Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strategy to enhance agricultural productivity. In this article, we provide an overview of the progress made in the alternate cotton-peanut intercropping, specifically focusing on its yield benefits, environmental impacts, and the underlying mechanisms. In addition, we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment, pest management options, and the mechanisms of root-canopy interactions. This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production.

Background Light is a critical factor in plant growth and development, particularly in controlled environments. Light-emitting diodes (LEDs) have become a reliable alternative to conventional high pressure sodium (HSP) lamps because they are more efficient and versatile in light sources. In contrast to well-known specialized LED light spectra for vegetables, the appropriate LED lights for crops such as cotton remain unknown.
Results In this growth chamber study, we selected and compared four LED lights with varying percentages (26.44%-68.68%) of red light (R, 600-700 nm), combined with other lights, for their effects on growth, leaf anatomy, and photosynthesis of cotton seedlings, using HSP lamp as a control. The total photosynthetic photon flux density (PPFD) was (215 ± 2) μmol·m^-2·s^-1 for all LEDs and HSP lamp. The results showed significant differences in all tested parameters among lights, and the percentage of far red (FR, 701-780 nm) within the range of 3.03%-11.86% was positively correlated with plant growth (characterized by leaf number and area, plant height, stem diameter, and total biomass), palisade layer thickness, photosynthesis rate (P_n), and stomatal conductance (G_s). The ratio of R/FR (4.445-11.497) negatively influenced the growth of cotton seedlings, and blue light (B) suppressed stem elongation but increased palisade cell length, chlorophyll content, and P_n.
Conclusion The LED 2 was superior to other LED lights and HSP lamp. It had the highest ratio of FR within the total PPFD (11.86%) and the lowest ratio of R/FR (4.445). LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.

Background Water deficit is an important problem in agricultural production in arid regions. With the advent of wholly mechanized technology for cotton planting in Xinjiang, it is important to determine which planting mode could achieve high yield, fiber quality and water use efficiency (WUE). This study aimed to explore if chemical topping affected cotton yield, quality and water use in relation to row configuration and plant densities.
Results Experiments were carried out in Xinjiang China, in 2020 and 2021 with two topping method, manual topping and chemical topping, two plant densities, low and high, and two row configurations, i.e., 76 cm equal rows and 10+66 cm narrow-wide rows, which were commonly applied in matching harvest machine. Chemical topping increased seed cotton yield, but did not affect cotton fiber quality comparing to traditional manual topping. Under equal row spacing, the WUE in higher density was 62.4% higher than in the lower one. However, under narrow-wide row spacing, the WUE in lower density was 53.3% higher than in higher one (farmers’ practice). For machine-harvest cotton in Xinjiang, the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m^-2 or equal rows with 18 plants m^-2.
Conclusion： The plant density recommended in narrow-wide rows was less than farmers’ practice and the density in equal rows was moderate with local practice. Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.

Background Natural and synthetic plant growth regulators are essential for plant health, likewise these regulators also play a role in increasing organic production productivity and improving quality and yield stability. In the present study, we have evaluated the effects of foliar applied plant growth regulators, i.e., moringa leaf extract (MLE) and mepiquat chloride (MC) alone and in combination MC and MLE on the conventional cotton cultivar (CIM 573) and transgenic one (CIM 598). The growth regulators were applied at the start of bloom, 45 and 90 days after blooming.
Results The application of MC and MLE at 90 days after blooming significantly improved the relative growth rate, net assimilation rate, the number of bolls per plant, and seed cotton yield. Likewise, the combined application of MLE and MC at 90 days after blooming significantly boosted the nitrogen uptake in locules, as well as the phosphorus and potassium uptake in the leaves of both cotton cultivars. The application of MLE alone has considerably improved the nitrogen uptake in leaves, and phosphorus and potassium contents in locules of Bt and conventional cotton cultivars. Similarly, Bt cotton treated with MLE at 90 days after blooming produced significantly higher ginning out turn and oil contents. Treatment in combination (MLE + MC) at 90 days after blooming produced considerably higher micronaire value, fiber strength, and staple length in conventional cultivar.
Conclusion The natural growth enhancer, MLE is a rich source of minerals and zeatin, improving the nutrient absorption and quality of cotton fiber in both conventional and Bt cotton cultivars.

Background Cotton (Gossypium hirsutum L.), adapted to tropical and subtropical regions of the world, is highly sensitive to low temperatures throughout its life cycle. The objective of this study was to evaluate the mitigating effects of different doses of animal-derived (0.25%, 0.50%, and 1.00% Isabion® ), seaweed-based (0.165%, 0.330%, and 0.660% Proton®) biostimulants, as well as a copper (Cu)-containing fungicide application, on cotton cultivar Lazer seedlings at the four true leaves (V4) stage. The plants were exposed to a low temperature of 5 °C for 48 h, and the changes in morphological (seedling fresh and dry weight, plant height, and stem diameter) and physiological parameters (leaf temperature, chlorophyll content, relative water content, electrolyte leakage, and relative injury) were examined.
Results The results revealed that chilling stress reduced plant growth, while biostimulants helped protect the plants and overcome the adverse effects of chilling. Under chilling stress, there was a considerable reduction in seedling fresh weight (SFW), seedling dry weight (SDW), plant height (PH), stem diameter (SD), leaf temperature (LT), and relative water content (RWC). Cotton seedlings treated with the animal-derived biostimulants showed significantly enhanced SFW, SDW, PH, SD, LT, chlorophyll content (Chl), electrolyte leakage (EL), and relative injury (RI), although there were no positive changes in RWC. No significant differences in the morphological traits were observed among the doses of seaweed biostimulants. For SDW, PH, EL, and RI, the best results were obtained with the application of a fungicide containing copper.
Conclusion These results show the efficiency of the biostimulant and fungicide treatments in mitigating low-temperature stress in cotton seedlings. Applying a copper-containing fungicide to cotton seedlings helped to counteract the negative effects of low-temperature stress and to protect the plants from damage by maintaining electrolyte balance. Among the biostimulant applications, all levels of animal-derived biostimulant applications, as well as the 0.660% level of the seaweed-derived biostimulant, led to increased tolerance of cotton plants to chilling stress.

Lessons learned from past experiences push for an alternate way of crop production. In India, adopting high density planting system (HDPS) to boost cotton yield is becoming a growing trend. HDPS has recently been considered a replacement for the current Indian production system. It is also suitable for mechanical harvesting, which reducing labour costs, increasing input use efficiency, timely harvesting timely, maintaining cotton quality, and offering the potential to increase productivity and profitability. This technology has become widespread in globally cotton growing regions. Water management is critical for the success of high density cotton planting. Due to the problem of freshwater availability, more crops should be produced per drop of water. In the high-density planting system, optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs. Deficit irrigation is a tool to save water without compromising yield. At the same time, it consumes less water than the normal evapotranspiration of crops. This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation. Based on the current research and combined with cotton production reality, this review discusses the application and future development of deficit irrigation, which may provide theoretical guidance for the sustainable advancement of cotton planting systems.

Machine picking in cotton is an emerging practice in India, to solve the problems of labour shortages and production costs increasing. Cotton production has been declining in recent years; however, the high density planting system (HDPS) offers a viable method to enhance productivity by increasing plant populations per unit area, optimizing resource utilization, and facilitating machine picking. Cotton is an indeterminate plant that produce excessive vegetative growth in favorable soil fertility and moisture conditions, which posing challenges for efficient machine picking. To address this issue, the application of plant growth retardants (PGRs) is essential for controlling canopy architecture. PGRs reduce internode elongation, promote regulated branching, and increase plant compactness, making cotton plants better suited for machine picking. PGRs application also optimizes photosynthates distribution between vegetative and reproductive growth, resulting in higher yields and improved fibre quality. The integration of HDPS and PGRs applications results in an optimal plant architecture for improving machine picking efficiency. However, the success of this integration is determined by some factors, including cotton variety, environmental conditions, and geographical variations. These approaches not only address yield stagnation and labour shortages but also help to establish more effective and sustainable cotton farming practices, resulting in higher cotton productivity.

