Cotton Lint Yield Research Articles

Abstract Potassium (K) deficiency is a common yield‐limiting factor in cotton ( Gossypium hirsutum L.) production, requiring effective management to minimize yield losses and maintain fiber quality. We evaluated how K availability influences cotton lint yield and fiber quality. Ten fertilizer‐K rate (0–187 kg K ha −1 ) trials were conducted on silt loam soils with soil‐test K (STK) ranging from very low to above optimum during the 2023 and 2024 growing seasons. Cotton was planted in raised beds and furrow‐irrigated, and lint yield, turnout, and fiber quality (i.e., fiber length, micronaire, uniformity, strength, and elongation) were measured at maturity. Cotton lint yield was positively affected by fertilizer‐K rates ( p ≤ 0.10) at STK ≤ 114 mg K kg −1 . Yields were maximized at responsive sites with applications of 56 kg K ha −1 in long‐term trials and 37, 75, or 112 kg K ha −1 in single‐site‐year trials, showing yield increases of 20%, 53%, 47%, and 70% compared to the no‐K control, respectively. Lint turnout and fiber quality were affected by K availability. Overall, at yield‐maximizing fertilizer‐K rates, lint turnout was 2.4% greater across cultivars in relation to the control. Similarly, fiber elongation increased by 0.35%. At sites with Very Low STK, as little as 37 kg K ha −1 increased lint uniformity and strength up to 0.67% and 1.84 g tex −1 . Micronaire increased on average by 0.50, with greatest values occurring with 112 kg K ha −1 application. These findings suggest adequate K management is key to maximizing both cotton yield potential and fiber quality.

Root-knot nematode (Meloidogyne incognita) (RK) causes yield losses in cotton. Small-plot variety trials were conducted in the southern High Plains of Texas to evaluate RK density (2nd-stage juveniles + eggs/500 cm3 soil) and cotton (Gossypium hirsutum) lint yield across commercially identified RK-resistant varieties. These varieties were compared to susceptible varieties (SUS) in nine trials over two years. Only a subset of resistant and SUS varieties was included in each location. Varieties that had consistently lower (p = 0.05) transformed RK densities (LRK) compared to SUS were DP 2143NR B3XF (6 of 9 trials), DP 2141NR B3XF (3 of 6 trials), DP 2436NR B3TXF (2 of 5 trials), PHY 205 W3FE (2 of 4 trials), PHY 332 W3FE (3 of 4 trials), PHY 411 W3FE (2 of 3 trials), PHY 415 W3FE (2 of 3 trials), PHY 443 W3FE (3 of 4 trials), PHY 475 W3FE (3 of 4 trials), and PHY 480 W3FE (2 of 2 trials). In contrast, FM 765AX, FM 823AXTP, FM 868AXTP, and ST 6000AXTP did not exhibit reduced LRK densities relative to SUS in any trial. Varieties that had consistently higher (p = 0.05) yield than SUS included FM 765AX (2 of 3 trials), PHY 475 W3FE (2 of 4 trials), and PHY 480 W3FE (1 of 2 trials). Cotton producers should consider both the level of resistance of a variety as well as yielding ability in a region when making variety choices for planting cotton in RK fields.

This study was conducted to evaluate the yield potential, yield components and some agronomic traits of 8 natural color cotton elite lines, which were improved by the National Corn and Sorghum Research Center [NCSRC], tested with 2 check varieties; Dora11, and Srisumrong60 in the early rainy season of 2022 at the NCSRC, Faculty of Agriculture, Kasetsart University, Nakhon Ratchasima Province, Thailand. The randomized complete block design [RCBD] with 3 replications was used with 25 plants/row, 4 rows/experimental unit, and data were recorded from middle row. It was found that 9 of 11 recorded traits of the tested cotton varieties/lines were significantly different. It comprised no. of days to 50% boll opening (107-114 days), plant ht (135-164 cm), no. of vegetative branch (1.2-3.4 branches/plant), no. of fruiting branch (12.3-14.6 branches/plant), seed wt (8.2-13.4 g/100 seeds), boll wt (4.28-5.71 g/boll), seed cotton yield (194-262 kg/rai), cotton lint yield (70-108 kg/rai), and ginning outturn (30.9-41.9%). While no. of days to 50% flowering (53-55 days) and no. of boll/plant (51.7-58.3 balls/plant) had a non-significant difference. The result of this study indicated that natural color cotton lines W535, W537 and W536 had a trend for higher lint yield than Dora11, Srisumrong60. The lint yields were 108, 105, 103, 93 and 80 kg/rai, respectively. While other 5 natural color lines had lint yield of 70-94 kg/rai.

