691. Papadakis I. E., Tsiantas P. I., Tsaniklidis G., Landi M., Psychoyou M., Fasseas C. 2018. Changes in sugar metabolism associated to stem bark thickening partially assist young tissues of Eriobotrya japonica seedlings under boron stress. Journal of Plant Physiology , 231(337-345. Pennisi M., Gonfiantini R., Grassi S., Squarci P. 2006. The utilization of boron and strontium isotopes for the assessment of boron contamination of the Cecina River alluvial aquifer (central-western Tuscany, Italy). Applied Geochemistry , 21(4): 643-655. Pommerrenig B., Junker A., Abreu I., Bieber A., Fuge J., Willner E., Bienert M. D., Altmann T., Bienert G. P. 2018. Identification of Rapeseed ( Brassica napus L.) Cultivars With a High Tolerance to Boron-Deficient Conditions. Frontiers in Plant Science , 9. Riaz M., Yan L., Wu X. W., Hussain S., Aziz O., Jiang C. C. 2018. Boron deprivation induced inhibition of root elongation is provoked by oxidative damage, root injuries and changes in cell wall structure. Environmental and Experimental Botany , 156(74-85. Sarafi E., Siomos A., Tsouvaltzis P., Chatzissavvidis C., Therios I. 2017. Boron toxicity effects on grafted and non-grafted pepper ( Capsicum annuum ) plants. Journal of Soil Science and Plant Nutrition , 17(2): 441-460. Shorrocks V. M. 1997. The occurrence and correction of boron deficiency. Plant and Soil , 193(1-2): 121-148. Simón-Grao S., Nieves M., Martínez-Nicolás J. J., Cámara-Zapata J. M., Alfosea-Simón M., García-Sánchez F. 2018. Response of three citrus genotypes used as rootstocks grown under boron excess conditions. Ecotoxicology and Environmental Safety , 159(10-19. Simón I., Díaz-López L., Gimeno V., Nieves M., Pereira W. E., Martínez V., Lidon V., García-Sánchez F. 2013. Effects of boron excess in nutrient solution on growth, mineral nutrition, and physiological parameters of Jatropha curcas seedlings. Journal of Plant Nutrition and Soil Science , 176(2): 165-174. Tang Y. R., Qiu Y. R., Li X., Qin H. Y., Wang J., Zhang S. J., Han Y. C., Feng L., Wang G. P., Yang B. F., Lei Y. P., Xiong S. W., Zhi X. Y., Du W. L., Xin M. H., Li Y. B., Li X. F. 2024. Increased overyielding probability and yield stability from a 5-year cotton-based intercropping. European Journal of Agronomy , 156( Voxeur A., Fry S. C. 2014. Glycosylinositol phosphorylceramides from Rosa cell cultures are boron-bridged in the plasma membrane and form complexes with rhamnogalacturonan II. Plant Journal , 79(1): 139-149. Wahid M. A., Saleem M., Irshad S., Khan S., Cheema M. A., Saleem M. F., Tung S. A. 2020. Foliar feeding of boron improves the productivity of cotton cultivars with enhanced boll retention percentage. Journal of Plant Nutrition , 43(16): 2411-2424. Wang X. Y., Li D., Yu Y. 2022. Current Situation and Optimization Countermeasures of Cotton Subsidy in China Based on WTO Rules. Agriculture-Basel , 12(8). Xu F. S., Wang Y. H. 2017. Advances in studies on crop boron nutrition and application of boron fertilizers in China. Journal of Plant Nutrition and Fertilizer , 23(6): 1556-1564. Yeates S. J., Constable G. A., Mccumstie T. 2010. Irrigated cotton in the tropical dry season. III: Impact of temperature, cultivar and sowing date on fibre quality. Field Crops Research, 116(3): 300-307. Zhang Z., Qiu S., Thistlethwaite R. J., Yao X. F., Tan D. K. Y., Wang D. S., Yang G. Z. 2024. Optimizing nitrogen application methods and frequency to increase cotton yield in summer direct sown condition. Industrial Crops and Products , 213. Zhao N., Geng Z., Zhao G. Y., Liu J. G., An Z. T., Zhang H. S., Ai P. F., Wang Y. Q. 2024. Integrated analysis of the transcriptome and metabolome reveals the molecular mechanism regulating cotton boll abscission under low light intensity. BMC Plant Biology , 24(1). Tables Table 1 Effect of boron rate on cotton yield and yield components (Yancheng, and Xinghua, CCRI 425 and Siza 3) Cultivars B rate (kg B hm -2 ) Yancheng Xinghua Boll number (10 4 no.hm -1 ) Seed cotton weight boll -1 (g) Seed cotton yield (kg hm -1 ) Boll number (10 4 no.hm -1 ) Seed cotton weight boll -1 (g) Seed cotton yield (kg hm -1 ) CCRI 425 0 81.9 e 3.9 a 3229 e 61.3 d 4.5 a 2800 c 1.0 89.1 d 4.0 a 3588 d 64.3 bc 4.6 a 2980 b 1.5 92.7 c 4.1 a 3833 bc 65.3 b 4.6 a 3023 b 2.0 97.2 b 4.1 a 4012 a 71.2 a 4.5 a 3213 a 2.5 99.9 a 4.1 a 4065 a 69.3 a 4.5 a 3104 a 3.0 96.3 b 4.1 a 3973 ab 66.8 b 4.5 a 3012 b 3.5 89.1 d 4.1 a 3710 c 63.3 c 4.4 a 2832 c CV (%) 6.6 1.8 7.8 5.2 1.4 4.8 Siza 3 0 50.7 c 5.7 a 2895 d 54.4 d 5.5 a 3003 e 1.0 53.7 b 5.7 a 3073 c 60.3 b 5.5 a 3360 c 1.5 54.8 b 5.7 a 3171 b 62.8 b 5.4 a 3454 b 2.0 57.0 a 5.8 a 3341 a 66.3 a 5.4 a 3621 a 2.5 57.0 a 5.9 a 3397 a 64.8 a 5.5 a 3571 a 3.0 54.4 b 5.9 a 3257 ab 61.3 b 5.5 a 3429 c 3.5 52.2 bc 6.0 a 3149 bc 57.9 c 5.5 a 3236 d CV (%) 4.2 2.2 5.3 6.6 0.9 6.2 Variety (V) *** ** *** * * * Boron (B) *** ns *** *** ns *** V×B *** ns *** * ns * Coefficient of variation, CV (%) = Standard deviation/Average ×100%; Different lowercases within the same variety and column indicate significant difference at 0.05 probability. Table 2 Effect of boron rate on cotton yield and yield components (Nanjing, CCRI 425) B rate (kg B hm -2 ) Boll number (number plant -1 ) Seed cotton weight boll -1 (g) Seed cotton yield (g plant -1 ) FB1-4 FB5-8 FB9+ Total FB1-4 FB5-8 FB9+ Average FB1-4 FB5-8 FB9+ Total 0 2.2 c 4.5 b 2.8 c 9.5 c 5.0 b 5.3 b 5.0 b 5.1 a 11.0 d 23.8 c 14.0 c 48.85 d 1.0 2.4 b 4.8 a 3.0 b 10.2 b 5.1 ab 5.4 ab 5.1 ab 5.2 a 12.2 c 25.9 b 15.3 b 53.46 c 1.5 2.5 ab 4.9 a 3.2 a 10.6 a 5.2 a 5.5 a 5.1 ab 5.3 a 13.0 bc 26.9 ab 16.3 a 56.27 b 2.0 2.6 a 4.9 a 3.2 a 10.7 a 5.2 a 5.6 a 5.2 a 5.3 a 13.5 b 27.4 a 16.6 a 57.60 a 2.5 2.6 a 5.0 a 3.3 a 10.9 a 5.2 a 5.6 a 5.2 a 5.3 a 13.5 a 28.0 a 17.1 a 58.68 a 3.0 2.5 ab 5.0 a 3.3 a 10.8 a 5.1 ab 5.5 a 5.1 ab 5.2 a 12.7 c 27.5 a 16.8 a 57.03 a 3.5 2.4 b 4.8 a 3.1 ab 10.3 b 5.0 b 5.5 a 5.0 b 5.1 a 12.0 c 26.4 b 15.5 b 54.08 c CV% 5.6 3.5 5.7 4.6 1.7 1.9 1.6 1.6 7.2 10.1 9.2 10.0 Coefficient of variation, CV (%) = Standard deviation/Average ×100%; Different lowercases within the column indicate significant difference at 0.05 probability. Supplementary Files supplementary.docx Cite Share Download PDF Status: Published Journal Publication published 01 Apr, 2026 Read the published version in Journal of Cotton Research → Version 1 posted Reviewers agreed at journal 21 Jun, 2025 Reviewers invited by journal 18 Jun, 2025 Editor assigned by journal 17 Jun, 2025 First submitted to journal 14 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6896139","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":472984582,"identity":"9e038339-598d-491a-8d5c-ee5f9e90c241","order_by":0,"name":"Shanshan Wang","email":"","orcid":"","institution":"Nanjing Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Shanshan","middleName":"","lastName":"Wang","suffix":""},{"id":472984583,"identity":"1da51351-1bd7-4203-90b7-be58d4fd7037","order_by":1,"name":"Cheng Wang","email":"","orcid":"","institution":"Nanjing Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Cheng","middleName":"","lastName":"Wang","suffix":""},{"id":472984584,"identity":"9345d3de-059f-4837-a9f7-54d0faba2199","order_by":2,"name":"Yutian Zhang","email":"","orcid":"","institution":"Nanjing Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Yutian","middleName":"","lastName":"Zhang","suffix":""},{"id":472984585,"identity":"a06cca7b-a30a-482e-9f0a-491edc8accea","order_by":3,"name":"Xingjia Liang","email":"","orcid":"","institution":"Nanjing Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Xingjia","middleName":"","lastName":"Liang","suffix":""},{"id":472984586,"identity":"8f38aae6-57e3-4c62-b25a-72ba680c0100","order_by":4,"name":"Zhiguo Zhou","email":"","orcid":"","institution":"Nanjing Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Zhiguo","middleName":"","lastName":"Zhou","suffix":""},{"id":472984587,"identity":"25701752-716c-40ed-bc66-3a4fb7af12bf","order_by":5,"name":"Wei Hu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyUlEQVRIiWNgGAWjYFACxjYGhgoGZjCbh3gtZ0jTwsAG1kW8FoPjzW2PeefdYeefkcD44G0bg7w5QS1nDrYb8257xixxI4HZcG4bg+HOBgJazG4ktknzbjvMzHAjgU2at40hweAAIS33HwK1zDnMLH8jgf03cVpuMAK1NBxmNgDawkyUFvsziW2Sc44dZjY887BZcs45CcMNhLRIth9/JvGm5nCy3PHkgx/elNnIE7QFBpKBcdoApCWIVA8EdsQrHQWjYBSMghEHACT6PnFcp60xAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-0835-3209","institution":"Nanjing Agricultural University","correspondingAuthor":true,"prefix":"","firstName":"Wei","middleName":"","lastName":"Hu","suffix":""}],"badges":[],"createdAt":"2025-06-15 02:44:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6896139/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6896139/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s42397-026-00257-1","type":"published","date":"2026-04-01T15:58:43+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":85051662,"identity":"91f34f00-3eed-4f6d-b2d6-5ae2f311a58c","added_by":"auto","created_at":"2025-06-20 11:48:46","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":56925,"visible":true,"origin":"","legend":"\u003cp\u003eQuadratic\u003cstrong\u003e \u003c/strong\u003erelationship between B application rate and seed cotton yield. Response curves of CCRI 425 (a) and Siza 3 (b) at Yancheng and Xinghua.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-6896139/v1/432cc77af785b5d269270c8a.png"},{"id":85052387,"identity":"84326879-cb81-4f5e-b8bf-3adc7e6a56eb","added_by":"auto","created_at":"2025-06-20 11:56:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":53686,"visible":true,"origin":"","legend":"\u003cp\u003eQuadratic\u003cstrong\u003e \u003c/strong\u003erelationship between B application rate and bud shatter rate. Response curves of CCRI 425 (a) and Siza 3 (b) at Yancheng and Xinghua. The gray area shows the range of B application rates at the maximum seed cotton yield for CCRI 425 and Siza 3 at the two experimental sites, respectively.