Fiber Quality Parameters Research Articles

Effect of limited drip irrigation regime on yield, yield components, and fiber quality of cotton under Mediterranean conditions

Limited irrigation regime, known as deficit irrigation, is a common practice to cope with limited water availability. A two-year field experiment was conducted in order to determine the effect of limited irrigation regime on the growth, yield and fiber quality traits of cotton crop (Gossypium hirsutum L.). The experiment was set up as a split plot design with four replicates, two main plots (irrigation treatments) and two sub-plots (cotton cultivars). Plant water status, expressed in terms of the water potential index (WPI), growth in leaf area and biomass weight, seed yield, boll number, boll weight and fiber quality parameters were measured throughout the growing seasons. The adopted irrigation schemes produced a clear differentiation among cultivars concerning their plant water status. Water shortage resulted in more negative leaf water potential and water potential index and lower leaf area index and biomass values. Seed cotton yield and boll numbers per plant were positively affected by increased irrigation amounts while mean boll weight was less affected by irrigation levels. In particular, deficit irrigation resulted in 23% and 38% decreases in LAI, 29% and 27% in biomass, 16% and 28% in seed yield and 25% in boll numbers for Julia and Zoi, respectively, compared to the well-watered treatments. Fiber length was shortened in response to water stress while fiber strength, fineness and uniformity index were not consistently affected by irrigation levels. Negative linear functions of all parameters, with the exception of mean boll weight and lint percentage, against WPI values revealed significant differences in Y-intercepts and regression slopes between the two cultivars, indicating greater adaptability for ‘Julia’ in water stress conditions. In general, use of limited drip irrigation regime with 50% of water requirement had significant benefits in terms of saved irrigation water although it leads to a moderate decrease in yield without significant negative impact on the fiber quality parameters.

Reproductive and Fiber Quality Responses of Upland Cotton to Moisture Deficiency

Quantitative information between water deficit and cotton (Gossypium hirsutum L.) reproductive potential and fiber quality is needed to improve cotton model predictability. An experiment was conducted by seeding Upland cotton cultivar, Texas Marker (TM)‐1, in sunlit growth chambers. Four water stress treatments, 100, 80, 60, and 40% of daily evapotranspiration of the control, were imposed during flowering for plants grown at optimum temperature and nutrient supply. Soil moisture content and midday leaf water potential (LWP) were measured twice weekly during treatment period. Photosynthetic measurements taken during the stress treatments were correlated with midday LWP. New flowers and bolls were tagged daily to estimate boll maturation period (BMP). Plant‐ and boll‐component dry weights were recorded at end of the experiment. Lint sample collected, grouped based on average LWP during BMP, were analyzed for fiber quality parameters. Declining photosynthetic rates as plants experience water deficits were mostly to stomatal limitation, but non‐stomatal factors played a role as stress progressed. Seedcotton and seed weight, boll numbers, and total biomass declined significantly at severe water deficit treatments reflecting declining trends of photosynthesis. Fiber length, strength, and uniformity declined linearly with decrease in LWP, whereas fiber micronaire increased with decrease in LWP. Fiber strength was most responsive to changes in LWP followed by micronaire, length, and uniformity. Immature fiber content increased and fiber maturity ratio declined with diminishing LWP. The functional relationships between LWP and fiber properties will be useful to develop fiber sub‐models under optimal temperature and nutrient, but varying moisture conditions.

Grazing Winter Rye Cover Crop in a Cotton No‐Till System: Yield and Economics

Winter annual cover crop use is limited in conservation management systems in the United States. Grazing cover crops could encourage cover crop adoption if returns offset establishment costs without reducing crop yields. A 4‐yr field experiment was conducted near Watkinsville, GA, in which a rye (Secale cereale L.) cover crop was grazed by cattle or roller‐crimped before planting cotton (Gossypium hirsutum L.). Cattle consumed about 2.4 Mg ha−1 of forage annually but amounts were variable due to weather conditions. Rye residue remaining at cotton planting averaged 6.7 Mg ha−1 for non‐grazed compared with 1.7 Mg ha−1 for grazed treatments. Cotton yields tended to be better in the non‐grazed treatment but were significantly different only in 2009 when yields were reduced in the grazed treatment due to soil compaction. Four‐year average lint yield was 120 kg ha−1 greater for the non‐grazed treatment. Cotton fiber quality parameters were generally better in the non‐grazed treatment but not enough to change crop price. Differences between grazed and non‐grazed returns ranged from $–26 to $355 and averaged $81 ha−1 when based on market year prices. The difference in average return increased to $110 ha−1 when based on 2012 market year prices. Although negative effects of soil compaction were observed the final year, returns from grazing have the potential to offset establishment costs of a rye cover crop and increase profits for cotton producers in the Southern Piedmont of the United States.

