Fiber Quality Index Research Articles

Impact of active root zone soil potassium levels on cotton yield and fiber quality under no tillage.

Potassium deficiency significantly hinders cotton growth and development, adversely affecting yield and fiber quality. Applying potassium fertilizer is a common practice to address potassium deficiency in the soil. However, the effectiveness of potassium fertilizer application depends on the appropriate soil potassium levels in cotton fields. This study used a randomized block design with six different soil potassium levels and conducted experiments across 18 micro-zones in the field. This study aimed to investigate the response of cotton yield and quality to different soil potassium levels, to try to clarify the suitable soil potassium levels for cotton growth, so as to provide practical and effective help for determining the amount of potash fertilizer in the cotton field. The results showed that the seedcotton yield was increasing, with the soil potassium level increased under no tillage. There was no significant difference among K4, K5, and K6 on seedcotton yield, which were significantly higher than K1 and K2. As soil potassium levels increased, the proportion of autumn boll and the proportion of outer boll also increased, indicating that higher soil potassium levels support the better growth and development of cotton in the middle and late stages, leading to increased boll sets and higher yields. Additionally, the available potassium content in the 0-40-cm soil layer was significantly correlated with yield and yield parameters but not with fiber quality indices. It is concluded that K4 treatment could provide sufficient potassium to meet the growth and development needs of cotton. Potassium fertilizer application is recommended when the available potassium content in the 0-40-cm soil layer falls below 122.88 mg kg-1 in the cotton field.

Integrative transcriptomic and metabolomic analysis revealed the molecular mechanisms of fiber length difference between the micropylar end and chalazal end of ovule in interspecific hybrid cotton (Gossypium hirsutum × Gossypium barbadense)

Cotton fiber is an indispensable raw material in the textile industry. Fiber length is an important fiber quality index, and the research on fiber length is also quite abundant. However, on the same ovule, there are only a few studies on the difference in fiber length development between the micropylar end and the chalazal end of the ovule. We elucidate the mechanism of fiber length differences at both ends of the ovule through the phenomics, transcriptome, and metabolome. The results show that 20, 25, and 30 days post anthesis (DPA) are the pivotal stages to causing the difference in fiber length at two ends of the ovules. Through the KEGG annotation of differentially expressed genes (DEGs), it was found that flavonoid biosynthesis, plant hormone signal transduction, and phenylpropanoid biosynthesis are enriched in DEGs, and similar conclusions were drawn in the analysis of differential abundant metabolites (DAMs). The results of in vitro culture of ovules showed that chlorogenic acid in the flavonoid pathway and scopolin downstream of the phenylpropanoid pathway have significant effects on fiber growth. Our research provide insights into the mechanism of cotton fiber elongation.

Enhancing cotton (Gossypium hirsutum L.) productivity and quality with magnetized ionized water and Bacillus subtilis intervention under film-mulched drip irrigation in saline soil in Xinjiang

