bluuebunny/crossref_metadata_2025_split huggingface dataset:
Winter Wheat Yield and Grain Protein across Varied Landscape Positions
Authors: Fiez Timothy E. , Miller Baird C. , Pan William L. 
Published: July 2010

AbstractWinter wheat (Triticum aestivum L.) yield varies greatly among landscape positions in the Palouse region of eastern Washington, yet N fertilizer is typically applied uniformly. Varying N fertilizer rates within fields to match site‐specific N requirements can increase fertilizer use efficiency; however, spatially variable N management programs are limited by their ability to predict site‐specific yield potentials and the resultant N requirements. The objective of this study was to ascertain the role of yield components and soil properties in determining soft white winter wheat grain yield and protein when N application rates are varied among landscape positions. Nitrogen fertilizer (0 to 140 kg N ha−1) was fall‐applied on footslope, south‐backslope, shoulder, and north‐backslope landscape positions at each of two farms in 1989 and in 1990. Grain yield among landscapes varied by up to 55% in 1990 and by up to 33% in 1991. Landscape position grain yields increased by 199 kg ha−1/(cm precipitation + soil water reduction) (r2 = 0.51) and by 706 kg ha−1 per 100 spikes m‐2 (r2 = 0.76). Grain protein concentration among landscapes increased by 2.7 g kg−1 per each increase of 10 kg residual soil NO3−N ha−1 (r2 = 0.82). The large differences in grain yield among landscape positions may justify spatially variable N application. Improved N management should favorably reduce soft white winter wheat protein concentrations by minimizing high residual N levels as well as improve net returns and reduce environmental degradation. The basis for this improved N management may be site‐specific yield estimates calculated from soil water availability and spike density.
Yielding Ability and Yield Stability of Linseed in Central Europe
Authors: Diepenbrock Wulf A. , Léon Jens , Clasen Knut 
Published: July 2010

AbstractSuccessful linseed (Linum usitatissimum L.) cropping in Central Europe depends on yielding ability and yield stability of cultivars, as well as on reliability of production systems. During 1991 and 1992, two experiments spread over 14 representative locations in Germany and one location in Switzerland were conducted to analyze the effects of cultivar, N fertilization, and seeding rate on yield and, especially, on yield stability. Experiment 1 tested the effects of seeding rate (200, 400, 600, and 800 seeds m−2) and N fertilization rate (60 and 100 kg N ha−1) at nine locations. Experiment 2 investigated yield performance and yield stability of 16 cultivars and lines at nine locations. At 60 kg N ha−1, 200 and 800 seeds m−2 resulted in the lowest yields. Additionally, 200 seeds m−2 was associated with significant yield instability. At 100 kg N ha−1, seed yields reached a plateau at seeding rates of 400 and 600 seeds m−2. At 800 seeds m−2, yield decreased significantly. Only the 400 seeds m−2 rate resulted in significant yield stability. Two cultivars (Atalante, McGregor) and two lines (DSV‐5, DSV‐6) were superior in yield to other genotypes, but only Atalante and DSV‐6 were both high yielding and stable in yield. Adjusting seeding rate in relation to soil‐available N is a useful tool to optimize linseed production in a given location. It is concluded that high‐yielding cultivars are available that respond adequately to production potential at each of the selected locations.
A Computer Program Relating Solute Potential to Solution Composition for Five Solutes
Authors: Michel Burlyn E. , Radcliffe David 
Published: July 2010

AbstractData required to prepare solutions with desired solute potentials at any temperature from 0 to 40°C are scattered, often have inappropriate units, and usually require involved calculation or are not available. We wished to prepare a program so that anyone could obtain pertinent information simply. Adequate published data could be found only for mannitol, PEG 8000, NaCl, KCl, and sucrose, with water displacement by mannitol and PEG 8000 having to be measured. The program sends tabular output to the screen and it may be written in a disk file, making observation of relationships and preparation of graphical representation simple. A sequence of data may be generated over temperature, concentration, or potential ranges by specifying an initial value, interval size, and number of intervals. Values are given for temperature, water density, molal and molar concentrations, g solute g−1 water, osmotic coefficient, g and mL water displaced g−1 solute, solute potential (MPa), and g solute and g water needed for a requested volume of solution.
Seedbed Residue and Seed Size Relationships in Winter Barley
Authors: Chastain Thomas G. , Ward Kathy J. , Wysocki Donald J. 
Published: July 2010