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-6896139/v1/f99e1a50e9912f3635887fa6.png"},{"id":85051665,"identity":"cd002947-0514-4675-88e7-f45125d7eb1f","added_by":"auto","created_at":"2025-06-20 11:48:47","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":141263,"visible":true,"origin":"","legend":"\u003cp\u003eQuadratic\u003cstrong\u003e \u003c/strong\u003erelationship between B application rate and boll number, and boll size. Response curves of CCRI 425 (a \u0026amp; c) and Siza 3 (b \u0026amp; d) at Yancheng and Xinghua. The gray area shows the range of B application rates at the maximum seed cotton yield for CCRI 425 and Siza 3 at the two experimental sites, respectively.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-6896139/v1/33a8e3458d983dcb265e8a3e.png"},{"id":85052547,"identity":"e26b0d30-86e8-4f4f-a565-5d71cf7e28a4","added_by":"auto","created_at":"2025-06-20 12:04:47","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":102258,"visible":true,"origin":"","legend":"\u003cp\u003eQuadratic\u003cstrong\u003e \u003c/strong\u003erelationship between B application rate and seed cotton yield (a), and bud shatter tare (b), and boll number (c), and boll size (d) for CCRI 425 at Nanjing. The gray area shows the range of B application rates at the maximum seed cotton yield for CCRI 425 at the two experimental sites.\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-6896139/v1/2a2061159c65dfa421cc6249.png"},{"id":106344505,"identity":"5669fedd-b12a-4408-83ce-976a0bb7226a","added_by":"auto","created_at":"2026-04-07 16:15:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1185163,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6896139/v1/548135cc-cdb8-4216-ac73-dfa1202f2c53.pdf"},{"id":85052390,"identity":"d01f0857-bda4-4e50-812d-d830e64209a4","added_by":"auto","created_at":"2025-06-20 11:56:47","extension":"docx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":130820,"visible":true,"origin":"","legend":"","description":"","filename":"supplementary.docx","url":"https://assets-eu.researchsquare.com/files/rs-6896139/v1/816d4e901dd5d2ed45adee5d.docx"}],"financialInterests":"","formattedTitle":"Optimization of appropriate boron fertilization application range for cotton (Gossypium hirsutum L.) based on two varieties in boron-deficient soils","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCotton (\u003cem\u003eGossypium hirsutum\u003c/em\u003e L.) constitutes a vital global source of textile fibers, edible oils, industrial feedstocks, and livestock feed protein (Li et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In China, cotton production is geographically concentrated within three major agroecological zones: the Northwest Inland Cotton Belt, the Yangtze River Valley Cotton Zone, and the Yellow River Basin Cotton Region (Li et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Xu \u0026amp; Wang, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Following nationwide agricultural restructuring initiatives, cotton cultivation areas have demonstrated a consistent annual decline (Feng et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2024\u003c/span\u003e; Wang et al., \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Remarkably, aggregate production has remained stable through compensatory yield intensification, achieving 3.6% annual productivity gains per unit area (Feng et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The current national average yield of 1,933 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e masks significant regional disparities, with suboptimal productivity levels persisting in both the Yellow River and Yangtze River basins (Tang et al., \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2024\u003c/span\u003e; Wang et al., \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), indicating significant potential for yield optimization through improved agronomic practices (Zhang et al., \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eBoron (B), an essential micronutrient for vascular plants, plays pivotal roles in numerous physiological and biochemical processes (Riaz et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Its multifunctional characteristics include: regulation of meristematic cell division and elongation, mediation of phenolic compound metabolism and lignin biosynthesis (Dong et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), maintenance of plasma membrane integrity and cell wall architecture (Voxeur \u0026amp; Fry, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), and modulation of auxin and cytokinin signaling pathways (Chen et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). These fundamental processes directly influence reproductive development, particularly pollen tube growth, floral organogenesis, and ultimately, yield formation (Gimeno et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Garcia-Sanchez et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Since its identification as an essential element in 1923, B deficiency has been documented in over 300 crop species across over 80 nations (Shorrocks, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e1997\u003c/span\u003e). China contains the world\u0026rsquo;s largest B-deficient arable area, with with \u0026gt;\u0026thinsp;33\u0026nbsp;million hectares of arable land exhibiting B deficiency (Liu et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). The Yangtze and Yellow River cotton-growing areas are particularly impacted, where suboptimal soil available B concentration (\u0026lt;\u0026thinsp;0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) constitute a primary constraint on yield potential (Lu et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Recent field trials demonstrate that boric acid application at 13.5 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e increases cotton yield by 17% in the Yangtze River Valley (Li et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), confirming B deficiency as a critical limiting factor in these production systems.\u003c/p\u003e \u003cp\u003eContemporary physiological research indicates that B exhibits limited phloem mobility in cotton (Landi et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), necessitating continuous soil availability throughout the growing season due to the cotton\u0026rsquo;s infinite growth habit. While plants primarily absorb B as boric acid and borate ions, the high solubility of these compounds renders them susceptible to leaching through precipitation and irrigation events (Brdar-Jokanovic, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Garcia-Sanchez et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), thereby exacerbating soil B depletion under intensive cultivation regimes (Dhassi et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Although B supplementation effectively addresses deficiency, the therapeutic-to-toxic threshold is remarkably narrow (Dridi et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Lopes et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Excessive B application or irrigation with B-rich water induces phytotoxicity manifestations (Pennisi et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) including: growth inhibition, morphological aberrations (Sim\u0026oacute;n-Grao et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), and marginal leaf chlorosis/necrosis (Sarafi et al., \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Comprehensive soil analysis across China\u0026rsquo;s cotton belt have established four distinct B availability zones, high-response zone (\u0026lt;\u0026thinsp;0.2 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): Characterized by \u0026ldquo;bud abortion\u0026rdquo; and \u0026ldquo;flower shedding\u0026rdquo;, yielding\u0026thinsp;\u0026gt;\u0026thinsp;20% increases with B supplementation, significant-response zone (0.2\u0026ndash;0.5 mg kg-1): Exhibiting petiolar annular formations, yielding 10\u0026ndash;20% improvements, moderate-response zone (0.5\u0026ndash;0.8 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): Occasional petiolar rings, \u0026lt; 5% yield enhancement, potential-response zone (\u0026gt;\u0026thinsp;0.8 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e): Yield response dependent on fertilizer formulation and application timing (Xu \u0026amp; Wang, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Notably, substantial genotypic variation exists in B utilization efficiency among cotton cultivars, with nutrient-efficient genotypes demonstrating superior adaptation to low-B environments (Pommerrenig et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Liu et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe optimization of B management strategies with the objective of enhancing cotton yield represents a significant research focus within the domain of crop nutrition research. However, the considerable heterogeneity in soil B availability across geographic regions and soil texture classes poses significant challenges for B management in cotton production systems. Cotton is a crop that has been cultivated across a wide range of ecological zones on a global scale. It is notable that the conditions under which cotton is cultivated vary considerably, with significant differences in the application B fertilizer. Given the polygenic inheritance of yield-related traits and the critical influence of B management, this investigation aimed to: (1) determine the yield potential of two conventional varieties for two conventional cultivars across different soil conditions in B-deficient regions, (2) establish yield-maximizing B application ranges through nonlinear regression analysis of experimental data, (3) validate the optimal B application range through yield component analysis (boll density, boll mass, biomass allocation, and abscission rates) of column planting trials. The ultimate objective was to develop soil-specific B management protocols for maximizing seed production, thereby providing scientific basis for precision nutrient management in B-deficient agroecosystems.