bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Biocidal Treatments on Cation Exchange Capacity and Fusarium Blight of Soybean in Delaware Soils
Authors: Sandler H. A. , Carroll R. B. , Sparks D. L. 
Published: July 2010

AbstractFusarium wilt has caused significant losses in soybean [Glycine max (L.) Merr.] production and is very difficult to control because it is caused by the soil‐borne fungus Fusarium oxysporum. A better understanding of the relationship between soil characteristics and the pathogen and between biocidal treatments and physiochemical properties is needed, especially for soils that appear to be suppressive. The effects of antoclaving and Vapam fumigation on cation exchange capacity, organic matter content, clay content, pH, and Fusarium wilt of soybean were determined for several different Delaware soil types (Typic Hapludults, Typic Qnartzipsamments, and Typic Umbraquults). ‘Essex’ soybean was grown in the treated soils that had been infested, prior to planting, with 6.3 × 104 viable spores per gram of dry soil of a pathogenic Fusarium oxysporum isolate. Treatments were arranged on the greenhouse bench in a randomized completeblock design with five replications. Cation exchange capacity generally increased with fumigation and decreased with autoclaving, but differences were not significant for all soils. Organic matter content increased following fumigation in three soils, and pH values were lowered by both biocidal treatments in all soils except a Matapeake silt loam. Disease incidence and severity were affected differently for each soil type.
Reed Canarygrass Binary Mixtures with Alfalfa and Birdsfoot Trefoil in Comparison to Monocultures
Authors: Jones T. A. , Carlson I. T. , Buxton D. R. 
Published: July 2010

AbstractMaintenance of both components in a grass‐legume mixture is an important objective of temperate perennial grassland management, yet one species is often lost from the stand within a few growing seasons. Our objective was to study factors that influence the persistence of reed canarygrass (Phalaris arundinucea L.) in binary mixture with alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.). Two divergent cycle‐2 specific leaf weight (SLW) populations of reed canarygrass were grown in binary alternate‐row mixture under a three‐cut‐per‐year management with each of four legume cultivars: Olympic and Baker alfalfa and Norcen and Dawn birdsfoot trefoil. By the eighth harvest, alfalfa had competitively excluded reed canarygrass. Calculations of relative yield total indicated that competition between alfalfa and reed canarygrass was for de Wit's different space (the two species limited by different factors to at least some extent and therefore at least somewhat complementary in their exploitation of environmental resources) at early harvests. Birdsfoot trefoil mixtures reached equilibrium by the spring after establishment, with botanical composition thereafter varying from 67 to 81% legume. In contrast to alfalfa‐reed canarygrass mixtures, competition between birdsfoot trefoil and reed canarygrass was for the same space (the two species strictly limited by and competing for the same factors) at early harvests and for different space at late harvests. No yield differences between SLW populations were found in mixture, although high SLW yielded 19% more than low SLW in monoculture over eight harvests. Reed canarygrass had higher in vitro digestible dry matter concentration in mixture than in monoculture as long as reed canarygrass yields in mixture did not exceed yields in monoculture. Legumes were taller and more mature in mixture than in monoculture at early harvests. Increased height and advanced maturity may be mechanisms responsible for the legume's dominance. Performance of forage species for agronomic and quality traits in monoculture, however, did not predict their performance in mixture.
Canopy Carbon Dioxide Profile in Relation to Row Spacing of ‘Essex’ Soybean
Authors: Francis Paul B. , Parks W. L. 
Published: July 2010

AbstractLittle field work has been done on how row spacing in soybean [Glycine max (L.) Merr.] alters the canopy microclimate. Canopy CO2 profiles were measured for ‘Essex’ soybean planted in 0.25‐, 0.38‐, and 0.51‐m row spacings with or without a wheat (Triticum aestivum L.) straw mulch (4.5 Mg ha−1) in 1983, and in 0.13‐, 0.25‐, 0.51‐, and 0.76‐m row spacings with no mulch treatment in 1984, under irrigation on Sequatchie loam (a fine‐loamy, siliceous, thermic Typic Hapudult). Canopy CO2 for individual treatments and days was modeled as a function of time of day and height, with R2 values ranging from 0.52 to 0.97. Analysis of covariance for pooled data during reproductive growth indicated significant differences in CO2 among row spacings in the upper three fourths of the canopy. Upper canopy level CO2 was 5 to 15 µL L−1 lower after midday but slightly higher at dusk in the narrower versus wider row spacings and seemed related to a higher leaf density. Mulching did not influence canopy CO2. After midday, the CO2 in the row middles was 5 to 10 µL L−1 lower than over the drill for the 0.76‐m row spacing, which had incomplete canopy closure. Horizontal deviations in CO2 were not evident in the treatments that had complete canopy closure. Carbon dioxide profile variations observed among row spacings seemed to be highly related to leaf area density.
Hybrid Hard Red Spring Wheat Seed Production Potential
Authors: Howey S. J. , Spilde L. A. , Edwards I. B. , Laskar W. J. 
Published: July 2010