Cotton, a crucial commercial fibre crop, depends heavily on seed-associated characteristics like germination rate, vigour, and resistance to post-harvest deterioration for both production and lint quality. Serious cellular damage during post-harvest processes such as delinting, prolonged seedling emergence periods, decreased viability, increased susceptibility to infections, and lipid peroxidation during storage pose serious problems to seed quality. The performance of seeds and total crop productivity are adversely affected by these problems. Traditional methods of seed improvement, like physical scarification and seed priming, have demonstrated promise in raising cotton seed vigour and germination rates. Furthermore, modern approaches including plasma therapies, magnetic water treatments, and nanotechnology-based treatments have shown promise in improving seed quality and reducing environmental stresses. By offering sustainable substitutes for conventional approaches, these cutting-edge procedures lessen the need for fungicides and other agrochemicals that pollute the environment. This review explores various conventional and emerging strategies to address the detrimental factors impacting cotton seed quality. It emphasizes the importance of integrating classical and advanced approaches to enhance germination, ensure robust crop establishment, and achieve higher yields. In addition to promoting sustainable cotton production, this kind of integration helps preserve the ecosystem and create resilient farming methods.

Premature senescence in Bacillus thuringiensis (Bt) cotton has emerged as a significant challenge to the formation and realization of fiber yield and quality since its commercialization in 1997. Initially, premature senescence was thought to be an inherent trait associated with the Bt gene. However, subsequent research and practice have demonstrated that it is not directly linked to the Bt gene but rather results from a physiological imbalance between the sink and source, as well as between the root and shoot in Bt cotton. This short review provides an overview of the causes, mechanisms, and control measures for premature senescence in Bt cotton. It offers valuable insights for future research and the sustainable application of transgenic crops.

Background Zinc (Zn), being the most deficient micronutrient, can largely limit plant growth and development on alkaline calcareous soil. Crop species and varieties within species differently require Zn for optimum productivity. The current study aimed to optimize Zn level and mode of application for better growth, yield, and fiber quality of cotton (Gossypium hirsutum L.). The experimental plan comprised a control group with no Zn application, three Zn levels through soil application, i.e. 5 mg·kg^-1 (SZn5), 10 mg·kg^-1 (SZn10), and 15 mg·kg^-1 (SZn15), two levels of foliar application including 0.5% (FZn0.5) and 1% (FZn1) Zn solution, and various combinations of soil plus foliar application. Two cotton cultivars, CIM-663 (Bt) and Cyto-124 (non-Bt) were used, and each treatment was replicated thrice.
Results Zinc nutrition caused a significant (P ≤ 0.05) improvement in growth, yield, physiological, and fiber quality characteristics of both cotton cultivars. All levels and modes of Zn application were found effective in improving cotton productivity on alkaline calcareous soil. However, integrated soil application and foliar spray showed superiority over sole soil or foliar application. Among different treatments, SZn15 + FZn1 caused the highest improvement in most of the observed growth and yield traits. The said treatment maximally increased the leaf Zn concentration by 270.5% and 218.4% with a subsequent increase in plant height 23.2% and 28.0%, monopodial branches 40.7% and 42.1%, sympodial branches 37.2% and 35.2%, seed cotton yield 32.5% and 36.6%, and lint yield 30.0% and 34.6% in CIM-663 and Cyto-124, respectively, compared with the control. SZn15 + FZn1 also caused the highest increase in relative water contents 32.6% and 22.4%, chlorophyll contents 92.0% and 67.1%, and stomatal conductance 112.8% and 100.8% in CIM-663 and Cyto-124, respectively, compared with the control. Among the fiber quality characteristics, fiber fineness was maximally improved by 19.7% and 15.9% in CIM-663 and Cyto-124, respectively, with SZn15 + FZn1 compared with the control. Leaf Zn concentration was positively correlated with fiber length (R² = 0.717 3), fiber strength (R² = 0.548 3), and fiber fineness (R² = 0.637 9) of both cotton cultivars grown with different levels and application modes of Zn. The benefit-cost ratio was remarkably improved with Zn nutrition, and the highest value of 1.64 was found in CIM-663 at SZn10 + FZn1 and SZn15 + FZn1.
Conclusion The plant growth, physiological, yield, and fiber quality characteristics of cotton cultivars were significantly improved with Zn supply at different levels and modes of application. SZn15 + FZN1 could be recommended to get optimum seed cotton yield and fiber quality of cotton on alkaline calcareous soil.

Background The mulch-free subsurface drip irrigation system demonstrated water-saving potential as an alternative to traditional mulch-based drip irrigation while also eliminating residual film pollution at source. However, delayed sowing is unavoidable in mulch-free cultivation in ecological regions with a short frost-free period. Intercropping with cumin, which has a shorter growth period, served as an effective strategy to improve land use efficiency during the early growth stages of cotton. Therefore, a two-year field experiment was conducted to study the effects of intercropping cumin at the seeding rate of 2.5 (ID1), 3.85 (ID2), and 5.2 (ID3) kg·hm^-2 on cotton growth, interspecies competition, fiber quality, and water use efficiency (WUE), as well as system economic benefits under subsurface drip irrigation. Monocropping cotton was used as the control (CK) treatment.
Results At the initial flowering (IF) stage (the end of the co-growth period of cotton and cumin), cotton plant height in ID2 and ID3 treatments decreased by 5.93%-16.53% and 10.87%-31.11%, respectively, cotton stem diameter by 11.41%-14.25% and 3.37%-26.49%, respectively, and vegetative biomass by 14.46%-30.65% and 22.59%-49.91%, respectively, compared with CK treatment. With the increase in cumin density, the crop growth rate (CGR) and compensation effect in cotton tended to significantly decrease at the IF stage regardless of organs considered. For the non-co-growth period (after harvesting cumin), cotton reproductive organ biomass in ID2 and ID3 treatments increased by 4.09%‒14.61% at the boll opening stage, crop growth rate in reproductive organs by 20.74% and 74.26% from peak boll to boll opening stages compared with CK treatment, due to an enhancement of 19.09% and 49.30% in the compensation effect. Compared with ID1, the aggressivity treated by ID2 and ID3 decreased by 12.82%-46.34% and 17.95%-31.71%, respectively. However, owing to a greater number of green bolls in the upper canopy at the harvest stages in the ID3 treatment, the system production value (closely related to yield) treated by ID2 was 11.69%-16.89%, 6.56%-20.02%, and 16.48%-59.83% greater than that of the ID1, ID3, and CK treatments, respectively. This also led to the highest WUE and net profit under the ID2 treatment.
Conclusion Intercropping cumin with medium density improved the cotton biomass accumulation characteristics and increased resources such as land and water utilization efficiency and economic benefits through a stronger compensation effect after harvesting cumin under subsurface drip irrigation without mulch. This study not only provides alternatives to residual film pollution in arid cotton fields but also establishes a sustainable agro-ecological-economic planting paradigm by reducing plastic use and enhancing water and fertilizer use efficiency, holding significant implications for advancing resource-efficient agricultural systems.

Background Agroecological cropping systems are recognised as an alternative way to ensure the sustainability of cotton (Gossypium hirsutum L.) production in the context of climate change and degradation of soil fertility. A study was conducted in Benin from 2020 to 2023 to compare six different cotton cultivars in three agroecological cropping systems in two cotton-growing zones. Plough-based tillage plus incorporation of cover crop biomass (PTI), conservation agriculture with strip tillage (CA_ST), and conservation agriculture with no tillage (CA_NT) were compared with the reference plough-based tillage (PT). The objective was to identify morpho-physiological traits of cotton that increase yield in agroecological cropping systems. Our approach combined a field experiment and crop simulation model (CSM) of CROPGRO-Cotton to evaluate the effects of genotype (G) × environment (E) × management (M) interactions on seed cotton yield (SCY).
Results Cultivars Tamcot_camde and Okp768 and simulated ideotypes performed best in CA systems. Increased seed mass, large and thick leaves, and later maturity were identified as beneficial for yield enhancement in CA systems. Cultivars and ideotypes that combine these traits also resulted in better nitrogen and water use efficiencies in CA systems. Under different climate scenarios up to 2050, ideotypes designed could increase SCY in Benin.
Conclusion A set of morpho-physiological traits associated with vegetative vigour is required to ensure a good SCY in agroecological cropping systems. These results provide scientific evidence and useful knowledge for breeders and research programmes on cropping systems focused on the adaptation of cotton to climate change.

