Improving tall fescue shade tolerance : identifying candidate genotypes

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Tall fescue (Schedonorus arundinaceus) is genetically variable for many agronomic traits, so it might be possible to increase its persistence and productivity in shaded agroforestry applications. The objective of this research was to identify high yielding, shade-tolerant genotypes. Seed was obtained from eight families: seven plant introductions of European origin: 234718, 234720, 234882, 234884, 235018, 235019, 235036, and one cultivar (Kentucky 31). Two sequential experiments were conducted to select genotypes for dry mass yield during April to September. Experiment (Exp) 1 included 30 genotypes of each of the eight families randomly assigned to each of two microenvironments: artificially shaded with fabric and unshaded. Maximum and minimum yields were 93.9 and 47.1 g family-1 for Kentucky 31 and 235036, respectively. After 1 yr, the proportion of vigorous survivors in Exp 1 was greater in the unshaded than shaded environment (0.40 and 0.09, respectively), and ranged from 0 to 0.56 (235036 and Kentucky 31, respectively). Forty robust genotypes (one later died) from four families (234718, 234720, 235019, and Kentucky 31) were selected from shaded and unshaded microenvironments of Exp 1, clonally propagated, and evaluated in pots for 2 yr in Exp 2. Shade-selected Kentucky 31 yielded more (31.0 g plant-1) in shade than other shade-selected families (25.2 to 25.8 g plant-1). Eleven genotypes in the top quartile (yield [greater than] 33.0 g plant-1) were selected for further testing. All genotypes were endophyte (Neotyphodium coenophialum)-infected. Future research will include seed increases and measuring yield in shaded, water-deficit conditions of a tree understory.David M. Burner (1) and Chuck P. West (2) ; 1. USDA-ARS, Dale Bumpers Small Farms Research Center, 6883 South State Hwy. 23, Booneville, AR 72927. 2. University of Arkansas, 1366 W. Altheimer Drive, Fayetteville, AR 72704.Includes bibliographical references

Correlates of sociometric status in Russian preschoolers: Aggression, victimization, and sociability

© 2016 Elsevier Ltd. Few studies have assessed behavioral correlates of preschool children\u27s peer sociometric status in cultures outside North America. This study focuses on 221 Russian preschoolers (108 boys, 113 girls). Correlates included physical and relational forms of aggression/victimization and sociable behavior. Confirmatory Factor Analyses (CFA) established that study instruments originally developed with U.S. preschoolers worked well in Russia. Findings in regard to aggression, sociability, and victimization were generally consistent with previous research with American and Italian preschoolers, particularly in regard to controversial status children. Our findings further challenge the notion that controversial children are consistently savvy in their social interactions. They and rejected children were most likely to be physically and relationally victimized by their peers

American political affiliation, 2003–43: a cohort component projection

The recent rise and stability in American party identification has focused interest on the long-term dynamics of party bases. Liberal commentators cite immigration and youth as forces which will produce a natural Democratic advantage in the future while conservative writers highlight the importance of high Republican fertility in securing Republican growth. These concerns foreground the neglect of demography within political science. This paper addresses this omission by conducting the first ever cohort component projection of American partisan populations to 2043 based on survey and census data. A number of scenarios are modeled, but, on current trends, we predict that American partisanship will shift much less than the nation’s ethnic composition because the parties’ age structures are similar. Still, our projections find that the Democrats gain two to three percentage points from the Republicans by 2043, mainly through immigration, though Republican fertility may redress the balance in the very long term

Dynamic Deformation Measurements of an Aeroelastic semispan model”, AIAA Paper 2001-2454

The techniques used to acquire, reduce, and analyze dynamic deformation measurements of an aeroelastic semispan wind tunnel model are presented. Single-camera, single-view video photogrammetry (also referred to as videogrammetric model deformation, or VMD) was used to determine dynamic aeroelastic deformation of the semispan "Models for Aeroelastic Validation Research Involving Computation" (MAVRIC) model in the Transonic Dynamics Tunnel at the NASA Langley Research Center. Dynamic deformation was determined from optical retroreflective tape targets at 5 semispan locations located on the wing from the root to the tip

Using sketchup to simulate tree row azimuth effects on alley shading

Effect of row azimuth on alley crop illumination is difficult to determine empirically. Our objective was to determine if SketchUp (Trimble Inc., Sunnyvale, CA) could be used to simulate effect of azimuth orientation on illumination of loblolly pine (Pinus taeda L.) alleys. Simulations were conducted for trees in East–West, North–South, Northeast–Southwest, and Northwest–Southeast azimuth orientations assuming tree size parameters and row spacing of a 14-yr-old plantation near Booneville, AR. SketchUp predicted that the East–West azimuth allowed significantly more illumination at the alley surface during April to August compared to other azimuths, and significantly less illumination than other azimuths during October to February. SketchUp could assist the design and placement of pine plantations in the landscape for agroforestry practices, reducing the time and costs associated with in-field testing at plantation scale