AbstractThe success of cytoplasmic male sterile (CMS) hybrid wheat (Triticum aestivum L.) depends greatly on the female seed production potential. Objectives of this experiment were to evaluate male sterile seeding rate and pollinator planting delay in relation to CMS or chemical hybridizing agent (CHA) production systems on hybrid hard red spring wheat seed yield. Field experiments were conducted on a Wheatville silt loam (course‐silty, over clayey, frigid Aeric Calciaquoll) at Kragnes, MN. Spikes were wind and hand pollinated to compare CMS and CHA stigma receptivity during flowering. A CMS (Triticum timopheevi Zhuk. cytoplasm) line was used in 1984 and 1985. A CHA version was obtained in 1985 by applying SD 84811. Male steriles were planted at 22.4, 56.0, and 89.6 kg ha−1 in each of three crossing blocks, which were characterized by pollinator planting delays of 0, 68, and 136 growing degree days (GDD) in 1984, and 0, 85, and 170 GDD in 1985. The highest CMS female yield (2.0 Mg ha−1) utilized the 89.6 kg ha−1 rate and 68 GDD delay in 1984. Positive relationships were observed in 1984 between yield and pollinator delay for the 22.4 kg ha−1 rate, while higher rates had similar but limited yield responses. CMS yields were more than 200% of CHA yields. CMS stigma receptivity periods were similar over years. CMS and CHA stigma receptivity periods were similar for duration and time of peak intensity, but CHA seed sets were generally lower. Additional knowledge on flowering characteristics, environmental interactions, and genotypic compatibility with CHAs may be necessary before hybrid hard red spring wheat production becomes a viable option.
Fall Harvest Management of Alfalfa. II. The Implications of Photosynthesis, Respiration, and Taproot Nonstructural Carbohydrate Accumulation on Fall Harvest Management
Authors: Edmisten K. L. , Wolf D. D. 
Published: July 2010

AbstractAlfalfa (Medicago saliva L.) harvests may be delayed by rainfall, environmental conditions that retard growth, or unfavorable weather for hay curing. Fall harvests may be delayed until dates that may affect winter survival. Harvests made between 20 September and 20 October have generally been considered detrimental to alfalfa stands in geographical areas such as western Virginia, presumably because regrowth depletes reserves needed for winter survival and spring growth. The objective of this study was to determine if photosynthesis following late harvests can help offset losses of total nonstructural carbohydrates (TNC) in taproots and allow more flexible fall harvest management than is currently recommended. ‘Arc’ alfalfa was managed to achieve 50 d of growth prior to final fall harvests made 16 September or 2, 16, or 30 October for 2 yr. The soil was a mixture of Landisburg silt loam (fine‐loamy, mixed, mesic Typic Fragiudult) and Greendale silt loam (fine‐loamy, siliceous, mesic Fluventic Dystrochrept). Gross photosynthesis, plant respiration, and TNC were measured at 2‐wk intervals in the fall following each final fall harvest. In a parallel study, three levels of shade were imposed following each fall harvest date to evaluate the influence of photosynthetic rate on TNC levels and plant persistence. Fall regrowth and plant maintenance were not dependent on root TNC accumulation, and TNC levels ranged from 234 to 295 g kg−1 by 15 December. Photosynthesis offset respiration losses for regrowth and maintenance during the fall. High photosynthetic rates (1.0 to 19.9 μmol CO2, m−2 s−1), compared to respiration (0.1 to 4.2 μmol CO2, m−2 s−1), on a land‐area basis were possible due to temperatures occurring within the optimum range for photosynthesis of alfalfa during 68% of the daylight hours from September through November. Slow regrowth, low respiration rates, and relatively high photosynthetic rates resulting from cool temperatures limited TNC losses following fall harvests. This favorable environmental period lasts much longer in Virginia than at northern latitudes, where most fall harvest management research has been conducted, and allowed sufficient recovery of alfalfa harvested with 50 d of growth in the fall.
Potential of Inhibitors for Increasing Response of Lowland Rice to Urea Fertilization
Authors: Buresh R. J. , De Datta S. K. , Padilla J. L. , Chua T. T. 
Published: July 2010

