Fiber Quality Parameters Research Articles

Effect of different canopy management and mulching practices on yield parameters and fiber quality parameters of Bt cotton under drip fertigation

Effect of different canopy management and mulching practices on yield parameters and fiber quality parameters of Bt cotton under drip fertigation

Morphophysiological and biochemical responses of cotton (Gossypium barbadense L.) to nano zinc (ZnO-NPs) and Azospirillum sp. under water deficit stress conditions

Water deficit stress (WDS) is one of the most significant abiotic limiting factors in cultivated crops, including cotton (Gossypium barbadense L.). With global climate change and the destruction of ecological balance, the frequency and severity of drought events are increasing in many regions around the world. Therefore, the aim of the present work was to investigate the potential of using nano zinc particles (ZnO-NPs), plant growth-promoting rhizobacteria (Azospirillum sp.), and their combination to mitigate the negative impacts of WDS on cotton var. Giza 96. Extended irrigation intervals of 30 and 45 days led to considerable decreases in plant height, chlorophyll content, relative water content (RWC), yield, and cotton fiber quality compared to the optimal irrigation interval (every 15 days). When applied individually or in combination, ZnO-NPs and Azospirillum sp. can ameliorate the negative effects of WDS on cotton growth and productivity. Overall, the use of Azospirillum sp. and ZnO-NPs, either individually or in combination, has demonstrated their potential to enhance cotton growth and yield parameters (plant height, dry weight, leaf area, chlorophyll pigment, seed index, seed yield, and lint%) under prolonged irrigation intervals during 2021 and 2022 seasons. Antioxidant enzymes activity comprising catalase (CAT), peroxidase (POD), and polyphenol oxidase (PPO) and proline content were increased under drought stress. Cotton fiber quality parameters including length, strength, and micronaire were insignificantly affected under low irrigation rate. The combination of ZnO-NPs and Azospirillum sp. provided the most effective mitigation of WDS during both experimental seasons, outperforming the effects of individual applications.

INFESTATION OF DIFFERENT INSECT PESTS ON NOVEL COTTON CULTIVARS AND THEIR IMPACTS ON COTTON FIBER QUALITY PARAMETERS

Pakistan is the 5th largest producer of cotton in the world. Exports of cotton and textile products have a share of around 60 percent in overall exports of the country. A field experiment was conducted to evaluate the different fiber quality parameters in relation to different insect pest populations. The introduction of this new types of cultivars may satisfy the needs of farmers for better quality and quantity, laborers who harvest crops, and other investors, including those in the cotton sector. A field research was carried out at the Cotton Research Station, Faisalabad, Pakistan, during the year 2023 cotton cultivars (VH-447, FH-1133, BH-228, SLH-94, MNH-S GOLD, BH-227, FH-1214, MNH-1095, VH-442, MNH-1090, RH-BAGHO BAHAR, MNH-1050, and MNH-TP) were evaluated for resistance to sucking pests such as whitefly (Bemisia tabaci); jassid (Amrasca biguttula biguttula); and thrips (Thrips tabaci) as well as bollworms such as pink bollworm (Pectinophora gossypiella); spotted bollworm (Earias insulana; E. vitelli); and American bollworm (Helicoverpa armigera). There were notable variations across the genotypes in terms of the population of sucking and bollworm insect pest infestation, which lowers cotton production and negatively affects fiber quality. FH-1133 showed the lowest average populations of thrips (1.00/leaf), jassid (0.27/leaf), and whiteflies (2.00/leaf), indicating the highest resistance. The average population (9.84%) of pink bollworm larvae in residual boll. The virus percentage on different cotton genotypes recorded after 30, 60, 90, and 120 days was 0.00, 9.00, 14.00, and 19.00%, respectively. The cultivar FH-1133 was observed to be good for all other genotypes of cotton due to its yield (2372.50 kg/acre), and it had the following lint quality attributes: GOT (46.50%), staple length (28.50 mm), fiber fineness (4.70 µg/inch), and fiber strength (33.20 g/tex).