Genetic association of within‐boll yield components and boll morphological traits with fibre properties in upland cotton (Gossypium hirsutum L.)

AbstractKnowledge of genetic relationships between within‐boll yield components and fibre quality is essential for simultaneous improvement of lint yield and fibre quality in upland cotton (Gossypium hirsutum L.). Nine parents and their F1 progeny with reciprocals from a 3 × 6 factorial mating design were grown in 2008 and 2009. Seven within‐boll yield components and two boll morphological traits and the three fibre quality parameters were analysed based on a conditional additive/dominance (AD) genetic model. Results showed that boll length contributed to the largest proportion of phenotypic, additive and dominance variances for UHM length; seed index contributed to the largest proportion of phenotypic and additive variances for fibre strength; boll width made the largest contribution to phenotypic and additive variances and the second largest contribution to dominance‐by‐environment interaction variance for micronaire, indicating that they played an important role than the other traits for fibre length, strength and fineness/maturity, respectively. It is worthy of note that those correlations between boll shape and fibre quality apply only to the nine parents and the resultant hybrids in this study and do not imply a cause and effect relationship.

Timing of Episodic Drought Can Be Critical in Cotton

Episodes of drought stress in upland cotton (Gossypium hirsutum L.) can be detrimental to vegetative growth, yield characteristics, and fiber quality, depending on the specific growth stage drought occurs. Growth, yield, fiber quality, and boll distribution were compared among four cotton cultivars subjected to four growth‐stage specific drought periods that were repeated in three studies over 2 yr in West Texas. Drought timings occurred at pinhead square, early bloom, and two periods of stress during peak bloom. Both years of the study were hot and dry, with minimal rainfall during the episodic drought treatments. Yield was not significantly different among cultivars, nor was there a significant cultivar × irrigation interaction related to cotton yield. However, there were differential effects on fiber quality among cultivars subjected to the different episodic drought timings. Drought stress during squaring resulted in significantly shorter plants with fewer nodes; however, yield was comparable to the highest yields among the other drought stress treatments, and fiber quality parameters were significantly improved compared to all other treatments except full irrigation. The early flowering growth stage was the most sensitive to drought stress and produced the lowest yields, the lowest fruit retention, and poor fiber quality. Drought events at peak bloom resulted in similar yield losses to those at squaring, but poorer fiber quality. This information may be crucial for producers who either have competing demands for water resources or who want to maximize profits or resources after the occurrence of a drought episode.

Relative Performance of DifferentBtCotton Cultivars Expressing Single and Dual Toxin for Pest Infestation, Yield and Fibre Quality Parameters

Present investigation assess the performance of 9 Bt transgenic cotton hybrids, viz. Four Bollgard I (Ankur 2226 Bt, JKCH 1945 Bt, NCEH 9 Bt and RCH 134 Bt), five Bollgard II (RCH 134 BG II, Tulasi 9 BG II, Ankur Jassi BG II, MLCH 315 BG II and KDCHH 441 BG II) along with one non-Bt hybrid (LHH 144) for insect pests, diseases, yield and fibre quality parameters at Cotton Research Farm, Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana. Overall mean boll infestation was comparatively low in Bt cotton hybrids ranging from 0.0 to 1.51 and 0.0 to 0.92 per cent on boll and loculi basis, respectively as against 12.37 and 6.70 per cent in non-Bt check LHH 144. Evaluation of Bt hybrids against cotton leaf curl disease was carried out under screen house conditions at Ludhiana and under field conditions at Regional Station, Abohar along with local non Bt variety F 1861 (resistant check) and RS 921 (susceptible check). Among all genotypes, only LHH 144 was found to be resistant to cotton leaf curl disease. All the hybrid entries showed resistance to bacterial blight due to low incidence, however found susceptible to fungal foliar disease. Therefore selection towards CLCuD and sucking pest tolerance in transgenic hybrids is crucial to realize the full potential of transgenic plants for sustainable cotton production. Among all hybrids, RCH 134 Bt recorded the highest mean seed cotton yield (2342 kg/ha) as compared to other test Bt hybrids (851 to 2083 kg/ha) and non-Bt hybrid, LHH 144 (1491 kg/ha). All Bt hybrids were superior to non-Bt LHH 144 with 8 to 57 per cent increase in yield except Ankur 2226 Bt, JKCH 1945 Bt, NCEH 9 R Bt, MLCH 315 BG II and KDCHH 441 BG II which were inferior suggesting that selection of superior genotypes with better yield characteristics is vital for developing transgenic cotton.