Trials were conducted during three years from 2021-22 to 2023-24 at Main Cotton Research Station, Navsari Agricultural University, Surat, Gujarat to study the effect of nitrogen levels on yield of cotton and to find out the efficacy of growth retardants on plant canopy of cotton grown under high density planting system. Nine treatment combinations comprising of three nitrogen levels viz; 375 kg N/ha, 300 kg N/ha and 225 kg N/ha with three treatments of growth retardants viz; Cycocel spray @ 50 g a.i./ha in each spray at 60 and 75 days after sowing, Mepiquat chloride spray @ 37.5 g a.i./ha in each spray at 60 and 75 days after sowing and Control (water spray at 60 and 75 days after sowing) were laid out in factorial randomized block design. Nitrogen levels significantly influenced on growth parameters viz; plant height, number of sympodial branches/plant, sympodial length and days to 50 % flowering, yield attributes viz; number of bolls/plant and boll weight, seed cotton yield (kg/ha), lint yield (kg/ha) and stalk yield (kg/ha). Important growth and yield parameters viz; plant height, number of sympodial branches/plant, sympodial length, days to 50 % flowering, number of bolls/plant and boll weight, seed cotton yield (kg/ha), lint yield (kg/ha) and stalk yield (kg/ha) were significantly influenced by growth retardant treatments. Conclusion of the experiment was drawn that application of 300 kg nitrogen/ha in five equal splits at 30, 60, 75, 90 and 105 days after sowing along with 40 kg P2O5/ha as basal dose and spraying of mepiquat chloride 5 % AS @ 37.5 g a.i./ha at 60 and 75 days after sowing found optimum for obtaining higher seed cotton yield as well as net returns from Bt cotton hybrid grown with high density planting system maintaining 60 x 45 cm spacing under irrigated condition of south Gujarat.

Cotton-growing regions face heat stress during flowering and boll development, adversely affecting reproductive fitness, yield, and quality. Identifying and incorporating superior physiological and reproductive traits into elite genetic background may improve yield potential under stress. This study quantified the effects of heat stress (36/24 °C, HS) on 25 traits of 16 upland cotton cultivars during the reproductive stage, compared to control conditions (32/24 °C, CNT). Under HS, all cultivars exhibited transpirational cooling, withstomatal conductance increasing by 1-fold and transpiration by 1.6-fold compared to CNT. Under HS, leaf temperature was 3.5 °C higher than CNT plants, and PSII quantum efficiency dropped by 20% compared to CNT. HS also reduced the ratio of reproductive to vegetative dry mass (57%), indicating poor resource partitioning towards reproductive organs. The specific leaf area was increased by 34%, whereas the leaf chlorophyll index dropped by 28% under HS compared with CNT. When exposed to HS, pollen germination was reduced by 71% across cultivars compared to the CNT. While some cultivars maintained similar boll and seed numbers between CNT and HS, a corresponding tolerance was not observed in seed cotton yield. On average, seed cotton yield and lint yield decreased by 19% and 26% under HS, respectively. In contrast, seed yield remained stable, suggesting a disproportionate reduction in intra-boll components. Seed oil content and fiber quality, except for fiber uniformity, displayed susceptibility to HS. Multidimensional responses of cotton cultivars to HS highlight the need to map genetic loci governing heat tolerance. This knowledge is essential for pinpointing effective breeding targets.

