Understanding drought stress responses and the identification of phenotypic traits associated with drought are key factors in breeding for sustainable cotton production in limited irrigation water of semi-arid environments. The objective of this study was to evaluate the responses of upland cotton lines to rainfed and irrigated conditions. We compared selected agronomic traits over time, final yield and fiber quality of cotton lines grown in irrigated and rainfed trials. Under rainfed conditions, the average number of squares per plant sharply declined during weeks 10 to 14 while the average number of bolls per plant significantly reduced during weeks 13 to 15 after planting. Therefore, weeks 10 to 14 and weeks 13 to 15 are critical plant growth stages to differentiate among upland cotton lines for square and boll set, respectively, under drought stress. Variation in square and boll set during this stage may translate into variable lint percent, lint yield and fiber properties under water-limited conditions. Lint yield and fiber quality were markedly affected under rainfed conditions in all cotton lines tested. Despite significantly reduced lint yield in rainfed trials, some cotton lines including 11-21-703S, 06-46-153P, CS 50, L23, FM 989 and DP 491 performed relatively well under stress compared to other cotton lines. The results also reveal that cotton lines show variable responses for fiber properties under irrigated and rainfed trials. Breeding line 12-8-103S produced long, uniform and strong fibers under both irrigated and rainfed conditions. The significant variation observed among cotton genotypes for agronomic characteristics, yield and fiber quality under rainfed conditions indicate potential to breed cotton for improved drought tolerance.

Cotton breeding progress stagnation, changing production conditions, and continued high fiber quality demands are challenging the cotton industry in Burkina Faso. The F₁ populations developed by half diallel crosses between germplasm from Texas A&M AgriLife Research and Burkina Faso were evaluated for several agronomic traits. The aim was to identify the most promising parents and hybrids for further varietal improvement. Three AgriLife parents helped improve the most important targeted traits. Parent 15-3-416 reduced days to 50% flowering (−3.14 days) and shortened plant height (−22.25 cm) in hybrids while 16-2-216FQ improved their fiber percentage (+2.68%). Hybrids with Burkina Faso elite cultivar E32 as male parent and the three best AgriLife parents as the females showed good specific combining ability (SCA). FK37 × 15-10-610-7 and FK64 × 15-10-610-7 showed heterosis for earliness by reducing, respectively, days to 50% flowering (−4.27 days) or days to 50% boll opening (−3.95 days) below parent means. E32 × 16-2-216FQ and FK64 × 16-2-216FQ increased fiber percentage by +1.75% and +2.06%, respectively. FK64 × 15-3-416 increased seed index (SI) (+0.62 g) and fiber percentage (+1.19%), while maintaining other traits at the parents’ average levels. E32 × 15-3-416 showed the most heterosis for desired improvements, reducing days to 50% flowering (−4) and increasing the number of bolls/vegetative branch (+3.05), number of bolls/fruiting branch (+6.38), number of bolls/plant (+13.49), boll weight (+1.53 g), SI (+0.40 g), and fiber percentage (+1.18%). Inter-program crosses show the potential to enhance genetic diversity in Burkina Faso’s breeding program. Subsequent selection methods must be carefully applied considering the Burkina Faso breeding objectives for future cultivars.

Upland cotton is an important fiber and oilseed crop. Cottonseed produces approximately 15% of farm gate value in cotton production. Therefore, improvement of cottonseed oil can significantly increase the economic return of cotton production with the same land use and investment. However, genetic variation in cottonseed oil is highly limited within upland cotton, limiting the genetic gain in cottonseed oil. Introgression breeding can alleviate this bottleneck effect by introducing desirable genes from Pima to Upland cotton. The objective of this study was to evaluate introgression lines (ILs) for better cottonseed oil. A population of 590 ILs, developed from a cross between Acala 1517-99 and Pima, was grown in Las Cruces, NM in 2022 which was used for the fatty acid methyl ester analysis through gas chromatography. There was a high level of variation in cottonseed oil and fatty acids. In the biplot, cottonseed oil was positively correlated with oleic acid and negatively related with palmitic acid. The cluster analysis identified a group of ILs with the highest average oil and oleic acid. As a result, ILs with better oil profiles were identified for further testing and analysis toward the development of high-quality cotton varieties with higher and better oil.

The market value of cotton in exporting countries, such as Burkina Faso, depends on the quality of major fiber properties. A lack of variation among the genetic resources available in Burkina Faso hinders breeding progress to meet fiber quality demands in future cultivars. F₁ populations from a half diallel crossing scheme between lines developed at Texas A&M AgriLife cotton breeding program at Lubbock and germplasm accessed from Burkina Faso were evaluated for fiber property enhancement. Crosses exclusively within common origin materials did not result in highly enhanced hybrids. Hybrids within American materials expressed significant SCA effects undesirable for future cultivars in Burkina Faso. Five hybrids within the Burkina Faso material expressed significant SCA effects: two of them implicating FK37 as the better parent in transmitting superior targeted fiber traits to its progenies. Hybrid FK37xE9 significantly enhanced UHML, Str, UI and SFI but not Mic and Rd. Inter-program hybrids with at least one significant SCA effect were crosses with female American lines and male Burkina Faso parents. Hybrids E53x16-2-216FQ, E53x15-10-610-7 and E32x15-10-610-7 showed significantly improved Str and UI for the most economically important traits, which also include Mic, UHML, SFI, Rd and +b. Together, the GCA and SCA effects, heritability and correlations showed more additive than non-additive gene actions. Therefore, knowledge of the best combiners and hybrids could be used in the cultivar development process to enhance value with improved fiber characteristics.

CA 4011 (Reg. no. GP‐1149, PI 705597) is a noncommercial breeding line of cotton (Gossypium hirsutum L.) jointly released by Texas A&M AgriLife Research and the Agricultural Experiment Station at the University of Georgia‐Tifton. This cotton germplasm is a selection from CA 3084, a germplasm line released by Texas Agricultural Experiment Station in 1987. CA 3084 was derived from a cross of EPSM‐75‐AAAA‐3 and EPSM‐1224‐1‐74‐2‐4‐2‐1, historical breeding lines developed by the cotton breeding program at Texas Agricultural Experiment Station in El Paso. Progeny row of CA 4011 was selected for 2008 preliminary yield testing in Southern High Plains by the Texas A&M AgriLife Research cotton breeding program in Lubbock. In 2012, CA 4011 had less damage from thrips feeding injury than 22 other genotypes tested in a greenhouse assay but was equal to the resistant check TX110 (PI 163608). Performance testing for yield, fiber quality, and other related agronomic properties was conducted under organic management and on certified organic farms during 2012, 2013, and 2014 growing seasons. CA 4011 showed comparable yield and fiber quality to standard check cultivars grown in the Southern High Plains. Subsequent testing was done at the University of Georgia Coastal Plains Experiment Station in Tifton, GA, to evaluate for resistance to the foliar diseases areolate mildew and target spot. Disease ratings were taken in 2018 and 2019 growing seasons. CA 4011 showed favorable resistance to areolate mildew in comparison to susceptible checks, providing less leaf infection and defoliation.