AbstractThe full potential of biological inhibitors to increase the yield response of lowland rice (Oryza sativa L.) to urea fertilization has remained uncertain, because no chemical has been available to completely eliminate all gaseous loss of applied urea‐N. Two field 15N balance studies at multiple rates of urea with and without a urease inhibitor, phenyl phosphorodiamidate, were conducted in the Philippines. The urea was split broadcast into floodwater at 16 or 18 d after transplanting and at 5 to 10 d after panicle initiation. The applied urea‐15N not recovered in the rice and soil at crop maturity was assumed to represent total gaseous N loss and hence the potential savings in urea‐N that could be obtained with the use of an inhibitor that completely eliminated gaseous N loss. The potential savings in urea‐N consistently increased with increasing N rate. In 1985. the potential urea‐N savings were 17, 23, and 29% at 30, 60, and 120 kg N ha−1, respectively. In 1986, they were 13, 34, and 37% at 40,80, and 120 kg N ha−1, respectively. In each experiment, there was a significant quadratic response in grain yield to applied N. Models were developed for observed responses to applied urea and for potential yield responses to urea assuming complete elimination of gaseous N loss with no effect on rice other than increasing the availability of fertilizer‐N. Elimination of gaseous N loss could have increased grain yield by a maximum of 6 and 8% in 1985 and 1986. respectively. These percentages corresponded to 0.4 and 0.5 Mg ha−1 increases in grain yield, respectively.
Relating Calculated Leaf Area Index, Evapotranspiration, and Irrigation Method of Sugarcane
Authors: Shih S. F. 
Published: July 2010

AbstractThe determination of the considerable amount of water used in south Florida for crop production has been time‐consuming and expensive. The Standard Class A National Weather Service pan evaporation (SPE) has been used to estimate evapotranspiration (ET), but requires crop coefficients, ET/SPE, which vary with plant development stage, season, leaf area index (LAI), yield, and irrigation method. The objective of this study was to establish relationships among ET, SPE, LAI, yield of plant and two ratoon crops of sugarcane (Saccharum spp.), and two irrigation methods. Lysimeters were used for 3 yr (1980‐1982) on a Boca fine sand (loamy, siliceous, hyperthermic Arenic Ochraqualfs). Irrigation methods were drip irrigation and subirrigation systems. Total crop seasonal ET values were 1322 mm for drip irrigation, and 1275 mm for subirrigation. The sugarcane average yield under drip irrigation (143 t/ha) was significantly higher than that under subirrigation (119 t/ha), and was linearly related to the ET. The crop coefficient is curvilinearly related to the LAI. The relationship of ET/SPE to LAI was: 0.649 + 0.185 LAI − 0.025 LAI2 (R2 = 0.77) for both irrigation methods. The relationship of ET/SPE to LAI of the second ratoon under subirrigation was: 0.599 + 0.089 LAI − 0.011 LAI2 (R2 = 0.87).
Water‐Stress Effects on Alfalfa Forage Quality After Adjustment for Maturity Differences
Authors: Halim R. A. , Buxton D. R. , Hattendorf M. J. , Carlson R. E. 
Published: July 2010