\u003c/p\u003e"},{"header":"1. Materials and methods","content":"\u003cp\u003e\u003cstrong\u003e1.1 Experimental design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study utilized two cotton cultivars: early-maturing CCRI 425 (98-day growth cycle) and medium-early maturing Siza 3 (130-day growth cycle). Filed trials were conducted during the 2020 growing season at two locations in Jiangsu Province, China: Dafeng Original Seed Farm (33\u0026deg;20\u0026apos;N, 120\u0026deg;46\u0026apos;E), Yancheng, and Old Agricultural Technology Grain Growing Family Farm, Laowei Village (32\u0026deg;92\u0026apos;N, 119\u0026deg;85\u0026apos;E), Xinghua. A split-plot design was implemented with main plots as cultivar treatments (CCRI 425 vs. Siza 3), and subplots as seven B application rates (0, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e). Borax (sodium tetraborate decahydrate, Na₂B₄O₇\u0026middot;10H₂O; 11.3% B content) was homogenized with dry topsoil (0\u0026ndash;20 cm depth) and applied as basal fertilizer. Plot dimensions and planting densities differed between locations, at the Yancheng site, subplots measured 15 \u0026times; 3 m with planting densities of 37,050 plants ha\u003csup\u003e-1\u003c/sup\u003e for Siza 3 and 90,000 plants ha\u003csup\u003e-1\u003c/sup\u003e for CCRI 425, while at the Xinghua location, subplots of 15 \u0026times; 2.4 m were planted with both cultivars at a uniform density of 49,500 plants ha\u003csup\u003e-1\u003c/sup\u003e. All treatments were replicated three times. Conventional agronomic practices except B management were applied consistently.\u003c/p\u003e\n\u003cp\u003eIn 2021, follow-up experiments with CCRI 425 were conducted in controlled conditions using polyvinyl chloride (PVC) columns (49 cm height \u0026times; 23 cm diameter) within a rainout shelter at Nanjing Agricultural University\u0026rsquo;s Pailou Experimental Station (118\u0026deg;50\u0026apos;E, 32\u0026deg;02\u0026apos;N). Seven B treatments replicated three times. Irrigation protocols were modified while maintaining other field-derived parameters.\u003c/p\u003e\n\u003cp\u003eThe nutrient status of the topsoil (0\u0026ndash;20 cm) layer before the experimenting is shown in Table S1. The soil available B content at the Yancheng, Xinghua, and Nanjing trial sites was 0.36, 0.31, and 0.24 mg kg\u003csup\u003e-1\u003c/sup\u003e, respectively. All sites were classified as mildly B-deficient (0.2-0.5 mg kg\u003csup\u003e-1\u003c/sup\u003e) with distinct soil textures: loam (Yancheng), sandy loam (Xinghua), and clay (Nanjing). Meteorological data are presented in Fig. S1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1. 2 Measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eYield and yield component:\u0026nbsp;\u003c/strong\u003eFor field trials, seed cotton yield was quantified at physiological maturity through complete boll harvest from 4 m\u003csup\u003e2\u003c/sup\u003e (2 \u0026times; 2m) quadrats per plot. For column trials, ten uniformly growing plants per treatment were sampled at boll maturation, with air-dried bolls counted and weighed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhenological monitoring:\u003c/strong\u003e Ten representative plants per block were tagged for longitudinal assessment of floral development (total flower count, pigmentation stages at 1\u003csup\u003est\u003c/sup\u003e\u0026ndash;3\u003csup\u003erd\u003c/sup\u003e fruiting nodes), boll formation dynamics (total boll count, nodal distribution), and boll shedding rate (%). Measurements were recorded at 15-day intervals from first flowering.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBiometric analysis:\u003c/strong\u003e At 10, 17, 24, 31, and 38 days post-anthesis (DPA), 4\u0026ndash;6 bolls from 4\u003csup\u003eth\u003c/sup\u003e\u0026ndash;6\u003csup\u003eth\u003c/sup\u003e fruiting branches were sampled per treatment for dimensional analysis (length \u0026times; width) and biomass accumulation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.3 Statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData processing utilized: Microsoft Excel 2022 for preliminary calculations, SPSS 20.0 for ANOVA with LSD post-hoc testing (\u0026alpha;= 0.05), and Origin 2025 for graphical representation and nonlinear regression modeling. Optimal B application rates were determined through quadratic regression analysis of yield response curves.\u003c/p\u003e"},{"header":"2. Results","content":"\u003cp\u003e\u003cstrong\u003e2.1 Response of seed cotton yield and yield components to B fertilizer in field trials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSeed cotton yields for both cultivars across field experimental sites exhibited a consistent single-peak response to increasing B application rate (0\u0026ndash;3.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e), characterized by initial increases followed by subsequent declines. At the Yancheng trial site, maximum yields for CCRI 425 and Siza 3 were observed at 2.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e, which represented increases of 25.89% and 17.34%, respectively, compared to the no B application. Similarly, at the Xinghua site, peak yields occurred at 2.0 kg B ha\u003csup\u003e-1\u003c/sup\u003e, corresponding to yield enhancements of 14.74% and 20.58% relative to the control. Notably, cultivar CCRI 425 achieved its highest yield (4,065 kg ha\u003csup\u003e-1\u003c/sup\u003e) at the Yancheng site with 2.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e (Table 1).\u003c/p\u003e\n\u003cp\u003eAmong yield components, the coefficient of variation (CV) for boll number (4.2%\u0026ndash;6.6%) considerably exceeded that for seed cotton weight per boll (0.9%\u0026ndash;2.2%). Analysis of variance (ANOVA) revealed that cultivar had a significant effect (p \u0026lt; 0.05) on both yield and yield components, whereas B application significantly influenced only yield and boll number.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.2 Optimal B application rates for two cotton varieties in field trials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSeed cotton yield exhibited an initial increase followed by a subsequent decrease with elevated B application rates. A quadratic regression model was employed to characterize the relationship between B application rates (independent variable) and seed cotton yield (response variable) for both cultivars across two experimental sites. The downward-opening parabolic relationships yielded coefficients of determination (R\u003csup\u003e2\u003c/sup\u003e) exceeding 0.82 (p \u0026lt; 0.05), revealing a critical agronomic threshold beyond which yield returns to B application diminished. CCRI 425 achieved maximum yields of 3,115.8 and 3,982.1 kg ha\u003csup\u003e-1\u003c/sup\u003e at B application thresholds of 1.90 and 2.35 kg B ha\u003csup\u003e-1\u003c/sup\u003e in Xinghua and Yancheng, respectively (Fig. 1a). Similarly, Siza 3 reached peak yields of 3,557.0 and 3,298.3 kg ha\u003csup\u003e-1\u003c/sup\u003e at 2.05 and 2.36 kg B ha\u003csup\u003e-1\u003c/sup\u003e in Xinghua and Yancheng, respectively (Fig. 1b). These results indicate optimal B application ranges of 1.90\u0026ndash;2.35 kg B ha\u003csup\u003e-1\u003c/sup\u003e for CCRI 425 and 2.05\u0026ndash;2.36 kg B ha\u003csup\u003e-1\u003c/sup\u003e for Siza 3.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.3 Agronomic trait responses to B application within optimal threshold ranges\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBoll shedding rates displayed a parabolic response to increasing B application levels, initially decreasing before rising at higher concentrations. Quadratic regression analysis identified the B application rates for minimum boll shedding rates: CCRI 425 exhibited minimum shedding (31.7% and 37.5%) at 1.90 and 1.99 kg B ha\u003csup\u003e-1\u003c/sup\u003e in Xinghua and Yancheng, respectively (Fig. 2a). Similarly, Siza 3 showed minimal shedding 25.8% and 46.6% at 2.01 and 2.32 kg B ha\u003csup\u003e-1\u003c/sup\u003e in the respective locations (Fig. 2b).\u003c/p\u003e\n\u003cp\u003eCotton boll numbers exhibited significant variation (p \u0026lt; 0.05) across developmental stages in response to B fertilizer. Quadratic regression models indicated a non-linear relationship, with boll numbers initially increasing then decreasing under elevated B application rates, and peaking within the optimal B ranges for both cultivars. CCRI 425 attained maximum boll counts of 13.8 and 10.7 per plant in Xinghua (2.06 kg B ha\u003csup\u003e-1\u003c/sup\u003e) and Yancheng (2.24 kg B ha\u003csup\u003e-1\u003c/sup\u003e), respectively (Fig. 3a). Siza 3 achieved peak boll production of 15.2 and 13.0 per plant at 1.99 kg B ha\u003csup\u003e-1\u003c/sup\u003e in both locations (Fig. 3b).