Search Results (40)

Improving cotton yield without sacrificing fiber quality remains a major breeding challenge. In this study, a carpel-specific RNA interference construct targeting GhCKX3b was introduced into the elite upland cotton cultivar ‘Yuanmian 8’, which has high fiber quality but relatively low lint percentage. We evaluated the effects of this construct on cytokinin accumulation, yield-related traits, and fiber quality across T0, T1, and T2 generations. Carpel-specific suppression of GhCKX3b increased cytokinin content in T2 positive lines by 50.3% to 102.0% relative to wild-type. Transgenic lines consistently showed increased lint percentage, boll weight, and seeds per boll, while seed index decreased moderately. In the best-performing line, lint percentage increased from 36.4% to 45.8%, and boll weight from 6.30 g to 7.31 g. Multi-year field evaluations confirmed stable inheritance of these improvements across generations. Importantly, major fiber quality parameters—including length, strength, and micronaire—remained within high-quality cotton standards. These results indicate that carpel-specific GhCKX3b suppression effectively improves key yield components in a high-quality cotton background without compromising fiber quality. This study provides breeding-oriented evidence supporting the application of tissue-specific cytokinin regulation in cotton improvement. Full article

The optimal timing of chemical defoliation is a critical bottleneck in stabilizing yield and fiber quality for short-season cotton, particularly under the intensifying pressure of mechanized global production. Current practices rely heavily on population-level boll opening rates, often overlooking the physiological maturity of late-season bolls. Here, we investigate the trade-offs between late-boll development and defoliation-induced senescence in short-season summer cotton. Our results demonstrate that defoliation timing based on a specific heat-unit or temporal threshold after flowering—rather than simple visual indicators—is essential for maximizing biological potential. We identified a critical physiological window (43 days post-anthesis) that synergistically optimizes boll weight, seed cotton yield, and fiber micronaire. Beyond this window, delayed defoliation leads to excessive fiber coarsening and reduced spinnability, while earlier application terminates dry matter accumulation prematurely, incurring significant yield penalties. These findings provide a mechanistic basis for synchronizing reproductive maturation with mechanical harvesting requirements. By establishing a precision defoliation framework, this study offers a scalable strategy to enhance the economic sustainability and resource-use efficiency of short-season cotton systems in double-cropping regions globally. Full article

Cotton fiber length and maturity, two critical fiber qualities, are commonly determined in the U.S. by Uster high volume instrument (HVI) and advanced fiber information system (AFIS). The main objectives of this investigation were to compare how HVI lengths agree with AFIS lengths and to examine whether the fiber length is linked with fiber maturity between the Universal HVI length calibration cotton standards and diverse upland lint samples. HVI micronaire (MIC) and AFIS fineness showed insignificant differences from HVI length calibration cotton standards to lint samples. Although there were strong and significant correlations between HVI upper-half mean length (UHML) and either AFIS UQL (w) or AFIS L5% (n), the relationship between UHML and L5% (n) was better suited than between UHML and UQL (w) in scrutinizing fiber lengths. Meanwhile, analysis revealed a moderate correlation between AFIS L5% (n) length and AFIS maturity ratio (MR), indicating the possibility of improving AFIS L5% (n) length by regulating fiber MR development. Further, AFIS MR values were positive and moderate correlated with algorithmic M_IR values of attenuated total reflection Fourier transform infrared (ATR FT-IR) spectra. The results suggested the feasibility of the ATR FT-IR method along with M_IR analysis in estimating AFIS MR rapidly away from fiber testing laboratories. Full article

Cotton is a globally important economic crop and the foundational raw material for the textile industry, and the planting pattern plays a crucial role in determining both the yield and quality of cotton. The results demonstrated that compared with the use of the traditional wide–narrow row (66 + 10 cm) planting pattern, the use of uniform row spacing significantly increased cotton yield (pooled effect size = 0.09, p < 0.05; average yield increase of 9.41%) when interrow distances were homogenized to optimize the population canopy structure. Moreover, this approach comprehensively improved fiber quality, yielding an average increase of 2.02% in cotton fiber length (pooled effect size = 0.02, p < 0.001), an average increase of 8.32% in cotton breaking tenacity (pooled effect size = 0.08, p < 0.001), and an average decrease of 6.76% in the cotton micronaire value (pooled effect size = −0.07, p < 0.001). This study confirms that the use of a uniform row spacing planting pattern is a key agronomic measure for simultaneously achieving high yield and superior fiber quality in cotton, providing both theoretical and practical insights into the optimization of cotton cultivation patterns. Full article

