bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic Management Practices on Athletic Fields: Part 1. The Effects on Color, Quality, Cover, and Weed Populations
Authors: Miller Nathaniel A. , Henderson Jason J. 
Published: April 2012

ABSTRACTMany organic products have been used effectively in turfgrass management programs, but their exclusive use in athletic field maintenance and effect on playing surface quality has not been extensively researched. The objectives were to determine the effects of management regimes and overseeding during simulated traffic on (i) turfgrass color and quality, (ii) percent cover, and (iii) weed populations. The experimental design was a 2 × 6 factorial, with two overseeding levels (overseeded and not overseeded) of a perennial ryegrass (Lolium perenne L.) blend during traffic and six management regimes: (i) conventional, (ii) organic manure (OMan), (iii) organic protein (OPro), (iv) organic manure plus compost tea (OMan+CT), (v) organic protein plus compost tea (OPro+CT), and (vi) none or the control. This research was conducted over 2 yr on a mature stand of ‘Langara’ Kentucky bluegrass (Poa pratensis L.) on a Paxton sandy loam soil. Fall traffic was simulated with a Cady Traffic Simulator. The conventional treatment consistently produced higher quality turfgrass, lower weed counts, and better mid‐ to late‐fall color. Weed populations were significantly less with the conventional regime. Overseeding increased cover at the end of the traffic periods by 32% in the first year and by 103% in the second year. Overseeding was also beneficial to turfgrass color and quality and in reducing weeds. The conventional treatment also retained significantly higher turfgrass cover than the organic regimes under trafficked conditions late into the fall in 2008. However, no difference in late fall cover between the conventional and organic management regimes was observed in late fall 2009. Compost tea applications showed no enhancement of turfgrass color, quality, or cover over the entire duration of the study.
Haploid Fertility in Temperate and Tropical Maize Germplasm
Authors: Kleiber Daniel , Prigge Vanessa , Melchinger Albrecht E. , Burkard Florian , San Vicente Félix , Palomino Guadalupe , Gordillo G. Andrés 
Published: April 2012

ABSTRACTDoubled haploid (DH) technology facilitates rapid development of homozygous inbred lines for hybrid breeding in maize (Zea mays L.). However, the required artificial chromosome duplication step, which commonly involves toxic and costly chemicals, represents a bottleneck. Exploiting the haploids’ natural fertility may enable abolishment of artificial treatments and enhance efficiency of line development. We screened haploid populations derived from U.S. Corn Belt and tropical germplasm for the proportion of fertile haploids (FP) and the number of intact seeds (IS) on selfed ears and examined the effects of environments, heterotic groups, maturity groups, and population types on FP and IS. The FP ranged from 0 to 20% under field conditions and from 0 to 70% under greenhouse conditions. Tropical elite germplasm had higher median FP and mean IS than tropical landrace accessions. The Corn Belt heterotic group Stiff Stalk had higher median FP than Iodent and Lancaster while early germplasm showed higher median FP than the other maturity groups. Significant (p > 0.01) genetic variance for FP was observed among elite Corn Belt materials and heritability was 0.79, indicating that recurrent selection to increase FP is promising. We propose that artificial chromosome duplication is not necessary for DH line production from germplasm with high FP. This seems particularly relevant to enable small maize breeding programs in developing countries to adopt the DH technology for line development.
Genetic Structure in a Core Subset of Cultivated Barley Germplasm
Authors: Fu Yong‐Bi 
Published: April 2012

ABSTRACTCultivated barley (Hordeum vulgare L. subsp. vulgare) is one of the economically most important cereals with a large number of germplasm accessions conserved worldwide. A core subset of 571barley accessions representing 94 countries was developed, genotyped using 30 informative simple sequence repeat (SSR) markers, and analyzed with several common approaches. The distance‐based analysis of the 230 SSR allele profile revealed a major division of the barley accessions that explained 6 to 8% SSR variation. The model‐based Bayesian analyses revealed six optimal clusters that captured 17.5% SSR variation. The clusters varied in size from 34 to 160, consisted of accessions from many countries and regions, and were well represented by accessions with various important agronomic traits such as kernel row number and growth habit. Such germplasm partitions were further supported from principal component and neighbor‐joining analyses. A mini core subset of 219 accessions from 94 countries was thus developed for future structural inferences. Interestingly, the revealed genetic structure is consistent with the known barley domestication history. Therefore, the inferred optimal clusters may provide the best possible structural description of the current global cultivated barley gene pool and also are useful for future barley research in association mapping, adaptation, and domestication.
Sources of Resistance to Stem Rust (Ug99) in Bread Wheat and Durum Wheat Identified Using Focused Identification of Germplasm Strategy
Authors: Endresen Dag Terje Filip , Street Kenneth , Mackay Michael , Bari Abdallah , Amri Ahmed , De Pauw Eddy , Nazari Kumarse , Yahyaoui Amor 
Published: April 2012