\u003c/p\u003e\n\u003cp\u003eBoll dimensions displayed significant developmental-stage-dependent responses to B application. At 38 DPA, maximum boll size of CCRI 425 and Siza 3 varieties was significantly increased by 16.9%\u0026ndash;17.7% and 30.0%\u0026ndash;30.8%, respectively, under B application treatment compared to no B application. With the exception of Siza 3 in Yancheng, quadratic models demonstrated maximum boll size attainment within optimal B ranges. CCRI 425 exhibited peak boll sizes of 19.3 cm\u003csup\u003e2\u003c/sup\u003e (Xinghua: 2.11 kg B ha\u003csup\u003e-1\u003c/sup\u003e) and 18.1 cm\u003csup\u003e2\u003c/sup\u003e (Yancheng: 1.98 kg B ha\u003csup\u003e-1\u003c/sup\u003e) (Fig. 3c), while Siza 3 reached maxima of 15.1 cm\u003csup\u003e2\u003c/sup\u003e (Xinghua: 2.03 kg B ha\u003csup\u003e-1\u003c/sup\u003e) and 14.8 cm\u003csup\u003e2\u003c/sup\u003e (Yancheng: 1.65 kg B ha\u003csup\u003e-1\u003c/sup\u003e) (Fig. 3d).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2.4 Validation of optimal B application rate in column planting trials conducted in Nanjing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVertical distribution analysis of fruiting branches revealed distinct canopy-layer responses to B application in Nanjing. The lower canopy (FB1\u0026ndash;4) contributed 22.81% of total yield, achieved maximum productivity (22.90% increase) at 2.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e. Similarly, the middle canopy (FB5\u0026ndash;8), accounting for 48.22% of total yield, peaked at 17.40% higher productivity under this rate. The upper canopy (FB9+), representing 28.96% of yield, was optimized at a 22.57% increase with 2.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e. B application exerted significant influences (p \u0026lt; 0.05) on both boll number and seed cotton weight per boll across canopy layers. The CV for boll number substantially exceeded that of seed cotton weight, with lower canopy branches exhibiting higher boll densities compared to central and upper strata. Relative to the no B application, the maximum increases in boll number (14.7%) and seed cotton weight per boll (4.6%) were observed predominantly at 2.5 kg B ha\u003csup\u003e-1\u003c/sup\u003e (Table 2).\u003c/p\u003e\n\u003cp\u003eFor CCRI 425, seed cotton yield per plant in Nanjing exhibited a parabolic response characterized by an initial increase followed by a decline with escalating B application. Quadratic regression analysis identified a peak yield of 57.6 g plant\u003csup\u003e-1\u003c/sup\u003e at 2.25 kg B ha\u003csup\u003e-1\u003c/sup\u003e, aligning with the previously determined optimal range (Fig. 4a). Quadratic models for CCRI 425 further demonstrated critical agronomic optima within the validated B application range: Minimum boll abscission rate (56.40%) at 2.17 kg B ha\u003csup\u003e-1\u003c/sup\u003e (Fig. 4b), Maximum boll number (11.9 per plant) at 2.15 kg B ha\u003csup\u003e-1\u003c/sup\u003e (Fig. 4c), peak boll size (21.3 cm\u003csup\u003e2\u003c/sup\u003e) at 1.97 kg B ha\u003csup\u003e-1\u003c/sup\u003e (Fig. 4d).\u003c/p\u003e"},{"header":"3. Discussion","content":"\u003cp\u003eSince B was first identified as an essential micronutrient for plant growth, B deficiency has emerged as a critical global production constraint, currently affecting hundreds of crop species across more than 80 countries (de Bang et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Lilay et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Field trials of B application to cotton in China demonstrated seed cotton yield increase of 17% (Li et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), confirming that B deficiency is still a key limiting factor in China\u0026rsquo;s cotton production system. Although supplemental B fertilizer is considered an important strategy to mitigate the decline in cotton yield in B-deficient areas, the unusually narrow range of adequacy between B deficiency and toxicity thresholds for B fertilizer management in cotton (Brdar-Jokanovic, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Under-application limits yield potential, while cumulative effects of over-application or long-term application may lead to phytotoxicity in subsequent crops (Bogiani et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Given this precision-dependent balance, where B deficiency (\u0026lt;\u0026thinsp;0.5 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and toxicity (\u0026gt;\u0026thinsp;2.0 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) thresholds differ by only a few ppm, precise optimization of B fertilization is required to maximize yields while promoting efficient use of B fertilizer resources. Furthermore, substantial heterogeneity in soil B availability across geographic regions and soil texture classes poses a major challenge for B management in cotton production systems. As a globally grown crop spanning numerous ecological zones, cotton is grown under markedly different environment conditions, each with different climatic regimes, soil properties and fertilizer application rates (Garcia-Sanchez et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThis study investigated two conventional cotton cultivars extensively cultivated in Jiangsu Province, planted across two geographically distinct long-term intensively cultivated fields with contrasting soil types. Pre-experimental soil analyses confirmed deficient soil available B levels (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), in the range of soil available B in regions demonstrating significant B fertilization responsiveness (Xu \u0026amp; Wang, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Both cultivars exhibited marked yield responses to B supplementation, with seed cotton yields increasing by 25.89% (CCRI 425) and 17.34% (Siza 3) in Yancheng, and 14.74% (CCRI 425) and 20.58% (Siza 3) in Xinghua relative to B-free controls. These results establish B as the key yield-limiting factor under these edaphic conditions. This is related to the primary physiological function of B in maintaining cell wall structural integrity through the formation of the boronic acid dimeric rhamnogalacturonanⅡ-B (RG-Ⅱ-B) complex, which stabilizes the pectin network and regulates cell wall porosity, and whose main functions are cell wall formation and cell division (Gimeno et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Previous studies have characterized the anatomical disruption caused by B deficiency, particularly the formation of brown petiole rings, as leading to impairment of phloem transport and photosynthetic efficiency, ultimately affecting reproductive organ development and seed cotton productivity (Li et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Lilay et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). In addition, B is involved in multiple metabolic pathways, including nucleic acid and carbohydrate metabolism, protein synthesis, phosphorus cycling, phenolic compound metabolism, and phytohormone regulation (Papadakis et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), which results in enhanced plant defense against abiotic stresses such as such as salt stress, drought, and heavy metal overload, providing yield stability in cotton.\u003c/p\u003e \u003cp\u003eThe critical role of B in facilitating photoassimilate translocation from source leaves to reproductive sinks (Panter et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) ensures proper boll development and biomass accumulation (Wahid et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), aligning with the observed yield enhancements. In this study, the CV for boll number significantly exceeded that of boll weight across B treatment (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), which is because boll number is more responsive to environmental fluctuations due to its sensitivity as a real-time indicator of plant physiological status. This differential response underscores boll number as the principal determinant of seed cotton yield. Boll shedding, a natural adaptive mechanism in cotton, typically accounts for 70% of the total number of nodes (Ertek \u0026amp; Kanber, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). In response to biotic and abiotic stresses, the internal development of plants and external stimuli will affect the expression of genes, leading to changes in hormones and enzymes and other endogenous substances, resulting in a significant increase in the rate of abscission (Zhao et al., \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), so the growth and development of bolls have a direct impact on the cotton yield. Mechanistically, B enhances reproductive structure development and assimilate partitioning to fruiting organs (Padbhushan \u0026amp; Kumar, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Wahid et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), directly correlating with the reduced boll abscission rates observed in this study. Prior research on sandy loam soils demonstrated that foliar B application (1.0 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) maximized boll numbers, achieving 63\u0026ndash;75% increases over controls (Mehran et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Wahid et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), corroborating our findings.