ContextSoil salinity stress and limited nutrient availability significantly impede crop production. Addressing these challenges, the activation of irrigation water and soil enhancement strategies have proven increasingly effective in improving crop production in saline soils. In particular, magnetized ionized water technology has been shown to augment the leaching of soil salinity, while Bacillus subtilis has been applied to increase nutrient availability. However, information on the synergistic effects of magnetized ionized water and B. subtilis are presently limited. ObjectiveThis study aimed to investigate the potential of utilizing B. subtilis in combination with magnetized ionized water to enhance cotton (Gossypium hirsutum L.) production and understand its underlying driving mechanism. MethodsA two-year field experiment explored the impact of varying amounts of B. subtilis, with two types of irrigation water [non-magnetized-ionized water (NMIW) and magnetized ionized water (MIW)] on soil conditions (pH, salt accumulation, and nutrient content), and cotton growth (dry matter, nutrient accumulation, seed cotton yield, and quality) in southern Xinjiang's saline soil. The experiment included five B. subtilis levels (0, 15, 30, 45, and 60 kg ha−1) with NMIW (designated as B0, B1, B2, B3, and B4) and MIW (designated as MB0, MB1, MB2, MB3, and MB4). ResultsMIW and B. subtilis significantly (p < 0.05) reduced soil pH and salt accumulation, while B. subtilis significantly (p < 0.01) increased soil residual nitrate nitrogen and residual available phosphorus content in the 0–40 cm soil layers compared to B0. Furthermore, a significant increase (p < 0.05) in cotton dry matter, nitrogen, and phosphorus accumulation was observed with both measures compared to B0. Seed cotton yield (Y), water productivity (WP), and fiber quality index (FQI) also showed significant improvements (p < 0.05). Compared with the NMIW treatments, the MIW treatments resulted in an average increase in Y of 5.7%, WP of 3.7%, and FQI of 20.2%. Similarly, B. subtilis treatments, compared to no B. subtilis treatments, led to an average increase in Y by 10.6%, WP by 6.9%, and FQI by 29.1%. Quadratic function relationships with Y, WP, and FQI were established using B. subtilis amount as an independent variable. The appropriate range of B. subtilis amount under MIW treatment, corresponding to 99.5% of the maximum values of Y, WP, and FQI, was determined to be 51.1–56.4 kg ha−1. ConclusionMIW and B. subtilis have been found to increase nutrient accumulation in cotton by reducing 0–40 cm soil salinity and alkalinity and increasing 0–40 cm soil nutrient content, thereby enhancing cotton production. To optimize the cotton cultivation under film-mulched drip irrigation in saline soil of southern Xinjiang, China, it is recommended to apply 51.1–56.4 kg ha−1B. subtilis under MIW.

Statistical analysis of Cotton-Jute blended ratio for producing good quality blended yarn

The present world is focusing on sustainable products. Most of the natural products collected from are environmentally friendly. In the textile sector the main raw material is fiber. Most textile products are made from the natural cotton fibers. But because of the shortage of this fiber, most of the researchers are looking forwards to other sources of natural fibers. Here in Bangladesh the natural jute fiber is available and the textile industries are making jute products but the jute products are comparatively lower price than cotton products. That's why some factories are making cotton-jute blended yarn to minimise the cost and increase the product's quality and appearance. Here in this research work, it was tried to identify the best cotton-jute blended ratio for producing good quality yarn. 80C-20 J, 60C-40 J and 40C-60 J blended ratios are compared with 100 C and 100 J yarn to analyse the results. The CV m%, Thick/Km +50 %, Neps/Km +200 %, IPI, RKM and Elongation% of blended yarns are evaluated and compared the results between the ratios. After that the yarn quality index (YQI) was calculated to identify the ratio which indicates a relation between yarns strength, elongation% and CVm. The other quality index was fiber quality index (FQI) which indicates a relation between fibers strength, fiber mean length, elongation% and fiber fineness. One way ANOVA was applied to see the significance level between the independent variables. Box plot was applied to see the visual effect of statistical analysis at the same time the regression results show the impact of cotton-jute ratio with an equation, through which it was easy to identify the perfect ratio. It was found that higher percentage of cotton and lower percentage of jute fiber blended yarn shows good results than others. The products which were made from the ratios were shown good results for their different use of purposes.

Development of a cotton fiber quality simulation module and its incorporation into cotton crop growth and development model: GOSSYM

GOSSYM is a mechanistic, process-level cotton crop simulation model. It can simulate the growth and development of cotton under different environmental and management conditions and provide information on crop growth and development, various stresses, and yield. The current model version does not have the capability of simulating cotton fiber quality. Cotton fiber quality is as significant as fiber quantity. In this study, a cotton fiber quality simulation module is developed and integrated into GOSSYM. The functional relationships between the fiber quality and the major factors influencing fiber quality (temperature, water, and nutrient status) are established based on the temperature, water, and nutrient-controlled sunlit soil plant atmospheric research (SPAR) chamber experiments. In the developed model, the potential fiber quality in terms of four major fiber quality indices (fiber length, fiber strength, micronaire, and uniformity) is estimated based on the temperature function, and actual fiber quality indices are determined by reducing potential quality as a function of water and nutrient status in the crop. The newly developed model's fiber quality modeling capabilities are demonstrated using illustrative examples from a case study. Illustrated examples analyze the effect of different temperatures, nitrogen fertilizer application rates, irrigation, planting date, and atmospheric carbon dioxide concentrations on fiber quality indices. Simulation results are discussed by correlating them with underlying processes (growth and development, water, and nitrogen status), literature data, and functional relationships incorporated into the fiber quality module in GOSSYM. The model has demonstrated a reasonable simulation of fiber quality. The developed model can be a valuable tool for accurate cotton fiber quality simulations, lint yield production, fiber quality optimization, and making policy decisions under varying environmental and management conditions.