Selection of Plus Tree Based on Growth Performance and Fiber Morphology Characteristics as Improved Sources for Propagation of <i>Eucalyptus camaldulensis</i>

One of the most successful techniques in planting trees is tree improvement in which trees with high qualities are selected for mass plantation. This study seeks to identify good properties of Eucalyptus camaldulensis through selective phases. Sixty Eucalyptus camaldulensis trees (30 ten-year-old and 30 five-year-old) were randomly selected through stratified sampling from two plantation sites in Kurdistan region, North of Iraq. The trees were examined for fiber morphology and quality parameters such as height, number of branches, diameter and straightness. In the first phase of property selection, sixteen trees with high rank in growth properties and fiber morphology were selected. In the final phase of selection, the selected trees were re-examined according to the number of properties and fiber morphology features and seven trees with the highest number of good parameters were chosen. The 7 selected trees had higher qualities in growth characteristics and fiber morphology compared with the other trees in the sample. This article reports on a selection method for E. camaldulensis trees through tree improvement techniques. The results of the study indicates that high genotype qualities were identified among both 5- and 10-year-old E. camaldulensis trees as the final selection consisted of three 5-year-old trees and four 10-year-old trees.

Evaluation of Seed Cotton Cleaning Equipment Performance at Various Processing Rates

The processing rate per unit width of seed cotton cleaning equipment–cylinder cleaners and stick machines– recommended by manufacturers is 4.9 to 8.2 bales h-1 m-1 (1.5 to 2.5 bales h-1 ft-1). Survey data has indicated that many gins exceed this processing rate. Little research has been conducted with picker-harvested cotton, and higher rates that have been achieved in commercial gins have not been tested. Two independent experiments were performed to evaluate the effects of processing rates significantly higher than recommended on the performance of the cylinder cleaners and stick machine. Seed cotton was processed through a typical sequence of gin machinery: cylinder cleaner, stick machine,cylinder cleaner, extractor-feeder, gin stand, and lint cleaner. The quantity of material removed by each cleaner was measured and the fiber content of the waste was determined. Foreign matter content of the seed cotton and ginned lint and fiber quality parameters were also measured. The first study tested four cultivars of cotton harvested in 2008. The second experiment tested two cultivars harvested in 2009 at two seed cotton moisture levels. Lower processing rates increased the amount of material removed by the first stage cylinder cleaner and stick machine. Five of six cultivars tested had low fiber loss from the seed cotton cleaning system, while the other cultivar had an average fiber loss of 3.37 kg bale-1 (7.43 lb bale-1). Processing rate did not have a statistically significant effect on fiber loss; although a trend of increasing fiber loss from the stick machine at higher rates was observed for the cultivar with higher fiber loss. No effect on fiber quality due to processing rate was observed. More research is needed to determine the economic impact of higher than recommended processing rates, as extractor-feeders and lint cleaners may compensate for poorer cleaning, but were not tested at rates typically used in commercial gins.