Background Irrigation has been a strategy used to reduce losses due to drought, which combined with a good supply of nitrogen (N), can improve the protective system of cotton plants. The objective of this study was to investigate the effects of irrigated and rainfed cotton cultivation using different rates and sources of N. Cotton cultivation was carried out in Selvíria-MS field in the 2017/2018 harvest. The experiment was conducted in randomized blocks, which were designed in a 4 × 2 × 2 factorial scheme. The factors were composed of 0, 40, 80, and 150 kg·hm^-2 level of N, using two sources of N under rainfed and irrigated systems.
Results The provision of irrigation provided an increase in the levels of chlorophylls (Chl) a, Chl b, total Chl, carotenoids, pheophytin, leaf chlorophyll index (LCI), N content, nitrate (NO₃^-), sucrose (SUC), the number of vegetative and reproductive branches, boll mass, and seed cotton productivity. There was no effect of N sources on any of the characteristics evaluated. Application of 150 kg·hm^-2 level of N increased in 11%, 59%, 22%, 15%, 15% and 17% in LCI, NO₃^-, N, total amino acids (TA), SUC, and proline concentration in leaves, compared with 0 kg·hm^-2 of N, respectively. Application of 150 kg·hm^-2 level of N improved the leaf catalase activity (CAT) under the irrigation system; however, in a rainfed system, the highest CAT was observed at rates of 0 and 150 kg·hm^-2 level of N. Irrigation increased in 55%, 117%, 68%, 46%, 8%, 36%, 24%, 118%, 48%, 10%, 11% and 72% in Chl a, Chl b, total Chl, CAR, LCI, pheophytins (Pheo), SUC, NO₃^-, the number of vegetative branches, the number of reproductive branches, mass of 20 bolls and seed cotton yield compared with rainfed system, respectively, however, the antioxidant system and the ammonium content of plants was stimulated by rainfed cultivation.
Conclusions Antioxidant responses increased during droughts in cotton farming, which may be connected to oxidative stress-related losses. Better N metabolism, photosynthetic pigments, and manufacturing components were all made possible by irrigated cultivation. The delivery of 150 kg·hm^-2 of N in topdressing in cotton agriculture promoted the N metabolism, sucrose, total amino acids, and the plant’s defense mechanism against oxidative stress.

In response to the need to improve the efficiency of cotton disease and pest detection, this paper proposed an enhanced detection model named YOLOv5sMBT, based on YOLOv5s, for identifying cotton diseases and pests in leaf images. The model incorporates 3 key improvements over the original YOLOv5s framework: a multi-scale feature extraction network (Multi-scale) was constructed to enhance feature extraction capabilities; and a Transformer attention mechanism was integrated between the feature extraction network and the neck network, combined with the C3 module to form C3TR, thereby improving the model’s attention to target features; a BiFPN (Bidirectional feature pyramid network) structure was introduced to efficiently fuse shallow and deep features. A dataset of 2 179 leaf images covering 4 common cotton diseases and pests (Nesidiocoris tenuis, spider mite, wilting, aphid) was used for validation. The dataset was split into training, validation, and test sets in a 3∶1∶1 ratio. Experimental results showed that the YOLOv5sMBT model achieved a mean average precision (mAP) of 0.838, outperforming the original model (mAP of 0.799). This study provides a reference for the intelligent detection of cotton diseases and pests.

Global cotton production faces mounting pressure to reconcile rising fiber demand with urgent sustainability imperatives, including water scarcity mitigation, greenhouse gas reduction, and agrochemical pollution control. Traditional practices, constrained by fragmented objectives and inherent trade-offs among yield, fiber quality, labor efficiency, and ecological impact, struggle to address these systemic challenges. Building upon previous concept of collaborative cultivation, this review for the first time introduces and comprehensively elaborates Multi-objective Integrated Cotton Cultivation (MOICC) —also referred to as Integrated Cotton Cultivation (ICC)—a transformative paradigm centered on three pillars: dynamic trade-off management (e.g., region-specific priority adjustment), systematic technology integration (precision seeding, dense planting, chemical regulation, water-nutrient synergy, targeted defoliation), and resource circularity (spatiotemporal optimization, waste recycling). MOICC leverages key physiological mechanisms—ethylene signaling enhancing stress-resilient seedling establishment; jasmonate-mediated pathways improving water/nutrient efficiency; canopy light competition coupled with hormonal regulation eliminating manual pruning; and growth regulators concentrating boll maturation—to overcome sustainability bottlenecks. Case studies from diverse Chinese agro-ecosystems (e.g., Xinjiang, Yangtze/Yellow River basins) and intercropping systems demonstrate significant synergies: yield gains (8–22%), resource efficiency improvements (water use efficiency increased by ≥20%, nitrogen productivity up to 35 kg kg^-1), and enhanced environmental performance (labor reduction 30–40%, carbon footprint reduction 24–37%, agrochemical savings: nitrogen reduction of 15–20%, pesticides reduction of 25%). Crucially, MOICC resolves core conflicts through integrated optimization: yield versus quality (via≥70% inner-position bolls), labor-saving versus eco-safety (precision defoliant timing), and productivity versus emissions (root-zone nitrogen monitoring). Future research priorities include deciphering multi-scale stress adaptation, developing intelligent decision-support systems (e.g., AHP-NSGA-II integration), advancing carbon-neutral value chains, addressing socio-economic adoption barriers, and fostering policy synergy. MOICC establishes a conceptually globally scalable pathway toward high-yield, superior-quality, resource-efficient, and ecologically sustainable cotton production, providing a viable framework for sector-wide sustainability transition and demonstrating adaptability to other major cropping systems.

In order to investigate regulatory effects of cotton chemical capping agents in the Liaohe River Basin, a comparative experiment was conducted from 2019 to 2020 at the Liaoning Institute of Industrial Crops (Liaoyang, Liaoning). The study used chemical capping agent from China Agricultural University, composed of 25% Mepiquat chloride (1,1-dimethyl-piperidinium chloride, DPC) and auxiliary naphthenate, with two application timings (July 13^th and July 18^th) and three concentration levels (750, 1125 and 1500 mL/hm²). A total of six treatments were set up, using no-topping as control (CK). Hormone contents including indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellin (GA₃), and zeatin (ZR) were continuously measured in the main stem apex (0-5 cm) and sub-apex (5-10 cm). Plant growth parameters, including plant height (PH), number of fruit branches (NFB), average length of upper fruit branches (LFB), and average length of upper internodes (LUI) on the main stem, were also systematically observed and recorded. The variations in IAA and ABA contents were directly proportional to the concentration of the chemical agent, whereas changes in ZR content exhibited an inverse relationship. The fluctuation in GA₃ content was most pronounced at medium concentration. The variations in IAA, ABA and ZR contents of different dosages were more evident when treatment was applied on July 13^th, while no obvious differences were observed in GA₃ content between the two application timings. IAA content showed marked variation at the main stem apex, whereas ZR content varied more noticeably at the sub-apex; in contrast, ABA and GA₃ levels exhibited only slight differences between the two sampling sites. Chemical capping effectively inhibited plant growth. The inhibitory effects on NFB and LFB intensified with treatment concentration increasing. For the July 13^th application, the degree of inhibition on PH was positively correlated with treatment concentration, whereas for the July 18^th application, the suppression of both PH and LUI was more pronounced at medium treatment concentration. Following treatment with a chemical capping agent, the levels of IAA and GA₃ at the apical region of the main stem decreased significantly, whereas ABA content increased markedly, and ZR content remained relatively unchanged. Furthermore, the reductions in IAA and ABA levels were directly proportional to the concentration of the capping agent, with earlier application resulting in more pronounced effects. Notably, IAA content at the apex of the main stem and ZR content in the subapical exhibited significant changes. Plant development was inhibited after capping treatment, and this growth suppression was consistent with the observed hormonal fluctuations. In the future, combined with the yield and fiber quality indicators, the application parameters of chemical capping agent can be optimized, and a simplified cultivation technology system suitable for the cotton area of Liaohe River Basin can be established.