Sustainable agriculture necessitates the exploration of organic fertilizers to promote both crop productivity and soil health. The objective of this two-year study was to evaluate the effects of different combinations of processed cattle manure on the yield and quality of cotton crops, with a focus on determining the optimal dosage of these fertilizers. Parameters including seed cotton yield, lint yield, ginning percentage, and physiological traits such as chlorophyll content and normalized difference vegetation index (NDVI) were analyzed. Results revealed significant differences in yield and physiological traits among fertilizer treatments. Notably, combinations involving cattle manure as base fertilizer exhibited superior performance compared to synthetic fertilizer alone. The application of 230 kg da-1 of cattle manure as base fertilizer, in particular, resulted in optimal yield and quality, highlighting the potential of organic fertilizers in enhancing crop productivity. While synthetic fertilizers tended to enhance chlorophyll content, cattle manure applications promoted a more balanced improvement in yield components without compromising plant vigor. Integrating processed cattle manure into fertilizer regimes emerges as a promising strategy for sustainable cotton production. The dose of processed manure fertilizer will provide ten times less use than the dose of normal manure fertilizer. This will make the use of manure fertilizers more active and the use of organic fertilizers more widespread.

Abstract The physiological utility of nitrogen (N) and zinc (Zn) in cotton (Gossypium hirsutum L.) is interlinked, but the level of their contribution to nutritional balance and production remains unexplored. Therefore, this study explored the interactive effects of N and Zn on cotton lint yield, seed yield, and fiber quality under field conditions. The experiment was conducted from 2016 to 2021 within a randomized complete block design replicated five times, testing a full factorial treatment structure with four N rates (34, 67, 101, and 134 kg N ha−1) and four Zn rates (0, 6, 11, and 17 kg Zn ha−1). Overall, cotton lint and seed yield were significantly influenced by the three‐way interaction between N, Zn, and year. Applying just N never resulted in high yield, except in 2017. Each year, applications of 101 kg N ha−1 and 6 kg Zn ha−1 were found to be the optimum rates, and in 2021 this combination resulted in the highest lint (1804 kg ha−1) and seed cotton (4484 kg ha−1) yields, while the lowest lint yield was recorded in 2016 when 34 kg N ha−1 was applied alone. Increasing N rates from 34 to 101 kg N ha−1 reduced micronaire by 6%, while the opposite was observed with Zn. Overall, the synergistic effects of both N and Zn were noted. Lint, seed, and fiber quality responses to N and Zn varied slightly each year, underscoring the annual environmental variations and the need for adaptive nutrient management plans.

The introduction of cover crops, owing to their positive effects on soil organic carbon (SOC) sequestration, is a potential management practice that can mitigate agricultural greenhouse gas emissions. In this study, we leveraged a 42-year-old continuous cotton (Gossypium hirsutum L.) experiment under no tillage, to evaluate the effect of hairy vetch (Vicia villosa; HV) and no cover crop (NC) under N rates of 0 (no fertilizer [NF]) and 67kg N ha-1 (fertilized [F]), on net global warming potential (GWP) and greenhouse gas intensity (GHGI). The annual SOC sequestration rate was not significantly different in the F (115.1kgha-1year-1) and HV (107.4kgha-1year-1) treatments compared to the NF (103.2kgha-1year-1) and NC (110.8kgha-1year-1) treatments. Soil under HV and F treatments behaved as a net source of GHGs in 2022, with a GWP of 243 and 294kg CO2-eq ha-1year-1, respectively. By contrast, in 2023, these treatments were net sinks of GHGs. Despite the increase in cotton lint yield under legume cover cropping and N fertilization, the GHGI followed the same trend as the net GWP, being net source of GHG in 2022 and a net sink in 2023. Nearly all estimated C gains were offset by N2O emissions under these treatments in 2022-2023. Our results indicate that GHG mitigation through the adoption of legume cover cropping within cotton systems in humid subtropical climates is constrained by low soil C sequestration potential and elevated N₂O emissions.