Evaluation of Commercial Cotton Harvesting Systems in the Southern High Plains

<abstract><title><italic>Abstract. </italic></title> Cotton production practices have changed in the Southern High Plains of the United States over the last decade resulting in increased yields and improved fiber quality. Moreover, the majority of U.S. cotton now competes in a global fiber market that demands higher quality fiber for ring spun yarn than the former domestic open-end market. The brush-roll stripper harvester is the predominate machine used to harvest the Southern High Plains cotton crop, but interest in spindle pickers has increased recently in efforts to better preserve fiber quality, enhance profitability, and maintain the market share of U.S. cotton in the global fiber market. This work was conducted to compare yields, fiber quality, and agronomic parameters between picker and stripper-based harvest systems under commercial production and ginning conditions. Large-scale harvest system comparison tests were conducted at seven sub-surface drip irrigated sites across the Texas High Plains during the 2008-2010 crop years using brush-roll strippers with field cleaners and spindle pickers. Four cotton modules harvested from each site under each harvest method were ginned by a commercial gin. Compared to picker-harvested cotton, stripper-harvested cotton had 1096 kg ha^-1 higher seed cotton yield which increased ginning charges by $72.40 ha^-1. Seed and lint yields were 217 and 108 kg ha^-1 higher, respectively, for stripper-harvested cotton resulting in $88.78 ha^-1 higher total production revenue. Notwithstanding higher lint yield for the stripper system, custom harvesting was $51.38 ha^-1 more expensive for the picker system due to the custom harvesting rates used (picking: $0.22 per lint kg; stripping: $0.18 per lint kg). Except for strength and reflectance that showed no difference by harvest method, all High Volume Instrument (HVI) fiber quality parameters were improved for picker-harvested cotton. Due to improved HVI fiber quality and a substantial decrease in the number of bark contaminated bales, lint value was higher for picker-harvested cotton. However, increased lint value was offset by decreased yield such that net revenue was $66.76 ha^-1 higher for stripper-harvested cotton across all sites.

Evaluation of cotton fiber maturity measurements

Cotton fiber maturity, degree of secondary cell wall thickening relative to the perimeter, is one of the most important fiber quality and processing parameters of cotton. Immature fibers result in low dye uptake, increased fiber breakage, fabric defects, and waste. Because of that, breeders, cotton producers, spinners, and textile manufacturers desire cotton lint that is mature. However, fast and reliable methods to quantify maturity that fit into the current breeding and marketing systems are not available. The reference method to measure fiber maturity is the cross-section method, where 1μm thick fiber cross-sections are evaluated under a microscope. It is time consuming, tedious, and impractical for high volume measurement of fiber maturity. Interest is rising toward rapid routine instruments to measure fiber maturity such as the Advanced Fiber Information System (AFIS) and the cottonscope. The AFIS instrument individualizes and presents individual fibers to electro-optical sensors in order to measure fiber maturity while the cottonscope uses polarized light microscopy and image analysis to measure the maturity of fiber snippets. 104 reference cotton samples were tested with these three methods to assess the potential of these maturity measurements. Both AFIS and cottonscope maturity measurements show good correlations with the reference method. At this stage of our investigations it appears that the cottonscope may be faster than the AFIS and that its dynamic range is similar to that of the reference method. Both AFIS and cottonscope require a very small sample size (500mg for AFIS and 50mg for cottonscope). Therefore, both can be used in various cases where we only have access to a small sample (single boll sample for example). Nevertheless, obtaining a representative sample of the lint to be tested could be challenging.

Exploitation of Heterotic Pools of Hirsutum and Barbadense for Developing Potential Inter Specific Hybrids in Cotton