Naturally colored cotton offers ecological advantages by eliminating the need for chemical dyeing; however, its limited fiber quality restricts its commercial utilization. The main goal of this study was to evaluate the potential of the SSR marker BNL1604 for marker-assisted selection in naturally colored cotton (G. hirsutum L.) and to assess fiber quality variation among hybrid progenies derived from crosses between colored and elite white-fiber cultivars. As an expected outcome of this approach, we also assessed whether hybridization of naturally colored lines with elite white-fiber cultivars could contribute to the improvement of fiber quality traits in segregating progenies. Five colored lines (brown and green), three elite cultivars, and fifteen derived F₃ progenies were analyzed. Fiber traits, including upper half mean length (UHML), strength, elongation, and micronaire, were measured using HVI. Genotyping was conducted with BNL1604, and in silico mapping localized this marker to chromosome A07, with a homoeologous region on D07. White-fiber cultivars exhibited superior fiber length (33.4–35.4 mm) and strength (>31 g·tex⁻¹) compared with colored lines. Several F₃ hybrids exhibited transgressive segregation (progeny with trait values significantly exceeding those of both parents, as confirmed by frequency distribution and ANOVA analyses). For instance, the F₃ (C-6577 × L-4099) hybrid achieved UHML values of 30.51 mm and strength > 31.93 g·tex⁻¹. Most progenies maintained optimal micronaire (4.0–4.9). It was concluded that the presence of the 107 bp allele of BNL1604 marker was strongly associated with high-quality fiber, specifically improved fiber strength and length. In silico annotation revealed candidate genes near the BNL1604 locus linked to fiber development. These findings highlight the potential of combining hybridization with selection based on the presence of this 107 bp allele to develop high-quality, naturally colored cotton cultivars. Full article

Chemical defoliation is an important management practice in cotton to facilitate mechanical harvesting and leaf removal and maintain lint quality. Recent advances in precision agriculture have enabled the development of autonomous robotic platforms with a targeted side-spraying system that can achieve good canopy penetration while preventing soil compaction and crop mechanical damage. A side-wise spraying system allows for application of defoliant at different canopy heights. However, information on the effects of staggered defoliation on cotton fiber quality is limited. Thus, field research was conducted to evaluate the effects of various staggered application timing intervals (15, 10, 8, 5, and 3 days) on fiber quality and compare them with standard over-the-top broadcast applications. Staggered defoliation affected fiber length, with significant differences observed for upper half mean length, fiber length based on weight, and upper quartile length. Fiber maturity was also influenced by staggered defoliation timing, with a 15-day interval resulting in the lowest micronaire and higher immature fiber content. The effects of staggered defoliation on other parameters, such as strength, uniformity, and trash characteristics, varied across locations. The findings highlight the potential of robotic systems for chemical spraying and emphasize the need for further research on more precise and targeted application of defoliants to improve fiber quality. Full article

Cotton is one of the most important crops worldwide, having considerable economic importance in Greece. This study aimed to evaluate the fiber quality traits of partially interspecific cotton lines under contrasting irrigation and nitrogen environments within a strip-split block field design. Experiments conducted over two consecutive years include a control (commercial cultivar Celia) and four partially interspecific lines of the Pa7 generation (Gossypium hirsutum × G. barbadense). Three irrigation and two nitrogen fertilization levels were applied. Significant differences were observed among genotypes and environments for all fiber quality traits, with some year-to-year variation. Genotypic response for yellowness was influenced by fertilization. Across the two experimental years, a strong Fertilization × Environment interaction was observed, and in the second year, a Genotype × Fertilization × Environment interaction was detected for the uniformity index. Pa7 lines consistently outperformed Celia in fiber length (≈33 vs. 30 mm) and elongation (≈7.0 vs. 5.5%), while exhibiting higher yellowness values. Fiber strength, micronaire, uniformity, and reflectance varied between years but remained within acceptable ranges. Overall, Pa7 lines demonstrated superior fiber quality and stability under variable conditions, highlighting their potential for breeding programs. These findings support the importance of integrating interspecific germplasm with suitable irrigation–nitrogen management to improve cotton fiber performance and resilience under diverse cultivation environments. Full article