AbstractForage quality of alfalfa (Medicago sativa L.) often is higher in water‐deficit‐stressed plants than in nonstressed plants. At least part of the improvement could result from a delay in plant development due to the water stress. The objective of this study was to determine forage quality response of alfalfa to water stress and to relate this to corresponding changes in plant maturity, phonological development, and growth. ‘Apollo II’ alfalfa was grown in 100‐L containers set into the ground and protected by a movable rain shelter. Plants were watered either weekly or twice weekly to 112,100, 88, 76, and 64% of field capacity during 2 yr. Regrowth herbage was harvested at five weekly intervals beginning 3 wk after the initial cut. Plants were divided into stem bases (portion of stems below and including the sixth node), stem tops, and leaves before forage quality analyses were conducted. Plant maturity decreased linearly with increasing water stress. Averaged over the harvests, leaf‐to‐stem ratio (LSR) increased from 0.60 in the well‐watered treatments to 0.72 in the most severely stressed treatment. Delayed plant maturity and node number did not account fully for the increase in LSR under water stress. In vitro digestible dry matter (IVDDM) in stems, which increased by about 9% under water stress, was largely accounted for by delayed plant maturity. In stem bases, crude protein (CP) concentration increased by 11% with increasing water stress, even after accounting for differences in plant maturity. Cellulose concentration, expressed on a cell‐wall (CW) basis, decreased whereas CW hemicellulose concentration increased with water stress in both leaves and stems, and these changes were not entirely attributable to differences in plant maturity and growth. Thus, the slowing of plant maturation and growth during water stress accounted for much, but not all, of the changes in forage quality.
Predicting Superior Yielding Spring Wheat and Oat Cultivars using Past Yield Data
Authors: Gellner J. L. 
Published: July 2010

AbstractAgronomists use data from yield trials when recommending the greater yielding (top‐yielding) cultivars of spring wheat (Triticum aestivum L.) and oat (Avena saliva L.) to growers. At most land grant universities, cultivar recommendations are based on 3‐yr yield means. It is not clear, however, that this procedure is the best predictor of top‐yielding cultivars in the subsequent year. Using South Dakota cultivar performance testing data, eight different yield means were derived from various combinations of previous years' yield data. These eight predictors were assessed for their ability to identify the five top‐yielding cultivars in the subsequent year. Mean yield data were used from 1972 to 1987 for six and five locations for spring wheat and oat, respectively. The eight predictors were compared for differences in mean number of top‐yielding cultivars identified with Friedman rank sum two‐way analysis of variance. Also, predictors were compared to the expected mean number of top‐yielding cultivars identified if cultivar selection was random. The effectiveness of prediction from yield trials with varying coefficient of variation or least significant difference values was assessed. When averaged across all locations, selecting cultivars by mean yields using only the previous year, or using all yield data available for each cultivar, identified the largest number of top‐yielding cultivars in the subsequent year. These predictors were also superior to random selection in one of 11 locations. For oat, prediction was better from yield trials with CV values below 10.7 or LSD values below 8.7. For this data set, cultivar recommendations based on fewer than 3‐yr yield data were equally effective at predicting top‐yielding cultivars as those using 3 yr of yield data.
Tall Fescue Rhizome Production as Influenced by Bermudagrass Competition and Cutting Frequency
Authors: Bouton J. H. , Whitehead F. C. , De Battista J. P. 
Published: July 2010

AbstractThe rhizome trait in tall fescue (Festuca arundinacea Schreb.) should impart better persistence and competitive ability in areas marginal for its adaptation or in mixed swards. This is especially true in the southern range of its adaptation where tall fescue‐bermudagrass [Cynodon dactylon L. (Pers.)] pastures predominate. This study was conducted to investigate the effects of bermudagrass competition and cutting frequency on rhizome production and growth among different tall fescue genotypes on a Cecil sandy loam soil (clayey, kaolinitic, thermic Typic Hapludult). The effects of cutting frequencies of 1 and 6 wk or 2 and 4 wk were evaluated in two separate experiments among three rhizomatous and three non‐rhizomatous genotypes space‐planted into a clean tilled area or into a common or ‘Coastal’ bermudagrass sod. Bermudagrass competition depressed rhizome production, tillering, and plant size across all genotypes. Little effect was recorded for these same characters with frequent cutting unless done weekly. There were significant differences among genotypes for rhizome production. Highly rhizomatous genotypes survived better and grew larger in bermudagrass than non‐ or weakly‐rhizomatous genotypes, indicating the rhizome trait may impart better performance in tall fescue grown in bermudagrass mixtures.
The Impact of Maturity and Genotype on Blend Performance in Group V and Group VII Soybean Cultivars
Authors: Gizlice Ziya , Carter T. E. , Burton J. W. 
Published: July 2010