In response to the salt stress caused by NaCl and Na₂SO₄ in saline soil that restricts cotton production, and the problem that single salt stress identification is not comprehensive, in order to screen stable salt-tolerant varieties and comprehensively evaluate the salt tolerance of different materials, this study used 75 land cotton varieties as the experimental materials and simulated salt stress with 150 mmol/L NaCl and Na₂SO₄. The five traits such as germination potential, germination rate, hypocotyl length, root length and fresh weight were measured. Principal component analysis, membership function method and cluster analysis were used to comprehensively evaluate the salt tolerance. The results revealed as follows. (1) Compared with the control group, both salt stresses had different degrees of inhibitory effects on various germination indicators, and the inhibitory effect of Na₂SO₄ was stronger than that of NaCl. (2) Cluster analysis showed that under the Euclidean distance of 5, both salt stresses could divide the tested materials into 5 salt tolerance grades. Under NaCl salt stress, there were 6 high-tolerance varieties (accounting for 8.00%), 13 salt-tolerant varieties (accounting for 17.33%), 22 medium-tolerant varieties (accounting for 29.33%), 25 sensitive varieties (accounting for 33.33%), and 9 highly-sensitive varieties (accounting for 12.00%); under Na₂SO₄ salt stress, there was only 1 high-tolerance variety (accounting for 1.33%), 6 salt-tolerant varieties (accounting for 8.00%), 16 medium-tolerant varieties (accounting for 21.33%), 37 sensitive varieties (accounting for 49.33%), and 15 highly-sensitive varieties (accounting for 20.00%). (3) Under both salt stress conditions, materials with consistent salt tolerance performance were 22 in total, including 1 high-tolerance variety and 1 salt-tolerant variety. The salt tolerance of different land cotton varieties at the germination stage showed significant differences. 'Zhongmiansuo 96B' and 'Xinluzhong 73' were stable salt-tolerant varieties under both salt stress conditions. In the future, combined with the identification of salt tolerance at the seedling stage and molecular marker analysis, the research on the salt tolerance mechanism can be deepened, providing more comprehensive support for cotton salt-tolerance breeding.

Legume-based intercropping enhances asymbiotic biological nitrogen fixation (BNF); however, the underlying mechanisms remain unclear, including the roles of soil keystone diazotroph taxa with varying niche breadths. A field experiment was conducted to evaluate soil BNF variations between rhizosphere and bulk soils in peanut/cotton intercropping systems and monocultures. BNF activities were measured by nitrogen fixation rates, nitrogenase activity, and nifH gene abundance. Phylogenetic null models, co-occurrence networks, and niche breadth analysis were applied to investigate the roles of diazotrophic keystone taxa and their ecological niches. Rhizosphere soils exhibited 7.8–125.5% higher BNF potentials than bulk soils, whereas intercropping systems showed 11.6–323.0% increases over monocultures for nitrogen fixation rate, nitrogenase activity, and nifH gene abundance (all P<0.05). Diazotrophic community composition and diversity differed significantly, with Proteobacteria (excluding Alphaproteobacteria) enriched in intercropping and rhizosphere soils, while Cyanobacteria and Firmicutes were less abundant. Deterministic processes, particularly heterogeneous selection, dominated community assembly in the rhizosphere (91.9%) and intercropping soils (86.3%). The co-occurrence networks consistently revealed more complex and interconnected communities in intercropping and rhizosphere soils that were dominated by opportunistic diazotrophs (78.8–85.9%), followed by specialists (10.2–18.5%) and generalists (1.38–3.80%). Keystone taxa, including opportunists such as Azoarcus, Azohydromonas, and Steroidobacter, and generalists like Pseudomonas and Azotobacter, correlated positively with microbial biomass carbon and nitrate nitrogen, contributing to enhanced BNF. Peanut/cotton intercropping enhances BNF by selectively enriching the keystone diazotrophic taxa with varying ecological roles, particularly opportunists and generalists. Such targeted intercropping strategies can optimize BNF, improve soil fertility, and promote sustainable agricultural production.

Hydraulic theory predicts a positive coupling between leaf hydraulic conductance (K_leaf) and stomatal conductance (g_s); however, this theory has not been fully supported by observations, and the underlying mechanisms remain unclear.  Currently, subdividing K_leaf into leaf hydraulic conductance inside xylem (K_x) and outside xylem (K_ox) offers a new perspective for elucidating the regulatory mechanism of K_leaf on g_s.  Optimal planting density can enhance water use efficiency (WUE) by optimizing g_s; however, the changes in leaf hydraulic properties during this process and its regulation of g_s and WUE remain unclear.  We examined the relationships between K_x and K_ox with g_s, photosynthetic rate (A_N), and WUE, and investigated the structural basis determining K_ox in cotton under eight planting densities of 12, 18, 24, 36, 48, 60, 72, and 84 plant m^-⊃2;.  The results showed that as the increase of planting density, K_leaf and A_N remained consistent while K_ox and g_s decreased significantly.  K_ox was significantly influenced by leaf thickness and the volume fraction of inter-cellular air space.  K_leaf and K_x showed no correlation with A_N or g_s, but K_ox exhibited a significant positive correlation with g_s.  Furthermore, K_ox is significantly negatively correlated with WUE.  These findings suggest that K_ox modulates g_s to reduce water loss while maintaining A_N, thereby enhancing WUE in cotton under various planting densities.

【Objective】In light of the shortage of water resources and the lower fertility and poor quality of soils in Xinjiang, this study explored the effects of varying irrigation volumes and ratios of organic to inorganic fertilizer application under aerated drip irrigation on the soil quality, cotton growth, yield, and water use efficiency of cotton fields. The objective was to provide a theoretical basis for determining an irrigation and fertilization model for cotton in Xinjiang that was water-saving, highly efficient, and sustainable. 【Method】Field experiments were conducted in the 146th Regiment area of the Xinjiang Production and Construction Corps in 2023 and 2024. Under aerated drip irrigation, two irrigation volumes (W1: 80%ET_C and W2: 100%ET_C, where ET_C represents the crop evapotranspiration) and five ratios of organic to inorganic fertilizer application (OF1: 100% chemical fertilizer, OF2: 75% chemical fertilizer + 25% organic fertilizer, OF3: 50% chemical fertilizer + 50% organic fertilizer, OF4: 25% chemical fertilizer + 75% organic fertilizer, OF5: 100% organic fertilizer) were set up to study their impacts on the physical and chemical properties of soil quality, cotton growth including leaf area index (LAI), dry matter accumulation, yield, and water use efficiency (WUE). 【Result】The Soil Quality Index (SQI) increased with the rising proportion of organic fertilizer, showing an average increase of 9.9%-28.8% in the combined application of organic and inorganic fertilizers over the two years compared with the application of chemical fertilizer alone. Under deficit irrigation, soil moisture content, LAI, dry matter accumulation, and yield significantly decreased, while Water Use Efficiency (WUE) significantly increased. Under the two irrigation levels (W1 and W2), soil moisture content, cotton LAI, and dry matter accumulation first increased and then decreased as the proportion of organic fertilizer increased. Under W1, these indicators reached their maxima with the W1OF3 treatment, whereas under W2, their maxima were observed with the W2OF2 treatment. Compared with chemical fertilizer alone (OF1), the combined application of organic and inorganic fertilizers increased soil moisture content, LAI, and dry matter accumulation by 0.4%-5.2%, 4.1%-19.8%, and 3.7%-18.8% over two years, respectively. Over two years, the maximum seed cotton yield was observed under W2OF2 treatment, with an average yield of 6 739.99 kg·hm^-2, but the highest WUE was achieved under the W1OF3 treatment, with an average value of 1.42 kg·m^-3. The SQI, seed cotton yield, and WUE under different treatments were evaluated using the membership function method, TOPSIS method, and grey relational analysis, respectively. A comprehensive evaluation was carried out using an integrated differential combination evaluation model, determining the optimum treatment as W1OF3. 【Conclusion】Considering the priority of water-saving, while ensuring yield, and aiming to improve Water Use Efficiency (WUE) and soil quality, it was recommended that under aerated drip irrigation, applying 80% ET_C for irrigation water volume and a combined application of 50% organic fertilizer and 50% chemical fertilizer, for serving as the optimal management measure for water-saving and efficient production in cotton fields in Xinjiang.