AbstractUnderstanding how winter barley (Hordeum vulgare L.) seeds and seedling plants interact with crop residue in the seedbed is essential for development of planting recommendations for dryland conservation tillage systems. Field trials were conducted in 1990–1991 (Trial 1) and 1991–1992 (Trial 2) near Pendleton, OR, to determine the effects of seedbed crop residue, seed size, and cultivar on emergence, growth, and yield of winter barley. Seedbed residue cover (32–45%) did not affect seedling emergence rate in Trial 1. Seed‐soil contact was apparently reduced in high‐residue seedbeds, but emergence was reduced only when seed‐zone water content was <120 g kg−1 in Trial 2. More water was present in the seedbed at the time of seeding in Trial 1 than in Trial 2. Low‐residue seedbeds were drier than moderate‐ or high‐residue seedbeds at the time of seeding in both trials. Final stand density and subsequent plant growth were not influenced by seedbed residue (up to 49% residue) in either trial. Spike production was reduced by high residue and test weight was reduced by moderate and high residue in Trial 1. Grain yield and plumpness were lowest when barley was sown in low residue in Trial 2. Seedlings produced from large seeds emerged more rapidly and produced higher density stands than small seeds in Trial 1 but not Trial 2. Plants grown from large seed were somewhat larger in spring, but seed size had no other effect on growth or yield. Grain plumpness was greater in plants grown from large seed in Trial 1 but not Trial 2. No differences in stand establishment were detected among the cultivars tested. Higher seedbed residues should not be viewed as detrimental to achieving good winter barley performance in conservation tillage systems.
Water and Nitrogen Effects on Winter Wheat in the Southeastern Coastal Plain: II. Physiological Responses
Authors: Frederick James R. , Camberato James J. 
Published: July 2010

AbstractThe application of N to winter wheat (Triticum aestivum L. emend. Theil.) generally increases leaf reduced N concentration (LRN), thereby potentially increasing the rate and duration of leaf photosynthesis during grain fill. For nonirrigated winter wheat grown on the southeastern Coastal Plain of the USA, however, increasing the rate of spring‐applied N has been found to result in greater plant water deficits and lower leaf CO2 exchange rates (CER) during the grain‐filling period. This 2‐yr study was conducted to determine the effects of spring N rate on the rate and duration of leaf photosynthesis in winter wheat grown with irrigation and to examine the relationship between leaf CER and LRN as affected by spring N rate, soil water treatment, and wheat growth stage. Wheat was grown with different rates of spring‐applied N (0, 45, 90, and 135 kg N ha−1) under irrigated and nonirrigated conditions. Leaf CER generally increased with increased spring N under irrigated conditions but decreased under nonirrigated conditions. Higher leaf CER with irrigation, as opposed to without irrigation, resulted in greater vegetative dry weights during the early stages of grain fill. Leaf CER was closely associated with LRN during grain fill under irrigated conditions, but greater stomatal closure with increased spring N resulted in deviations from this relationship under nonirrigated conditions. The dates of initial decline in LRN of the flag leaf and leaf area index (LAI) were similar for all treatments and in both years. Only under irrigated conditions did increases in spring N rate delay the complete loss of leaf area and photosynthetic activity during grain fill. Compared with 1992, the rate of decline in LAI, LRN, and CER during grain fill was more rapid in 1993, when air temperatures were warmer. Results indicate that supplemental water is needed on the southeastern Coastal Plain for high rates of spring‐applied N to increase the rate and duration of leaf photosynthesis in winter wheat during the grain‐filling period.
Developing and Validating a Model for a Plant Growth Regulator
Authors: Reddy K. Raja , Boone Mariquita L. , Reddy A. R. , Hodges Harry F. , Turner Sammy B. , McKinion James M. 
Published: July 2010

