Colored Cotton Cultivars Research Articles

Fiber Quality of Colored Cotton As a Function of Potassium Fertilization in the Semi-Arid Region

ABSTRACT Naturally colored fiber cotton is an essential alternative green and organic for the textile industry, as it does not require chemical dyeing. However, the low availability of potassium during production can directly affect the quality of the fiber. Based on this, this study aimed to evaluate the fiber quality in naturally colored cotton cultivars submitted to potassium fertilization in a semi-arid region. The experimental design was in randomized blocks, with four replications, and the treatments were arranged in split plots. In the plot, the following were allocated: five K rates (0, 60, 120, 180, and 240 kg ha−1 of K2O); and in the subplots, the four colored cotton cultivars (BRS Rubi, BRS Safira, BRS Topázio, and BRS Verde). The results showed that K is involved in the length, uniformity, short fiber index, micronaire index, and reliability index of naturally colored cotton fibers. A longer fiber length of 30.45 mm was obtained at a dose of 240 kg ha−1 of K2O for the cultivar BRS Topázio. In addition, a higher uniformity (84.95%) was achieved with the dose of 240 kg ha−1 of K2O for BRS Verde. The dose of 240 kg ha−1 of K2O reduced (8.62% and 11.28%) the short fiber index in the cultivars BRS Rubi and BRS Safira, respectively.

Enhanced potassium use by colored cotton cultivars in the semiarid region of Brazil

Proper potassium (K) fertilization management is crucial for optimizing yield and minimizing environmental impacts in colored fiber cotton cultivars, particularly in semiarid regions. This study aimed to assess the efficiency of K use by colored cotton cultivars under K fertilization in a semiarid region. Two experiments were conducted in 2019 and 2021, representing two agricultural seasons. The experimental design employed randomized blocks with split plots and four replications. The main plots consisted of five randomized K doses (0, 60, 120, 180, and 240 kg ha-1 of K2O), while subplots included four cultivars of colored cotton (BRS Rubi, BRS Safira, BRS Topázio, and BRS Verde). The results revealed that BRS Rubi exhibited superior agronomic efficiency with a dose of 60 kg ha-1 of K2O in both agricultural seasons. The maximum efficiency of K use by colored cotton cultivars was achieved with a dose of 240 kg ha-1 of K2O in the semiarid region of Brazil. The cultivars BRS Rubi and BRS Topázio demonstrated the highest use efficiency. Furthermore, BRS Topázio displayed the highest K accumulation in plant shoots during both seasons.

Yield and Quality of Naturally Colored Cotton Fiber Fertilized with Phosphorus Rates in the Brazilian Semiarid

ABSTRACT Cultivating naturally colored fiber cotton has excellent potential for the Northeast of Brazil. However, its cultivation in the semiarid occurs with low use of technology and inputs in soils with the low phosphorus content. This work evaluated the productivity and fiber quality of naturally colored cotton cultivars under phosphorus fertilization in the Brazilian semiarid region. The experimental design was randomized blocks, with treatments arranged in split plots and four replications. The five P doses were allocated in the main plot, and four cotton cultivars were in the subplots. Variance analyses were performed for the characteristics evaluated in each agricultural harvest. Tukey test was used to compare the averages for cultivars and agricultural harvests. Increased P availability increased productivity and fiber quality of naturally colored cotton cultivars. Maximum fiber yield was obtained at 240; 240; 199.11, and 60 kg ha−1 in the first crop, respectively. The maximum fiber length was reached at 80.86 kg ha−1 in the BRS Verde cultivar. The maximum uniformity was obtained with the 138.49 kg ha−1, and the cultivar BRS Topázio obtained greater uniformity. Fiber strength increased with the application of P2O5.

In silico analysis of the regulatory gene families for proanthocyanidins biosynthesis in the genus Gossypium L.