This study investigated the effects of irrigation quotas under mulch drip irrigation on cotton growth, water consumption characteristics and yield, aiming to provide a theoretical basis for water saving, yield increase, and efficiency improvement in cotton production in northern Xinjiang. A field experiment was conducted from 2022 to 2024, with four irrigation quotas: 30.0 mm (I20), 37.5 mm (I25), 45.0 mm (I30), and 52.5 mm (I35). The effects of different irrigation quotas on cotton growth, water consumption patterns, and yield were analyzed. The results showed that plant height increased with higher irrigation quotas, reaching the maximum under I30 and I35 treatments. Leaf area index (LAI) and relative chlorophyll content (SPAD) showed a trend of first increasing and then decreasing, reaching the peak during I30 treatment. The water consumption at each growth stage increased with higher irrigation quotas, and the crop coefficient gradually rose. The seed cotton yield and lint yield showed a trend of first increasing and then decreasing with the increase of irrigation quota, among them, the yield under I30 treatment was the highest, with average values of 5535.35 kg/hm² and 2348.42 kg/hm² respectively. A fitting analysis between water consumption and yield indicated that the optimal water consumption range was 491.93-571.61 mm. A comprehensive evaluation showed that the I30 treatment achieved the highest scores across all three growing seasons. In conclusion, the I30 treatment can achieve optimal cotton yield under drip irrigation in northern Xinjiang. This study provides a theoretical basis for water-saving and high-yield cotton cultivation in the region.

Background Mepiquat chloride (MC) is a widely used plant growth regulator in cotton (Gossypium hirsutum L.). It regulates endogenous hormone content and crosstalk to control plant height and promote lateral root (LR) development. However, the roles of cytokinins (CTKs) in the MC-induced increase in LR number in cotton seedlings remain unclear. Therefore, in this study, whole-genome transcriptome analysis was performed to elucidate the molecular mechanisms, CTK transformation, and CTK signaling pathway response to MC in cotton roots.
Results In the present study, MC reduced the contents of the active CTK trans-zeatin (tZ) and N⁶-isopentenyladenine (iP) but increased the levels of the nucleoside CTK trans-zeatin riboside (tZR) and N⁶-isopentenyladenine riboside (iPR). RNA-seq data showed that the CTK biosynthesis genes GhIPTs and active CTK catabolism genes GhCKXs were obviously upregulated after MC treatment. The CTK-activating enzyme gene GhLOGs was repressed compared with the control. Furthermore, MC inhibited the expression of GhAHK4 and GhARR2/12, which are involved in the CTK signaling pathway, and activated the IAA-IAA14-ARF7/19 signaling module. Meanwhile, MC increased the expression levels of genes involved in sucrose synthesis, the cell cycle, cell division, and cell wall biosynthesis pathways. Silencing the GhCKX family separately decreased the LR number and active indole-3-acetic acid (IAA) level. The expression levels of GhPIN1, GhARF7, GhARF19, GhLBD16, GhLBD18, GhLBD29, and GhLBD33 were downregulated, but GhARR2/12 and GhIAA14 were upregulated. The total content of active CTKs was noticeably increased. The results of silencing the GhLOGs family were opposite to those of silencing GhCKXs. Silencing GhARR12 could upregulate GhPIN1 expression and increase LR number. In addition, the silenced GhCKXs, GhLOGs, and GhARR12 were less responsive to MC-induced LR growth than the control.
Conclusion These results suggested that MC treatment could upregulate CTK-nucleoside biosynthesis and CTK metabolism genes to decrease active CTK levels, promoting crosstalk between CTKs and auxin signaling pathways to enhance LR initiation.

Background Achieving a synergistic enhancement in both the yield and insect resistance of Bt cotton holds substantial importance for boosting farmers' income and ecological advantages. This study investigated the impact of amino acid foliar fertilizer (AAF) on the yield and Cry1Ac protein (CP) content, providing valuable insights for enhancing its productivity and insect-resistance capabilities. In 2021, Sikang 1 and Sikang 3 were treated with AAF once (A1) and water (CK) during the peak flowering stage. In 2022, AAF was sprayed one (A1), two (A2), and three (A3) times, respectively, with CK serving as the control.
Results Compared with the control, the A3 treatment increased seed cotton yield (SCY) by 16.0% and CP by 40.98% at 30 days after flowering. AAF application enhanced soluble protein content (SP) and glutamate pyruvate transaminase (GPT) activity, while suppressing protease and peptidase activities. Concurrently, AAF improved sucrose metabolism through elevated sucrose content and increased activities of sucrose synthase (SS) and sucrose conversion enzyme (SCE), which were also positively correlated with yield. A lower ratio of carbon-to-nitrogen (C/N) was linked to higher yields and CP content. Path analysis confirmed that SP, GPT, SS, and SCE demonstrated positive effects on CP content and SCY, respectively. Peptidase activity had negative effects on CP and SCY. The C/N ratio had negative effects on SCY and CP, respectively.
Conclusions Triple foliar application of AAF maintained lower C/N ratios with enhanced carbon metabolism and protein synthesis capacity, thereby simultaneously increasing both Cry1Ac protein content and yield in Bt cotton. These findings provide critical insights for improving both pest resistance and agronomic performance in Bt cotton cultivation.

Background Cotton lodging has become increasingly prevalent due to extreme environmental conditions and agronomic practices, severely compromising yield, fiber quality, and mechanical harvesting efficiency. However, research on cotton lodging remains limited, with most studies focusing on individual or isolated indices rather than a comprehensive system. This study systematically compared four lodging-resistant varieties (LR-1, LR-2, LR-3, LR-4) and four lodging varieties (L-1, L-2, L-3, L-4) across multiple indices: morphological traits, boll distribution, internode filling degree, stem density, mechanical strength, anatomical structure, and chemical composition.
Results The results showed that at the boll-opening stage, lodging-resistant varieties exhibited higher density in the first (increased by 11.6%) and third (increased by 23.5%) basal internodes compared with lodging varieties and significantly greater filling degree in the first (increased by 22.6%), second (increased by 23.1%), and third (increased by 26.1%) basal internodes; significantly higher stem puncture strength (increased by 41.2%) and stem bending resistance (increased by 38.2%); and a significantly lower stem lodging coefficient (19.0% lower in lodging-resistant varieties). Additionally, lodging-resistant varieties showed significantly enhanced anatomical structures, including greater cortex thickness, more mechanical tissue layers, and larger pith cavity, xylem, and phloem areas. Conversely, no significant differences were observed in morphological traits, boll distribution, or chemical composition between the lodging-resistant and lodging types.
Conclusion Lodging-resistant varieties exhibited thicker cortical tissue and mechanical tissue layers, along with larger xylem area and phloem area in basal internodes. These structural characteristics provide superior support for the filling degree and density of basal internodes, thereby enhancing stem puncture strength and bending resistance, and ultimately improving lodging resistance in cotton. These findings provide a theoretical basis for reducing the occurrence of cotton lodging.

Crop chemical regulation using plant growth regulators (PGRs) represents a key strategy for achieving high-efficiency cotton production in China. This review synthesizes four decades of research on mepiquat chloride (MC), an inhibitory PGR pivotal to optimizing cotton growth architecture, stress resilience, and yield-quality parameters. We detail MC's stage-specific roles—from root development and flowering acceleration to canopy optimization and assimilate partitioning—and its mechanistic interactions with hormones (e.g., gibberellin suppression, cytokinin enhancement) under biotic/abiotic stresses. Furthermore, we conceptualize MC deployment into three evolutionary tiers: (1) symptom-guided remedial application, (2) systemic growth-stage programming, and (3) integrated management with agronomic practices. These paradigms, supported by field validation across China's cotton belts, offer a roadmap for precision regulation. Future advancements in nano-formulations, digital agriculture, and PGR synergism are discussed to unlock next-generation yield frontiers.