The elite barbadense combiners namely DB 533 and DB 534 were indentified for creation and exploitation of recombinational variability for combining ability. In 2007- 2008 this cross was made and early segregating generations were raised during 2008- 2009 / 2009-2010, out of 171 F3 lines 53 were identified based on productivity and fiber quality and advanced to succeeding generations. In F4 generation 28 barbadense lines were utilized to assess recombinational variability for combining ability. These selected F4 lines were crossed with 4 hirsutum testers figuring in the heterotic box identified in this study. The derived F1 crosses (28 x 4) were compared with the bench mark crosses (two barbadense lines x 4 hirsutum testers) of the heterotic box, best Bt check hybrid (MRC 6918) and non Bt check (DCH 32). The derived F1 crosses revealed considerable variability for per se performance measured in terms of productivity and fiber quality traits. Many derived F1 crosses were found to be more productive than non Bt check DCH 32 (48 hybrids) and the Bt check MRC 6918 (35 hybrids). The potential crosses like DH 98-27 X (DB 533 x DB 534 F4 IPS 49), DH 98-27 X (DB 534 x DB 533 F4 IPS 22) and DH 98-27 X (DB 533 x DB 534 F4 IPS 52) recorded highest per se performance for seed cotton yield. These crosses also recorded high value for yield attributing characters like number of bolls per plant, mean boll weight, seed index and number of sympodia per plant. These potential crosses recorded highly significant heterosis over mid parent for seed cotton yield. Apart from showing high productivity the potential cross DH 98-27 X (DB 533 x DB 534 F4 IPS 49 showed higher value of photosynthetic rate, stomatal conductance and fiber quality parameters. This potential cross is example for blending of yield characters, physiological parameters and fiber quality. The set of 28 lines distinguished for the ability to combine with each tester. The efficiency of tester in distinguishing of these F4 lines was determined based on mean seed cotton yield of 28 crosses and co-efficient of variability. In derived F1 crosses, tester DH 98-27 (T1) revealed high mean and also higher co-efficient of variance as compared to the other three testers for seed cotton yield. Both DH 98-27 and DH 18-31 were found to be efficient testers on the basis of high mean and high co-efficient variance. Considering mean and co-efficient variance as parameters T1 was found to be more efficient in distinguishing the barbadense F4 lines for their combining ability for utilized to distinguish lines. A method of sub grouping the F4 lines against each tester was done. Based on this elite combiner F4 lines were identified against each tester. This approach helped in sub grouping the F4 lines against a pair of hirsutum testers and identifying lines for deriving sub populations against hirsutum testers. Both the lines DB 533 x DB 534 F4 IPS 49 and DB 534 x DB 533 F4 IPS 22 have combined very well with four hirsutum testers. This suggests that these two barbadense lines can recombined to initiate second phase of creating recombinational variability for combining ability. The segregating F4 lines obtained from this cross can be crossed to these four hirsutum testers and especially DH 18-31 and DH 98-27 because the mean of crosses with these testers (T1 and T4) was very high. The F4 lines which gave more potential crosses than bench mark crosses were identified as transgressive segregants for combining ability (positive). Among the population used in the combining ability study, DB 533 x DB 534 F4 IPS 49, DB 534 x DB 533 F4 IPS 22 and DB 533 x DB 534 F4 IPS 52 F4 lines combined very well with all the four testers and revealed transgressive positive segregation for combining ability. These parents reveal diversity with respect to the identity of dominant favourable alleles contained in them. We can expect segregation at more number of yield influencing dominant loci. As a result of this variability is released at more number of loci and thus recombinant lines having desirable blend of favourable alleles distributed between two parents are obtained. Such lines give rise to superior derived F1 crosses. Key word: Recombinational variability, Efficiency of tester, Transgressive segregation, Sub grouping the F4 lines

Identifying of Extra Long Staple Suitable Lines (&lt;i&gt;Gossypium barbadense&lt;/i&gt; L.) with Improved Fiber Qualities to Release New Lines As an Alternative for Suvin Variety of Barbadense

There is a steep rise in production of long staple cotton, while production of extra long staple, short staple and even medium staple cotton has come down drastically. Because of this, India is importing extra long staple cotton by causing heavy birth on exchequer and there is a need of improving performance of interspecific hybrids. This is possible through genetic improvement of barbadense lines. The elite barbadense combiners namely DB 533 and DB 534 were indentified for creation and exploitation of recombinational variability for combining ability. In 2007-2008 this cross was made and early segregating generations were raised during 2008-2009/2009-2010, out of 171 F 3 lines 53 were identified based on productivity and fiber quality and advanced to succeeding generations. The F3 lines were evaluated for productivity and fiber quality parameters realizing the emphasis laid on developing ELS (Extra Long Stable) cotton hybrids out of 171 F 3 lines, only 53 F 3 lines with acceptable fiber strength were utilized in this study. The barbadense population of F4 lines was selfed and material was advanced to F 5 generation during the same year. This study also focused attention on determining whether these barbadense lines can straight away be utilized as varieties for producing ELS cottons. Hence, 53 F 5 barbadense lines were evaluated for productivity traits and fiber quality traits and compared with Suvin known to be standard barbadense variety in international market. The potential barbadense line DB 533 x DB 534 F5 IPS 18 showed superiority over Suvin line for seed cotton yield, mean boll weight, seed index, ginning outturn, lint index, fiber micronaire value, fiber strength and S/L ratio and can be used for developing separate trait based populations with other barbadense lines for yield components and fiber quality. Confirmation of their superiority will enable release of these new lines as an alternative for Suvin variety of barbadense.