Dry topsoil restricts root growth and nutrient uptake in arid regions, thereby significantly reducing crop yield. Hydraulic lift occurs due to the dry topsoil and wet deep soil. This study investigates the effects of topsoil drought intensity (three field capacities in topsoil: 60–70% (W1), 50–60% (W2), and 40–50% (W3)) and nitrogen application rate (N1: 120, N2: 240, and N3: 360 kg ha⁻¹) on cotton quality and the distribution of nitrogen in soil and plant under hydraulic lift using a root-splitting device. The upper pot of the root-splitting device was 22 cm high, with a 26 cm top diameter and a 23 cm bottom diameter; the lower pot of the root-splitting device was 45 cm high, with a 48 cm top diameter and a 36 cm bottom diameter. Topsoil moisture was maintained at W1 without nitrogen application under the control treatment (CK). The W2 and W3 treatments (representing different topsoil drought intensities) were designed to compare the interactive effects of water and nitrogen fertiliser on nitrogen distribution and cotton quality with the CK treatment. Results indicate that the concentrations of nitrate nitrogen (NO₃⁻-N) in the 10–20 cm soil were generally higher than those in the 0–10 cm soil. The topsoil drought intensity and nitrogen application rate had significant impacts on nitrogen concentrations in cotton organs. The W2 treatment produced the maximum nitrogen concentration, except for the root nitrogen concentration in 2021. The nitrogen concentration in the roots and stems peaked at 240 kg ha⁻¹ of nitrogen application rate. The topsoil drought intensity and nitrogen application rate had considerable influences on the cotton dry matter. The nitrogen application rate had a significant impact on the following indexes: internal nitrogen-fertiliser use efficiency (INUE), physiological nitrogen-fertiliser use efficiency (PNUE), and nitrogen-fertiliser recovery efficiency (NRE), except for PNUE in 2020. The INUE of other treatments decreased by 13.82–43.44% compared with CK treatment. In 2021, fibre length and elongation were significantly impacted by the topsoil drought intensity, nitrogen application rates, and their interactions. The nitrogen application rate’s effects on the uniformity index were significant in 2020 and 2021. The hydraulic lift magnitude, NRE, and NO₃⁻-N in the 0–10 cm soil were significantly correlated with each other. There were correlations among cotton quality indexes: fibre length and strength, uniformity index and micronaire, and micronaire and elongation. These findings provide a reference for future research on the mechanism by which hydraulic lift participates in nitrogen distribution in soil and crops and also offer a new direction to utilize deep water to improve the utilization rate of water resources. Full article

Cottonseeds, rich in high-quality protein and fatty acids, represent a vital plant-derived feedstuff and edible oil resource. To systematically investigate genetic variation patterns in nutritional quality and screen superior germplasm, this study analyzed 26 nutritional quality traits and 8 fiber traits across 259 upland cotton (Gossypium hirsutum L.) accessions using multivariate statistical approaches. Results revealed significant genetic diversity in cottonseed nutritional profiles, with coefficients of variation ranging from 3.42% to 26.37%. Moreover, with advancements in breeding periods, the contents of protein, amino acids, and the proportion of unsaturated fatty acids (UFAs) increased, while oil content and C16:0 levels decreased. Correlation analyses identified significant positive associations (p < 0.05) between proteins, amino acids, UFAs, and most fiber traits, except for seed index (SI), fiber micronaire (FM), and fiber elongation (FE). Through a principal component analysis–fuzzy membership function (PCA-FMF) model, 13 elite accessions (F > 0.75) with high protein content, high UFA proportion, and excellent fiber quality were identified. These findings provide both data-driven foundations and practical germplasm resources for value-added utilization of cottonseed and coordinated breeding for dual-quality traits of nutrition and fiber. Full article