AbstractIt has been hypothesized that the divergent maturity of blend components is a major factor leading to the positive blend responses sometimes noted in soybean [Glycine max (L.) Merr.]. The objective of this study was to examine the association between cultivar maturity and blend performance in determinate soybean. Eight purelines (four from maturity group [MG] V and VII), and the 28 two‐way blend combinations of these purelines were evaluated for seed yield in eight North Carolina environments. Blend responses (expressed as a deviation of the blend yield from pure‐stand component average) were 0.1, 1.9, and 3.3% for MG V, intermaturity (MG V/ MG VII), and MG VII blends, respectively. The intermediate average response of the intermaturity (MG V/MG VII) blends is an indication that divergent maturity of the blend components has little effect on blend performance. This notion is further substantiated in that individual positive blend responses occurred more frequently in the MG VII blends than in the MG V/MG VII blends. Only the MG VII blend group showed a significant overall blend response (84 kg ha−1). The highest yielding MG V/MG VII blend, that of ‘Coker 237’ (MG VII) with ‘N77‐114’ (MG V), was composed of component cultivars that blended well even when no maturity factors were evident. We conclude that maturity differences may be incidental to better blend performance in determinate soybean. The range of individual blend responses was −9.7 to 9.1%, expressed as deviations from pureline component averages.
Ethephon Application and Nitrogen Fertilization of Irrigated Winter Barley in an Arid Environment
Authors: Pearson C. H. , Golus H. M. , Tindall T. A. 
Published: July 2010

AbstractLodging in barley (Hordeum vulgare L.) can result in grain loss, lower seed quality, increased disease, high grain moisture, reduced harvest efficiency, and lower milling grade. Application of N fertilizer to achieve high barley yields often results in increased lodging. Consequently, N applications are often reduced in order to lessen the potential for lodging. Use of plant growth regulators may permit higher N application rates without increased lodging. Field studies were conducted in an irrigated arid environment during 1986 and 1987 on Fruita sandy clay loam (fine‐loamy, mixed, mesic Typic Haplargid) soil. Ethephon [(2‐chloroethyl) phosphonic acid] was applied at 0.42 kg a.i. ha−1 to irrigated winter barley that received 56, 112, 168, and 224 kg ha−1 of spring‐applied N. The 1986 data indicated that, in the absence of lodging, ethephon did not affect barley grain yields. Ethephon increased grain yields in 1987 in association with reduced lodging. Plant height response to ethephon was similar across N rates. Ethephon shortened internode lengths on the upper portion of the culm and reduced lodging of winter barley grown at high N rates. Ethephon did not affect spikes m−2, kernel mass, kernels spike−1, or seed N content in either year. Application of higher N rates than traditionally used in irrigated winter barley increased grain yield and seed N content. In years when lodging occurred, ethephon was effective as an antilodging agent.
Crop Yield as Affected by Rotation and Nitrogen Rate. II. Grain Sorghum
Authors: Peterson Todd Andrews , Varvel G. E. 
Published: July 2010

AbstractCrop rotation is reported to increase grain sorghum [Sorghum bicolor (L.) Moench] yield in some, but not all cases. This study compares yield of continuous grain sorghum with that of sorghum grown (i) in a 2‐yr rotation with soybean [Glycine max (L.) Merr.]; (ii) in a 4‐yr oat + clover [Avena sativa (L.) + 80% Melilotus officinalis (L.) Lam., 20% Trifolium pratense]‐corn (Zea mays L.)‐soybean—grain sorghum rotation; and (iii) in a 4‐yr soybean—corn—oat + clover—grain sorghum rotation. Interactions between crop rotation and N rate were also determined. The study was conducted for 4 yr on a Sharpsbury silty clay loam (fine, montmorillonitic, mesic Typic Arguidoll). Continuous grain sorghum showed a greater response to fertilizer N than sorghum in rotation. Sorghum following legumes in rotation did not respond to applications of more than 90 kg N ha−1, while continuous sorghum increased with all levels of N applied. Yield of continuous sorghum was 3.4, 5.0, and 5.3 Mg ha−1 with 0, 90, and 180 kg N ha−1, respectively, while sorghum in rotation averaged 5.0, 5.4, and 5.3 Mg ha−1 at the same N rates. Differences between continuous and rotated sorghum were large without applied N, but were minimized or removed with N applications. Sorghum in the 2‐yr sorghum‐soybean rotation produced sustained high yields (5.0 Mg ha−1) without additions of N fertilizer.