Quality of cotton fiber and its relationship with meteorological conditions

Cotton (Gossypium hirsutum L., variety latifolium Hutch) is produced by more than 60 countries and, despite the quality and multiplicity of its seeds use it is grown mainly for the production of fibers. The quality of the fiber can differ between different production environments, being a key factor in determining the price and quality of cotton destined for textile products. These differences in quality are mainly associated with cultivars and meteorological conditions, which influence the indicative parameters of fiber quality. The knowledge of the factors that condition the quality of the cotton fiber is important for the definition of the regions with potential for the production of superior quality fibers. Thus, as a way to subsidize the production of better quality cotton fibers, this work aimed to identify and classify the factors that interfere with the quality of the cotton fiber. Data from meteorological variables and cotton fiber quality indices of 32 Brazilian cultivars were submitted to Pearson's correlation and cluster analyses. These analyses were performed considering three phases of the cotton cycle: total cycle; last 100 days of the cycle; and last 50 days of the cycle. Finally, the results of correlation and clustering analysis were compared. In general, considering the total cotton cycle, it was possible to obtain better statistical correlations between the meteorological variables and the quality of the cotton fiber.

Rational biochar application rate for cotton nutrient content, growth, yields, productivity, and economic benefits under film-mulched trickle irrigation

Biochar application to soils has been proven to be an efficient way for yield enhancement in agricultural systems. However, what is the most economical biochar application rate (BCAR) for cotton in saline-alkali soils in arid and semi-arid zones remains unclear. To narrow the gap, this study aims to investigate how biochar application affected the nutrient content, growth, yield, quality, and productivity of cotton, and to find the rational BCAR. The three-year field experiments of biochar application combined with plastic film mulched drip irrigation were conducted for cotton in Xinjiang, China. The biochar was continuously applied to the farmland at 0 (in 2018)+ 0 (in 2019)+ 0 (in 2020), 10 + 10 + 10, NT (no test)+ 25 + 25, 50 + 50 + 30, and 100 + 100 +NT t ha−1 during cotton growth period of 2018–2020. The cotton growth, yield, and quality indicators were observed and used for computing water-fertilizer productivity. The cost-benefit analysis was referred to recommend a rational BCAR. All four biochar application treatments increased the leaf/stem/root nutrient (N, P, and K) content than control during different cotton growth stages. The daily relative content of chlorophyll increased with the increasing BCAR and were larger at biochar treatments of 50 and 100 t ha−1 than 0, 10, and 25 t ha−1. The growth and yield-related indicators (plant height, stem diameter, leaf area index and seed yield), irrigation water productivity, and partial fertilizer (N, P, and K) productivity consistently increased than control under biochar application conditions, and the BCAR of 10 t ha−1 showed the greatest advantages in enhancing germination rates, cotton yields, water-fertilizer productivities, and financial income than biochar treatments of 0, 25, 50 and 100 t ha−1. However, neither cotton fiber quality indices (length, Micronaire, strength or uniformity index) were significantly affected by biochar applications. Based on the economic analysis, the rational BCAR was 10 t ha−1 each year (continued for three years) for cotton planting, which was a best dose that could be applied to arid zones and have not been reported before.