Understanding the influence of environmental factors on cotton performance is crucial for enhancing yield and fiber quality in the context of climate change. This study investigates genotype-by-environment (G×E) interactions in cotton, using data from 250 recombinant inbred lines (CCRI70 RILs) cultivated across 14 diverse environments in China’s major cotton cultivation areas. Our findings reveal that environmental effects predominantly influenced yield-related traits (boll weight, lint percentage, and the seed index), contributing to 34.7% to 55.7% of their variance. In contrast fiber quality traits showed lower environmental sensitivity (12.3–27.0%), with notable phenotypic plasticity observed in the boll weight, lint percentage, and fiber micronaire. Employing six machine learning models, Random Forest demonstrated superior predictive ability (R² = 0.40–0.72; predictive Pearson correlation = 0.63–0.86). Through SHAP-based interpretation and sliding-window regression, we identified key environmental drivers primarily active during mid-to-late growth stages. This approach effectively reduced the number of influential input variables to just 0.1–2.4% of the original dataset, spanning 2–9 critical time windows per trait. Incorporating these identified drivers significantly improved cross-environment predictions, enhancing Random Forest accuracy by 0.02–0.15. These results underscore the strong potential of machine learning to uncover critical temporal environmental factors underlying G×E interactions and to substantially improve predictive modeling in cotton breeding programs, ultimately contributing to more resilient and productive cotton cultivation. Full article

The continuous provision of nitrogen (N) to the crop is critical for optimal cotton production; however, the constant and excessive application of synthetic fertilizers causes adverse impacts on soil, plants, animals, and human health. The current study focused on the short-term effects (one-year study) of adding different rates of clinoptilolite zeolite, as part of an integrated nutrient management plan, and different rates of inorganic N fertilizer to improve soil and crop performance of cotton in three locations (ATH, MES, and KAR) in Greece. Each experiment was set up according to a split-plot design with three replications, three main plots (zeolite application at rates of 0, 5, and 7.5 t ha⁻¹), and four sub-plots (N fertilization regimes at rates of 0, 100, 150, and 200 kg N ha⁻¹). The results of this study indicated that increasing rates of the examined factors increased cotton yields (seed cotton yield, lint yield, and lint percentage), with the greatest lint yield recorded under the highest rates of zeolite (7.5 t ha⁻¹: 1808, 1723, and 1847 kg ha⁻¹ in ATH, MES, and KAR, respectively) and N fertilization (200 kg N ha⁻¹: 1804, 1768, and 1911 kg ha⁻¹ in ATH, MES, and KAR, respectively). From the evaluated parameters, most soil parameters (soil organic matter, soil total nitrogen, and total porosity), root and shoot development (root length density, plant height, leaf area index, and dry weight), fiber maturity traits (micronaire, maturity, fiber strength, and elongation), fiber length traits (upper half mean length, uniformity index, and short fiber index), as well as color (reflectance and spinning consistency index) and trash traits (trash area and trash grade), were positively impacted by the increasing rates of the evaluated factors. In conclusion, the results of the present research suggest that increasing zeolite and N fertilization rates to 7.5 t ha⁻¹ and 200 kg N ha⁻¹, respectively, improved soil properties (except mean weight diameter), stimulated crop development, and enhanced cotton and lint yield, as well as improved the fiber maturity, length, and color parameters of cotton grown in clay-loam soils in the Mediterranean region. Full article

Cotton is a crucial cash crop widely valued for its fiber. It is an important source of natural fiber and has diverse applications. Improving fiber quality is of significant economic and agricultural importance. Purple acid phosphatases (PAPs) are multifunctional enzymes critical for plant cell wall biosynthesis, root architecture modulation, low-phosphorus stress adaptation, and salt/ROS stress tolerance. In this study, a comprehensive genome-wide analysis of the PAP gene family was performed for four cotton species (G. hirsutum, G. barbadense, G. raimondii, and G. arboreum) to explore its potential role in improving fiber quality. A total of 193 PAP genes were identified in these species, revealing several conserved domains that contribute to their functional diversity. Phylogenetic analysis showed that the cotton PAP2 genes exhibited high homology with NtPAP12, a cell wall synthesis-related gene. Using cotton varieties with contrasting fiber thickness (EZ60, micronaire 4.5 vs. CCRI127, micronaire 3.5), qRT-PCR analysis demonstrated significantly higher expression levels of GhPAP2.2, GhPAP2.6, GhPAP2.8, and GhPAP2.9 in EZ60 fibers during 20–25 DPA compared to CCRI127. These results highlight the potential influence of PAP genes on cotton fiber development and provide valuable insights for improving fiber quality in cotton breeding. Full article