The flavonoid pigments provide cotton cultivars with various shades of the naturally colored fiber. Despite of the deep knowledge about the flavonoids biosynthesis pathway in cotton, the genetic features underlying its control are not fully understood. Particularly, data on regulatory genes for the proanthocyanidins (PAs) branch are incomplete for the genus Gossypium L. Here we report results of comprehensive in silico analysis of the R2R3-Myb, bHLH-Myc and WD40 regulatory gene families, involved in the biosynthesis of flavonoid pigment PAs in cotton. For the first time, we identified regulatory genes R2R3-Myb, bHLH-Myc and WD40, including paralogous and homoeologous copies, among all sequenced diploid and allotetraploid cotton species: G. hirsutum L., G. barbadence L., G. raimondii L. and G. arboreum L. All duplication events occurred in the genome of the common diploid ancestor of the genus Gossypium and were supported by a negative evolution (Ka/Ks < 1). However, the GhTTG1/GhTTG3 genes are proved to be the most conservative and predominantly supported by selection, while GhTT2/GhMYB10 and GhTT8 are more variable and suitable for further analysis. The thorough study has suggested that all genes, with the exception of GhTT8-A2, possibly involved in the PAs biosynthesis. Therefore, information about structural organization and functionality of the all MBW genes in cotton genome is represented here. Revealing of the allelic diversities among identified genes, associating with contrast phenotype, may be useful for marker-assisted selection or genome editing for creation of naturally colored cotton cultivars with agriculturally valuable traits.

Economical nitrogen dose for production of irrigated naturally colored cotton in the semi-arid region

ABSTRACT Determining the economical dose of nitrogen (N) for colored cotton can increase yield and income of farmers. The experiment was carried out under field conditions at the Experimental Farm of the Universidade Federal Rural do Semi-Árido, in the years 2016 and 2017. The objective was to determine the economical N dose for four colored cotton cultivars. The experimental design was in randomized blocks, with split plots and four repetitions. Five N doses (0, 50, 100, 150 and 200 kg ha-1) were randomized in the main plots and four colored cotton cultivars (BRS Safira, BRS Rubi, BRS Topázio and BRS Verde) were randomized in the subplots. The characteristics evaluated were seed cotton yield, cotton fiber yield, N concentration in leaf tissue, technical dose and economical dose of N. Higher yield of naturally colored cotton can be obtained using the economical doses of 140 kg ha-1 N for cultivars BRS Rubi and BRS Verde, 150 kg ha-1 N for BRS Topázio and 160 kg ha-1 N for BRS Safira. Highest yield was achieved with the cultivar BRS Topázio and lowest with the cultivar BRS Verde.

Host preference, acaricides effects and population growth of Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) on white and colored cotton cultivars.

White and colored fiber cotton cultivars have been developed to increase production and opportunities for family farming. The broad mite, Polyphagotarsonemus latus (Banks) is an important pest in cotton crops, nevertheless, different cotton cultivars may influence its host selection and population growth. For P. latus control, acaricides application is commonly performed, although less is known about the sublethal effects of these products. Thus, the host preference and instantaneous rate of increase (ri ) of P. latus were evaluated on white and colored cotton cultivars, as well as the lethal and sublethal effects of acaricides through mortality tests and population growth. In free-choice tests to evaluate host preference among white and colored cotton cultivars, no preference was observed for P. latus. The instantaneous ri values were positive for all tested cultivars, however, differences were observed between the colored BRS Rubi and the white BRS 201. The population growth of P. latus decreased with increasing concentrations of the acaricides abamectin, spirodiclofen, azadirachtin and spiromesifen. Nevertheless, azadirachtin and spiromesifen presented positive ri values even at the highest lethal concentrations (LC90 ), while abamectin and spirodiclofen provided negative ri values of P. latus from LC90 and LC70 , respectively. No host preference of P. latus was observed among white and colored cotton cultivar. Abamectin and spirodiclofen presented relevant sublethal effects that should be considered for the integrated management of this pest.

Nitrogen utilization efficiency by naturally colored cotton cultivars in semi-arid region

Knowledge on nitrogen (N) utilization efficiency in colored cotton enables the correct management of N fertilizers, optimizing yield and minimizing environmental degradation.The objective of this study was to evaluate the N utilization efficiency and to determine the accumulation of dry matter and N by naturally colored cotton cultivars subjected to N fertilization in the Brazilian semi-arid region.The experiment was carried out under field conditions, at the Farm of the Federal Rural University of the Semi-Arid, in 2016 and 2017. The experimental design was in randomized blocks with split plots and four replicates, randomizing five N doses (0; 50; 100; 150 and 200 kg ha-1) in the main plot and four colored cotton cultivars (BRS Safira, BRS Rubi, BRS Topazio and BRS Verde) in the subplots. Dry matter and N accumulations, agronomic, recovery, agrophysiological and physiological efficiencies in N utilization, and harvest index were evaluated. Cotton accumulates around 130 kg ha-1 of N along its cycle and directs 56.3% to seeds, 29% to leaves, 10.6% to stem and 3.8% to fibers. Nitrogen agronomic efficiency and recovery efficiency decrease with increased N doses. The cultivar BRS Topazio is the most responsive to N fertilization and the cultivar BRS Verde is the least responsive.