\u003c/p\u003e \u003cp\u003eFertilizer efficiency models provide a robust framework for optimizing the relationship between fertilizer inputs and crop productivity. Q modeling has become an established analytical approach in studies examining single-nutrient management (Luo et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Under controlled fertilization conditions, crop yield response is influenced not only by B application rates but also by the indigenous soil B supply, which represents the baseline plant-available B content prior to fertilization and constitutes a key determinant of crop yield response. While current understanding of indigenous B supply\u0026rsquo;s role in developing effective management strategies remains preliminary (Ahmed et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Cotton yield response to B application varied significantly across trial sites, mainly attributed to differences in native B supply levels. While seed cotton yield exhibited a positive quadratic relationship with B application in the results of this study (R\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.82 across field trials), diminishing yield gains occurred beyond optimal thresholds due to non-linear dynamics. This pattern likely reflects limitations in soil B bioavailability, cultivar-specific uptake saturation, and potential phytotoxicity at supraoptimal concentrations (Sim\u0026oacute;n et al., \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). The Q models effectively quantified regional yield variability by capturing these non-linear dynamics. Maximum yields of CCRI 425 occurring at B application rates of 1.9 and 2.36 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in Xinghua and Yancheng and at 2.05 and 2.36 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in Siza 3, highlighting the necessity of balancing soil B availability with cultivar-specific demand to optimize yield and resource efficiency.\u003c/p\u003e \u003cp\u003eColumn-planting trials for CCRI 425 in Nanjing (2.25 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) verified the theoretical optimum application rate, confirming cultivar-specific B requirements while revealing significant intraspecific differences across locations (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003e). These variations reflect differential B stress tolerance thresholds. The observed rate discrepancies between Yancheng and Xinghua further demonstrate how edaphic and climatic factors mediate B efficacy. Available B content, organic matter, pH and texture as key determinants of soil properties affecting B fertilizer use efficiency. Yield response was inversely related to soil available B levels, peaking in B-deficient soils, where supplemental B compensated for inherent limitations (Cordeiro et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Conversely, high natural B levels increased toxicity risk and reduced agricultural efficiency (Niaz et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Organic matter exhibited parabolically related to efficiency, peaking at moderate concentrations due to its dual role as a B reservoir versus immobilization agents (Atique ur et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Soil texture significantly moderated B retention, with coarse-textured soils exhibiting lower efficacy due to leaching, while fine-textured soils maintained better nutrient retention (Cordeiro et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). B bioavailability was pH-dependent, with maximal uptake occurring under acidic to weakly alkaline conditions and sharply decreasing at higher soil pH. Thermal and hydrological conditions strongly influenced B utilization (Yeates et al., \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Dusenge et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The optimal temperature range (25\u0026ndash;30 ℃) enhanced metabolic activity and photosynthetic efficiency and maximized yield response. Suboptimal temperatures (\u0026lt;\u0026thinsp;25 ℃) limited root growth and stomatal conductance and reduced B effectiveness. Notably, the sustained increase in yield at supraoptimal temperatures (\u0026gt;\u0026thinsp;30 ℃) may be attributed to B-induced activation of antioxidant enzymes and carbohydrate metabolism, which mitigated heat-induced oxidative stress. Extreme water conditions, either in excess (promoting leaching) or deficiency (reducing bioavailability), emphasize the need for balanced water management. These findings reinforce the imperative for soil-specific B management strategies to maximize cotton productivity (Liu et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eColumn-planting trials in Nanjing elucidated vertical canopy partitioning of B responses, with middle (FB5\u0026ndash;8) and upper (FB9+) canopy boll production demonstrating greater B sensitivity than lower strata (FB1\u0026ndash;4) (Table\u0026nbsp;3). Given the middle canopy\u0026rsquo;s disproportionate contribution to total yield (48.22%), B application primarily modulated yield-determining components in these strata. This vertical response gradient constitutes a novel finding, potentially linked to restricted B phloem mobility impeding redistribution to lower canopy organs (Landi et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Oikonomou et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Further investigation is warranted to elucidate the physiological mechanisms underlying this stratification.\u003c/p\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eThe application of supplemental B fertilizer significantly modulates yield components, particularly boll number, thereby enhancing seed cotton yield. Through integration of quadratic modeling, the optimal B application rates for yield maximization were established as 1.90\u0026ndash;2.36 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for CCRI 425 (14.74\u0026ndash;25.89% yield increase), 2.05\u0026ndash;2.36 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for Siza 3 (17.34\u0026ndash;20.58% yield increase). Within these ranges, critical agronomic traits, including boll number, boll shedding rate and boll size, exhibited optimal performance, aligning with physiological thresholds for reproductive efficiency. Vertical canopy analysis demonstrated that the most substantial response of B fertilization on seed cotton yield was the middle canopy seed cotton yield, and the yield component with the same most significant variance was the number of cotton bolls. These findings underscore the importance of cultivar- and site-specific B management strategies to reconcile yield optimization with nutrient use efficiency in intensive cotton production systems.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003eAll co-authors have consent for submission of manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003eAll relevant data are within this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003eThe authors declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eThis work was supported by China Agriculture Research System (CARS-15-14), Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry (CIC-MCP).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e Conceptualization, W.H.; data collection, S.W., C.W., Y.Z. and X.L.; formal analysis, S.W. and W.H.; funding acquisition, W.H.; investigation, S.W., C.W., Y.Z. and X.L.; methodology, S.W. and C.W.; writing\u0026mdash;original draft, S.W., C.W. and Y.Z.; writing\u0026mdash;review and editing, S.W., C.W. and W.H.; All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAhmed N., Masood S., Abid M., Mustafa G., Ali M. A., Ahmad S., Qayyum M. F. 2018. Determination of residual and cumulative boron requirements for cotton and wheat crops grown under calcareous soil conditions. \u003cem\u003eCommunications in Soil Science and Plant Analysis\u003c/em\u003e, 49(9): 1092-1098.\u003c/li\u003e\n \u003cli\u003eAtique Ur R., Farooq M., Rashid A., Nadeem F., Stuerz S., Asch F., Bell R. W., Siddique K. H. M. 2018. Boron nutrition of rice in different production systems. A review. \u003cem\u003eAgronomy for Sustainable Development\u003c/em\u003e, 38(3).\u003c/li\u003e\n \u003cli\u003eBogiani J. C., Sampaio T. F., Abreu C. H., Rosolem C. A. 2014. Boron uptake and translocation in some cotton cultivars. \u003cem\u003ePlant and Soil\u003c/em\u003e, 375(1-2): 241-253.\u003c/li\u003e\n \u003cli\u003eBrdar-Jokanovic M. 2020. Boron Toxicity and Deficiency in Agricultural Plants. \u003cem\u003eInternational Journal of Molecular Sciences\u003c/em\u003e, 21(4).\u003c/li\u003e\n \u003cli\u003eChen X., Humphreys J. L., Ru Y. Q., He Y. T., Wu F. H., Mai J. W., Li M., Li Y. L., Shabala S., Yu M., Smith S. M. 2022. Jasmonate signaling and remodeling of cell wall metabolism induced by boron deficiency in pea shoots. \u003cem\u003eEnvironmental and Experimental Botany\u003c/em\u003e, 201.\u003c/li\u003e\n \u003cli\u003eCordeiro L. F. D., Cordeiro C. F. D., Ferrari S. 2022. Cotton yield and boron dynamics affected by cover crops and boron fertilization in a tropical sandy soil. \u003cem\u003eField Crops Research\u003c/em\u003e, 284.\u003c/li\u003e\n \u003cli\u003eCordeiro L. F. D., Malenowtch J. V. C., Cordeiro C. F. D., Detoni J. A. C., Furlani E., Jr., Ferrari S. 2024. Improving cotton yield and fiber quality in different tropical soils with boron fertilization. \u003cem\u003eAgronomy Journal\u003c/em\u003e, 116(3): 1540-1550.\u003c/li\u003e\n \u003cli\u003eDe Bang T. C., Husted S., Laursen K. H., Persson D. P., Schjoerring J. K. 2021. The molecular-physiological functions of mineral macronutrients and their consequences for deficiency symptoms in plants. \u003cem\u003eNew Phytologist\u003c/em\u003e, 229(5): 2446-2469.