Cotton micronaire (MIC) is an essential fiber quality index that characterizes both fiber maturity and fineness components. This study compared how MIC affects the fiber high volume instrument (HVI) and advanced fiber information system (AFIS) qualities between Deltapine^® and PhytoGen upland varieties. There were noticeable differences among HVI and AFIS qualities from Deltapine^® fiber samples and PhytoGen samples, with significant differences om HVI strength and elongation. MIC development benefited fiber HVI strength enhancement and also HVI short fiber index (SFI), AFIS neps, AFIS short fiber contents, and AFIS immature fiber content (IFC) reduction, all of which were desired. Adversely, MIC evolution could cause undesired HVI Rd lowering, HVI +b boosting, and AFIS UQL(w), and a decrease in L5%(n) in fiber. Further, MIC values were not related with lint turnout, but they were positively and greatly correlated with algorithmic M_IR values of the attenuated total reflection in Fourier transform infrared (ATR FT-IR) spectra. The results demonstrated the applicability of the ATR FT-IR technique combined with the M_IR approach for rapid laboratory MIC assessment at early MIC testing in remote/breeding locations. Full article

Estimating cotton fiber quality early in the season, or its field variability, is impractical due to limitations in current methods, and it has not been widely explored. Similarly, few studies have tried estimating the parameters contributing to in-season cotton yield using UAV-based sensors. Thus, this study aims to explore the potential of using UAV-based multispectral images to estimate important in-season parameters, such as intercepted photosynthetically active radiation (IPAR), cotton height, the number of mainstem nodes, leaf area index (LAI), and end-of-the-season yield and cotton fiber quality parameters. Research trials were carried out in 2018 and 2020 in two experimental fields. In both years, a randomized complete block design was used with three cotton cultivars (2018), three plant growth regulators (2020), and three different irrigation levels to promote variability (both years). Cotton growth parameters were collected throughout the season on the same dates as UAV flights. Yield and fiber quality data were collected during harvest. The VI-based models used in this study were mostly sensitive to differences in cotton growth and final yield but less sensitive in detecting variation in cotton fiber quality indicators, such as length, strength, and micronaire, early in the season. The best performing regression model among the three fiber quality indicators was achieved in 2020, using a combination of four VIs, which explained 68% of the micronaire variability at 71 DAP. Results from this study also showed that multispectral-based VIs can be applied as early as the squaring stage at around 44 DAP to estimate most cotton growth indicators and final lint yield. Multiple linear regression validation models for height using NDVI, GNDVI, and RDVI obtained an R² of 0.62, and for LAI using MSR and NDVI an R² of 0.60. For lint yield, the best regression model combined four VIs and explained 66% of the yield variability. The ability to capture the variability in important growth and yield parameters early in the season can provide useful insights on potential crop performance and aid in in-season decisions. Full article

The quality of cotton fiber plays a pivotal role for both producers and processors, influencing the market value and end-product quality. Certain cotton fiber properties, such as length, strength, micronaire, and uniformity index, are crucial determinants of cotton quality. Despite its prominence as a cotton-producing region, the Aegean region in Türkiye lacks comprehensive studies examining the quality of its cotton fiber across different subregions and seasonal variations. This study aimed to address this gap by investigating the variations in cotton fiber quality across different years and subregions within the Aegean. This study involved the evaluation of a total of 368,686 individual fiber quality analyses conducted over seven years across three subregions within the Aegean in Türkiye. The fiber samples collected from Bergama, Söke, and Menemen underwent high-volume instrument (HVI) analysis to evaluate the variations in cotton fiber quality across years and subregions, considering the phenological stages of cotton and climate conditions. The findings highlighted significant variations in the fiber quality traits among subregions, with environmental factors such as temperature and humidity playing crucial roles. Higher average daily temperatures during the flowering stage to boll formation contributed to higher strength values, while limitations on fiber length were observed due to prevalent high temperatures. Additionally, variations in micronaire values were linked to temperature and humidity conditions during boll development stages. This study underscores the importance of comprehensively considering climatic factors to understand their impacts on cotton fiber quality and suggests further research into the cotton plant’s phenology and specific climate conditions for a more thorough understanding of environmental effects on fiber quality. Full article