Selection of productive early maturing cotton genotypes with improved fibre quality parameters

The purpose of this article was to study productivity and fibre quality of different cotton genotypes under conditions of Turkestan region of Kazakhstan to determine the most promising genotypes for commercial cultivation. Four genotypes were selected: Tashkent-6, Maktaral-5027, Namangan-1 and Bukhara-8. The study included analysis of such parameters as germination and sprouting time, plant height, flowering and maturity time, yield, number of bolls and fibre quality characteristics. The results showed that Tashkent-6 and Maktaral-5027 had the best parameters: yield 3.8 t/ha and 3.5 t/ha, flowering time 55 days and maturity 120 days, plant height 120 cm and 115 cm, number of bolls 45 and 42. The fibre quality of these genotypes was also high: length 32 mm and 31 mm, tensile strength 30 g/tex and 29 g/tex, fineness 2.5 dtex and 2.6 dtex. Namangan-1 and Bukhara-8 genotypes showed moderate results: yield 3.2 t/ha and 3.0 t/ha, flowering time 60 days and ripening time 130 days, plant height 110 cm and 105 cm, number of bolls 40 and 38, fibre length 30 mm and 29 mm, tensile strength 28 g/tex and 27 g/tex, fineness 2.8 dtex and 2.9 dtex. Statistical analysis confirmed the significance of differences between genotypes. The results of the study confirmed high productivity and fibre quality of genotypes Tashkent-6 and Maktaral-5027, which makes them promising for commercial cultivation in Kazakhstan, while genotypes Namangan-1 and Bukhara-8 also have potential for certain agronomic conditions

Increasing dissolved oxygen concentration of irrigation water is beneficial to nitrogen uptake of cotton under mulched drip irrigation

ContextEnhancing crop nitrogen absorption is crucial for improving nitrogen fertilizer utilization efficiency. Soil oxygen conditions play a vital role in influencing crop nutrient uptake. However, the impact of dissolved oxygen concentration in irrigation water on cotton’s nitrogen absorption remains unknow under mulched drip irrigation conditions. RESEARCH QUESTION: This study aimed to investigate whether the dissolved oxygen concentration in irrigation water affects cotton’s nitrogen uptake. METHODS: Urea was utilized as the nitrogen fertilizer, and 5 dissolved oxygen concentration of irrigation water were set in the experiment by adding sodium percarbonate (CK: 3.9 mg L−1, CO1: 9.2 mg L−1, CO2: 13.3 mg L−1, CO3: 17.3 mg L−1, CO4: 25.5 mg L−1). RESULTS: The results showed that increasing the dissolved oxygen concentration in irrigation water could increase the soil urease activity and bacterial operational taxonomic units (OTU), which may be beneficial to the urea decomposition and nitrogen cycling function. Towards the end of the cotton growth period, oxygenation irrigation led to an increase in nitrate nitrogen and ammonium nitrogen content in the soil. The average nitrate nitrogen content in the 0–60 cm soil layer of CO1, CO2, CO3 and CO4 increased by 12.4 %, 14.7 %, 15.9 % and 17.3 % respectively compared with CK. Similarly, the average ammonium nitrogen content of CO1, CO2, CO3 and CO4 in the 0–40 cm soil layer increased by 8.9 %, 11.7 %, 12.0 % and 11.6 % respectively compared with CK. Increasing the dissolved oxygen concentration in irrigation water resulted in elevated dry matter accumulation in cotton. The total dry matter of CO1, CO2, CO3 and CO4 increased by 9.5 %, 12.6 %, 14.6 % and 16.8 % respectively compared with CK. Additionally, the nitrogen concentration in each cotton organ also exhibited an increase. The total nitrogen accumulation of CO1, CO2, CO3 and CO4 increased by 26.1 %, 36.2 %, 48.2 % and 53.1 % respectively compared with CK. Furthermore, increasing the dissolved oxygen concentration in irrigation water also facilitated nitrogen migration to cotton bolls (boll shell + seed + fiber). The cotton boll nitrogen accumulation of CO1, CO2, CO3 and CO4 increased by 1.8 %, 3.4 %, 4.2 % and 4.2 % (absolute value) compared with CK (reached significant level). Finally, the lint yield and fiber quality parameters (micronaire, fiber elongation, fiber breaking strength) exhibited further improvement with the increase in dissolved oxygen concentration in irrigation water. CONCLUSIONS: Increasing the dissolved oxygen concentration in irrigation water promotes nitrogen absorption in cotton, facilitates nitrogen accumulation in cotton bolls, and enhances nitrogen fertilizer utilization efficiency. Moreover, it positively impacts cotton lint yield and fiber quality.