AbstractMepiquat chloride (MC), 1,1‐dimethylpiperidinium chloride, is a systemic plant growth regulator used extensively to regulate vegetative growth in cotton (Gossypium hirsutum L. and G. barbadense L.). Yield responses to MC have been erratic, probably due to the difficulty in choosing the proper rate and timing of application. We developed a model based on data collected by spraying various amounts of MC on 25‐d‐old plants. The effect of MC on various physiological parameters was measured. Stem elongation rate was reduced 38% due to 30 µg g−1 of MC, while leaf area expansion rate and photosynthesis was reduced 30%. The model adjusts the projected leaf expansion, stem elongation, and photosynthetic rates based on the crop growth status and concentrations of MC in the tissues. The MC subroutine was incorporated into GOSSYM‐COMAX, a combined simulation model for plant growth and decision aid for cotton crop management. We tested the model against data for plant heights, mainstem nodes, and yields from several cropping systems across the U.S. Cotton Belt. The simulation results agreed closely with the observed field data. The new model reduced the overall variability 32% for predicting plant heights, 4% for predicting number of mainstem nodes, and 17% for predicting lint yields over the previously published MC model. When used in association with GOSSYM‐COMAX, the MC model may provide an effective tool for selecting precise timing and amounts of mepiquat chloride needed to optimize the proper use of the chemical.
Cropping Systems for Perennial Ryegrass Seed Production: II. Minimum Tillage Systems for Changing Cultivars in Certified Seed Production
Authors: Young William C. , Youngberg Harold W. 
Published: July 2010

AbstractFew studies have been conducted to evaluate certified grass seed crop establishment under no‐till systems. Four field studies were conducted near Corvallis, OR, between 1985 and 1989, to evaluate the acceptability of 1‐ and 2‐yr no‐till crop rotation systems between two perennial ryegrass (Lolium perenne L.) cultivars grown for certified seed production under the genetic purity requirements of Association of Official Seed Certifying Agencies (AOSCA). Four rotation systems were used: 1‐ and 2‐yr red clover (Trifolium pratense L.), 1‐yr meadowfoam (Limnanthes alba L.), and 2‐yr meadowfoam‐spring pea (Pisum sativum L.). Afterharvest residue from a diploid perennial ryegrass was either burned or flail‐chopped (nonburned) before drill‐seeding the rotation crops. A tetraploid perennial ryegrass followed after rotation crops to assess contamination from seedlings of the first perennial ryegrass (diploid) seed crop. For all rotation sequences, the number of ryegrass plants growing between planted rows and the percentage of diploid seed in the harvested tetraploid seed crop exceeded AOSCA seed certification standards. Burning the stubble did not reduce the number of volunteer seedlings to the level acceptable for seed certification. We concluded that 1‐ or 2‐yr rotation sequences out of perennial ryegrass seed production using minimum tillage systems were not sufficient to meet the cultivar purity standards for production of certified seed, even when burning preceded establishment of the rotation crops. Also, burning ryegrass stubble prior to establishment of the rotation species had little effect on seed yield of the following ryegrass crop. Burning the stubble of the first‐year ryegrass crop established after rotation species, however, improved the seed yield of the second‐year crop.
Renovation Effects on Bahiagrass Productivity
Authors: Williams M. J. , Kalmbacher R. S. 
Published: July 2010

AbstractProduction declines in perennial grass swards have been attributed to soil compaction and a phenomenon referred to as root‐bound sod. The effect of renovation equipment on the productivity of bahiagrass (Paspalum notatum Flügge) was evaluated for 2 yr (1991–1993) at the USDA‐ARS Subtropical Agricultural Research Station (STARS) and the University of Florida Agricultural Research and Education Center at Ona. Water infiltration and penetrometer resistance were determined in mid‐April, immediately pre and post treatment, with either of two styles of bladed (chopper or bladed) or a spiked piece of equipment and at 12, 26, and 52 wk post treatment. Forage dry matter (DM) production and tiller density were determined every 4 wk. Penetrometer resistance was reduced in the upper 15 to 20 cm of the soil immediately post treatment (average of 3.2 and 8.0 kg cm2 at the 10‐cm depth at Ona and STARS, respectively, in 1991), but remained detectable at subsequent post‐treatment times only at STARS. Water infiltration was enhanced only once during the 2 yr (approximately 60 mm h−1 increase). Tiller density was not affected by renovation at Ona (750 tillers m−2 average), but at STARS it declined an average of 20% for bladed or chopper‐treated plots in 1991–1992, due to death of uprooted tillers (1320 tillers m−2 untreated vs. 1065 tillers m−2 average bladed‐type equipment). Forage DM production of renovated plots was less than or equal to that of the untreated plot at each sample date at both sites both years. Based on this study, use of these types of renovation equipment in April on bahiagrass swards in Florida cannot he recommended.
Use of Near Infrared Reflectance Spectroscopy to Screen Ethiopian Mustard for Seed Weight
Authors: Velasco Leonardo , FernÁndez‐MartÍnez JosÉ , De Haro Antonio 
Published: July 2010

