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Evaluating the cultivars' performance is an important step in the cotton breeding process. Therefore, we tested the yield, fiber quality and within-boll yield components of genotypes, and associations among observed characters were estimated. Ten cotton genotypes inc., Bomba, Özbek 100, Ramses, May 455, Bir 949, Fiona, Şahin 2000, Sahra, Sasha and Eva, were planted in a Randomized Complete Block Design with four replications in 2022. The highest seed cotton yield was recorded in Sasha and Bomba genotypes. Ramses performed the higher ginning out-turn (47.70%) and favorable fiber fineness (4.62 mic.). Bir 949 (32.65 mm), Ramses (31.49 mm) and Sasha (31.31 mm) for fiber length; Sasha (35.18 g tex-1 ) and Sahra (34.08 g tex-1 ) for fiber strength exhibited desirable performances. The highest relative leaf water content (%) as a drought indicator was recorded in Ramses (67.79), Fiona (67.45), Şahin 2000 (65.25) and Bomba (65.11). The number of fibers per seed ranged from 10.82 thousand (Özbek 100) to 13.00 thousand (Bir 949). It was concluded that it seemed difficult to associate the seed cotton yield, fiber quality and relative leaf water content. Therefore, the genotypes in which all three traits are optimized should be emphasized. [ABSTRACT FROM AUTHOR]

Optimizing irrigation strategies is crucial for sustaining cotton production in the face of growing water scarcity. The three-year experimental study (2020–2022) focused on the impact of varying irrigation amounts (320, 370, and 420 mm) and frequencies (4-, 8-, and 12-day intervals) on cotton growth, yield, yield components, and fiber quality in southern Xinjiang. Employing a completely randomized design with three replications, the results indicated higher irrigation amounts resulted in numerically 2.5–7.5% higher lint yields compared to those under medium and low irrigation amounts, notably significant in 2021. Boll density emerged as the primary yield component influencing yield loss due to irrigation amount, followed by seed cotton weight boll−1. Increased boll density was associated with a greater total number of fruiting sites. Additionally, the increased seed cotton weight boll−1 could be linked to an increased seed number boll−1 and a decreased boll fraction at the lower fruiting branches with lower seed cotton weight boll−1. Higher irrigation frequency improved lint yield by increasing boll density, though a significant effect was observed only in 2020. Increased irrigation amounts generally led to longer fiber lengths but lower micronaire values, while increased irrigation frequency resulted in longer, stronger fibers and reduced micronaire values. Furthermore, the highest yield stability was observed under the condition of high irrigation amount and high frequency. This study holds certain guiding significance for water resource management in cotton production in arid regions. [ABSTRACT FROM AUTHOR]

Optimizing irrigation strategies is crucial for sustaining cotton production in the face of growing water scarcity. The three-year experimental study (2020–2022) focused on the impact of varying irrigation amounts (320, 370, and 420 mm) and frequencies (4-, 8-, and 12-day intervals) on cotton growth, yield, yield components, and fiber quality in southern Xinjiang. Employing a completely randomized design with three replications, the results indicated higher irrigation amounts resulted in numerically 2.5–7.5% higher lint yields compared to those under medium and low irrigation amounts, notably significant in 2021. Boll density emerged as the primary yield component influencing yield loss due to irrigation amount, followed by seed cotton weight boll−1. Increased boll density was associated with a greater total number of fruiting sites. Additionally, the increased seed cotton weight boll−1 could be linked to an increased seed number boll−1 and a decreased boll fraction at the lower fruiting branches with lower seed cotton weight boll−1. Higher irrigation frequency improved lint yield by increasing boll density, though a significant effect was observed only in 2020. Increased irrigation amounts generally led to longer fiber lengths but lower micronaire values, while increased irrigation frequency resulted in longer, stronger fibers and reduced micronaire values. Furthermore, the highest yield stability was observed under the condition of high irrigation amount and high frequency. This study holds certain guiding significance for water resource management in cotton production in arid regions.