\u003c/li\u003e\n \u003cli\u003eDhassi K., Drissi S., Makroum K., Er-Rezza H., Amlal F., Houssa A. A. 2019. Soil Boron Migration as Influenced by Leaching Rate and Soil Characteristics: A Column Study. \u003cem\u003eCommunications in Soil Science and Plant Analysis\u003c/em\u003e, 50(14): 1663-1670.\u003c/li\u003e\n \u003cli\u003eDong X. C., Jiang C. C., Wei S. W., Jiao H. J., Ran K., Dong R., Wang S. M. 2022. The regulation of plant lignin biosynthesis under boron deficiency conditions. Physiologia Plantarum, 174(6).\u003c/li\u003e\n \u003cli\u003eDridi I., Tlili A., Fatnassi S., Hamrouni H., Gueddari M. 2018. Effects of boron distribution on sugar beet crop yield in two Tunisian soils. \u003cem\u003eArabian Journal of Geosciences\u003c/em\u003e, 11(15).\u003c/li\u003e\n \u003cli\u003eDusenge M. E., Duarte A. G., Way D. A. 2019. Plant carbon metabolism and climate change: elevated CO\u003csub\u003e2\u003c/sub\u003e and temperature impacts on photosynthesis, photorespiration and respiration. \u003cem\u003eNew Phytologist\u003c/em\u003e, 221(1): 32-49.\u003c/li\u003e\n \u003cli\u003eErtek A., Kanber R. 2003. Effects of different drip irrigation programs on the boll number and shedding percentage and yield of cotton. \u003cem\u003eAgricultural Water Management\u003c/em\u003e, 60(1): 1-11.\u003c/li\u003e\n \u003cli\u003eFeng L., Chi B. J., Dong H. Z. 2022. Cotton cultivation technology with Chinese characteristics has driven the 70-year development of cotton production in China. \u003cem\u003eJournal of Integrative Agriculture\u003c/em\u003e, 21(3): 597-609.\u003c/li\u003e\n \u003cli\u003eFeng L., Wan S. M., Zhang Y. L., Dong H. Z. 2024. Xinjiang cotton: Achieving super-high yield through efficient utilization of light, heat, water, and fertilizer by three generations of cultivation technology systems. \u003cem\u003eField Crops Research\u003c/em\u003e, 312.\u003c/li\u003e\n \u003cli\u003eGarcia-Sanchez F., Simon-Grao S., Martinez-Nicolas J. J., Alfosea-Simon M., Liu C., Chatzissavvidis C., Perez-Perez J. G., Camara-Zapata J. M. 2020. Multiple stresses occurring with boron toxicity and deficiency in plants. \u003cem\u003eJournal of Hazardous Materials\u003c/em\u003e, 397.\u003c/li\u003e\n \u003cli\u003eGimeno V., Sim\u0026oacute;n I., Nieves M., Mart\u0026iacute;nez V., C\u0026aacute;mara-Zapata J. M., Garc\u0026iacute;a A. L., Garc\u0026iacute;a-S\u0026aacute;nchez F. 2012. The physiological and nutritional responses to an excess of boron by Verna lemon trees that were grafted on four contrasting rootstocks. \u003cem\u003eTrees-Structure and Function\u003c/em\u003e, 26(5): 1513-1526.\u003c/li\u003e\n \u003cli\u003eLandi M., Margaritopoulou T., Papadakis I. E., Araniti F. 2019. Boron toxicity in higher plants: an update. \u003cem\u003ePlanta\u003c/em\u003e, 250(4): 1011-1032.\u003c/li\u003e\n \u003cli\u003eLi H. J., Wang J. W., Huang X. L., Zhou Z. G., Wang S. S., Hu W. 2023. Phosphate fertilization promotes fiber elongation by affecting sucrose inversion, K plus accumulation, and malate synthesis in cotton fiber. \u003cem\u003eField Crops Research\u003c/em\u003e, 303.\u003c/li\u003e\n \u003cli\u003eLi M. F., Peng W. Y., Li H. T., Huang X. J., Z.Q. Z. 2016. Effects of the combined application of nitrogen and boron on the yield，petiole annulus and nutrient uptake of cotton. \u003cem\u003eSoil and Fertilizer Sciences in China\u003c/em\u003e, 4: 97-102.\u003c/li\u003e\n \u003cli\u003eLi M. F., Zhao Z. Q., Zhang Z. H., Zhang W., Zhou J., Xu F. S., Liu X. W. 2017. Effect of boron deficiency on anatomical structure and chemical composition of petioles and photosynthesis of leaves in cotton (\u003cem\u003eGossypium hirsutum\u003c/em\u003e L.). \u003cem\u003eScientific Reports\u003c/em\u003e, 7.\u003c/li\u003e\n \u003cli\u003eLilay G. H., Thiebaut N., Du Mee D., Assuncao A. G. L., Schjoerring J. K., Husted S., Persson D. P. 2024. Linking the key physiological functions of essential micronutrients to their deficiency symptoms in plants. \u003cem\u003eNew Phytologist\u003c/em\u003e, 242(3): 881-902.\u003c/li\u003e\n \u003cli\u003eLiu S., Song B., Sehar S., Adil M. F., Lin X., Huo J., Zhao X., Riaz M. 2024. Variations in rhizosphere soil dominant and pathogenic flora improve boron-efficient \u003cem\u003eBeta vulgaris\u003c/em\u003e L. yield under boron deficit. \u003cem\u003eJournal of Cleaner Production\u003c/em\u003e, 444.\u003c/li\u003e\n \u003cli\u003eLopes P., Campos C. N. S., Teodoro P. E., Costa M. G., De Souza J. P., Jr., Prado R. D. 2023. The synergistic effects of soil-applied boron and foliar-applied silicon on cotton fiber quality and yield. \u003cem\u003eBMC Plant Biology\u003c/em\u003e, 23(1).\u003c/li\u003e\n \u003cli\u003eLu K. S., Yan L., Riaz M., Babar S., Hou J. Y., Zhang Y. L., Jiang C. C. 2023. Exogenous boron alleviates salt stress in cotton by maintaining cell wall structure and ion homeostasis. \u003cem\u003ePlant Physiology and Biochemistry\u003c/em\u003e, 201.\u003c/li\u003e\n \u003cli\u003eLuo L. C., Wei P., Peng S. Y., Wang X. X., Chai R. S., Zhang C. C., Kadambot S. H. M., Palta J. A. 2024. Rational phosphorus stewardship for sustainable maize production in China: A meta-analysis. \u003cem\u003eEuropean Journal of Agronomy\u003c/em\u003e, 153.\u003c/li\u003e\n \u003cli\u003eMehran M., Ashraf M., Shahzad S. M., Shakir M. S., Azhar M. T., Ahmad F., Alvi A. 2023. Growth, yield and fiber quality characteristics of Bt and non-Bt cotton cultivars in response to boron nutrition. \u003cem\u003eJournal of Cotton Research\u003c/em\u003e, 6(1): 1.\u003c/li\u003e\n \u003cli\u003eNiaz A., Ahmad W., Zia M. H., Malhi S. S. 2013. Relationship of soil extractable and fertilizer boron to some soil properties, crop yield, and total boron in cotton and wheat plants on selected soils of Punjab, Pakistan. \u003cem\u003eJournal of Plant Nutrition\u003c/em\u003e, 36(3): 343-356.\u003c/li\u003e\n \u003cli\u003eOikonomou A., Ladikou E. V., Chatziperou G., Margaritopoulou T., Landi M., Sotiropoulos T., Araniti F., Papadakis I. E. 2019. Boron Excess Imbalances Root/Shoot Allometry, Photosynthetic and Chlorophyll Fluorescence Parameters and Sugar Metabolism in Apple Plants. \u003cem\u003eAgronomy-Basel\u003c/em\u003e, 9(11).\u003c/li\u003e\n \u003cli\u003ePadbhushan R., Kumar D. 2015. Yield and Nutrient Uptake of Green Gram (\u003cem\u003eVigna radiata\u003c/em\u003e L.) as Influenced by Boron Application in Boron-Deficient Calcareous Soils of Punjab. \u003cem\u003eCommunications in Soil Science and Plant Analysis\u003c/em\u003e, 46(7): 924-939.\u003c/li\u003e\n \u003cli\u003ePanter P. E., Seifert J., Dale M., Pridgeon A. J., Hulme R., Ramsay N., Contera S., Knight H. 2023. Cell wall fucosylation in Arabidopsis influences control of leaf water loss and alters stomatal development and mechanical properties. \u003cem\u003eJournal of Experimental Botany\u003c/em\u003e, 74(8): 2680-2691.\u003c/li\u003e\n \u003cli\u003ePapadakis I. E., Tsiantas P. I., Tsaniklidis G., Landi M., Psychoyou M., Fasseas C. 2018. Changes in sugar metabolism associated to stem bark thickening partially assist young tissues of Eriobotrya japonica seedlings under boron stress. \u003cem\u003eJournal of Plant Physiology\u003c/em\u003e, 231(337-345.\u003c/li\u003e\n \u003cli\u003ePennisi M., Gonfiantini R., Grassi S., Squarci P. 2006. The utilization of boron and strontium isotopes for the assessment of boron contamination of the Cecina River alluvial aquifer (central-western Tuscany, Italy). \u003cem\u003eApplied Geochemistry\u003c/em\u003e, 21(4): 643-655.\u003c/li\u003e\n \u003cli\u003ePommerrenig B., Junker A., Abreu I., Bieber A., Fuge J., Willner E., Bienert M. D., Altmann T., Bienert G. P. 2018. Identification of Rapeseed (\u003cem\u003eBrassica napus\u003c/em\u003e L.) Cultivars With a High Tolerance to Boron-Deficient Conditions. \u003cem\u003eFrontiers in Plant Science\u003c/em\u003e, 9.\u003c/li\u003e\n \u003cli\u003eRiaz M., Yan L., Wu X. W., Hussain S., Aziz O., Jiang C. C. 2018. Boron deprivation induced inhibition of root elongation is provoked by oxidative damage, root injuries and changes in cell wall structure. \u003cem\u003eEnvironmental and Experimental Botany\u003c/em\u003e, 156(74-85.\u003c/li\u003e\n \u003cli\u003eSarafi E., Siomos A., Tsouvaltzis P., Chatzissavvidis C., Therios I. 2017. Boron toxicity effects on grafted and non-grafted pepper (\u003cem\u003eCapsicum annuum\u003c/em\u003e) plants. \u003cem\u003eJournal of Soil Science and Plant Nutrition\u003c/em\u003e, 17(2): 441-460.\u003c/li\u003e\n \u003cli\u003eShorrocks V. M. 1997. The occurrence and correction of boron deficiency. \u003cem\u003ePlant and Soil\u003c/em\u003e, 193(1-2): 121-148.\u003c/li\u003e\n \u003cli\u003eSim\u0026oacute;n-Grao S., Nieves M., Mart\u0026iacute;nez-Nicol\u0026aacute;s J. J., C\u0026aacute;mara-Zapata J. M., Alfosea-Sim\u0026oacute;n M., Garc\u0026iacute;a-S\u0026aacute;nchez F. 2018. Response of three citrus genotypes used as rootstocks grown under boron excess conditions. \u003cem\u003eEcotoxicology and Environmental Safety\u003c/em\u003e, 159(10-19.\u003c/li\u003e\n \u003cli\u003eSim\u0026oacute;n I., D\u0026iacute;az-L\u0026oacute;pez L., Gimeno V., Nieves M., Pereira W. E., Mart\u0026iacute;nez V., Lidon V., Garc\u0026iacute;a-S\u0026aacute;nchez F. 2013. Effects of boron excess in nutrient solution on growth, mineral nutrition, and physiological parameters of Jatropha curcas seedlings. \u003cem\u003eJournal of Plant Nutrition and Soil Science\u003c/em\u003e, 176(2): 165-174.