Genetic analysis of yield and fiber quality traits in cotton (Gossypium hirsutum L.) under full and deficit irrigation conditions using full diallel method

The aim of the study was to assess the genetic structure and quantitative heritability of cotton yield, yield components and fiber quality parameters under well-watered (100%) and deficit (50%) irrigation conditions using a complete full diallel cross method with six cotton genotypes. The F1 and F2 generations were obtained to study the effect of irrigation conditions on genotypic variation and maternal effects on the traits studied. Parental, F1 and F2 generations were growed under full and deficit irrigation conditions and selected agronomic and fiber quality traits were measured. The data were analysed using various methods, including Griffing Method I, Model I analysis of variance, full diallel table analysis of variance, Jinks-Hayman diallel hybrid analysis. The Jinks-Hayman analysis of variance showed that dominant effects were more important in the inheritance of all traits, as indicated by the negative value of the difference between the additive variance and the dominance variance (D-H1). In addition, the average degree of dominance (H1/D)1/2 was greater than 1, indicating the predominance of dominant gene action in inheritance. The study concluded that starting selection in the F5–F6 generation is appropriate for drought resistant cotton breeding studies. It also emphasised the importance of conducting drought resistant cotton breeding under drought conditions due to the differences in gene movement between well-watered irrigation and drought stress conditions. The study highlighted the importance of population selection, environmental factors, data collection and analysis interpretation in breeding studies. It suggested that the Griffing diallel analysis method is suitable for hybrid breeding studies, while the Jinks-Hayman type analysis method is suitable for studying the genetic structures of populations.

Retting with efficient microbial consortium helps in improving jute fibre quality and profitability: a study in Eastern India

Aim: To determine the effect of application of microbial consortium for faster retting of jute (Corchorus spp.) over conventional retting without microbial consortium on jute fibre recovery and fibre quality improvement. Methodology: Large scale retting trials of jute were conducted in five important jute growing districts of West Bengal, India for four consecutive years with and without microbial consortium. After completion of jute retting, fibre was extracted manually, processed and dry fibre weight was recorded. Jute fibre samples were collected and analysed for fibre quality parameters. The fibre strength was estimated using electronic fibre bundle strength tester, fibre fineness by air flow method and root content is measured as the length of fibre up to which root is present out of the total length of the fibre and is expressed as percent length. Results: Application of microbial consortium reduced the retting duration and root content in jute fibre in all the locations irrespective of years. The jute fibre recovery increased by 9.64 to 10.97% and 9.73 to 10.63% with microbial consortium over without microbial consortium respectively in different locations and different years under study. The maximum jute fibre yield with (33.17 q ha-1) and without microbial consortium (29.89 q ha-1) was recorded in Murshidabad district. Nadia district recorded significantly higher fibre strength of 24.92 g tex-1 and lowest retting duration of 11.92 days with microbial consortium among all the locations. Interpretation: The application of microbial consortium improved the fibre recovery and fibre quality leading to the increase in net income by ₹15624 to ₹18017 ha-1 of jute farmers. Hence, the application of microbial consortium for jute retting can be used extensively by the jute farming community in jute growing states of India for faster retting of jute along with quality fibre production, higher net income and doubling farmers’ income. Key words: Corchorus spp., Fibre quality, Jute retting, Microbial consortiu