ABSTRACTThe focused identification of germplasm strategy (FIGS) has been validated using predictive computer models in simulation studies to predict a priori known trait scores. This study was designed as a “blind” study where the person calculating the computer model did not know the actual trait scores. This study design provides a more realistic test of the predictive capacity of the FIGS approach compared to previous studies. Furthermore this study also explored the suitability of FIGS for the identification of resistance in bread wheat (Triticum aestivum L. subsp. aestivum) and durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] to Ug99—a strain of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) and typified to race TTKSK. The predictions were validated against a dataset with the screening of wheat accessions conducted in Yemen in 2008. Only a small training set representing 20% of the trait screening results was disclosed to the person conducting the data analysis for the calibration of the prediction model. The hit rate for identification of Ug99‐resistant accessions was more than two times higher when using the FIGS approach compared to a random selection of accessions. These results suggested that FIGS was well suited for the identification of samples with resistance to fungal pathogens. It is therefore recommended that FIGS approach be used as a complement to expert knowledge and experience when selecting accessions for plant breeding and crop research activities.
Genotypic and Phenotypic Variability in Three Prairie Acacia Accessions
Authors: Noah Ray L. , Muir James P. , Brady Jeffrey A. , Wittie Roger D. , Kattes David H. , Pitman William D. , Rea Gary L. , Brakie Melinda R. 
Published: April 2012

ABSTRACTThis study examined three prairie acacia [Acacia angustissima var. hirta (Mill.) Kuntze var. hirta (Nutt.) B.L. Rob.] accessions from Texas for genetic overlap, adaptation to a wide range of latitudes, as well as seed and herbage yield, nutritive values, and effect of forage harvest on seed production at Stephenville, TX. The southernmost accession (Kingsville prairie acacia; KPA) yielded >400% more (P ≤ 0.05) herbage (3483 kg dry matter ha−1 yr−1) at Stephenville, TX, than the other entries the third year after establishment. Herbage removal negatively (P ≤ 0.05) affected seed yield, which was as much as 2590 kg ha−1 yr−1 for unharvested Plains germplasm prairie acacia (PPA) the second year after establishment. Final percent plot cover differed (P ≤ 0.05) among locations (Knox City, TX, 50%; Stephenville, TX, 100%; Nacogdoches, TX, 99%; Homer, LA, 61%). Differences (P ≤ 0.05) in leaf:stem ratios, some nutritive values, and crude protein yields were measured among accessions, with KPA showing the most promise where there were differences. Genetic analysis of inter–simple sequence repeat markers indicated the least within accession difference between two north Texas accessions (91 and 92% similarity) and the most difference between these two and KPA (79% similarity), which also presented a taller, woodier growth habit. Genetic variation within prairie acacia germplasm collected in Texas is expressed primarily in herbage production.
Analysis of U.S. Genetically Engineered Crop Regulation and Litigation
Authors: McGinnis Esther E. , Meyer Mary H. , Smith Alan G. 
Published: April 2012

ABSTRACTThe commercial potential of genetically engineered (GE) crops has not been fully realized in the United States. Over the past decade, environmental litigation dramatically affected the pace of GE crop development, testing, and deregulation. The U.S. Animal and Plant Health Inspection Service (APHIS) regulates GE organisms that may pose a risk to plant or animal health. However, recent litigation initiated by nongovernmental organizations such as the Center for Food Safety and the International Center for Technology Assessment has exposed APHIS's vulnerability to lawsuits under the National Environmental Policy Act (NEPA) for failing to assess the environmental risks of novel GE crops. In these cases, APHIS committed two types of mistakes. First, APHIS did not differentiate between traditional GE crops whose risks are well characterized and novel GE crops that may raise unique environmental risks and societal issues based on their distinctive biology. Consequently, it did not adequately evaluate the legally defined environmental risks of these novel crops. Second, APHIS did not fully appreciate NEPA's sweeping scope and focus on procedural compliance to ensure transparent and thorough environmental decision making. As a result, APHIS impeded the development and commercialization of GE crops and must take a more defensive posture in the future to deter costly and lengthy NEPA litigation in the case of novel GE crops.
Fiber and Yarn Performance of Upland Cotton with Improved Fiber Bundle Strength
Authors: Gregory K. , Ng E. H. , Smith W. , Hequet E. , Hague S. 
Published: April 2012