\u003c/li\u003e\n \u003cli\u003eTang Y. R., Qiu Y. R., Li X., Qin H. Y., Wang J., Zhang S. J., Han Y. C., Feng L., Wang G. P., Yang B. F., Lei Y. P., Xiong S. W., Zhi X. Y., Du W. L., Xin M. H., Li Y. B., Li X. F. 2024. Increased overyielding probability and yield stability from a 5-year cotton-based intercropping. \u003cem\u003eEuropean Journal of Agronomy\u003c/em\u003e, 156(\u003c/li\u003e\n \u003cli\u003eVoxeur A., Fry S. C. 2014. Glycosylinositol phosphorylceramides from Rosa cell cultures are boron-bridged in the plasma membrane and form complexes with rhamnogalacturonan II. \u003cem\u003ePlant Journal\u003c/em\u003e, 79(1): 139-149.\u003c/li\u003e\n \u003cli\u003eWahid M. A., Saleem M., Irshad S., Khan S., Cheema M. A., Saleem M. F., Tung S. A. 2020. Foliar feeding of boron improves the productivity of cotton cultivars with enhanced boll retention percentage. \u003cem\u003eJournal of Plant Nutrition\u003c/em\u003e, 43(16): 2411-2424.\u003c/li\u003e\n \u003cli\u003eWang X. Y., Li D., Yu Y. 2022. Current Situation and Optimization Countermeasures of Cotton Subsidy in China Based on WTO Rules. \u003cem\u003eAgriculture-Basel\u003c/em\u003e, 12(8).\u003c/li\u003e\n \u003cli\u003eXu F. S., Wang Y. H. 2017. Advances in studies on crop boron nutrition and application of boron fertilizers in China. \u003cem\u003eJournal of Plant Nutrition and Fertilizer\u003c/em\u003e, 23(6): 1556-1564.\u003c/li\u003e\n \u003cli\u003eYeates S. J., Constable G. A., Mccumstie T. 2010. Irrigated cotton in the tropical dry season. III: Impact of temperature, cultivar and sowing date on fibre quality. Field Crops Research, 116(3): 300-307.\u003c/li\u003e\n \u003cli\u003eZhang Z., Qiu S., Thistlethwaite R. J., Yao X. F., Tan D. K. Y., Wang D. S., Yang G. Z. 2024. Optimizing nitrogen application methods and frequency to increase cotton yield in summer direct sown condition. \u003cem\u003eIndustrial Crops and Products\u003c/em\u003e, 213.\u003c/li\u003e\n \u003cli\u003eZhao N., Geng Z., Zhao G. Y., Liu J. G., An Z. T., Zhang H. S., Ai P. F., Wang Y. Q. 2024. Integrated analysis of the transcriptome and metabolome reveals the molecular mechanism regulating cotton boll abscission under low light intensity. \u003cem\u003eBMC Plant Biology\u003c/em\u003e, 24(1).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e Effect of boron rate on cotton yield and yield components (Yancheng, and Xinghua, CCRI 425 and Siza 3)\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"98%\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 13px;\"\u003e\n \u003cp\u003eCultivars\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 13px;\"\u003e\n \u003cp\u003eB rate\u003c/p\u003e\n \u003cp\u003e(kg B hm\u003csup\u003e-2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 36px;\"\u003e\n \u003cp\u003eYancheng\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 36px;\"\u003e\n \u003cp\u003eXinghua\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003eBoll number\u003c/p\u003e\n \u003cp\u003e(10\u003csup\u003e4\u003c/sup\u003e no.hm\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eSeed cotton weight boll\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003e(g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003eSeed cotton yield\u003c/p\u003e\n \u003cp\u003e(kg hm\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003eBoll number\u003c/p\u003e\n \u003cp\u003e(10\u003csup\u003e4\u0026nbsp;\u003c/sup\u003eno.hm\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003eSeed cotton weight boll\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003e(g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003eSeed cotton yield\u003c/p\u003e\n \u003cp\u003e(kg hm\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"8\" valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003eCCRI 425\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e81.9 e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e3.9 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3229 e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e61.3 d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e2800 c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e89.1 d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e4.0 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3588 d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e64.3 bc\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e2980 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e92.7 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e4.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3833 bc\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e65.3 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3023 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e97.2 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e4.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4012 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e71.2 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3213 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e99.9 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e4.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4065 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e69.3 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3104 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e3.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e96.3 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e4.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3973 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e66.8 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3012 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e89.1 d\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e4.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3710 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e63.3 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.4 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e2832 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eCV (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e5.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e1.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"8\" valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003eSiza 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e50.7 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e5.7 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e2895 d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e54.4 d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.5 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3003 e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e53.7 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e5.7 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3073 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e60.3 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.5 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3360 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e54.8 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e5.7 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3171 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e62.8 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.4 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3454 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e57.0 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e5.8 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3341 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e66.3 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.4 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3621 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e57.0 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e5.9 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3397 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e64.8 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.5 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3571 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e3.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e54.4 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e5.9 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3257 ab\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e61.3 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.5 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3429 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e52.2 bc\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e6.0 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3149 bc\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e57.9 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.5 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e3236 d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eCV (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e4.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e5.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eVariety (V)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003e**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eBoron (B)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003eV\u0026times;B\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 12px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eCoefficient of variation, CV (%) = Standard deviation/Average \u0026times;100%;\u0026nbsp;Different lowercases within the same variety and column indicate significant difference at 0.05 probability.