Abstract Accurately quantifying the net ecosystem exchange (NEE) of CO2 is a critical prerequisite for developing alternative farm management strategies to enhance carbon sequestration in biological systems and reduce greenhouse gas emissions. A 2‐year study quantified the NEE of CO2 from cotton (Gossypium hirsutum L.) on silty clay in farm‐scale fields using an eddy covariance approach. On a seasonal scale, NEE and evapotranspiration were 8836 kg CO2 ha−1 and 367 mm, respectively, in 2017, and 10,759 kg CO2 ha−1 and 430 mm in 2018. Harvested cotton lint yields were 1269 and 1569 kg ha−1 in 2017 and 2018, respectively. The water use efficiency (WUE) for lint production (WUElint) and ecosystem level WUE for NEE (WUENEE) across the two seasons was nearly constant. WUElint was 3.5 and 3.6 kg lint ha−1 mm−1, respectively, in 2017 and 2018, and WUENEE was 24 and 25 kg CO2 ha−1 mm−1. The NEE and WUE measured in this study can be used as a benchmark for comparing carbon sequestration potential in cotton production. However, further research is needed to understand NEE responses to long‐term climate variability and to develop climate‐smart crop‐soil management strategies.

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.

The field experiment was conducted during the monsoon seasons of 2019–20 and 2020–21 at ICAR-Central Institute for Cotton Research (CICR), Nagpur, Maharashtra. Bt cotton (Gossypium hirsutum L.) hybrids was introduced in India by the private seed industry in 2002. Hybrid seeds were expensive and its cultivation is input intensive, cotton breeders from the public sector R & D institutes released Bt cotton varieties in 2020 suitable for planting under low input situations. This study evaluated the production potential of four Bt varieties released and notified in India, from the ICAR-Central Institute for Cotton Research, Nagpur. The varieties, ICAR-CICR ‘PKV081- Bt’, ICAR-CICR ‘Suraj Bt’, ICAR-CICR ‘Rajat Bt’, and ICAR-CICR ‘GJHV 374 Bt’ were evaluated in a split plot design under rainfed conditions on a Vertisol, with four planting densities, viz. 0.37 lakh (90 cm × 30 cm), 0.55 lakh (90 cm × 20 cm), 0.74 lakh (90 cm × 15 cm) and 1.1 lakh plants/ha (90 cm × 10 cm). The results indicated that there were significant differences among varieties and plant densities with respect to seed cotton yield, lint yield, boll weight, days to first open flower and earliness index. ICAR-CICR ‘PKV081-Bt’ was the most productive variety, yielding 2,639 kg seed cotton/ha at 0.37 lakh plants/ha. The interaction (variety × plant density) was significant for seed cotton yield, lint yield and boll density. Concerning seed cotton yield, for varieties, ‘PKV 081 Bt’ and ‘Rajat Bt’, 0.37 lakh plants/ha was optimum whereas for ‘Suraj Bt’ and ‘GJHV 374 Bt’, 0.74 lakh plant/ha was optimum plant density. At densities of 0.74 and 1.1 lakh plant/ha, the plant height increased and the maturity was delayed. The study highlights the importance of selecting appropriate Bt varieties and optimizing planting density to increase the productivity of rained cotton on Vertisols of Central India.

Cotton lint yield and quality variability in Georgia, USA: Understanding genotypic and environmental interactions

The lint harvest index (HI) of cotton is the ratio of cotton lint yield to the total aboveground biomass of cotton, which is not yet clear in arid-zone cotton areas. In 2022–2023, large-scale sampling was carried out in Xinjiang, and the HI of different variety types of cotton in Xinjiang and their key drivers were clarified using methods such as random forest modeling (RFM) and structural equation modeling (SEM). The results show that the overall cotton HI in Xinjiang ranged from 0.276 to 0.333 and 0.279 to 0.328 for the Xinluzao (XLzao) variety types, and from 0.276 to 0.333 for the Xinluzhong (XLzhong) variety types. The results of the SEM analysis show that the latitude (−0.99) and planting density (0.50), in the climatic geography factors, and available potassium in soil (0.88), in the soil nutrient factors, have the greatest effects on the overall cotton HI in Xinjiang. The key driving factors of cotton HI were found to be different among different variety types. This study aimed to clarify the HI of different variety types of cotton in arid-zone cotton and to explore its key driving factors. This was undertaken in order to provide a theoretical basis for the accurate estimation of cotton and cotton straw yields in the arid zone.