Relationships between yield components and lint yield are complicated because of interrelationships among them. Traditionally, the exploration of these interrelationships was analyzed by path coefficients which requires a priori knowledge of the cause and effect relationships. Commonality analysis is a method of multiple regression to dissect the total effects of yield components to yield into direct effects and indirect effects. This study was designed to dissect relationships of yield components to yield based on commonality analysis and determine correlated selection responses of yield to selections of different yield components. Selections were made within 300 F3 plants in 2017 for the top seventy-five plants by LP and six within-boll yield components, lint weight per seed, seeds per boll, seed surface area, lint weight per fiber (LWF), lint weight per unit seed surface area, and lint number per unit seed surface area. F4 progenies were evaluated in field with two replicates in 2018. Direct coefficients of the seven single yield components ranged from 0.00 to 0.18 with LP as the largest contributor. Indirect coefficients of multiple components ranged from − 0.04 to 0.08. Five single yield components and five multiple yield components were chosen for selections based on their relatively large coefficients to yield. The correlated selection response (CR) of lint yield, 1684 kg ha−1, in F4 was significantly positive to selections by LP, but the CR of seed size and fiber length was negative to the selection by LP. The CR of lint yield, 1769 kg ha−1, to selections by multiple yield components of LP-LWF, had 5% increase compared with the selection by LP alone. There was no significant CR of seed size and fiber length to these selections. This study was a first application of commonality analysis in crop breeding and results provide evidence for its feasibility in exploration of interrelationships among yield components in breeding. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) yield is determined by whole-plant and within-boll yield components. Little information exists regarding within-boll yield component variations related to the planting date. This study aimed to investigate whether the differences in within-boll yield components will largely explain yield variation across planting dates under a double cropping system of wheat (Triticum aestivum L.) and short-season cotton. Two contemporary cotton cultivars were grown in the field with four different planting dates (PD MAY10 , PD MAY20 , PD MAY30 and PD JUN10) for the 2019–2021 growing seasons. Climatic variables and cotton growth periods, plant mapping, extensive yield components and fiber quality assessments were recorded each year. Compared to PD MAY10 , the lint yields of PD MAY20 , PD MAY30 and PD JUN10 were reduced by 3.8%, 14.7% and 44.1%, respectively. The significant yield loss in PD JUN10 could be explained by the variations in yield components. At the canopy level, boll density was the greatest contributor (75.6–90.8%) to yield loss. Moreover, within bolls, lint mass per seed (11.2–18.2%) and lint mass per unit seed surface area (11.9–16.2%) accounted for the most yield loss. In addition, seed number per boll, lint mass per seed and lint mass per unit seed surface area decreased by 1.0–6.2%, 7.3–15.0% and 5.5–13.4% for PD JUN10 relative to PD MAY20 , PD MAY30 and PD JUN10 , respectively. The number of fibers per seed and the seed index remained relatively stable among the planting dates across all three years. No significant differences in fiber length and fiber strength were observed among planting dates in 2019 and 2020, while shorter and weaker fibers were observed for the earliest planting date in 2021, possibly because of extreme rainfall that occurred at the end of July, indicating that a deteriorated environment could reduce the effect of the planting date. Among all climatic variables, the daily maximum temperature during the flowering and boll development stage had the strongest correlation with the lint yield. The first three planting dates generally produced comparable lint yields and fiber qualities. Therefore, it might be important to plant short-season cotton before May 30th in the Yellow River Valley to maintain relatively high yield and fiber quality. This study provided new results to assist decision making regarding cotton planting date in double cropping of wheat and cotton in the Yellow River Valley. • Yield differences between planting dates can be traced to within-boll yield components. • Quantifying the contribution of within-boll yield components to lint yield variation. • Within boll, the lint mass per seed explains the most yield variation between planting dates. • The daily maximum temperature during the flowering and boll development stage showed the highest correlation with lint yield. [ABSTRACT FROM AUTHOR]

Combining ability and heterosis for within-boll yield components and fibre quality traits were carried out using line × tester mating system in upland cotton at the University of Agriculture, Faisalabad, Pakistan.Variance due to specific combining ability was greater than general combining ability for all the traits depicting the importance of non-additive genetic effects.The line BH-89 was found to be good general combiner for lint mass per boll, seed volume per 100 seeds, surface area per seed and lint percentage. NIAB-999 was good general combiner for fibre fineness. The third line which was actually the F1 of the first two lines performed better regardingseed number per boll, seed mass per bolland fibre strength.Among testers, NIAB-78 exhibited higher GCA effects for seed number per boll, lint mass per boll and fibre fineness while CIM-1100 proved to be good general combiner for seed volume per 100-seeds, surface area per seed and lint percentage. NIAB-999 × VH-144 exhibited the highest SCA effects regarding seeds per boll and seed mass per boll while the cross NIAB-999 × CIM-70 was considered desirable for seed volume per 100-seeds and surface area per seed. Maximum heterosis over better parent for lint mass per boll and lint percentage was observed for the cross BH-89 × NIAB-78 while for seed volume per 100-seeds and surface area per seed, NIAB-999 × CIM-240 was the best. [ABSTRACT FROM AUTHOR]

Cotton productivity on a per-hectare basis is low in Pakistan. As boll is the basis for seed cotton yield, within-boll yield components can potentially serve as the most basic determinants of cotton productivity on a per unit land area basis. Before attempting the improvement of any trait, it is necessary to know the genetic mechanism lying behind its inheritance. The current study aimed to estimate the genetic basis of within-boll yield components in cotton. The research trials were conducted at the research area of the Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan. Epistasis was found to be involved in all traits such as average boll weight, seed number boll-1, seed mass boll-1, lint mass boll-1, lint mass seed-1, seed index, seed volume 100-seeds-1, seed density, and surface area seed-1. Additive variance was greater in magnitude than dominance variance for traits such as lint mass boll-1 and lint mass seed-1 in cross I and for seed number boll-1, seed mass boll-1, and lint mass seed-1 in cross II. The magnitude of both variances was nearly equal for seed density in cross I and seed number boll-1 in cross II. While dominance variance was found to be greater in magnitude than additive variance for all the remaining traits in both crosses, the degree of dominance (H/D) in cross I was partial for lint mass boll-1 and lint mass seed-1. We found complete dominance for seed density and overdominance for the remaining traits. While in cross II the degree of dominance was partial for seed mass boll-1 and lint mass seed-1, complete dominance was found for seed number boll-1 and overdominance for the remaining traits. [ABSTRACT FROM AUTHOR]