Fiber quality and wood basic density of species of the Savannah for productive purposes

The objective of this study was to qualify the wood of the species Astronium fraxinifolium, Enterolobium gummiferum, Eriotheca pentaphylla, and Plathymenia reticulata of the Brazilian Cerrado for forestry productive purposes based on the classification of their wood basic density and fiber quality indices. Discs were removed at a height of 1.3 m from the ground, and opposing wedges were obtained. The analyzed parameters were: wood basic density, fiber dimension, and fiber quality indices. The wood basic density was negatively correlated with fiber length and thickness. E. pentaphylla presented low basic density, long fiber length, and greater fiber wall thickness. On the other hand, A. fraxinifolium, E. gummiferum, and P. reticulata woods presented medium/high basic density, short fiber length, and quality indices that foster them for energy purposes, paper production, and use in floors and civil construction.

Novel intra-boll yield components and Q-score can further evaluate the effect of phosphorus fertilizer on cotton yield and fiber quality

Novel intra-boll yield component traits and fiber quality indices have been used by breeders to select suitable Gossypium hirsutum L. lines, but there is little research on how these traits change during cultivation practices, especially fertilizer application. We hypothesized that these novel traits have obvious responses to phosphorus (P) fertilizer, which would explain the variation in yield and fiber quality under different P conditions. To address this hypothesis, a field test was conducted with a low-P sensitive cotton cultivar (Lu 54) and a low-P tolerant cotton cultivar (Yuzaomian 9110) under different P fertilizer rates (0 as control, 100, and 200 kg P2O5 ha−1) from 2016 to 2018. The results showed that P fertilizer application (100, and 200 kg P2O5 ha−1) increased the lint yield, and bolls per ha contributed most to the increase in lint yield, followed by boll weight and lint percentage. The increased bolls per ha under P fertilizer application was due to the accelerated process of boll forming and the slowing of shedding process. The increased boll weight under P fertilizer application could be explained by the higher seed biomass per boll and fiber biomass per boll, especially the latter. The higher seed biomass per boll was due to the increased seeds per boll, and higher fiber biomass per boll should be attributed to the increased fibers per seed under P fertilizer application. The positive contribution of lint percentage to lint yield formation under P fertilizer application could be attributed to the increased fiber biomass per seed. P fertilizer application decreased fiber micronaire, indicating that fiber thickness was decreased by extra P fertilizer, which might be associated with the negative effects of increased fibers per seed and fiber density. In addition, P fertility application promoted the elongation of fiber cells and fiber length uniformity, and increased fiber strength. The end result was an increase in the comprehensive fiber quality index (Q-score) after P application. Moreover, compared to Yuzaomian 9110, yield traits including lint yield, bolls per ha, seeds per boll, seed index, and SSA, and quality indices including fiber length, fiber strength, and Q-score were more sensitive to P fertilizer application in Lu 54.

Green Degumming Technology of Hemp and a Comparison between Chemical and Biological Degumming.

This paper provides an efficient and environmentally friendly biochemical degumming method for hemp fiber, which can address the problems of high temperature, high pressure, and extreme pollution of the traditional chemical method and the harsh reaction conditions of biological degumming, such as a long reaction time and pH. In the biochemical method, dilute solutions of alkali pectinase lyase and chemical additives were used to process the hemp fiber and then the fiber composition and structure were investigated. A comparison of the chemical, biological, and biochemical degumming methods shows that the biochemical method can replace the chemical one causing a similar degumming effect, both being better than the biological method. The best proportion of the biochemical solution was found to be 1.5% alkali pectinase lyase, and for chemical auxiliaries the total amount of alkali was ≤0.4% and the total amount of salt was ≤0.8%. The best conditions of the biochemical degumming process were determined to be a bath ratio of 1:10, reaction temperature of 60 °C, and the time of 60 min. After degumming, the composition of the fiber was as follows: lignin 3.69%, pectin 4.09%, hemicellulose 13.34%, and cellulose 78.87%. The fiber quality index of fibers dealt by the biochemical method shows that the linear density was 4.66 dtex, length was 35.6 mm, and fracture strength was 64.5 cN/dtex, which were higher than those treated by the chemical method. This shows that the biological degumming method can be a green degumming method with higher efficiency, lower consumption, and pollution, as well as has a broad application scope.