BackgroundSoil available phosphorus (AP) deficiency significantly limits cotton production, particularly in arid and saline-alkaline regions. Screening cotton cultivars for low phosphorus (P) tolerance is crucial for the sustainable development of cotton production. However, the effect of different growth media on the screening outcomes remains unclear. To address this, we evaluated the low P tolerance of 25 cotton cultivars through hydroponic culture at two P levels (0.01 and 0.5 mmol•L−1 KH2PO4) in 2018 and field culture with two P rates (0 and 90 kg•hm−2, in P2O5) in 2019.ResultsIn the hydroponic experiments, principal component analysis (PCA) showed that shoot dry weight (SDW) and P utilization efficiency in shoots (PUES) of cotton seedlings explained over 45% of the genetic variation in P nutrition. Cotton cultivars were subjected to comprehensive cluster analysis, utilizing agronomic traits (SDW and PUES) during the seedling stage (hydroponic) and yield and fiber quality traits during the mature stage (in field). These cultivars were grouped into four clusters: resistant, moderately resistant, moderately sensitive, and sensitive. In low P conditions (0.01 mmol•L−1 KH2PO4 and 4.5 mg•kg−1 AP), the low-P-resistant cluster showed significantly smaller reductions in SDW (54%), seed cotton yield (3%), lint yield (− 2%), fiber length (− 1%), and fiber strength (− 3%) compared with the low-P-sensitive cluster (75%, 13%, 17%, 7%, and 9%, respectively). The increase in PUES (299%) in the resistant cluster was also significantly higher than in the sensitive cluster (131%). Four of the eight low-P-tolerant cotton cultivars identified in the field and six in the hydroponic screening overlapped in both screenings. Two cultivars overlapped in both screening in the low-P-sensitive cluster.ConclusionBased on the screenings from both field and hydroponic cultures, ZM-9131, CCRI-79, JM-958, and J-228 were identified as low-P-tolerant cotton cultivars, while JM-169, XM-33B, SCRC-28, and LNM-18 were identified as low-P-sensitive cotton cultivars. The relationship between field and hydroponic screening results for low-P-tolerant cotton cultivars was strong, although field validation is still required. The low P tolerance of these cultivars was closely associated with SDW and PUES.

The field experiment was carried out at the Central Farm, AC &RI (Agricultural College and Research Institute), TNAU, Madurai, Tamil Nadu during Kharif season 2024. The study aimed to evaluate the effects of different nutrient management strategies on the growth, yield components and productivity of coloured cotton. The experiment followed a randomized block design (RBD) with nine treatments based on nitrogen equivalence, incorporating different organic manures in comparison to inorganic fertilizers, with each treatment replicated three times. The results revealed that growth parameters such as plant height, dry matter production, leaf area index, chlorophyll content, number of monopodial branches plant-1 , days to 50% flowering and days to 50% boll bursting were significantly enhanced by the application of 100% NPK based on site-specific recommendation (T2), which statistically at par with 100% NPK through blanket recommendation (T1). Yield attributes including number of fruiting branches plant-1 , number of fruiting points plant-1 , number of bolls plant-1 , number of bolls m-2 , boll setting percentage and boll weight, along with seed cotton yield, lint cotton yield, stalk yield and biological yield, which also showed a significant increase with the application of 100% NPK through site-specific recommendation (T2). Organic treatments, including the complete organic package (T9), cover cropping with 75% N through vermicompost (T4) and cover cropping with 75% N through poultry manure (T5), exhibited comparable results to inorganic treatments. Future research should focus on optimizing organic nutrient management strategies and integrating cover crops to enhance soil health and ensure sustainable cotton production.