Elucidating the phenotypic basis of multi-environment stability for fiber yield and quality traits of cotton (Gossypium hirsutum L.) using 498 recombinant inbred lines

Understanding genotype-environment interactions and trait relationships is pivotal for guiding breeding efforts aimed at stabilizing cotton varieties across diverse environments while boosting yield and fiber quality. The study aimed to assess genotypic variability and stability in 10 agronomic and fiber quality traits across four environments (Anyang in 2020 and 2021 and Weixian in 2020 and 2021) for three parental lines (ZR014121, CCRI60, and EZ60) and their corresponding 498 recombinant inbred lines (RILs) populations. The results indicated that the analysis of variance showed significant genotype and genotype-by-environment effects for all measured traits. Analysis of correlation revealed highly significant positive correlations between seed cotton yield and each of boll weight (r = 0.95), lint yield (r = 0.90), and between boll weight and lint yield (r = 0.90), while highly significant negative correlations were noticed between fiber maturity and fiber elongation (r = −0.52) and between fiber length and lint percentage (r = −0.38). Furthermore, the weighted average of absolute scores (WAASB) was calculated for each trait, revealing moderate to high stability for some yield traits and fiber quality parameters. Also, the multi-trait stability index (MTSI) applied to these RILs populations identified G13 as the most stable line (MTSI = 5.5) and S23 as the least stable (MTSI = 12.1). Selecting 25 RILs with the lowest MTSI values (5.5–6.47) revealed elite stable lines with favorable trait values, providing a valuable genetic resource for developing high-performance cotton cultivars in diverse environments.

Harnessing the association between morphological, biochemical and fibre quality traits in desi cotton (Gossypium arboreum) genotypes

An experiment was conducted during the rainy (kharif) seasons of 2019 and 2020 at the research farm of Chaudhary Charan Singh Haryana Agriculture University, Hisar, Haryana to study the relationship between morphological, biochemical and fibre quality parameters in 150 desi cotton [Gossypium arboreum (L.)] genotypes in augmented design. Findings of the experiment indicated that the seed cotton yield per plant was significantly and positively correlated with all the traits except days to first flower (-0.226) and plant height (-0.521), while, negatively correlated with biochemical and fibre quality traits. Thus, while improving other traits, seed cotton yield per plant will also increase. Fibre quality traits like fibre length was significant and positively (0.754) correlated with fibre strength but negatively correlated with seed cotton, suggesting quality and quantity can not be improved simultaneously. Hence selection should be done very precisely that as one can not be compromised. Path analysis also revealed that the maximum contribution towards yield was by the number of bolls per plant (0.57), boll weight (0.33), GOT (0.11) and the number of monopods (0.10). Fibre quality parameters did not show any significant contribution directly or indirectly to seed cotton yield. The five traits, viz. number of bolls per plant, number of monopods, ginning outturn (%), seed index (g) and number of seed per boll can contribute to the improvement in cotton. Overall, the significance of this study lies in its potential to yield improvement in desi cotton.

Characteristics of the New Fiber Flax Variety HERA in Terms of Fiber Quality Parameters Regard to Agronomic Assessment and Seeds Quality

ABSTRACT The work deals characteristics of new flax Hera variety in terms of fiber quality with regard to agronomic assessment and seeds quality. The results of the analyzes were related to the reference varieties Nike, Sara and Modran grown in Poland in 2022 season. The study included evaluation of agrotechnical experiment, flax straw and fiber evaluation taking into account the morphology and surface as well cross section of flax fiber. Moreover, seeds quality assessment were conducted. Hera variety was characterized by the highest total (6.27 t/ha, 0.627 kg/m2) and straw yield (5.16 t/ha, 0.516 kg/m2). Straw of Hera variety was characterized by the best average total (78.5 cm) as well as average technical (66.5 cm) length and average diameter (1.43 mm). In addition, it has fiber to raw straw content (16.42%) at a level comparable to the reference varieties. The metrological analysis of the fiber showed that the Hera variety fiber can be a good raw material for production of yarns.