Optimal irrigation amount and nitrogen rate improved seed cotton yield while maintaining fiber quality of drip-fertigated cotton in northwest China

Improving the quality of cotton fiber is an important way to increase the competitiveness of cotton in the international market. However, how to improve fiber quality as much as possible without significantly reducing seed cotton yield is still a challenge to the cotton industry. A two-year field experiment was conducted in 2018 and 2019 to investigate the effects of irrigation amount and nitrogen rate on seed cotton yield and fiber quality traits of drip-fertigated cotton in northwest China. A comprehensive evaluation model was also developed to determine the optimal supply range of water and nitrogen to simultaneously improve seed cotton yield and fiber quality. There were four irrigation amounts (W0.6-60 % ETc, W0.8-80 % ETc, W1.0-100 % ETc and W1.2-120 % ETc, ETc was the crop evapotranspiration) and four nitrogen rates (N250-250 kg N ha−1, N300-300 kg N ha−1, N350-350 kg N ha−1 and N400-400 kg N ha−1). Increasing irrigation amount and nitrogen rate had positive effects on seed cotton yield. However, there was no significant difference in seed cotton yield between W1.0 and W1.2 and between N350 and N400. The optimal seed cotton yield was obtained under W1.0N350 in both 2018 (6655.58 kg ha−1) and 2019 (6309.3 kg ha−1). Water use efficiency (WUE) increased with the increase of nitrogen rate, and decreased with the increasing irrigation amount. Nitrogen partial factor productivity (PFPN) increased with the increase of irrigation amount, and decreased with the increasing nitrogen rate. There was a positive correlation between irrigation amount and fiber length, fiber strength, fiber quality index (FQI) and textile parameter, but a negative correlation with micronaire and short-fiber index. Fiber length, fiber strength, FQI and textile parameter first increased and then decreased with the increasing nitrogen rate. Irrigation amount and nitrogen rate had no significant effect on maturity index. There were strong correlations between the results of various evaluation methods, but the ranking differed among the methods. Based on the comprehensive evaluation model, the optimal combination of irrigation amount and nitrogen rate was W1.0N350. Through the combination of multiple regression and spatial analysis, the optimal supply range of irrigation amount of 334∼450 mm and nitrogen rate of 320∼400 kg ha−1was able to obtain over 90 % of the optimal seed cotton yield and 80 % of the optimal fiber quality.

Association analysis of drought tolerance traits of upland cotton accessions (&amp;lt;italic&amp;gt;Gossypium hirsutum &amp;lt;/italic&amp;gt;L&amp;lt;bold&amp;gt;.&amp;lt;/bold&amp;gt;)

<p indent=0mm>Drought stress is an important factor that leads to severe reduction in cotton fiber yield and quality worldwide, and new cotton varieties with high-yield, high-quality and drought-tolerant characteristics have been the goal for cotton breeding. In this study, 217 upland cotton accessions were selected for drought stress experiments and association study. The drought stress treatment panels were supplied with 50% the water volume of the controls, until the seedlings emerged. A total of 18 traits including agronomic traits, fiber yield indices and fiber quality indices, were investigated at two locations and for two years. After drought stress, there were significant differences in response between populations, and significant differences in phenotypic traits between control and treatments. The phenotypic data were analyzed by BLUP, and the drought resistance coefficient of each trait was calculated. A total of 393 loci were detected by 214 SSR marker in the tested cotton accessions. The average gene diversity coefficient was 0.402, with the range of 0.072–0.631; and the average PIC value was 0.329, ranging from 0.070 to 0.560. Genetic structure analysis showed that the group could be divided into two subgroups and it had no obvious correspondence with geographical origin. There were detected extremely 76 significant loci (<italic>P </italic>< 0.01), with explanation rate ranging from 2.931% to 7.218%, by association study using drought resistance coefficient (DRC) of 18 traits. Fourteen SSR marker could be detected by two or more traits at the same time. These results could provide a theoretical basis and reference for the parents selection and drought-resistant molecular marker-assisted breeding in cotton.