\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e Effect of boron rate on cotton yield and yield components (Nanjing, CCRI 425)\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"91%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 9px;\"\u003e\n \u003cp\u003eB rate\u003c/p\u003e\n \u003cp\u003e(kg B hm\u003csup\u003e-2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29.0534%;\" colspan=\"5\"\u003e\n \u003cp\u003eBoll number\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(number plant\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\u003cbr\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 33.3646%;\" colspan=\"5\"\u003e\n \u003cp\u003eSeed cotton weight\u003c/p\u003e\n \u003cp\u003eboll\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003e(g)\u003c/p\u003e\u003cbr\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29.6157%;\" colspan=\"5\"\u003e\n \u003cp\u003eSeed cotton yield\u003c/p\u003e\n \u003cp\u003e(g plant\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e\u003cbr\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB1-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB5-8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB9+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB1-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB5-8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB9+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eAverage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB1-4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB5-8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003eFB9+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 7px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.2 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e4.5 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.8 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e9.5 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.0 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.3 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.0 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e11.0 d\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e23.8 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e14.0 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e48.85 d\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.4 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e4.8 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.0 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.2 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.4 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e12.2 c\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e25.9 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e15.3 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e53.46 c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.5 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e4.9 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.3 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e13.0 bc\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e26.9 ab\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e16.3 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e56.27 b\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e4.9 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.7 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.3 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e13.5 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e27.4 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e16.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e57.60 a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.0 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.3 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.9 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.6 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.3 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e13.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e28.0 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e17.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e58.68 a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e3.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.5 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.0 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.3 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.8 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.2 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e12.7 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e27.5 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e16.8 a\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e57.03 a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e2.4 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e4.8 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.1 ab\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.3 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.0 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.5 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.0 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e5.1 a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e12.0 c\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e26.4 b\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e15.5 b\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e54.08 c\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003eCV%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e1.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e9.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"bottom\" style=\"width: 7px;\"\u003e\n \u003cp\u003e10.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eCoefficient of variation, CV (%) = Standard deviation/Average \u0026times;100%; Different lowercases within the column indicate significant difference at 0.05 probability.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-cotton-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cotn","sideBox":"Learn more about [Journal of Cotton Research](https://jcottonres.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/cotn/default.aspx","title":"Journal of Cotton Research","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Cotton (Gossypium hirsutum L.), Boron deficiency, Optimal boron fertilization rate, Yield components, Quadratic regression","lastPublishedDoi":"10.21203/rs.3.rs-6896139/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6896139/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBoron (B) deficiency critically constrains cotton productivity in China\u0026rsquo;s major cotton-growing regions, where soil available B levels widely fall below the sufficiency threshold (\u0026lt;\u0026thinsp;0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). This multi-site study (2020\u0026ndash;2021) quantified the optimal B application ranges for two regionally adapted cultivars (CCRI 425 and Siza 3) through field trials and column experiments across three B-deficient sites in Jiangsu Province. Quadratic regression modeling of seed cotton yield responses identified distinct optima: 1.90\u0026ndash;2.36 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for CCRI 425 and 2.05\u0026ndash;2.36 kg B ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for Siza 3, achieving yield increases of 14.7\u0026ndash;25.9% compared to B-free controls. Within these ranges, key agronomic traits demonstrated peak performance: boll shedding rates decreased by 11.3\u0026ndash;42.0%, boll number increased by 12.4\u0026ndash;22.0%, and boll size expanded by 16.9\u0026ndash;30.8%. The coefficient of variation for boll number (4.2\u0026ndash;6.6%) substantially exceeded that of boll weight (0.9\u0026ndash;2.2%), identifying boll number as the primary yield determinant. Vertical canopy analysis revealed that middle strata (FB5\u0026ndash;8) accounted for 48.2% of the total yield and was more sensitive in response to B fertilizer, likely attributable to restricted B phloem mobility. These findings provide a scientific framework for precision B management, balancing yield maximization with nutrient stewardship in B-deficient cotton systems.\u003c/p\u003e","manuscriptTitle":"Optimization of appropriate boron fertilization application range for cotton (Gossypium hirsutum L.) based on two varieties in boron-deficient soils","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-20 11:48:42","doi":"10.21203/rs.3.rs-6896139/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-06-21T07:21:37+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-18T09:02:46+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-17T13:42:24+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Cotton Research","date":"2025-06-14T22:42:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-cotton-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cotn","sideBox":"Learn more about [Journal of Cotton Research](https://jcottonres.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/cotn/default.aspx","title":"Journal of Cotton Research","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e5a7d9e0-1bf9-40d2-8dbe-acfe1714737d","owner":[],"postedDate":"June 20th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-07T16:09:18+00:00","versionOfRecord":{"articleIdentity":"rs-6896139","link":"https://doi.org/10.1186/s42397-026-00257-1","journal":{"identity":"journal-of-cotton-research","isVorOnly":false,"title":"Journal of Cotton Research"},"publishedOn":"2026-04-01 15:58:43","publishedOnDateReadable":"April 1st, 2026"},"versionCreatedAt":"2025-06-20 11:48:42","video":"","vorDoi":"10.1186/s42397-026-00257-1","vorDoiUrl":"https://doi.org/10.1186/s42397-026-00257-1","workflowStages":[]},"version":"v1","identity":"rs-6896139","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6896139","identity":"rs-6896139","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}