Background Aquaporins (AQPs) are integral membrane proteins belonging to the major intrinsic protein (MIP) family, playing a crucial role in water transport, cell elongation, and stress responses. However, their evolutionary dynamics and functional roles in Gossypium species remain poorly characterized.
Results In the present study, a total of 55, 54, 54, 103, 106, 108, and 104 AQP genes were found in G. herbaceum, G. arboreum, G. raimondii, G. barbadense, G. tomentosum, G. mustelinum, and G. darwinii, respectively. Phylogenetic analysis classified them into five conserved subfamilies (PIP, TIP, NIP, SIP, and XIP), with 95 genes showing synteny across species and 17 displaying divergence, suggesting subgenome differentiation. Transcriptome analysis revealed that specific GbAQP genes are involved in early salt stress responses and fiber development. Physiological assays demonstrated stronger salt tolerance in tetraploid cottons, particularly G. darwinii, compared with diploids. Co-expression network analysis linked AQPs to abiotic stress and fiber traits, and virus-induced gene silencing (VIGS) confirmed four AQP genes as critical for salt tolerance.
Conclusion This study provides comprehensive insights into the evolution, expression, and functional roles of AQPs in cotton, identifying key candidate genes for improving salt tolerance and fiber quality in Gossypium species.

Background Thidiazuron (TDZ) is a widely used chemical defoliant in commercial cotton production and is often combined with the herbicide Diuron to form the commercial defoliant mixture known as TDZ·Diuron (T·D, 540 g·L^-1 suspension). However, due to increasing concerns about the environmental and biological risks posed by Diuron, there is an urgent need to develop safer and more effective alternatives. Jasmonic acid (JA) and its derivatives are key phytohormones in organ senescence and abscission.
Results Greenhouse experiments at the seedling stage revealed that Me-JA (0.8 mmol·L^-1) alone did not induce defoliation. However, its co-application with TDZ (0.45 mmol·L^-1) at concentrations of 0.6, 0.8, and 1.0 mmol·L^-1 significantly enhanced defoliation efficacy. The most effective combination—TDZ with 0.8 mmol·L^-1 Me-JA—achieved a 100% defoliation rate at 5 days after treatment (DAT), 23.7 percentage points higher than TDZ alone, and comparable to the commercial TDZ·Diuron formulation with equivalent TDZ content. Field trials conducted in Beijing (Shangzhuang), Hebei (Hejian), and Xinjiang (Shihezi) confirmed that the combination of 0.6 mmol·L^-1 Me-JA with 1.70 mmol·L^-1 TDZ provided optimal defoliation performance. At 21 DAT, the defoliation rate increased by 13.5-16.3 percentage points compared with TDZ alone. Furthermore, boll opening rates improved by 5.7-12.7 percentage points relative to TDZ-only treatments. Phytohormonal analyses from the Shangzhuang site showed that the combined treatment significantly altered hormone levels in both leaves and petioles. Compared with TDZ alone, the mixture reduced concentrations of auxin (IAA), cytokinins (Z + ZR, iP + iPA, DHZ + DHZR), and gibberellic acid (GA₃), while increasing levels of JA, abscisic acid (ABA), and brassinosteroids (BR). These hormonal shifts may underlie the enhanced defoliation observed with the combined treatment. Importantly, the TDZ-Me-JA combination did not adversely affect cotton yield, yield components, or fiber quality.
Conclusion The combination of Me-JA and TDZ has a good defoliation effect without affecting crop yield or fiber quality. And it provides a promising foundation for the development of novel, environmentally friendly cotton defoliants.

One of the solutions to the global warming risk and other climate issues is to concentrate on research and development of utilizing biomass as a fossil fuel alternative. The current estimate of cotton residue waste in the world is about 50 million tons. This massive volume of biomass waste should be turned into clean energy to avert burning the stalks in open fields after cotton harvesting. Therefore, harmful emissions such as CO₂ will be reduced. This study aims to investigate the published literature to comprehend the bioenergy production from the thermal treatment of cotton stalks, including combustion, pyrolysis, carbonization, torrefaction, liquefaction, and gasification. Furthermore, the future outlook, utilization, and prospective challenges of agricultural biomass for biofuel production are discussed. According to the literature, biochar and bio-oil derived from cotton stalks have high heating values of about 27.5 and 37.2 MJ·kg^-1, respectively. These values are double those of cotton stalk raw materials, which make it a good candidate for bioenergy production. This article offers valuable insight into cotton stalk utilization via thermochemical treatment and provides a solid reference for researchers, policymakers, and other stakeholders in this field.

Elevated CO₂ (eCO₂) may mitigate stress-induced damage to cotton (Gossypium spp.) growth and development.  However, understanding the early-stage responses of cotton to multiple abiotic stressors at eCO₂ levels has been limited.  This study quantified the impacts of chilling (CS, 22/14°C, day/night temperature), heat (HS, 38/30°C), drought (DS, 50% irrigation of the control), and salt (SS, 8 dS m^–1) stresses on pigments, physiology, growth, and development of 14 upland cotton cultivars under ambient CO₂ (aCO₂, 420 ppm; current) and eCO₂ (700 ppm; future) levels during the vegetative stage.  The eCO₂ partially negated the effects of all stresses by improving one or more of the pigments, physiological, growth, and development traits, except CS.  For instance, HS at aCO₂ significantly increased stomatal conductance by 36% compared with non-stressed plants at aCO₂.  However, HS at eCO₂ significantly decreased stomatal conductance by 18% compared with HS at aCO₂.  The first squaring was delayed by one day under SS at aCO₂ but two days earlier under SS at eCO₂ than non-stressed plants at aCO₂.  Root and shoot dry mass and the total leaf area were significantly higher under all stresses, except for CS, at the eCO₂ compared with similar stresses at the aCO₂.  Most growth and development traits, including plant height, leaf area, and shoot dry mass, displayed a mirroring response pattern between aCO₂ and eCO₂ under all environments except CS.  Cultivars exhibited significant interaction with stressed environments.  Further, results revealed differential sensitivity and adaptation potential of cultivars to stress environments at varying CO₂ levels.  This study highlights the need to consider eCO₂ in designing breeding programs to develop stress-tolerant varieties for future cotton-growing environments.

【Objective】DUS (Distinctness, Uniformity, and Stability) testing provides important technical data for cotton variety approval and intellectual property protection, while the selection of similar varieties is a critical step in the process. Based on the revision of “NY/T 2469-2013, Protocol for the identification of cotton variety-SSR marker method”, this study aims further to construct a DNA fingerprint database for known upland cotton varieties for DUS testing in China and determine a genetic similarity threshold for rigorous and precise similar variety selection. 【Method】 Firstly, preliminary screening and subsequent re-screening were conducted on both the SSR primers from NY/T 2469-2013, and newly collected ones to identify a set of primers with stable PCR amplification, high polymorphism and clear peak patterns, replacing the original SSR primer set in the standard. Secondly, the selected SSR primers were employed to genotype the known cotton varieties to construct a DNA fingerprint database for those varieties. Finally, relationships between phenotypic and genetic differences of cotton varieties were investigated and a genetic similarity threshold for similar variety selection was determined. 【Result】 42 pairs of SSR primers covering all 26 chromosomes of upland cotton were selected, including 12 markers from the original standard. Among the selected 42 pairs of primers, 25 pairs amplified two loci, of which 23 revealed only one polymorphic locus, while the remaining two primer pairs (NAU1167 and HAU1413) had both loci showing polymorphism. A total of 164 alleles were detected from the 44 polymorphic loci, with the number of alleles at each locus ranging from 2 to 7. The polymorphism information content (PIC) of the loci varied from 0.15 to 0.66. 2 100 cotton varieties were genotyped using these primers. A DNA fingerprint database of known cotton varieties was constructed with a data integrity of 98.85%. Pairwise comparisons using the DNA data of 648 protected varieties, 843 approved varieties and 2 100 known upland cotton varieties revealed the distribution patterns of genetic differences between varieties among the three categories. More than 90.00% of comparisons in each category were concentrated in the range of 40.00%-70.00%. The proportion of variety pairs with genetic similarity exceeding 80.00% was 0.28%, 0.31% and 0.31% for the protected, approved and known varieties, respectively. Relationship analysis was conducted between phenotypic and genetic differences for 177 upland cotton varieties and their corresponding similar varieties. It was found that for the 54 cotton applications to which similar varieties with genetic similarity exceeding 90.00% existed, 18 (33.33%) failed to meet the distinctness requirement. In contrast, all 123 cotton applications with genetic similarity to their similar varieties below 90.00% could be clearly distinguished, exhibiting clear trait differences, thus fulfilling the distinctness criteria. The genetic similarity threshold for similar variety selection in upland cotton DUS testing based on these SSR markers could be set at 90.00%. For the variety pairs showing genetic similarity above this threshold, further field-based phenotypic evaluations are required. 【Conclusion】 In summary, NY/T 2469-2013, the standard for identifying upland cotton varieties using SSR markers, was revised. A DNA fingerprint database was constructed to support DUS testing of upland cotton in China. Furthermore, a genetic similarity threshold of 90.00% based on these SSR markers was established for selecting similar varieties, enhancing the precision and reliability of this process within DUS testing.