Qualitative characteristics of cashmere fiber of Chyangra goat of Nepal

This study assesses the different physical characteristics of cashmere fiber quality in Chyangra goats as wax percentage, length of pashmina fiber, fineness (diameter) of fiber obtained from different body parts (neck, belly, and back) in different locations of Mustang district of Nepal. In mid-March to mid-April 2022, cashmere samples were collected from thirty-four unrelated animals. Twenty-two animals were sampled from Upper Mustang and twelve were sampled from Lower Mustang; of which, 22 were male and 12 were female of 1, 2, 3, 4, and greater than 4 years of age. Cashmere fiber length was measured using measuring pad and ruler and fiber diameter was analyzed using the optical projection microscope method. The fixed effect model was used to analyze the least square mean for fiber length, diameter and wax percentage of Chyangra cashmere fiber considering various factors such as location, sex and age. The overall least square mean and standard error for fiber quality parameters namely wax percentage, fiber length and fiber diameter were 9.49±2.2%, 45.97±0.14 mm and 15.36±0.19 µm respectively. Even though there is a significant difference in the considered parameters by location, the fineness and length of the fiber of both locations was within the finest fiber ranging from 13-16 µm diameter and more than 40 mm length. The present study has evidenced that Chyangra goat of Nepal can be characterized as one of the finest Cashmere goats however some management steps must be taken to improve the quality (cleanliness) of fiber and the volume of fiber production. Significant differences were found in location, sex, and trend of difference in age of the animals indicating the potential to improve cashmere quality by adopting proper management and selection methods through selection of goats with larger body size and confirmation to obtain more quantity of fiber per animal.

Impact of intra‐boll yield components on lint production per boll and fiber quality in advanced cotton breeding lines

AbstractCotton (Gossypium hirsutum L.) lint yield and fiber quality are associated with various yield components. Research efforts addressing intra‐boll yield component contributors to lint production boll−1 are limited. Thus, a study was conducted in Tifton, Georgia with the objectives to quantify the contributions of intra‐boll yield components to lint production boll−1 and to identify yield components most strongly associated with lint production boll−1 in advanced breeding lines of upland cotton. Data collected included intra‐boll yield components and fiber quality parameters. A strong association was observed between lint production boll−1 and seedcotton weight boll−1 (r = 0.896) compared to lint production boll−1 and lint percent (LP, r = 0.574). For breeding lines with maximum lint weight boll−1, the contribution of seedcotton weight and LP ranged from 0.17 to 0.36 g boll−1 and 0.22 to 0.24 g boll−1, respectively, suggesting a relatively greater influence of seedcotton weight boll−1 on lint weight boll−1. Lint production boll−1 can be expressed as the product of seeds per boll, seed surface area, fiber density (FD), and individual fiber weight (IFW). IFW was the greatest contributor to lint production boll−1 for seven breeding lines and FD for nine breeding lines. A strong positive association was observed between lint production boll−1 and IFW (r = 0.656, p < 0.001); however, no significant association between lint weight boll−1 and FD suggesting a relatively greater influence of IFW on lint weight boll−1. Our work provides future direction aimed at improving lint yields through the selection of various yield components.