ABSTRACTThe U.S. cotton (Gossypium spp.) industry has shifted focus in recent years to an export market, necessitating further development of upland cotton (G. hirsutum L.) cultivars with superior fiber properties to maintain competitiveness. This study was conducted to compare both fiber and yarn performance of upland cotton genotypes with similar average fiber length but enhanced fiber bundle strength (Str) with two high quality commercial controls, ‘FM 832LL’ and ‘DP 491’. The high Str strains and commercial upland controls were grown in Weslaco, TX, during the summers of 2009 and 2010 with standard agronomic practices for south Texas, including furrow irrigation. Plots were spindle‐machine harvested, seedcotton ginned on a research gin without a lint cleaner, and lint and yarn tested at the Fiber and Biopolymer Research Institute (FBRI) in Lubbock, TX. Lint and yarn data collected included high volume instrument (HVI) and advanced fiber information system (AFIS) derived data and ring spun yarn data (mini‐spinning protocol). Years were different for almost every fiber and yarn property except Str, immature fiber content (IFC), yarn tenacity (Ten), work required for yarn breakage (Work to Break) and the number of thin places per kilometer that are at least 50% smaller in diameter than adjacent portions of yarn (Thin). All of the high Str strains had higher Ten in 2009 than the controls and 9 of the 11 had higher Ten in 2010. The high Str genotypes resulted in more even yarns (as determined with the Uster Tester 3 [Uster Technologies]).
Geostatistical Analysis of Quality Protein Maize Outcrossing with Pollen from Adjacent Normal Endosperm Maize Varieties
Authors: Machida Lewis , Derera John , Tongoona Pangirayi , Mutanga Onisimo , MacRobert John 
Published: April 2012

ABSTRACTNutritional advantages of quality protein maize (QPM) (Zea mays L.) over normal endosperm maize (NM) were previously demonstrated by several researchers. However, QPM grain quality loss occurs when a QPM crop receives pollen from NM. This is because the opaque‐2 gene allele that confers the QPM trait is recessive. The objective was to estimate outcrossing levels and patterns in QPM growing adjacent to NM. White grain QPM crops were grown on nine blocks of 0.21 ha each surrounded by at least a 10‐m band of yellow NM at two sites in Zimbabwe. At maturity 160 samples of five QPM ears each were randomly selected to determine outcrossing. Outcrossing was estimated as percentage of yellow kernels on each ear. Ordinary kriging was used to estimate outcrossing levels in areas that were not sampled. Both prediction and error surfaces were produced for each block using the best ordinary kriging model out of the available 11 in ArcMAP 9.2 computer package. Results indicated that five models (exponential, stable, pentaspherical, rational quadratic, and J‐Bessel) predicted outcrossing patterns of the nine experiments. Outcrossing levels were high (63 to 83%) in the peripheral areas of the QPM crops, but less than 20% outcrossing was observed on at least 60% of each of the crop areas with no significant compromise of QPM quality based on a QPM quality index of 0.8. In conclusion, QPM and NM can coexist, and ordinary kriging could be used in visualizing spatial distribution of outcrossing in a QPM crop.
Production and Economics of Grazing Alfalfa in the Southern Great Plains
Authors: Butler Twain J. , Biermacher Jon T. , Interrante Sindy M. , Sledge Mary K. , Hopkins Andrew A. , Bouton Joseph H. 
Published: April 2012

