A gronomy J our n al • Volume 110 , I ssue 1 • 2 018 47 D uring the past two decades, international demand for high cotton fi ber quality has increased because of the dominance of ring-spun yarn production. We hypothesized that minimizing the variability of cotton fi ber quality among fi bers within-bale could contribute to better spinning performance and yarn quality resulting in a better end-product with a lower cost of production. Th e variability in physical attributes among cotton fi bers within a bale has been shown to aff ect textile manufacturing effi ciency and the quality of the fi nished textile products (Smith and Cothren, 1999;Krifa, 2012). Cotton fi ber quality is naturally variable within a single seed, within a single boll, within the plant, and within the fi eld. Th ese sources of variability in fi ber quality contribute to within-bale fi ber-to-fi ber variability. One of the potential strategies to minimize the variability of fi ber quality among fi bers within a bale of cotton is to optimize the within-plant variability of cotton fi ber quality.Within-plant variability of cotton fi ber quality is determined by many factors, including the growth habit of the cotton plant, genetics, and environmental conditions during cotton fi ber development (Stewart, 1975;Faulkner et al., 2011;Kothari et al., 2015). Th e indeterminate fruiting habit of the cotton plant provides a signifi cant source of within-plant variation in cotton fi ber quality. American upland cotton is a highly indeterminate, perennial plant, which is grown in an annual cropping system (Lewis, 2002;Oosterhuis and Cothren, 2012). Cotton plants set fl owers in a predictable pattern. Along the main axis, the setting of fl owers occurs at the same fruiting position in 3-d intervals. Bolls set at each position along a single fruiting branch are set approximately 6 d apart (McClelland, 1916;Lewis, 2002). Th ree days aft er the fi rst fl ower sets in position one, the fi rst position boll on the next vertical node sets (Meredith and Bridge, 1973). Th is pattern is used for estimating relative diff erences in boll ages (Baker and Baker, 2010).Cotton plants set the fi rst position bolls at the bottom parts of the plants early in the season compared to bolls setting at the apical and distal positions. Bolls sets in the lower half of the plant and fi rst fruiting position bolls have more time and resources to develop mature fi bers. ABSTRACTPrevious studies have indicated diff erences in fi ber quality parameters including fi ber length and maturity within the canopy of cotton (Gossypium hirsutum L) plants. A 3-yr study was conducted to investigate the impact of within-plant variability on fi ber length and maturity of upland cotton cultivars widely grown on the High Plains of Texas. Twelve upland cotton cultivars were grown in a randomized complete block design with three fi eld replications, in Lubbock, TX, during the 2012, 2013, and 2014 growing seasons. A box-picking harvesting method was used to individualize samples so that the within-plan...

No abstract

Verticillium wilt, caused by Verticillium dahliae Kleb., leads to significant losses in cotton yield and fiber quality worldwide. To investigate Verticillium wilt impact on photosynthesis rate, yield, and fiber quality, six upland cotton genotypes, namely Verticillium susceptible (DP 1612 B2XF) and partially resistant (FM 2484B2F) commercial cultivars and four breeding lines, were grown to maturity under greenhouse conditions in soil either infested or not infested with V. dahliae microsclerotia. Photosynthetic rate, lint, and seed yield were all higher (p < 0.05) for FM 2484B2F than DP 1612 B2XF when infected with V. dahliae. When comparing healthy (H) to Verticillium wilt (VW) affected plants, fiber properties were greatly impacted. Micronaire decreased from 5.0 (H) to 3.6 (VW) with DP 1612 B2XF and 4.4 (H) to 4.1 (VW) with FM 2484B2F. The maturity ratio decreased from 0.90 (H) to 0.83 (VW) for DP 1612 B2XF and was unchanged for FM 2484B2F (0.90). Fiber properties such as short fiber content, nep count, fineness, and immature fiber content were also significantly affected under Verticillium wilt pressure. With Verticillium wilt affected plants, lines 16-13-601V and 17-17-206V performed similarly to FM 2484B2F for photosynthetic rate, yield, and all fiber properties measured. When selecting for improved cultivars in the presence of Verticillium wilt, it is important to select for relatively unchanged fiber properties under disease pressure in addition to reduced disease severity and increased yield.

There is limited information regarding the use of quinoa fresh leaves as a vegetable. Thus, the objective of this study was to promote quinoa green leaves as a vegetable, as well as to conduct a season extension feasibility study using high tunnels. The study was conducted during the spring seasons of 2020, 2021, and 2022 at the George Washington Carver farm of Lincoln University in Jefferson City, MO, USA. Three quinoa genotypes were used in a randomized complete block design (RCBD) with three replications over three years. Agronomic data and leaf nutritional analyses for young plants approximately 30 days old were evaluated. Among the three quinoa genotypes, genotype Ames 13724 gave the highest yield of leafy greens and was consistent over the three years. Additionally, the use of high tunnels served as a season extension tool by accelerating the production of quality fruits and vegetables outside typical growing seasons. The results indicated that season extension of quinoa leafy greens production in a high tunnel is possible with a three-week earlier harvest in early spring when fewer fresh vegetables are available in the markets. Farmers can increase farm income by selling this specialty vegetable in the early season for premium prices.

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.