Abstract Implementing an integrated system of reduced tillage and cover cropping holds promising potential for enhancing cotton (Gossypium hirsutum L.) production in the southeast, where soils are eroded and low in organic matter. A 4‐year field study was conducted on a Leeper silty clay loam at the Plant Science Center at Mississippi State University to investigate the combined effects of no‐till (NT) and conventional tillage (CT), with applied broiler litter (BL) and inorganic N fertilizer, in the presence of winter cover crops (WCCs) and absence of cover crops on cotton growth and yield. With WCC residues, NT had the greatest soil moisture in the drier year of 2022. Total aboveground biomass of WCC and nitrogen (N) accumulation were 72% and 60% greater in the 2019/2020 growing season than in the 2020/2021 and 2021/2022, and they were 24% and 22% greater with CT than NT. However, cotton dry matter (DM) was 22% greater with NT than CT. With WCC residues, cotton DM, N uptake, and leaf area index were greater by 25%, 21%, and 64%, respectively. Regardless of tillage and cropping systems, BL in the presence of WCC residues increased cotton lint yield by 67%, especially in years with less rainfall during cotton peak blooming and boll formation. This study revealed that the integration of NT with BL and inorganic N fertilizer in the presence of a cover crop can have a positive effect on cotton production. Implementing these practices could enhance long‐term sustainable cotton cultivation in southeastern United States agroecosystems.

Abstract Increases in cotton (Gossypium hirsutum L.) production across Oklahoma due to various circumstances have led to cotton planted on soils that have been traditionally managed for differing crops, specifically winter wheat. Many of these soils are possibly acidic in nature due to natural and anthropogenic activities such as excessive ammonia‐based fertilizer applications. Common wheat production practices such as banding phosphorus fertilizers with seed and planting aluminum (Al) tolerant varieties may have masked potential problems associated with crop performance in acidic soils. In response, this study was initiated to evaluate the impact of soil acidity on cotton production. This experiment was conducted in central Oklahoma in the 2019 and 2020 growing seasons. Cotton lint yield and lint quality were evaluated across a range of soil pH levels and associated potassium chloride extractable Al across a soil pH gradient of 4.0–8.0. Two cotton cultivars were planted to identify possible differences in response between genotypes. Soil acidity negatively impacted in‐season growth parameters such as plant height, node count, and boll count, as well as the primary variable of lint yield. A critical threshold at a soil pH level of 5.2 was identified as detrimental to cotton lint yield, corresponding with a lint yield loss of approximately 4.5% per pH unit decrease below the critical soil pH level of 5.2. This equates to a lint yield loss of 44.5 kg ha−1 per 0.1 change in soil pH, assuming 100% yield potential is approximately 989 kg ha−1 of lint for this specific growing environment.

Cotton (Gossypium spp.), often referred to as “white gold” and “the king of fibers”, is a major commercial fiber crop cultivated across various agroclimatic conditions, primarily used in the textile industry to manufacture fabrics. However, conventional white cotton production is associated with several environmental challenges including excessive water consumption, reliance on synthetic chemicals and the use of synthetic dyes, which contribute to soil degradation, water pollution and health hazards for farmers. In contrast, organic coloured cotton presents a sustainable alternative by naturally producing coloured fibres without the need for synthetic dyes. Additionally, it enhances soil fertility, conserves water and minimizes chemical inputs, providing ecological benefits while supporting the well-being of farming communities. The field experiments were carried out at the Central Farm, Agricultural College and Research Institute, TNAU, Madurai, Tamil Nadu, during the Kharif 2023 and Summer 2024 seasons. The present study aimed to evaluate the impacts of various nutrient management practices on the growth characteristics, yield attributes and yield of coloured cotton (Gossypium hirsutum L.) cv. Vaidehi 1. The experiment was designed using a randomized block design with nine treatments based on N-equivalence using different organic manures compared to inorganic fertilizers and replicated three times. The results indicated a significant increase in the growth characters (plant height, number of vegetative branches plant−1 and number of fruiting branches plant−1), yield attributes (number of fruiting points plant−1, number of bolls plant−1, number of bolls m−2, boll setting % and boll weight) and yield (seed cotton yield, lint cotton yield, stalk yield and biological yield) of coloured cotton with the application of 100% NPK applied through site-specific recommendation (T2), which was statistically on par with 100% NPK through blanket recommendation (T1). These were followed by the organic treatments like complete organic package (T9), cover crop with vermicompost (T4), cover crop with poultry manure (T5) and all other organic treatments during both seasons. No significant variations were recorded in the first fruiting node, length of fruiting branches as well as harvest index and lint percentage across the different nutrient management strategies.