Phenotypic plasticity and genetic variation of cotton yield and its related traits under water-limited conditions

Global warming is limiting availability of water resources in arid and semi-arid regions, and so understanding water use efficiency (WUE) is increasingly important for agricultural production in those areas. As China is the largest cotton producing area, the problem of balancing WUE and efficient cotton production is a major issue. In this study, we used a natural population of 517 Upland cotton accessions to conduct a water-controlled trial in south and north of Xinjiang over two years. A total of 18 traits including agronomic traits, fiber yield indices and fiber quality indices, were investigated for broad-sense heritability and coefficient of variation. Appropriate water limitation was found to promote the establishment of favorable agronomic traits in cotton, associated with an increased cotton yield of 8.46% in Xinjiang, at the expense of a certain degree of fiber quality, such as decreased fiber length and an over-higher micronaire value. We detected 33 QTL related to response to water limitation using a drought resistance coefficient (DRC), and 6 QTL were found using a comprehensive indicator of CIDT (comprehensive index of drought tolerance) at the genetic level by integrating resequencing data. Two novel QTL-hotspots including six differentially expressed genes (DEGs) were further identified related to the drought response of cotton. These findings not only suggested a new approach to irrigation of cotton fields in Xinjiang, but also provided abundant genetic evidence for genetic breeders to study drought improvement of crops.

Agronomic evaluation of polymer-coated urea and urease and nitrification inhibitors for cotton production under drip-fertigation in a dry climate

Interest in the use of enhanced-efficiency nitrogen (N) fertilizers (EENFs) has increased in recent years due to their potential to increase crop yield and reduce environmental N loss. Drip-fertigation is widely used for crop production in arid regions to improve water and nutrient use efficiency whereas the effectiveness of EENFs with drip irrigation remains unclear. A field experiment was conducted in 2015 and 2016 to examine the effects of EENFs on yield, N use and quality of cotton (Gossypium hirsutum) grown under drip-fertigation in arid NW China. Treatments included an unfertilized control and application of 240 kg N ha−1 by polymer-coated urea (ESN), urea alone, or urea plus urease (NBPT) and nitrification (DCD) inhibitors. ESN was all banded in the plant row at planting, whereas urea was applied with 20% N banded at planting and 80% N by six fertigation events over the growing season. Results showed there was generally no treatment effect on seed and lint yield, N concentration or allocations, N recovery efficiency and fiber quality index of cotton. A lack of treatment effect could be due to N supplied with drip-fertigation better synthesized with crop N needs and the relatively high soil native NO3− availability, which hindered the effect of polymer-coated urea and double inhibitors. These results highlight the challenge of the employment of EENFs products for drip-fertigation system in arid area. Further research is required to define the field conditions under which the agronomic efficiency of EENFs products may be achieved in accordance with weather conditions.

Densidade básica e dimensões de fibra de um clone de eucalipto cultivado em diferentes locais

No Brasil, as espécies do gênero Eucalyptus são amplamente cultivadas em razão, principalmente, de sua boa capacidade de adaptação. Porém, existe a possibilidade de o comportamento fisiológico diferir entre plantas transplantadas para ambientes com características diferentes. O objetivo deste trabalho foi determinar a densidade básica da madeira e as dimensões das fibras de um clone de Eucalyptys grandis x E. urophylla com oito anos de idade, plantado em dois locais. Coletaram-se amostras de três árvores de cada um dos locais. A densidade básica média do sítio 1 foi de 0,556 g cm-³, enquanto a do sítio 2 foi 0,542 g cm-³. O comprimento e o diâmetro das fibras não apresentaram diferença significativa entre os sítios, porém, a espessura da parede e o diâmetro do lúmen da fibra apresentaram variação em razão do ambiente. Os índices de qualidade de fibra indicam que o material genético é adequado para a produção de celulose nos dois locais.