ABSTRACTAlfalfa (Medicago sativa L.) is a high‐quality forage legume that may have potential to improve net returns to stocker cattle producers in the southern Great Plains. The objective of this 3‐yr field study was to compare the agronomic and economic performance of alfalfa grazing systems under two management strategies. Treatments were (i) continuous stocking for the entire growing season, referred to as full‐season grazing; and (ii) a late‐season rest, which was continuous stocking of alfalfa until 1 August. Steers (250 ± 25 kg initial body weight) were weighed every 28 d during each grazing season, and stocking rates were adjusted with put‐and‐take steers based on forage mass. In each 28‐d grazing period, forage mass and total gain (TG) were measured, allowing calculation of average daily gain (ADG). Animals had ADG of 0.93 and 1.05 kg d−1 and TG of 449 and 379 kg ha−1 on alfalfa for the full‐season grazing treatment and the late‐season rest (August termination), respectively. The 3‐yr average production cost ($278 ha−1) did not differ between the two management treatments; however, expected net return was greater (P < 0.01) for the full‐season alfalfa grazing treatment ($314 ha−1) compared to the 1 August termination date ($145 ha−1). Therefore, a late‐season rest from grazing was not economically beneficial to grazing alfalfa in this 3‐yr experiment, and grazing alfalfa with summer stockers may be a viable option for producers in the southern Great Plains.
Characterization and Effectiveness of Co‐inoculation of Sinorhizobium Strains on Annual Medics
Authors: Singh Ruchi , Interrante Sindy M. , Butler Twain J. , Young Carolyn A. 
Published: April 2012

ABSTRACTSelection and identification of better‐adapted annual medics with an appropriate rhizobia inoculum is crucial for improved forage quality and yield. The objectives of this study were to characterize 11 rhizobial strains used for an effectiveness study on annual medics and generate an inoculum blend suitable for annual medic species adapted to the southern Great Plains. Each strain was compared to reference rhizobia strains by polymerase chain reaction (PCR) based on repetitive sequences (rep‐PCR) and ribosomal gene sequences and analyzed for plant growth promoting (PGP) activities. Genetic characterization separated the strains into two groups belonging to Sinorhizobium medicae (seven isolates) and Sinorhizobium meliloti (four isolates). Three of the 11 strains tested positive for the PGP activities of indole acetic acid production and phosphate solubilization. A blend of three strains (NFmix3, consisting of WSM1115, 102F85, and M49), of which two were positive for PGP activities, was used in an effectiveness study for the annual medics Medicago minima (L.) Bartal., Medicago orbicularis (L.) Bartal., Medicago rigidula (L.) All., and Medicago rigiduloides E. Small. The NFmix3 association with three of the four annual medic species resulted in equivalent biomass production as that of the single specific strain. The NFmix3 blend would be suitable and more economic for use with a mixture of medic species that may provide expansion of the grazing season.
Signal Grass Litter Decomposition Rate Increases with Inclusion of Calopo
Authors: Siqueira da Silva Hiran Marcelo , Batista Dubeux José Carlos , Ferreira dos Santos Mércia Virginia , de Andrade Lira Mário , de Andrade Lira Mário , Muir James P. 
Published: April 2012

ABSTRACTLow N availability is a major limitation in tropical and subtropical pasture systems and one of the main causes for system degradation. Including legumes in forage mixes may enhance soil‐N presence and cycling, therefore mitigating the problem. To test this theory, signal grass [Brachiaria decumbens (Stapf) R. D. Webster] litter chemical composition and decomposition after inclusion of calopo (Calopogonium mucunoides Desv.) at 0, 50, or 100% of litter mass was evaluated. Litter samples were collected from both species and incubated by litter bag technique for 0, 4, 8, 16, 32, 64, 128, or 256 d in 2007 and 2008. Biomass decomposition was described by a simple exponential organic matter (OM) decay model (p < 0.0001; Y predicted [the remaining biomass at a given time of decomposition, predicted by the single exponential model] = 91.11–0.00451t and 94.16–0.00217t for year 1 and 2, respectively). Remaining biomass was lower (p < 0.05) in 2007 (28%) than 2008 (54%) following 256 d incubation at least in part because of greater lignin concentrations in 2008 litter. Pure signal grass litter C:N values were 74 to 76% greater (p < 0.05) than pure legume while the inclusion of 50% calopo reduced (p < 0.05) grass ratios by 62 to 64%. Net annual N mineralization increased (p < 0.05) from 27% without legume to 38% with legume inclusion at 50% of the grass litter, a nutrient cycling acceleration of 16% (p < 0.05). This research indicated that the inclusion of calopo will ameliorate N deficiency in soils of a signal grass pasture.
Screening Method and Response Surface Design for Drying Hybrid Maize to Maintain Seed Quality
Authors: Arisnabarreta Sebastián , Eslava Ezequiel T. , Cannon Paul 
Published: April 2012