Integration of Cotton Plant Resistance With Selected Organic Boll Weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae) Control Tactics

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is one of the key pests and limiting factors to cotton production in conventional and organic systems. We assessed the use of resistant and susceptible cotton cultivars, a neem-based insecticide (Natuneem), and trapping with an A. grandis grandis aggregation pheromone as possible control tactics. In the first of two growing seasons we evaluated resistance of colored fiber cotton cultivars BRS 200, BRS Rubi, BRS Safira, and BRS Verde, and white fiber cotton BRS Aroeira, against A. grandis grandis attack. In the second growing season we assessed three colored cotton cultivars grown in and without close association of BRS Aroeira, and two control tactics: the neem-based pesticide and trapping. Because BRS Aroeira showed resistance against A. grandis grandis in the first growing season, it was selected to be planted in close association with more susceptible colored cultivars in the second growing season. Field plots with white and colored cotton cultivars reduced the need to control A. grandis grandis using the neem-based pesticide. Control by the neem-based pesticide and by trapping were of comparable value although the traps provided measurable control during early cotton growth stages and the neem-based pesticide provided measurable control during later cotton growth stages.

Energetic characterization and evaluation of briquettes produced from naturally colored cotton waste.

Cotton crops generate millions of tons of lignocellulosic waste in Brazil that could be used in energy generation; however, the main destination of this raw material is soil incorporation. The aim of this work was to perform an energetic characterization and evaluation of briquettes produced from different agricultural waste of naturally colored cotton for power generation. The cultivars Brasil Sementes (BRS) Jade and Topazio were studied, with white cotton (BRS 286) as standard for comparison purposes. Two different parts of each species, stalk and cotton shell, were analyzed by bulk density, proximate analysis, higher heating value, cellulose, hemicellulose, protein, fat and lignin content, thermogravimetric analysis, and briquette mechanical strength. The results of the energetic characterization indicated a higher energetic potential of the colored species when compared with the white cotton, especially because of the volatile matter content, fixed carbon, and higher heating value. The briquette mechanical strength was higher in the samples formulated by a mixture of stalk and shell. Finally, it was concluded that the waste from colored cotton cultivars, Jade and Topazio, is capable to generate briquettes with good mechanical and physico-chemical characteristics, especially those formed by the mixture of stalk and shell.

Physiological Characteristics Associated with Fiber Development in Two Naturally Colored Cotton Cultivars

Core Ideas The dynamics of cellulose accumulation in colored cotton fiber increased in an S‐shaped curve, which was not asymmetric and could be simulated with Richards’ model (R2 &gt; 0.999). Chlorophyll concentrations (estimated by SPAD values) for colored cotton were lower, compared to white cotton, and the degradation rate was relatively faster. This resulted in lower contents of soluble sugar in the boll shell and the subtending leaf. In the boll shell and the fiber, colored cotton had lower ATPase, sucrose invertase, and UDPG‐PPase activities. At 40 DPA, the SS activity for colored cotton was lower than for white cotton. Naturally colored cotton (Gossypium hirsutum L.) fibers are commercially valuable, but low fiber quality limits their use. This study investigates changes in enzymes’ activities and substance contents involved in carbohydrate synthesis to provide a theoretical basis for improving colored cotton fiber quality. Brown cotton Xiangcaimian 2, green cotton Wanmian 39, and white cotton Sumian 9 (control) were used. Fiber cellulose accumulation for Xiangcaimian 2 and Wanmian 39 were lower than the control. Cellulose content was simulated by Richards’ equation (R2 &gt; 0.999) and follows an “S” pattern—initial slow accumulation 0–10 d post anthesis (DPA), then rapid 10–40 DPA, then slow 40–50 DPA. Maximum accumulation, the cumulative rate parameter, and maximum cumulative rate for cellulose of colored cotton were all lower for control. Further analysis showed SPAD chlorophyll meter readings, soluble sugar content, leaf sucrose invertase activity, adenosine triphosphatase, sucrose synthase, and uridine diphosphate glucose pyrophosphorylase (UDPG‐PPase) activities in colored fiber were lower than control. Results suggest insufficient nutrients for boll and fiber development, resulting in lower fiber quality and boll dry weight in colored cotton. Sucrose synthase and UDPG‐PPase activities in colored fiber were significantly correlated with fiber maturation (r = 0.884*, r = 0.914*) and fiber strength (r = 0.895*, r = 0.935*), indicating lower metabolite and enzyme activities in colored cotton reduced fiber quality. Therefore, it appears improving colored cotton fiber quality may require selection efforts to increase photosynthetic capacity in leaves and transportation capacity of carbohydrates in the boll to supply more nutrient during fiber development.