A two-year field trial (2021–2023) was conducted to evaluate the impacts of cover crop (CC) inclusion (cereal rye, crimson clover, mixtures of cereal rye and crimson clover, and fallow control) and nitrogen (N) fertilization (0, 22, 45, 90, 135, and 180 kg N ha−1) in cotton production in sandy soils. Cover crops were planted in October and terminated two weeks before cotton planting in May. The N was applied in split applications. Cover crop aboveground biomass was collected, oven dried, and weighed, and then used for C and N analyses. Soils were sampled at CC termination and analyzed for biogeochemical properties. Cotton lint yields and agronomic nutrient use efficiency (aNUE) were estimated. The CC mixtures provided higher organic C and N inputs as residue returns than individual species. Integrating CCs had limited impacts on measured soil properties. Integrating CCs resulted in positive, neutral, and adverse effects on lint yield and aNUE depending on species and growing seasons. Applying N at 22 kg ha−1 increased lint yields in 2022, while higher rates did not improve the yields further. Similar patterns of impacts were observed at the N rate of 45 kg ha−1 in 2023. The results indicated that integrating CC mixtures can favor long-term C and N sequestration in sandy soils. However, optimal management is essential to realize their benefits. Relevant research to better understand the decomposition of their residues would be beneficial in improving the management of desirable outcomes.

Abstract Two studies were conducted in 2022 and 2023 near Rocky Mount and Clayton, NC, to determine the optimal granular ammonium sulfate (AMS) rate and application timing for pyroxasulfone-coated AMS. In the rate study, AMS rates included 161, 214, 267, 321, 374, 428, and 481 kg ha−1, equivalent to 34, 45, 56, 67, 79, 90, and 101 kg N ha−1, respectively. All rates were coated with pyroxasulfone at 118 g ai ha−1 and topdressed onto 5- to 7-leaf cotton. In the timing study, pyroxasulfone (118 g ai ha−1) was coated on AMS and topdressed at 321 kg ha−1 (67 kg N ha−1) onto 5- to 7-leaf, 9- to 11-leaf, and first bloom cotton. In both studies, weed control and cotton tolerance to pyroxasulfone-coated AMS were compared to pyroxasulfone applied POST and POST-directed. The check in both studies received non-herbicide-treated AMS (321 kg ha−1). Before treatment applications, all plots (including the check) were maintained weed-free with glyphosate and glufosinate. In both studies, pyroxasulfone applied POST was most injurious (8% to 16%), while pyroxasulfone-coated AMS resulted in ≤4% injury. Additionally, no differences in cotton lint yield were observed in either study. With the exception of the lowest rate of AMS (161 kg ha−1; 79%), all AMS rates coated with pyroxasulfone controlled Palmer amaranth ≥83%, comparably to pyroxasulfone applied POST (92%) and POST-directed (89%). In the timing study, the application method did not affect Palmer amaranth control; however, applications made at the mid- and late timings outperformed early applications. These results indicate that pyroxasulfone-coated AMS can control Palmer amaranth comparably to pyroxasulfone applied POST and POST-directed, with minimal risk of cotton injury. However, the application timing could warrant additional treatment to achieve adequate late-season weed control.