Dynamic Deformation Measurements of an Aeroelastic Semispan Model

The techniques used to acquire, reduce, and analyze dynamic deformation measurements of an aeroelastic semispan wind tunnel model are presented. Single-camera, single-view video photogrammetry (also referred to as videogrammetric model deformation, or VMD) was used to determine dynamic aeroelastic deformation of the semispan 'Models for Aeroelastic Validation Research Involving Computation' (MAVRIC) model in the Transonic Dynamics Tunnel at the NASA Langley Research Center. Dynamic deformation was determined from optical retroreflective tape targets at five semispan locations located on the wing from the root to the tip. Digitized video images from a charge coupled device (CCD) camera were recorded and processed to automatically determine target image plane locations that were then corrected for sensor, lens, and frame grabber spatial errors. Videogrammetric dynamic data were acquired at a 60-Hz rate for time records of up to 6 seconds during portions of this flutter/Limit Cycle Oscillation (LCO) test at Mach numbers from 0.3 to 0.96. Spectral analysis of the deformation data is used to identify dominant frequencies in the wing motion. The dynamic data will be used to separate aerodynamic and structural effects and to provide time history deflection data for Computational Aeroelasticity code evaluation and validation

Small-Scale Mechanical Harvesting and Tractor-Caused Soil Compaction Reduce Early Growth in Sugarcane

Sugarcane is an important crop for sugar and biofuel production worldwide. It is mostly grown on hilly area by smallholders in China, which makes harvesting by a combine harvester impractical. Harvesting sugarcane by a small-scale harvester could be more practical. However, information about the impact of small-scale mechanical harvesting on soil compaction (SC), early growth and cane yield, and its yield components is still limited. The scarcity of quantitative information is equally true for the genotype and harvesting method interaction for traits describing early growth and final yield in sugarcane. Field experiments were conducted in a plant and two consequent ratoon crops (RCs) during 2016–2018 in Kaiyuan, Yunnan Province, China, to determine the impact of small-scale mechanical harvesting followed by tractor passages (SMH) on SC, sugarcane early growth and yield, and yield components, and to determine the genotype x treatment (harvesting methods, GT) interactions. The results indicated that, when compared to manual harvesting (MH), SMH significantly (p < 0.05) increased SC at 5, 10, and 20 cm depths by 0.6, 0.71, and 0.69 MPa for the first ratoon crop (RC), respectively; and increased by 1.4, 2.02, and 1.72 MPa at 10, 20, and 30 cm depths for the second RC, respectively. The amounts of underground bud bank (UBB) in RCs were nearly nine times the buds for establishing the plant crop (PC); positive correlations between the UBB and seedling counts were observed, with the highest correlations (r = 0.8453) occurring in May for the second RC. As compared with MH, stool damage and gaps were significantly higher in SMH; meanwhile, the UBB was lower in two RCs; the amount of seedlings, plant height, and height uniformity were significantly lower in SMH. Cane yield declined more in SMH, particularly declining by 20.59% from the first RC to the second RC. With respect to sugarcane production by SMH, the existence of significant GT interactions for stool damage, gaps, early seedling, millable stalks, and height uniformity at the maturing stage suggested that genotype selection trials should be conducted under the SMH rather than in MH

New Saccharum hybrids in S. spontaneum cytoplasm selected with RAPD and microsatellite markers

Identification of sugarcane F1 hybrids is difficult when selections are solely based on phenotypic traits. The objective of this study was to develop Saccharum hybrids in the cytoplasm of S. spontaneum with selections based on both phenotypic traits and molecular markers. Two crosses were made between a Saccharum spontaneum clone Djatiroto, and LCP 85-384, a commercial variety (Cross 97-3144), or CP 62-258, an elite clone (Cross 97-3146). Prior to crossing, the maternal inflorescences of Djatiroto were emasculated by a 45oC hot water treatment. After germination in the greenhouse, 96 progeny from each cross were transplanted to the field. Evaluations on stalk diameter (mm), Brix, and a RAPD marker OPA-11-366 were conducted on the first-ratoon crop the following year. The OPA-11-366 marker was reproducibly amplified from both sugarcane clones, but not from Djatiroto. Fifty progeny (52.1%) from Cross 97-3144 and 36 progeny (37.5%)from CROSS 97-3146 produced the RAPD marker. Five putative F1 progeny were selected from both crosses on the basis of large stalk diameter and high Brix, and the ability to produce the RAPD marker and were assigned US numbers based on the year of selection. US99-43, US99-44, US99-45, US99-46, and US99-47 were selected from Cross 97-3144; and US99-48, US99-49, US99-50, US99-51, and US99-52 were selected from Cross 97-3146. The hybrid nature of these progeny was also verified by the presence of male-specific microsatellite markers. This is the first report on the development of Saccharum hybrids in the cytoplasm of S. spontaneum through a combination of conventional and molecular breeding approaches. Availability of these F1 hybrids will enable sugarcane breeders to explore potential contribution of S. spontaneum cytoplasm in their breeding programs