Water-induced variation in yield and quality can be explained by altered yield component contributions in field-grown cotton

Novel yield component traits and fiber quality indices have been recently developed by breeders to screen for desirable cotton (Gossypium hirsutum L.) lines, but assessing these components in response to water-induced yield variability has received little attention. We investigated the hypothesis that differential sensitivities of whole-crop and intra-boll yield components to drought will largely explain water-induced yield and fiber quality variation in cotton. To test this hypothesis, two cotton cultivars were grown in the field under five contrasting irrigation regimes during the 2013 and 2014 growing seasons near Camilla, GA. Measurements included predawn leaf water potential (ΨPD) throughout the growing season and extensive yield component and fiber quality assessments at the end of the season. Water-induced yield variability was primarily associated with ΨPD at the flowering and boll development phase of crop growth. Boll density (bolls ha−1) was the dominant driver of drought-induced yield loss, but reduced boll mass and seed number per boll also contributed somewhat to yield loss. By comparison, increased drought severity decreased fiber density but increased individual fiber mass, producing a peak in total fiber weight per seed at a −0.7 MPa ΨPD irrigation threshold and increasing lint percentage in stressed treatments. Thus, the negative impacts of drought on overall boll mass and seed number per boll are partially offset by increased dry matter partitioning toward fiber growth. Fiber length declined with increased drought severity, whereas fiber micronaire increased in the most severely stressed treatments. This indicates that increasing drought severity during flowering and boll development decreases the number of individual fibers per seed and their final length, but their thickness is increased. The end result is a decline in the overall fiber quality index (Q-score) under drought stress.

Effects of planting dates and shading on carbohydrate content, yield, and fiber quality in cotton with respect to fruiting positions

Two cotton (Gossypium hirsutum L.) cultivars, Kemian 1 (cool temperature-tolerant) and Sumian 15 (cool temperature-sensitive) were used to study the effects of cool temperature on carbohydrates, yield, and fiber quality in cotton bolls located at different fruiting positions (FP). Cool temperatures were created using late planting and low light. The experiment was conducted in 2010 and 2011 using two planting dates (OPD, the optimized planting date, 25 April; LPD, the late planting date, 10 June) and two shading levels of crop relative light rate (CRLR, 100 and 60%). Compared with fruiting position 1 (FP1), cotton yield and yield components (fiber quality, leaf sucrose and starch content, and fiber cellulose) were all decreased on FP3 under all treatments. Compared with OPD-CRLR 100%, other treatments (OPD-CRLR 60%, LPD-CRLR 100%, and LPD-CRLR 60%) had significantly decreased lint yield at both FPs of both cultivars, but especially at FP3 and in Sumian 15; this decrease was mainly caused by a large decline in boll number. All fiber quality indices decreased under late planting and shading except fiber length at FP1 with OPD-CRLR 60%, and a greater reduction was observed at FP3 and in Sumian 15. Sucrose content of the subtending leaf and fiber increased under LPD compared to OPD, whereas it decreased under CRLR 60% compared to CRLR 100%, which led to decreased fiber cellulose content. Therefore, shading primarily decreased the “source” sucrose content in the subtending leaf whereas late planting diminished translocation of sucrose towards cotton fiber. Notably, as planting date was delayed and light was decreased, more carbohydrates were distributed to leaf and bolls at FP1 than those at FP3, resulting in higher yield and better fiber quality at FP1, and a higher proportion of bolls and carbohydrates allocated at FP3 of Kemian 1 compared to that of Sumian 15. In conclusion, cotton yield and fiber quality were reduced less at FP1 compared to those at FP3 under low temperature and low light conditions. Thus, reduced cotton yield and fiber quality loss can be minimized by selecting low temperature tolerant cultivars under both low temperature and light conditions.