Carbon partitioning in the boll plays an important role in fiber quality in colored cotton

Assays were conducted to examine the photosynthesis of stem leaves and subtending leaves of cotton bolls, the fiber-quality parameters length, strength and micronaire, and dry matter accumulation in fibers, seeds and burs during fiber development in the colored cotton cultivars ZX-1 and G-7 and the white cotton cultivar LMY28. The results showed that fiber-quality parameters were all lower in ZX-1 and G-7 than in LMY28. The final dry weight of fiber was significantly lower in ZX-1 and G-7 than in LMY28, whereas the final dry weights of the seed and bur were both significantly higher. The seed harvest index was significantly lower in ZX-1 and G-7 than in LMY28 after 35 days post anthesis, when the seed harvest index decreased in colored cotton and increased in white cotton. These results indicated that the differential carbon partitioning in the boll was a key factor that resulted in poor fiber-quality parameters length and strength in colored cotton. Further, the time required for rapid dry matter accumulation (T) and the maximum speed of fiber thickening (Vm) were both significantly lower in ZX-1 and G-7 than in LMY28 for fiber strength, and the maximum speed of dry matter accumulation (Vm) differed significantly for the dry matter accumulation in the fiber, seed and bur between colored cotton and white cotton. These results show that Vm is a key factor for dry matter accumulation in the fiber, seed and bur, as well as for fiber strength.

Biological aspects of Aphis gossypii Glöver, 1877 (Hemiptera: Aphididae) on colored lint cotton cultivars

This paper outlines the results of a study into the biological aspects of Aphis gossypii Glöver on colored cotton cultivars through the construction of life tables. In addition, we evaluate the influence of density of gossypol glands and trichomes of leaves on the biology of the aphid. Tests were conducted in a climate chamber at 25 ± 2°C, with relative humidity (RH) at 70 ± 10%, and a photophase of 12 hours, using the cultivars BRS Rubi, BRS Safira, and BRS Verde. Newly hatched nymphs were individually isolated in petri dishes containing leaf discs of cotton cultivars on a layer of water-agar (1%) of approximately 5 mm thick. An evaluation of the trichomes and gossypol gland densities of the cotton leaf plants was performed under a stereomicroscope, delimited to an area of 1 cm², and a count and identification of those on the surface was made. The feed substrates that were evaluated influenced the nymphal stage of A. gossypii. BRS Verde provided the shortest duration and BRS Safira was the longest during this phase. The cultivar BRS Verde, with the lowest density of trichomes, provided a large number of nymphs and led to a higher net reproductive rate (R0). Given these results, conclusions can be drawn that the colored cotton cultivars influence the duration of nymphal and adult stages of A. gossypii. The cultivar with a high density of trichomes on leaves (BRS Safira) adversely affects the fertility parameters of A. gossypii.

The relationship between cellulose content and the contents of sugars and minerals during fiber development in colored cotton cultivars

The contents of cellulose, total carbohydrates, sugars (fructose, glucose, galactose, sucrose, and cellobiose), and minerals (nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium) were determined at various stages of fiber development in the brown cotton cultivar ZX-1, the green cotton cultivar G-7, and the white cotton cultivar LMY28 of Gossypium hirsutum L. Cellulose contents during fiber development changed along S-shaped curves among the tested cotton cultivars. The cellulose content was significantly higher in the white cotton cultivar LMY28 than in the colored cotton cultivars ZX-1 and G-7 after 25 days post anthesis (DPA). Sugar and mineral contents showed significant changes during fiber development. Fructose, glucose, galactose, cellobiose, nitrogen, phosphorus, potassium, sulfur, and magnesium contents were essential for cellulose deposition during fiber development. In this study, glucose was shown to be a direct precursor and key sugar in cellulose biosynthesis in cotton cultivars. There may be a special mechanism in colored cotton cultivars that greater amounts of total carbohydrates, especially glucose, and minerals (nitrogen, phosphorus, potassium, sulfur, and magnesium) were consumed by the biosynthesis and deposition of fiber pigments than in the biosynthesis of cellulose. This finding could explain why the cellulose content was significantly lower in the colored cotton cultivars than in white cotton.

Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae)

Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae). The aphid Aphis gossypii is an insect pest that causes damage mainly at the beginning of the cotton plant development. The effect of resistance inductors silicon and acibenzolar-s-methyl (ASM) on the development of colored cotton plants were researched in the presence and absence of A. gossypii. Three colored cotton cultivars were sown in pots and individually infested with 25 apterous aphids, 13 days after the application of the inductors. Fifteen days after plant emergence, the silicon was applied at a dosage equivalent to 3 t/ha and acibenzolar-s-methyl in 0.2% solution of the product BION 500®. After 21 days of infestation the following parameters were evaluated: plant height, stem diameter, dry matter of aerial part and root, and total number of aphids replaced. It was verified that the plant height was reduced in the presence of aphids and all variables were negatively affected by the application of ASM. However, silicon did not affect plant development.

Relationship between Super-Molecular Structure Changes and Fiber Quality in Fiber Development Process of Colored Cotton Cultivars

In order to explore the reasons for poor quality of colored cotton fiber,the experiments were conducted with five cotton(Gossypium hirsutum L.) cultivars,including Zongxu 1(ZX1),Xincai 1(XC1),Longlumian 2(G-7),Lu 1-4560(4560),and the contrast of white cotton Lumianyan 28(LMY28).Dynamic changes of super-molecular structure and fiber quality and the relations between them in fiber development process of colored cotton were studied by X-ray diffraction technique.The results showed that the ultimate fiber length,fiber 3.2 mm gauge tenacity,fiber maturation and fiber micronaire of all cotton cultivars ranked as LMY28ZX-1 and XC-1G-7 and 4560.The corresponding crystalline grain size increased constantly and orientation parameters diminished gradually in fiber development process,but there were differences among different cultivars.Compared with the white cotton LMY28,ZX-1 and XC-1 had low initial value,too large amplitude and slightly lower termination value for crystalline grain size of fiber;low initial value,small diurnal variation and high termination value for orientation parameters.For G-7 and 4 560 fibers,the initial value of crystalline grain size was low,the increased amplitude was small and the termination value was slightly lower;the initial value of orientation parameters was high,diurnal variation was small and the termination value was high.The crystalline grain size had a correlation with 3.2 mm gauge tenacity(r = 0.89621*),as well as,the orientational distribution angle-ψ(°) and spiral angle-φ(°) had a negative correlation with fiber 3.2 mm gauge tenacity,fiber maturation and fiber micronaire(r=-0.93816* to -0.90233*),moreover,the orientational separate angle -α(°) had a negative correlation with fiber length(r=-0.97314**).In conclusion,the poor quality of colored cotton fiber is probably in relation to poor fiber 3.2 mm gauge tenacity,fiber maturation,fiber micronaire,fiber length,resulting from low initial value and termination value of crystalline grain size and high termination value of orientation parameters in fiber development process.

Characteristics of Fiber Quality in Cotton Development and Its Regulation by Hormone in Two Natural Colored-Cotton Cultivars

The brown cotton cultivar Xiangcaimian 2,green cotton cultivar Wanmian 39,and white fiber control cultivar Sumian 9 were used to study the fiber developmental characteristics and the effect of hormones on fiber quality with sampling different stages after anthesis.The results showed that fiber length of the brown and green cotton cultivar was lower than that of control,and that of the green cotton always lower than that of brown cotton.Compared with the control,the fiber strength,fiber micronaire,fiber maturation of natural-colored cotton were lower.The lower fiber length for the green cultivar was due to the less increase during 10 to 30 days post anthesis(DPA),the lower fiber strength,fiber micronaire,fiber maturation of natural-colored cotton were due to the slower growing speed at the pivotal stage.The IAA content at 10 DPA,the ABA content at 30 to 40 DPA in fiber of the two natural-colored cultivars were lower than that of Sumian 9.In comparison with control,in the treatment of applying 20 mg L-1 GA3,the IAA content in the fiber of Xiangcaimian 2 and Wanmian 39 at 20 DPA increased by 51.07% and 64.33%,respectively at boll opening stage,and fiber length also enhanced by 8.13% and 13.96%,respectively at boll open stage.The ABA content in fiber in the treatment applying 20 mg L-1 ABA at 40 DPA increased by 38.96% and 24.40% for Xiangcaimian 2 and Wanmian 39 respectively.The fiber strength,fiber micronaire,fiber maturation also enhanced at the boll opening stage,especially for Wanmian 39.Those results suggest that endogenous hormones affect fiber quality,application of ABA and GA3 with suitable concentration can increase the content of hormones in the natural-colored cotton fiber and advance the fiber quality,and the effect of different hormones are different.