Heterosis Performance of Seed Cotton Yield and Physiological Parameters in F&lt;sub&gt;1&lt;/sub&gt; Inter Specific Hybrids in Cotton

In order to known better the heterosis performance, yield and physiological parameters in 112 hybrids (F 1 ) and their parents the study initiated to create recombinational variability for combining ability, the elite barbadense lines DB 533 and DB 534 were crossed during 2007~2008. During two seasons 2008~2009 and 2009~2010 these barbadense crosses were advanced to F 2 and F 3 generations, respectively. The F 3 lines were evaluated for productivity and fiber quality parameters realizing the emphasis laid on developing ELS (Extra Long Stable) cotton hybrids out of 171 F 3 lines, only those F 3 lines with acceptable fiber strength were utilized in the study on recombinational variability of combining ability. During 2010~2011 those twenty eight F 4 lines of barbadense cross DB 533 × DB 534 depending on the higher value of fiber tenacity, were crossed with the selected four hirsutum testers viz., DH 98-27 (T 1 ), ZCH 8 (T 2 ), 178-24 (T 3 ) and DH 18-31 (T 4 ) selected based on earlier study. The derived F 1 crosses (28 barbadense lines x 4 hirsutum testers) were compared with the bench mark crosses (two barbadense lines x 4 hirsutum testers) of the heterotic box, best Bt check hybrid (MRC 6918) and non Bt check (DCH 32). Many derived F 1 crosses were found to be more productive than non Bt check DCH 32 (48 hybrids) and the Bt check MRC 6918 (35 hybrids). The potential crosses like DH 98-27 X (DB 533 x DB 534 F 4 IPS 49), DH 98-27 X (DB 534 x DB 533 F 4 IPS 22) and DH 98-27 X (DB 533 x DB 534 F 4 IPS 52) recorded highest per se performance for seed cotton yield. These potential crosses recorded highly significant heterosis over mid parent for seed cotton yield. They also recorded significant heterosis for other physiological parameters. Apart from showing high productivity the potential cross DH 98-27 X (DB 533 x DB 534 F 4 IPS 49 showed higher value of photosynthetic rate and stomatal conductance. This potential cross is example for blending of yield characters and physiological parameters.

An assessment of alternative cotton fibre quality attributes and their relationship with yarn strength

Knowing the yarn-strength performance potential of cotton fibre is advantageous to spinners during mill preparation, and to researchers developing new genotypes and management strategies to produce better fibre. Standard High Volume Instrument (HVI) fibre quality attributes include micronaire (a combined measure of fibre linear density and maturity) and bundle tensile properties. While these attributes relate well to yarn strength, alternative fibre quality attributes may better explain the variation in yarn strength. Two field experiments over two seasons were conducted to assess the fibre and yarn performance of some Australian cotton genotypes. The aim was to assess and compare alternative measures for micronaire, and to compare bundle and single-fibre tensile measurements, and assess the relative yarn-strength predictive performance of these attributes. Specific fibre measurement comparisons were for linear density (double-compression Fineness Maturity Tester (FMT) and gravimetric), maturity ratio (FMT, polarised light, calculated, and cross-sectional), and tensile properties (HVI bundle and Favimat Robot single fibre). Multiple linear regression models for yarn strength that included yarn manufacturing variables and standard HVI fibre quality parameters performed well (standard error of prediction (SEP) 2.40 cN tex–1). Multiple linear regression models performed better when alternatives to micronaire were used, e.g. using gravimetric linear density (SEP, 2.15 cN tex–1) or laser photometric determined ribbon width (SEP 1.71 cN tex–1). Yarn strength models were also better when single fibre tensile properties were substituted for bundle tensile properties (SEP 1.07 cN tex–1). The substitution of alternative fineness variables for micronaire or single-fibre strength for bundle strength in a simple fibre quality index also improved the prediction of yarn strength.