Development of a meta-model for the determination of technological value of cotton fiber using design of experiments and the TOPSIS method

ABSTRACTTo meet the requirements of the cotton spinning industry and achieve the best quality of ring-spun yarn, it becomes an imperative task to determine the technological values of cotton fibers. The availability of High Volume Instrument (HIV) data now makes it possible to evaluate the quality of cotton fiber with respect to some of its major physical properties. The fiber quality index (FQI), the spinning consistency index (SCI), and the multiplicative analytic hierarchy process (MAHP) are some of the popular approaches adopted by the spinning industry personnel to determine the quality values of cotton fibers. In this paper, while integrating the design of experiments (DoE) and the technique for order preference by similarity to ideal solution (TOPSIS), a regression meta-model is developed for determining the technological value of cotton fiber with respect to the TOPSIS score. This model identifies the statistically significant fiber properties and their interactions affecting the estimated TOPSIS score while fitting a polynomial to the experimental data in multiple linear regression analysis. It is observed that the uniformity index has no importance in quality value evaluation of the cotton fiber, although its interactions with other properties are statistically significant. A validation analysis shows an excellent degree of congruence of this meta-model with the existing models for cotton fiber quality determination.

Susceptible time window and endurable duration of cotton fiber development to high temperature stress

The development of the cotton fiber is very sensitive to temperature variation, and high temperature stress often causes reduced fiber yield and fiber quality. Short-term high temperature stress often occurs during cotton production, but little is known about the specific timing and duration of stress that affects fiber development. To make this clear, pot experiments were carried in 2014 and 2015 in a climate chamber using cotton cultivars HY370WR (less sensitive variety) and Sumian 15 (heat sensitive variety), which present different temperature sensitivities. Changes of the most important fiber quality indices (i.e., fiber length, fiber strength and marcironaire) and three very important fiber development components (i.e., cellulose, sucrose and callose) were analyzed to define the time window and critical duration to the high temperature stress at 34°C (max38°C/min30°C). When developing bolls were subjected to 5 days of high temperature stress at different days post-anthesis (DPA), the changes (Δ%) of fiber length, strength and micronire, as a function of imposed time followed square polynomial eq. as y=a+bx+cx2, and the time around 15 DPA was the most sensitive period for fiber quality development in response to heat stress. When 15 DPA bolls were heat-stressed for different durations (2, 3, 4, 5, 6, 7 days), the changes (Δ%) of fiber length, strength and micronire, as a function of stress duration followed logistic equations y=A1-A21+(X/X0)p+A2. Referred to that 5, 10 and 15% are usually used as criteria to decide whether techniques are effective or changes are significant in crop culture practice and reguard to the fiber quality indices change range, we suggested that 5% changes of the major fiber quality indices (fiber length, fiber strength and micronaire) and 10% changes of fiber development components (cellulose, sucrose and callose) could be taken as criteria to judge whether fiber development and fiber quality have been significantly affected by high temperature stress. The key time window for cotton fiber development in response to the high temperature stress was 13–19 DPA, and the critical duration was about 5 days.

Cotton genotypes selection through artificial neural networks.

Breeding programs currently use statistical analysis to assist in the identification of superior genotypes at various stages of a cultivar's development. Differently from these analyses, the computational intelligence approach has been little explored in genetic improvement of cotton. Thus, this study was carried out with the objective of presenting the use of artificial neural networks as auxiliary tools in the improvement of the cotton to improve fiber quality. To demonstrate the applicability of this approach, this research was carried out using the evaluation data of 40 genotypes. In order to classify the genotypes for fiber quality, the artificial neural networks were trained with replicate data of 20 genotypes of cotton evaluated in the harvests of 2013/14 and 2014/15, regarding fiber length, uniformity of length, fiber strength, micronaire index, elongation, short fiber index, maturity index, reflectance degree, and fiber quality index. This quality index was estimated by means of a weighted average on the determined score (1 to 5) of each characteristic of the HVI evaluated, according to its industry standards. The artificial neural networks presented a high capacity of correct classification of the 20 selected genotypes based on the fiber quality index, so that when using fiber length associated with the short fiber index, fiber maturation, and micronaire index, the artificial neural networks presented better results than using only fiber length and previous associations. It was also observed that to submit data of means of new genotypes to the neural networks trained with data of repetition, provides better results of classification of the genotypes. When observing the results obtained in the present study, it was verified that the artificial neural networks present great potential to be used in the different stages of a genetic improvement program of the cotton, aiming at the improvement of the fiber quality of the future cultivars.