ABSTRACTHybrid maize (Zea mays L.) ear drying is an expensive process and considered a bottleneck in seed production. The seed industry does not have an effective procedure to screen germplasm for drying temperature sensitivity and optimum drying conditions. The aims of this paper were (i) to develop a simple, rapid, and reliable technique to screen drying temperature tolerances and (ii) to exploit the response surface design (i.e., predictive model of the relationship between factors and the response) to identify optimum drying temperatures. Trials consisted of screening experiments, in which ears were constantly dried at 35 and 45°C, and response surface experiments, in which samples were subjected to different drying temperatures in two phases (30, 35, and 40°C for the first and 35, 40, and 45°C for the second drying phase). Standard germination, cold, and accelerated aging tests were conducted to measure the effect of drying regimes on seed quality. Drying hours and rates were determined. Drying hours and rate were reduced 36 and increased 44% in the stress treatment relative to the control, respectively. Genotypes differed in drying temperature tolerances only when the cold test was used in the analyses. The response surface design allowed identifying specific temperature combinations for the first and the second drying phases that optimized quality parameters. The results of this study can be useful tool for seed industries to optimize their drying process and seed quality.
Is Seed Iron Concentration Predictive of Resistance to Iron Deficiency in Soybean?
Authors: Wiersma John V. 
Published: April 2012

ABSTRACTWithin the last decade, studies involving numerous crops provide strong evidence that seed Fe concentration ([Fe]) is useful for identifying genotypes possessing superior resistance to Fe deficiency. It is our opinion that using seed [Fe] is equivalent or superior to using visual chlorosis score as a measure of Fe efficiency, that seed [Fe] can be used to identify resistance to Fe deficiency in the absence of Fe deficiency or in the presence of Fe deficiency exacerbated by applying high rates of fertilizer N, that conventional plant breeding can be used to increase seed [Fe] as a strategy for improving resistance to Fe deficiency, and that planting seed [Fe] can be used as a predictor of successful (nonchlorotic) seedling establishment. International agricultural agencies, such as HarvestPlus (CIAT, Cali, Columbia), have promoted using plant breeding as an intervention strategy focused on increasing micronutrient concentrations and bioavailabilities in crops consumed by populations with known micronutrient deficiencies. Can conventional plant breeding be used to increase seed [Fe] as a strategy to reduce Fe deficiency in soybean [Glycine max (L.) Merr.]? Evidence presented in this paper combined with earlier reports indicates that Fe‐efficient and Fe‐inefficient varieties appear to have seed [Fe] maxima that are distinctly different and seldom exceeded; that is, soybean plants tend to maintain [Fe] in the grain within predetermined, genetically controlled limits. Seed [Fe] can be regarded as an integrated measure of resistance to Fe deficiency that is manifest at maturity and that involves the coordinate expression of several genes regulating Fe reduction and uptake, transport, and storage.
Harrington Seed Destructor: A New Nonchemical Weed Control Tool for Global Grain Crops
Authors: Walsh Michael J. , Harrington Raymond B. , Powles Stephen B. 
Published: April 2012

ABSTRACTGlobal grain production is under threat from the escalating evolution of herbicide‐resistant weed populations. Worldwide, herbicide‐reliant grain crop production systems have driven the proliferation of herbicide resistant populations of major weed species. Alternatives or adjuncts to herbicides are needed for sustainable control of crop weeds in grain crops worldwide. Here we introduce and prove the ability of a new weed control tool, the Harrington Seed Destructor (HSD), to intercept and destroy weed seeds during grain crop harvest. The interception and destruction of weed seeds exiting the grain harvester in the chaff fraction during grain crop harvest is a hitherto unrealized opportunity. We have developed a cage mill‐based chaff processing unit that consistently destroys weed seed infesting grain crop chaff fractions. The subsequent construction of the HSD incorporating this unit had >95% weed seed destruction efficacy when used during commercial harvest of three major grain crops, wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and lupin (Lupinus angustifolius L.). The HSD system has the potential for a dramatic impact on global grain production by providing the unique combination of effective weed control with complete retention of grain crop harvest residues. Only herbicides offer this same combination of highly effective weed control and complete residue retention in large scale grain crop production systems.