Exploiting Morphophysiological Traits for Yield Improvement in Upland Cotton under Salt Stress

ABSTRACT The increased land salinization threatens land productivity, food security, and economic losses. The study used a comprehensive set of morpho-physiological, biochemical, and fiber quality parameters to examine the genetic variability of 24 cotton genotypes against 15 dSm-1 salt stress. The general linear model (GLM) effect revealed significant effects of salinity for studied accessions except for lint percentage and fiber strength. The genotype × treatment effects were also significant for all studied traits, while non-significant effects were observed for seed number per boll (SNB), potassium to sodium ratio (K+/Na+), K+, peroxidase (POD), and catalase (CAT). A notable reduction for all traits was observed except for fiber fineness, superoxide (SOD), CAT, POD, carotenoid contents, and hydrogen peroxide (H2O2), which were increased under saline conditions. Based on multivariate analyses, hybrids viz. MS-71× KAHKASHAN, followed by MS-71× CRS-2007 and NS-131× CRS-2007, performed well under both normal stressed conditions. Moreover, biochemical and agronomical traits in PCA validate that the MS-71× KAHKASHAN is the most desirable genotype under both conditions. Better hybrid performance under normal and 15 dSm-1 salt stress conditions supports the hybrid adaptability under salinity stress environments. The outcome would assist breeders in developing salt-tolerant cotton varieties under climate change scenarios.

Evaluating the impacts of wide row upland cotton (Gossypium hirsutum L.) production in Georgia

AbstractSuccess stories of wide row cotton production have generated producer interest across the cotton belt. The objective of this study was to quantify the effect of row spacing on (1) cotton growth and development and (2) lint yield and fiber quality in Georgia. The cotton cultivar Deltapine DP 1646 (Bollgard 2, XtendFlex; Bayer Crop Science) was planted in 2021 and 2022 in Tifton, GA, at row spacings of 91 cm, 122 cm, 152 cm, and 183 cm. Although canopy closure was delayed in wider row spacings compared to the 91‐cm spacing, all other crop growth and development trends did not differ among row spacings. Similarly, row spacing had no effect on the incidence of boll rot/hard lock. The 91‐cm row spacing yielded 1734 kg lint ha−1. The 183‐cm row spacing reduced yield by 15% compared with the grower's standard row spacing of 91 cm. Fiber quality parameters did not differ among row spacing treatments. Seed costs can be reduced in all wide row systems evaluated for cotton, and the 122 and 152‐cm row spacings had similar yields to the 91‐cm row spacing. However, Georgia growers produce peanuts (Arachis hypogea L.) and corn (Zea mays L.), the most common rotational crops for cotton producers, using a 91‐cm row spacing. Consequently, the simplest transition to wide row production would be the 183‐cm spacing, which incurred yield penalties in the current study. Thus, a 91‐cm row spacing is still the most feasible option for Georgia cotton producers.

COTTON GERMPLASM CHARACTERIZATION FOR DROUGHT TOLERANCE BASED ON MORPHO-PHYSIOLOGICAL AND FIBER QUALITY PARAMETERS

Drought tolerance is a quantitative trait that is exceedingly challenging to breed, especially for allotetraploids like cotton. The scenario of limited water resources necessitates developing droughttolerant cultivars that conserve significant irrigation water throughout the summer. Therefore, the presented study used a design to statistically analyze the morphological, physiological, and fiber quality parameters linked with drought tolerance, which is a comprehensive method for choosing better genotypes from the available cotton germplasm. Measuring these parameters ensued for plants grown under field conditions. The germplasm comprised 150 cotton genotypes studied at two water regimes, i.e., regular and water-stressed conditions for two consecutive seasons of 2015–2016 and 2016–2017. Data recording ran for different morpho-physiological and fiber quality parameters. Significant differences occurred for all the treatments, genotypes, and Genotype × Environment interaction for all the morphological, physiological, and fiber quality parameters under study. Additive Main effects and Multiplicative Interaction (AMMI) analysis and AMMI biplot analysis helped analyze the results, which revealed that the cotton genotypes FH-900, FH-901, FH-312, AS-1, AS-2, AS-3, RH510, RH-627, AR-2, AR-9, BH-118, BH-175, SLH-74, CIM-1100, CIM-598, and MM-58 were drought tolerant and ranked highest concerning stress condition. Moreover, correlation studies distinguished the relationship between relevant traits concerning drought tolerance.