Cotton (Gossypium spp.), a globally important cash crop, is increasingly threatened by abiotic stresses that significantly affect yield and fiber quality. In this study, data on 3,016 abiotic stress-related quantitative trait loci (QTLs) described in 31 published papers were integrated through meta-QTL analysis, a total of 34 MQTLs were identified. Nine major MQTLs with numerous initial QTLs, high R² values, narrow confidence intervals (CIs), and close colocalizations were successfully detected. Combined with the transcriptome data, the candidate gene GhPCMP-E17 was identified. Through virus-induced gene silencing (VIGS) technology, the role of GhPCMP-E17 in the response to abiotic stress was clarified. Compared with the TRV:00 plants, the GhPCMP-E17-silenced plants presented more severe wilting and yellowing under drought and salt stress conditions. Silencing GhPCMP-E17 weakens the function of antioxidant enzymes, thereby increasing the accumulation of reactive oxygen species. These results indicate that downregulation of GhPCMP-E17 gene expression enhances the sensitivity of cotton plants to drought and salt stress. This research provides excellent genetic resources for adaptive abiotic crop breeding in upland cotton.

Quantitative analysis of the regulation mechanism of drip frequency of emergence water on cotton seedling growth under different water content conditions in the ‘dry sowing and wet emergence’ model of sandy soil in southern Xinjiang was conducted, screening the optimal frequency suitable for sandy soil, and providing theoretical support for the optimization of cotton water-saving irrigation system in arid areas. ‘J8031’ was used as the test variety, and three soil relative water contents (W1: 10%-15%; W2: 15%-20%; W3: 20%-25%) and three drip frequency of emergence water (F1: 1 time; F2: 2 times; F3: 3 times) were set to explore its effects on soil physical properties, physiological and ecological indexes and root development of cotton seedlings. The results showed that soil water content, drip frequency and their interaction had significant effects on soil physical and chemical properties, plant growth and root development of cotton seedlings. With the increase of drip frequency, the soil compaction decreased significantly, while the soil EC value of each soil layer showed the opposite trend. In terms of seedling growth, the comprehensive performance of F1 treatment was the best under each water content condition, the seedling emergence rate was 85%-95%, the plant height was 24.94 cm in W2F1 combination, the stem diameter was 3.16 mm in W1F1 combination, and the dry matter accumulation was significantly higher than that of F2 and F3 treatments. In terms of root development, root weight, root mass density, root length density and other indicators were also the highest in F1 treatment. At the same time, the number of root tips in deep soil was more. The comprehensive fuzzy evaluation showed that the fuzzy comprehensive index of F1 treatment was the largest among the 10 indexes, which was the optimal drip management strategy to promote the emergence, strong seedling and root healthy development of cotton under different soil water contents. Under the condition of sandy soil in southern Xinjiang, the application of one-time seedling water in ‘dry sowing and wet emergence’ cotton field can effectively promote the emergence of cotton seedlings and is conducive to the growth and development of seedling stage.

To screen cotton varieties (lines) suitable for film-free cultivation under the dry sowing and wet-out soil sealing mode in the Alar reclamation area, Xinluzhong No.82 was taken as the control variety (CK), and the agronomic traits such as soil breaking rate, emergence rate, seedling preservation rate, emergence days, growth period, seed cotton, lint cotton yield, and the quality characteristics such as the average length of the upper part of the fiber of 14 investigated varieties (lines) including Tahe No.2 under this model were determined. The results showed that the soil breaking rate of the test materials on the 7th day after dripping the germination water was 31.82%-56.15%, the germination rate on the 14th day was 82.41%-97.05%, the seedling preservation rate was 68.38%-90.30%, and the germination days were 11.0-15.5 days. The growth period of the test materials was 129.0-148.5 days, the plant height was 69.78-88.04 cm, the position of the first fruit branch node was 6.36-9.14 nodes, the height of the first fruit branch node was 14.79-36.05 cm, the number of fruit branches was 6.71-8.96, and the number of fruit bolls per plant was 4.76-6.47. The weight of the bell was 4.96-6.26 g, and the lint percentage was 40.68%-44.47%. The seed cotton yield of the test materials ranged from 262.33 to 363.33 kg/667 m², and the lint cotton yield ranged from 112.13 to 155.88 kg/667 m². The average length of the upper half of the test materials ranged from 28.51 to 31.35 mm, the specific strength at break was between 26.51 and 34.95 cN/tex, the Macron value was between 3.70 and 4.65, the uniformity was 82.95%-86.04%, and the maturity was between 0.83 and 0.86. Overall, Tahe No.2, Z1112, 17-1609, and 17-1612 have the best overall performance. Tahe No.2 can be used for film-free cultivation in the Alar reclamation area, and Z1112, 17-1609, and 17-1612 can be used as film-free cotton breeding materials for further research.

Potassium (K) is a highly mobile nutrient element that continuously adjusts its demand strategy among and within cotton leaves through redistribution.  This indirectly leads to variations in the leaf potassium content (LKC, %) at different leaf positions.  However, owing to the interaction between light and leaf age, leaf sensitivity at different positions to this change varies, including the reflection and absorption of the spectrum.  How to selecting the optimal monitoring leaf position is an important factor in quickly and accurately evaluation of cotton LKC using spectral remote sensing technology.  Therefore, this study proposes a comprehensive multileaf position estimation model based on the vertical distribution characteristics of LKC from top to bottom.  This is aimed at achieving an accurate estimation of cotton LKC and optimizing the strategy for selecting the monitored leaf position. Between 2020 and 2021, we collected hyperspectral imaging data of the main stem leaves at different positions from top to bottom (Li, i=1, 2, 3, ... , n), during the cotton budding, flowering, and boll setting stages.  Vertical distribution characteristics, sensitivity differences, and spectral correlations of LKC at different leaf positions were investigated.  Additionally, the optimal range of the dominant leaf position for monitoring was determined.  Partial least squares regression (PLSR), random forest regression (RFR), support vector machine regression (SVR), and the entropy weight method (EWM) were used to establish LKC estimation models for single leaf and multileaf positions.  The results showed a vertical heterogeneous distribution of cotton LKC, with LKC initially increasing and then gradually decreasing from top to bottom, and the average LKC of cotton reaches its maximum value at flowering stage.  The upper leaf position demonstrated greater sensitivity to K and exhibited a stronger correlation with the spectrum.  The selected dominant leaf positions for the three growth stages were L1–L5, L1–L4, and L1–L2, respectively.  Based on the dominant leaf position monitoring range, the optimal single leaf position models for estimating LKC during the three growth stages were PLSR-L4, PLSR-L1, and SVR-L2, with The coefficient of determination of the validation set (R²val) of 0.786, 0.580, and 0.768, and the root-mean-square error of the validation set (RMSEval) of 0.168, 0.197, and 0.191, respectively.  The multileaf position LKC estimation model was constructed by EWM with R²val of 0.887, 0.728, and 0.703, and RMSEval of 0.134, 0.172, and 0.209, respectively.  In contrast, the newly developed multileaf position comprehensive estimation model yielded superior results, improving the stability of the model on the basis of high accuracy, especially during the budding and flowering stages.  These findings hold significant importance for investigating cotton LKC spectral models and selecting suitable leaf positions for field monitoring.