AbstractNear infrared reflectance spectroscopy (NIRS) provides a method for the simultaneous measurement of multiple quality traits in oilseed Brassica species, such as oil, protein, glucosinolate, and chlorophyll content. The incorporation of new traits into NIRS analysis should increase the information obtained from analyzed samples with little additional effort. The objective of this study was to determine the potential use of NIRS to screen intact‐seed samples of Ethiopian mustard (Brassica carinata Braun) for 1000‐seed weight. A calibration equation for this trait developed in 1992 using modified partial squares (MPLS) regression was successively expanded with new samples from the 1993 and 1994 crops. The 3‐yr calibration showed an r2 of 0.86 in external validation, indicating the reliability of NIRS for screening Ethiopian mustard samples for seed weight. This method could be particularly useful in large breeding programs, as it is less time consuming and more cost effective than conventional methods.
Yield, Psyllid Resistance, and Phenolic Concentration of Leucaena in Two Environments in Hawaii
Authors: Austin Michael T. , Early Richard J. , Brewbaker James L. , Sun Weiguo 
Published: July 2010

AbstractInterspecific hybridization in the genus Leucaena produces hybrid vigor, resulting in highly adaptable varieties that expand the growth range of the genus. This study was conducted to test the total biomass (combined stem and forage fraction), total forage dry matter (DM) yield, psyllid (Heteropsylla cubana Crawford) damage, and phenolic concentration of Leucaena F1 hybrids in comparison with species‐level selections in two distinctly different environments. A total of 19 Leucaena spp. and hybrid selections were tested for 2 yr at the Waimanalo and Mealani Research Stations in Hawaii. Thirteen species and hybrid selections were replicated three times and included species selections from L. pallida Britton & Rose; L. leucocephala (Lam.) de Wit; L. diversifolia (Schlechtend.) Benth. (2n = 4x); and L. trichandra (Zucc.) Urban [syn. L. diversifolia (Schlechtend.) Benth. subsp. trichandra (Urban) F.J. Pan] (2n = 2x). Additionally, five selections were interspecific F1 hybrids and two were advanced‐generation interspecific hybrids. Six other selections were augmented in the trials. Over 2 yr, L. pallida ✕ L. leucocephala F1 hybrids (K748 ✕ K636 and K748 ✕ K584) had the highest DM yield at both locations. At Waimanalo, K748 ✕ K636 produced 53.4 Mg ha−1 total DM biomass of which 24.6 Mg ha−1 was forage, while at Mealani, K748 ✕ K636 produced 29.4 Mg ha−1 total DM biomass and 9.6 Mg ha−1 forage. These yields were twice those of L. leucocephala at Waimanalo and eight times greater at Mealani. Leucaena leucocephala was the most susceptible to psyllid damage (P < 0.001), while the most resistant was L. trichandra (2n = 2x). Leucaena pallida hybrids had intermediate levels of psyllid resistance. Psyllid damage was negatively correlated with forage DM once at Waimanalo (r = −0.37, P < 0.05, n = 42). Forage phenolic concentration averaged 110 mg g−1 for all treatments at both locations and was correlated once to psyllid damage (r = 0.32, P < 0.05, n = 42) at Waimanalo. Superior yield, psyllid resistance and cold tolerance of L. pallida ✕ L. leucocephala hybrids was observed at low and high elevation sites.
Path Analysis and Ideotypes for Plantain Breeding
Authors: Ortiz Rodomiro , Langie Hilde 
Published: July 2010

AbstractPlantains (Musa spp., AAB group) are an important food crop in the humid lowlands of sub‐Saharan Africa. Understanding the relationships between growth characteristics and yield potential (t ha−1 yr−1) would be useful in developing an ideotype to guide breeding efforts for this crop. We investigated cause‐effect relationships, through path analysis, in yield potential of six plantain landraces (one giant and two medium French; one medium and one giant False Horn; one True Horn) under two production systems (perennial ratooning and replanting after harvest). Each landrace was selected as a random member of a particular type from the plantain gene bank, for a representative sample of the phenotypic diversity of the crop. The plantain landraces were grown for 6 yr in a split‐plot randomized complete block design, with four replications of 30 competing plants per subplot. Landrace was the main plot and production system was the subplot. There were few common pathways determining yield potential among the plantain landraces, so we could not define a common ideotype for plantain breeding. This suggests that plantains may possess different genes controlling similar pathways, or different traits contributing to yield potential. Also, the defined ideotypes differed for each landrace, according to the production system. Plantain breeders should consider those relationships that are affected by both genotype and production system when selecting for improved hybrid germplasm.
Using Early‐Season Leaf Traits to Predict Nitrogen Sufficiency of Burley Tobacco
Authors: MacKown Charles T. , Sutton Tommy G. 
Published: July 2010