Cotton farming systems in Australia: factors contributing to changed yield and fibre quality

This study was undertaken to identify factors in Australian cotton farming systems that influence yield and fibre quality of cotton and how these have changed with time after the wide adoption of Bollgard II® cultivars (containing the proteins Cry1Ac and Cry2Ab, providing easier control of Helicoverpa spp.) in the 2003–04 season. Data from Australian commercial cotton variety trials conducted from 2004 to 2011 were used to link management inputs, yield, and fibre quality. Restricted (residual) maximum likelihood (REML) and regression analyses were used to determine which factors had a significant effect on yield and fibre quality. Results showed that lint yield was significantly influenced by cultivar and growing region, and the interaction between region and the amount of applied nitrogen and phosphorus (kg ha–1), plant stand (plants ha–1), in-crop rainfall (mm) and the number of irrigations, season length (days), and days to defoliation. Generally, the same factors also influenced fibre quality. Regression analysis captured 41, 71, 50, 30, and 36% of the variability in lint yield, fibre length, micronaire, fibre strength, and trash, respectively, for irrigated systems. For dryland systems the variability captured was 97, 87, 77 80, and 78%, respectively. Changes in cotton farming systems from 2004 to 2011 have occurred with applied nitrogen fertiliser increasing under irrigation and decreasing under dryland systems. However, phosphorus fertiliser use has remained steady under irrigated and decreased under dryland systems, and the number of insect sprayings has decreased under both systems. Under irrigated systems, lint yield, fibre length, and trash levels increased while micronaire and fibre strength decreased. Under dryland systems, lint yield decreased while micronaire, fibre length, strength, and trash levels increased. All fibre quality parameters satisfied criteria that would not incur a penalty. The results considering which factors are the most important and which are of lesser importance provide some insight to changes in management in both irrigated and dryland systems and the effect on lint yield and fibre quality and provide some basis for future investment in research and development and extension to the Australian cotton industry.

Dietary fibre sources in bread: Influence on technological quality

The Response Surface Methodology was employed to study the effects of adding different dietary fibre sources (wheat bran, resistant starch and locust bean gum), on process and quality parameters of pan bread. The experiments were carried out according to a 23 central composite rotational design (CCRD). With the experimental results or responses, the effect of each variable was calculated and the interactions between them were determined. For some parameters, such as proofing time, crust colour acceptance, crust appearance acceptance, taste acceptance and aroma acceptance, fibre addition did not present a significant effect. For the remaining parameters evaluated, it was possible to establish a mathematical model to explain the effect of the different dietary fibre sources. High-speed mixing time, crumb colour acceptance, crumb appearance acceptance and texture acceptance were influenced by the three different fibre sources studied. Wheat bran was the only fibre source that influenced specific volume and crumb chroma and hue angle. Wheat bran and locust bean gum (LBG) contributed to retain moisture in the crumb during all the storage period.

Combining ability analysis for within-boll yield components in upland cotton (Gossypium hirsutum L.)

Cotton is an important cash crop worldwide, accounting for a large percentage of world agricultural exports; however, yield per acre is still poor in many countries, including Pakistan. Diallel mating system was used to identify parents for improving within-boll yield and fiber quality parameters. Combining ability analysis was employed to obtain suitable parents for this purpose. The parental genotypes CP-15/2, NIAB Krishma, CIM-482, MS-39, and S-12 were crossed in complete diallel mating under green house conditions during 2009. The F₀ seed of 20 hybrids and five parents were planted in the field in randomized complete block design with three replications during 2010. There were highly significant differences among all F₁ hybrids and their parents. Specific combining ability (SCA) variance was greater than general combining ability (GCA) variance for bolls per plant (9.987), seeds per boll (0.635), seed density (5.672), lint per seed (4.174), boll size (3.69), seed cotton yield (0.315), and lint percentage (0.470), showing predominance of non-additive genes; while seed volume (3.84) was controlled by additive gene action based on maximum GCA variance. Cultivar MS-39 was found to be the best general combiner for seed volume (0.102), seeds per boll (0.448), and lint per seed (0.038) and its utilization produced valuable hybrids, including MS-39 x NIAB Krishma and MS-39 x S-12. The parental line CIM-482 had high GCA effects for boll size (0.33) and seeds per boll (0.90). It also showed good SCA with S-12 and NIAB Krishma for bolls per plant, with CP- 15/2 for boll size, and with MS-39 for seeds per boll. The hybrids, namely, CP-15/2 x NIAB Krishma, NIAB Krishma x S-12, NIAB Krishma x CIM-482, MS-39 x NIAB Krishma, MS-39 x CP-15/2, and S-12 x MS-39 showed promising results. Correlation analysis revealed that seed cotton yield showed significant positive correlation with bolls per plant, boll size and seeds per boll while it showed negative correlation with lint percentage and lint per seed. Seed volume showed significant negative correlation with seed density. Seeds per boll were positively correlated with boll size and negatively correlated with bolls per plant lint percentage and lint per seed. Similarly, lint per seed exhibited positive correlation with lint percentage and boll size showed significantly negative correlation with bolls per plant. Presence of non-additive genetic effects in traits like bolls per plant, seeds per boll, lint per seed, seed cotton yield, and lint percentage is indicative of later generation selection or heterosis breeding may be adopted. For boll size, seed volume and seed density early generation selection may be followed because of the presence of additive gene action. The parental material used in this study and cross combinations obtained from these parents may be exploited in future breeding endeavors.