Genetic progress in seed and fiber quality traits of cotton in Argentina

Context:The Argentinian national cotton (Gossypium hirsutum L.) breeding program has demonstrated a 3.24 kg ha−1 y−1 genetic progress in lint yield from 1965 to date. Although previous studies have examined different trends in cotton lint yield, lint quality parameters, and other agronomic traits of cultivars over time, there have been no investigations in Argentina analyzing the genetic progress in the different components of technological fiber quality, cottonseed oil and protein composition. Objectives:(i) to estimate the genetic progress of the lint and seed quality parameters among cultivars released in Argentina since 1965, (ii) to evaluate the variation of genetic progress for the lint and seed quality parameters under different environmental conditions, and (iii) to determine the correlations between lint quality and lint yield traits. Method:This study was conducted over a two-year period, involving 20 cotton cultivars grown in four different environments (achieved through varying sowing dates) in Reconquista, Santa Fe, Argentina. Several fiber variables were evaluated, including upper half mean length (UHML), strength (Str), uniformity index (UI), micronaire (Mic), short fiber index (SFI), and spinning consistency index (SCI), as well as seed measurements, such as cottonseed oil content (Oil), protein content (Prot), and cottonseed oil fatty acid composition. Results:Significant differences were observed in all the quality parameters evaluated according to the environment and genotype, highlighting the importance of agronomic management in improving the different quality parameters. Oil content in the genotypes and years studied showed significant increases over time. Likewise, the maintenance of quality parameters despite the significant increases in lint yield and some of its components is considered a positive result for the Argentinian breeding program. Pearson correlation analysis showed that LY was positively correlated with UHML, UI, SCI, oil, and linoleic acid, whereas LY was negatively correlated with SFI, and both stearic and oleic acids. Conclusions:The data obtained from this study would serve as a basis for future research to explore the mechanisms responsible for altering or increasing both the fiber quality parameters and the concentrations of these by-products to improve cotton quality in Argentina.

Breeding of brown cotton for spinnable yarn in intraspecific and interspecific hybrids (G. hirsutum L. and G. barbadense L.)

The negative association between pigmentation and fiber quality characters negatively affects the success of coloured fiber cotton breeding. Unfavourable linkage can be broken by crossbreeding multiple genotypes with different genetic backgrounds. We crossed two brown varieties with two white barbadense and four white hirsutum varieties. In 2022, twelve hybrids and their parents were grown in Randomized Complete Block Design with four replications. Variance analysis of line × tester showed that the differences among genotypes, parents and crosses were highly significant for seed cotton yield (SCY), ginning out-turn (GOT), fiber quality parameters and colour parameters such as L* , a* and b* . Among brown colour cotton genotypes, Gelincik formed the best hybrids with barbadense varieties, Giza-75 and Bahar-82, in terms of fiber colour and quality parameters. The significant and positive standard heterosis for seed cotton yield per plant and fiber length were recorded in Gelincik × Bahar-82 hybrids. Giza-75 and Bahar-82 were good general combiners for fiber length and strength. Gelincik × Bahar-82 and Gelincik × Giza-75 with acceptable colour values and superior fiber quality traits were found to be usable both for pedigree selection and for further studies on the use of hybrid varieties. Therefore, we highlighted that barbadense varieties must be included in breeding coloured fiber cotton.