AbstractBurley tobacco (Nicotiana tabacum L.) requires large amounts of fertilizer N to produce high yields of good‐quality air‐cured leaf. On well‐drained soils, fertilizer N typically is applied as much as 4 wk before transplanting. This results in a delay of up to 9 wk before the onset of rapid growth and N accumulation at about 5 wk after transplanting. Abundant rainfall often occurs during this period and creates the potential for losses of soil and fertilizer N. An early‐season N‐sufficiency tissue test could guide the tobacco grower in adjusting fertilizer needs of the crop before the last cultivation, which normally occurs about 5 wk after transplanting. The objective of this study was to determine relationships among selected N‐nutrition‐related leaf traits of tobacco measured 3, 4, and 5 wk after transplanting and to determine if these traits are related to yields of air‐cured leaf. Burley tobacco was grown in 1993 at two locations, with 0 to 336 kg N ha−1 applied before transplanting. One site had a well‐drained soil; the other site, moderately well‐drained. Total N, extracted chlorophyll, and chlorophyll meter readings were measured on leaf lamina disks taken from lower leaves. Leaf yields at both sites were equivalent at 336 kg N ha−1, with increases in yield due to added N being less for the well‐drained soil. The response patterns of the leaf traits to fertilizer N were different for the two soil types and corresponded to the respective yield response patterns for each site. Neither extracted chlorophyll (335–760 mg m−2) nor chlorophyll meter readings (23.0–42.6 SPAD units) plateaued with increasing total N of leaf disks (3.50–6.26 g m−1, 41.2‐66.6 mg g−1 dry wt.). Models for linear relationships among leaf traits were significant (R2 = 0.60–0.66; P < 0.001). A 20% increase in relative yield corresponded to about a 25% increase in concentrations of total N and extracted chlorophyll, but only a 5% increase in chlorophyll meter readings. After more testing and calibration with comparisons to a high‐N‐fertility reference strip, these early‐season leaf tissue traits may prove useful in predicting sidedress fertilizer N requirements.
Cultivar, Nitrogen, and Moisture Effects on a Rice‐Wheat Sequence: Experimentation and Simulation
Authors: Timsina Jagadish , Singh Upendra , Badaruddin Mohammed , Meisner Craig 
Published: July 2010

AbstractRice (Oryza sativa L.) followed by wheat (Triticum aestivum L.) is a dominant cropping sequence under a range of management regimes in South Asia, with variable productivity. Simulation models can be used to extrapolate experimental results to other sites of interest in variable environments. Experiments were conducted to quantify the responses of two rice cultivars to three N regimes and two soil moisture regimes, followed by the responses of the succeeding two wheat cultivars to three N regimes, two soil moisture regimes, and two dates of planting, on a Haplaquept noncalcareous brown floodplain soil at the Wheat Research Center, Nashipur, Bangladesh. CERES‐Rice and CERES‐Wheat models were validated using the experimental data set, and then were used to estimate the grain yields at two other sites in Bangladesh. In rainfed plots, grain yields of ‘BR14’ rice were reduced by 48.8, 43.4, and 39.3% relative to irrigated plots, and those of ‘BR11’ were reduced by 49.1, 43.8, and 42.2% (P < 0.05), for 0, 90, and 135 kg N ha−1, respectively. The optimum N rate was between 90 and 135 kg ha−1. In the succeeding wheat crop, at 0 N, there were no significant differences between the two moisture regimes but, at high N (180 kg ha−1), irrigation promoted greater yield. Relative to the high‐N treatment, grain yields of irrigated ‘Kanchan’ wheat at 0 N were reduced by 73.0 and 71.6%, and of ‘Sowgat’ by 75.2 and 73.5%, for early and late plantings, respectively. Simulation investigated year‐to‐year variation in grain yields of both crops under their several N regimes. Rice yields tended to increase over years, but wheat yields had no definite trend. The simulation results indicated that, without N fertilizer application, N will be limiting across sites and long‐term weather conditions for both rainfed and irrigated crops. Field experimentation quantified actual crop responses to a range of management practices and allowed validating the models for the rice‐wheat sequence. The models were then used to extrapolate and generalize the results for two other sites in Bangladesh.