Rapid measurement of cotton fiber maturity and fineness by image analysis microscopy using the Cottonscope®

Two of the important cotton fiber quality and processing parameters are fiber maturity and fineness. Fiber maturity is the degree of development of the fiber’s secondary wall, and fiber fineness is a measure of the fiber’s linear density and can be expressed as mass per unit length. A well-known method for fiber maturity and fineness is a cross-section image analysis and microscopy measurement. In general, typical cross-section image analysis and microscopy methods for fiber maturity and fineness can be slow and tedious to perform. Much interest has been shown in improved and rapid routine measurements of fiber maturity and fineness in the laboratory. The Cottonscope® is a new small footprint instrument for measuring fiber maturity and fineness, consisting of a longitudinal measurement of weighted fiber snippets in water using polarized light microscopy and image analysis. A program was implemented to assess the potential and capabilities of the Cottonscope to measure cotton lint maturity and fineness and to determine the major operational impacts on the Cottonscope results. The measurement was fast and easy to perform. The major operational impact on the Cottonscope results was environmental conditions (room temperature and relative humidity), and its impact was a concern for fineness only. Very good method agreement was observed between the Cottonscope and image analysis and microscopy method for maturity and fineness, with moderate coefficients of determination, R2s, and low residuals. Recommended operational protocols for routine Cottonscope measurements were developed.

Response of foliar application of KNO 3 on yield, yield components and lint quality of cotton (Gossypium hirsutum L.)

Effect of potassium on fiber quality characteristics and nitrogen on vegetative growth tends to be more critical when deficiency is expected in a field. Foliar applications of potassium may be used to supplement soil applications to maximize yields and improve quality of cotton. A cotton variety NIAB-111 was sown at Crop Physiology Research area, University of Agriculture, Faisalabad to check the effect of KNO3. Four different levels of KNO3 were applied with a control and water in foliar applications varying the number of applications on different stages. The crop was sown in a randomized complete block design with split plot arrangement and was replicated thrice to observe the effect of potassium on growth yield and fiber quality of cotton. Plant height, biomass, number of bolls, number of leaves per plant and all fibre quality parameters were significantly affected by increasing concentrations of foliar potassium. In most of the cases, spraying 2% foliar potassium gave significant results. As number of leaves, number of sympodial branches, number of bolls, plant biomass, Ginning out turn (GOT%), fibre micronaire, fibre uniformity, fibre length and fibre strength were significant at 2% application of foliar potassium. But in case of boll weight, 2% spray of foliar potassium was dominated by 1.5% spray of foliar potassium. In some cases, like number of leaves, number of sympodial branches per plant, fibre strength, micronaire, fibre sci, fibre uniformity and ginning out turn, both concentrations 1.5 and 2% had statistically similar effects. Key words: Potassium nitrate, foliar application, growth, yield, lint quality, cotton.

Effects of Mycorrhiza on Fiber Quality Parameters, Root Characteristics and Yield of Organic Cotton (Gossypium Hirsutum L.)

Organic cotton consists of a new industrial crop product. Field experiment was conducted to determine the effects of mycorrhiza on fiber quality parameters and yield components of cotton crop (Gossypium hirsutum L.). The experiments, conducted during 2006 and 2007, were laid out in a split plot design with four replicates, two main plots (organic and conventional system) and two sub-plots (cotton varieties: Athena and Fandom). There were statistically significant differences in reflectance between these two varieties. Moreover, there were correlation between lint characteristics and regression as well as linear functions between AMF and statistical important values of lint characteristics.