Effect of Controlled Defoliant Application on Cotton Fiber Quality

Cotton (Gossypium hirsutum L.) is an important industrial crop. It is a perennial crop and has indeterminate growth habit, however, in most parts of the United States, it is grown as an annual crop with the application of growth regulators. Defoliation is a major production practice influencing harvester efficiency, fiber trash content, cotton yield, and fiber quality. Currently, defoliant application is done by using a conventional boom sprayer and aerial spraying in which both systems spray chemicals horizontally downwards from the top of the canopy, which causes minimal chemical to reach at bottom canopy. However, for successful defoliation, each leaf must receive the defoliant as chemicals do not move within the plant. Thus, a new autonomous ground sprayer was developed using robotics and pulse width modulation, which can be run in between two rows covering the whole canopy of the plant. Field research was conducted to study the effect of three duty cycles (20%,40%, and 60%) on cotton fiber quality using autonomous spraying system. The result indicated that the defoliants could be applied safely at either of the three duty cycles without compromising most of the fiber quality parameters except for nep/gm, length (Ln), L (5%), SFC, trash content in field 1 and micronaire, nep size, length (Ln), L (5%), SFC, and fiber fineness in field 2 which were significant. However, application of 20% duty cycle will significantly reduce the chemical use therefore, 20% duty cycle could be a good choice for the autonomous cotton defoliation. The development of autonomous spraying technology would encourage the development of new sprayer industries and the unmanned ground vehicle industries, together with the need for the global development of an agricultural system with broad market prospects and brings about huge economic, social, and ecological benefits.

Applying potassium to ruzigrass prior to cotton reduces the nitrogen requirement and improves yield in a sandy soil under low water availability

Nitrogen (N) and potassium (K) are the nutrients most extracted by cotton, and low-fertility sandy soil demands new management strategies to improve fertilization efficiency and yield. The objective of this study was to evaluate the effects of cover crops (fallow, velvet bean, ruzigrass, ruzigrass + velvet bean, inoculated ruzigrass (Azospirillum brasiliensis), and inoculated ruzigrass (Azospirillum brasiliensis) + velvet bean), potassium application timing (pre-planting or post-planting), N rate (80 and 120 kg ha−1) and growing season on cotton yield, yield components, and yield quality. Cover crop dry matter production was higher in the first growing season (2018/2019) than in the second growing season (2019/2020). In the season with the worst climatic scenario (2018/2019), the anticipation K increased number bolls, boll weight and fiber yield under lower application N rates (80 kg ha−1). The inoculated ruzigrass + velvet bean consortium increased fiber yield when 120 kg ha−1 of N was applied at pre-planting K. The fiber quality parameters were influenced by growing season and management. Pre-planting K application increased short fiber content (SFI) with cotton under inoculated ruzigrass. In summary, K application prior to cotton planting in sandy soil in years of rainfall instability enables higher fiber yields under lower N rates (80 kg ha−1), but with regular rainfall K management did not affect cotton yield under inoculated ruzigrass + velvet bean at higher N rate (120 kg ha−1).

Genotypic and environmental contributions to lint yield, yield components, and fiber quality in upland cotton from Arkansas variety trials over a 19‐year period

AbstractLint yields and their underlying yield components can be substantially influenced by genotype and environment. Thus, the objectives of the current study were to quantify genotypic and environmental contributions to lint yield, yield components, and fiber quality in multi‐site variety trials conducted in Arkansas over a 19‐year period, to identify the traits most strongly associated with lint yield, and to quantify long‐term trends in the aforementioned traits. Annual assessments included lint yield, seeds per hectare (SPH), intra‐boll yield components, and fiber quality parameters. Production environment accounted for a higher percentage of all yield variability in 15 out of 19 years. However, four years were identified in which genotypic contributions were greater than environmental contributions. Genotype was a dominant driver of variability in lint percent, lint index, seed score, seed index, fibers per seed, fiber density, fiber length, strength, and uniformity. Production environment was the dominant driver of variability in SPH, and micronaire. Correlations between yield components and yield varied substantially from year to year, even when genotype was the primary yield driver. A regression function that utilized lint index and SPH was a stronger and more consistent indicator of genotypic variation in lint yield than any single yield component. Finally, long‐term trends show that lint percent has increased significantly over the past 19 years, whereas seed index has declined 19.6% for cotton varieties with the highest lint yields.