Moisture deficit stress reduce lint yield by affecting yield and basic within-boll yield components. Field experiments were conducted in the Aegean region of Turkey during 2008 and 2009 to observe the responses of three cotton cultivars differing in maturity and seed size to deficit water stress under different plant densities. Deficit irrigation inversely affected boll distribution, yield components and within-boll yield components. It is interesting to note that yield components in this investigation differed greatly between M-2005 (late-maturing and large-seeded cultivar), and Carmen (late-maturing and smaller-seeded cultivar) and Flash (early-maturing and smaller-seeded). Non-significant irrigation x plant density for all investigated characters except for boll distribution showed that the response of cotton plant to water stress was determined by cotton genotype. Deficit irrigation inversely affected yield components and within-boll yield components. Deficit water stress decreased boll number located upper and distal positions; total seed surface area per m², and seed number per m² for M-2005 more than Carmen and Flash. These results suggest late-maturing and also small-seeded cultivar would be preferable under deficit irrigation, and that cultivars with small seed are able to produce higher lint yield thorough the production of more bolls, seeds, and total seed surface area m-2 than large-seeded cultivars. [ABSTRACT FROM AUTHOR]

Relationships between lint yield and within-boll yield components are important for genetic improvement of lint yield in cotton ( Gossypium hirsutum L.) cultivars. F plants derived from crosses between germplasm lines and high yielding cultivars were analyzed to determine the contributions of within-boll yield components to lint yield and to select parents with desirable combining ability for multiple within-boll yield components. Forty-five F hybrids were planted at two field sites in 2010 and 2011 with 4 and 3 replicates, respectively. There were a total of six yield components analyzed including lint percentage (LP), seed number per boll, lint weight per seed (LW_S), seed surface area per seed, lint weight per unit seed surface area (LW_SA), and lint number per unit seed surface area (LN_SA). The contributions of these yield components to lint yield were analyzed by commonality analysis that separated the contributions to lint yield into the unique contributions of single yield components and the common contributions of the single yield components with one or more other yield components. The unique contributions of the six yield components to lint yield ranged from 1.6 to 21 % of total variation for lint yield in the 2-year experiments. The greatest common contributions to lint yield among all combinations of the six yield components were identified for a combination of four components, LP, LW_S, LW_SA, and LN_SA with 67 and 44 % of the total variation of lint yield in 2010 and 2011, respectively. Results suggest that all four of these yield components should be considered simultaneously in breeding for genetic improvement of lint yield. The germplasm line SP225 was detected as a good combiner with positive general combining ability (GCA) for LP (1.4 %), LW_SA (0.03 mg mm), and LN_SA (14.3 no mm), and favorable GCA for fineness (−3.1 mg km). [ABSTRACT FROM AUTHOR]

Knowledge 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. [ABSTRACT FROM AUTHOR]

Within-boll yield components are the most basic contributors to lint and seed yield of cotton ( Gossypium hirsutum L.), which is a major source of natural fiber and edible oil throughout the world. Little information is available on genetic effects and heterosis of these traits in cotton. Three cotton cultivars and six breeding lines differing in within-boll yield components were used for this study. Parents and their F progeny with reciprocals from a 3×6 factorial mating design were grown at Jiangxi Agricultural University experimental farm in 2008 and 2009. Seven within-boll yield components and two boll bur characters were analyzed under an additive-dominance genetic model with genotype and environment interaction. Additive effects were significant for all traits and dominance effects were significant for all traits except seed mass per seed. Genetic variances for lint mass per seed, SM/S and boll bur weight were primarily additive variances ranging from 39.6 to 58.9 %. Lint mass per boll and seed number per boll variances were primarily due to dominance genetic effects ranging from 36.4 to 48.8 %. Dominance and additive effects were equally important for boll weight, seed mass per boll and boll bur percentage. Additive and additive × environment effects were more important than other effects for lint percentage. A802-1 had the best mean performance and additive effects increasing BW, SM/B, S/B and SM/S, but reduced LP and LM/S. A9-1 and Lu40534 had additive effects associated with increasing LP. The two crosses A9-1×Lu40534 and Tezsh×33B were detected with favorable heterozygous dominant effects and heterosis over best parent for BW, LP, LM/B, SM/B and S/B. Favorable genotypic and phenotypic correlations were identified between within-boll lint yield components (LM/B, LM/S) and within-boll seed yield components (SM/B, S/B, SM/S). These results indicate that simultaneous genetic improvement of multiple within-boll yield components can be expected in breeding populations derived from these cotton cultivars and breeding lines. [ABSTRACT FROM AUTHOR]