The purpose of this study was to clarify the characteristics of nutrient content in the topsoil of high-yield cotton fields in the 7^th Division of Xinjiang Production and Construction Corps, and to provide scientific fertilization basis for cotton production. Topsoil samples from high-yield cotton fields in seven major cotton planting regiment towns of the 7^th Division reclamation area were analyzed. Using the method of combining field sampling and laboratory test, with reference to The Soil Nutrient Classification Standard of Xinjiang Cotton Fields and The Soil Salinization Degree Classification Standard of Xinjiang, statistical methods were employed to evaluate soil nutrient content and salinity. The results showed that soil pH in the plough layer ranged from 7.58 to 8.10 (neutral to slightly alkaline); total soluble salt averaged 1.81 g/kg (non-saline to mildly saline); soil organic matter averaged 12.39 g/kg (deficient); total nitrogen averaged 0.105% (high); available phosphorus and potassium averaged 28.33 mg/kg (medium) and 409.91 mg/kg (high), respectively. For micronutrients, available boron averaged 2.56 mg/kg (high); zinc averaged 0.55 mg/kg (medium-low); iron averaged 10.93 mg/kg (medium-high); manganese averaged 5.96 mg/kg (low), and copper averaged 1.04 mg/kg (medium-high). Fertilization strategies are recommended that nitrogen and phosphorus fertilizers should be rationally applied in production, the amount of potassium fertilizer should be properly controlled, and the sufficient application of organic fertilizer should be ensured. In addition, attention should be paid to the supplement of trace elements such as zinc and manganese, and boron, iron and copper fertilizers should be applied according to the growth of cotton.

Background The geo-traceability of cotton is crucial for ensuring the quality and integrity of cotton brands. However, effective methods for achieving this traceability are currently lacking. This study investigates the potential of explainable machine learning for the geo-traceability of raw cotton.
Results The findings indicate that principal component analysis (PCA) exhibits limited effectiveness in tracing cotton origins. In contrast, partial least squares discriminant analysis (PLS-DA) demonstrates superior classification performance, identifying seven discriminating variables: Na, Mn, Ba, Rb, Al, As, and Pb. The use of decision tree (DT), support vector machine (SVM), and random forest (RF) models for origin discrimination yielded accuracies of 90%, 87%, and 97%, respectively. Notably, the light gradient boosting machine (LightGBM) model achieved perfect performance metrics, with accuracy, precision, and recall rate all reaching 100% on the test set. The output of the LightGBM model was further evaluated using the SHapley Additive exPlanation (SHAP) technique, which highlighted differences in the elemental composition of raw cotton from various countries. Specifically, the elements Pb, Ni, Na, Al, As, Ba, and Rb significantly influenced the model's predictions.
Conclusion These findings suggest that explainable machine learning techniques can provide insights into the complex relationships between geographic information and raw cotton. Consequently, these methodologies enhances the precision and reliability of geographic traceability for raw cotton.

Background Cotton is an industrial crop renowned for its multifaceted applications in the textiles, pharmaceuticals, and biofuel industries. Plant regeneration through somatic embryogenesis (SE) plays a crucial role in the genetic improvement of cotton. There is a strong correlation between SE and zygotic embryogenesis (ZE) in plants. Furthermore, the strategy of ectopic expression of cotton genes into the model plant Arabidopsis has been a widely accepted approach for functional study.
Result Based on previous spatial transcriptomics of cotton somatic embryos, two genes, GhHAT5 and GhCRK29, were identified. They are highly expressed in cotyledon and epidermal cells of cotton cotyledonary embryos, respectively. In this study, GhHAT5 and GhCRK29 were ectopically expressed in Arabidopsis to investigate their functions. The result showed that in Arabidopsis zygotic embryos, the overexpression of GhHAT5 promoted the development of apical embryonic upper-tier cells and embryonic cotyledon, while the overexpression of GhCRK29 promoted the development of apical embryonic lower-tier cells and embryonic radicle. Given the similarities between somatic and zygotic embryogenesis, these findings suggest that GhHAT5 and GhCRK29 are involved in cotton SE. We also speculate that these genes may promote the expression of the Arabidopsis endogenous gene AtSCR, which is crucial for embryonic development.
Conclusion These results revealed that GhHAT5 and GhCRK29 regulate embryonic development and are essential in advancing our understanding of cotton SE and facilitating targeted genetic manipulation strategies to improve industrial crop traits and agricultural sustainability.

The study aimed to explore the yield traits and identify key factors for increased production in the cotton cultivar ‘Liaomian 21’. Based on the data of 2018 to 2021 regional tests, the high yield, stable yield and related agronomic characters of the variety were analyzed using principal component analysis and path analysis. The results showed that ‘Liaomian 21’ showed good high yield, stability and adaptability. Lint yield was significantly positively correlated with the number of bolls per plant, pre-frost flowering rate, single boll weight and lint percentage; 5 principal components were extracted from the principal component analysis, and their cumulative contribution rate was 87.94%; path analysis showed that the factors affected lint yield of ‘Liaomian 21’ were the number of bolls per plant (0.583), lint percentage (0.459), and single boll weight (0.369) in terms of contribution rate. Studies have shown that ‘Liaomian 21’ is a cotton variety with stable yield, strong adaptability and excellent quality. It has good salt resistance and is suitable for large-scale promotion and application in the Yellow River Basin, especially in saline-alkali land.

To address issues related to reduced growth rate, shifting center of gravity, and nutritional loss after cotton topping, this study examines the effects of ‘Xinluzao No.62’ on morphological and yield indicators under chemical and traditional manual topping methods. The goal is to elucidate cotton’s growth response to different topping techniques. Thirty cotton plants were subjected to chemical and manual topping treatments, with measurements being taken at specific intervals (0, 7, 15, and 30 days after topping) for plant height, number of fruit branches, and number of bolls per plant. Additionally, prior to leaf defoliation agent application, the number of seeded and unseeded bolls was recorded to determine the boll setting rate. Each treatment aimed to assess cotton harvest density, average single-plant bell weight, single-bell weight, and lint percentage, with subsequent calculation of seed cotton and lint yield. Results indicated that chemical topping of cotton led to a significant increase in plant height and fruit branches within 30 days compared to artificial topping. The number of large and small bells decreased initially (0-15 days) after topping but increased after 30 days. Parameters such as flocculation rate, single bell weight, lint percentage, and yield decreased, while the number of single bells increased. Ultimately, manual topping resulted in slightly higher yields than chemical topping, with no discernible difference between treatments. It is advisable to employ artificial topping in cotton fields with robust cotton, substantial plant biomass, and late topping to expedite the transition from vegetative to reproductive growth, fostering trellis development. Conversely, for fields with weak cotton growth, chemical topping is recommended to balance nutrition and reproductive growth, achieve topping effects, prevent mechanical damage from artificial topping, and maximize cotton’s production potential.

In order to identify safe and efficient foliar herbicides suitable for cotton fields in Hubei Province, the effect and safety of 9 herbicides on weed control and cotton yield were compared and analyzed in this study by directional spray of stems and leaves after seedling. The results showed that 21 days after treatments, the control effect of 30% topramezone SC 27 ga.i./hm², 5% imazethapyr AS 100 ga.i./hm², 21% glufosinate-P-ammonium SL 820 ga.i./hm², 51% flumioxazin WG 60 ga.i./hm² and 50% prometryn WP 1050 ga.i./hm² on total grass fresh weight in cotton field were 99.40%, 86.07%, 91.17%, 98.81% and 99.34%, respectively. It was significantly higher than 25% sulfonsulfuron WG 26 ga.i./hm², 15% nitrone SC 190 ga.i./hm² and 10% pyrisulfuron WP 30 ga.i./hm². Yield analysis indicated that all herbicide treatments significantly increased the yield of ‘Gangmian 13’ cotton, with 21% glufosinate-P-ammonium SL 820 ga.i./hm² and 51% flumioxazin WG 60 ga.i./hm², showing the greatest yield increase. Safety evaluation revealed that only 15% mesotrione SC 190 ga.i./hm² posed potential risks to cotton, manifested as a significant reduction in root diameter. Field demonstration (compared to manual weeding) confirmed that both 21% glufosinate-P-ammonium SL 820 ga.i./hm² and flumioxazin WG 60 ga.i./hm² enhanced the yield of ‘Gangmian 13’. In conclusion, 21% glufosinate-P SL and 51% flumioxazin WG applied via directional foliar spraying at tested rates are recommended for weed control in cotton fields. This approach delivers significant efficacy while maintaining crop safety.