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Department of Agronomy and Horticulture: Faculty Publications

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Articles 1261 - 1290 of 1713

Full-Text Articles in Life Sciences

Conversion Of Aflp Bands Into High-Throughput Dna Markers, K. Meksem, E. Ruben, D. L. Hyten, K. Triwitayakorn, D. A. Lightfoot Jan 2001

Conversion Of Aflp Bands Into High-Throughput Dna Markers, K. Meksem, E. Ruben, D. L. Hyten, K. Triwitayakorn, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

The conversion of AFLP bands into polymorphic sequence-tagged-site (STS) markers is necessary for high-throughput genotype scoring. Technical hurdles that must be overcome arise from genome complexity (particularly sequence duplication), from the low-molecular- weight nature of the AFLP bands and from the location of the polymorphism within the AFLP band. We generated six STS markers from ten AFLP bands (four AFLPs were from co-dominant pairs of bands) in soybean (Glycine max). The markers were all linked to one of two loci, rhg1 on linkage group G and Rhg4 on linkage group A2, that confer resistance to the soybean cyst nematode (Heterodera …

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Two Large-Insert Soybean Genomic Libraries Constructed In A Binary Vector: Applications In Chromosome Walking And Genome Wide Physical Mapping, K. Meksem, K. Zobrist, E. Ruben, D. L. Hyten, T. Quanzhou, H-B. Zhang, D. A. Lightfoot Oct 2000

Two Large-Insert Soybean Genomic Libraries Constructed In A Binary Vector: Applications In Chromosome Walking And Genome Wide Physical Mapping, K. Meksem, K. Zobrist, E. Ruben, D. L. Hyten, T. Quanzhou, H-B. Zhang, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

Large DNA insert libraries in binary T-DNA vectors can assist in the isolation of the gene(s) under-lying a quantitative trait locus (QTL). Binary vectors facilitate the transfer of large-insert DNA fragments containing a QTL from E. coli to Agrobacterium sp. and then to plants. We constructed two soybean large-insert libraries from cv. Forrest in the pCLD04541 (V41) binary vector after partial digestion of genomic high-molecular-weight DNA with BamHI or HindIII. The libraries contain 76,800 clones with an average insert size of 125 kb, and therefore represent 9.5-fold haploid genome equivalents. Colony hybridization using a chloroplast-specific probe infers that …

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Crop Rotation And Nitrogen Effects On Normalized Grain Yields In A Long-Term Study, Gary E. Varvel Sep 2000

Crop Rotation And Nitrogen Effects On Normalized Grain Yields In A Long-Term Study, Gary E. Varvel

Department of Agronomy and Horticulture: Faculty Publications

Effects of year-to-year variability in agricultural production systems have always been a concern, but few studies are conducted for a long enough period of time where management system evaluations and assessments can be made. Given this limitation, questions about whether management systems are effective at reducing temporal variability remain in production agriculture. These questions prompted investigation of a long-term crop rotation study to determine effects of crop rotation and N fertilization practices in a rainfed environment on normalized grain yields. Sixteen years of grain yield data from an experiment with seven cropping systems (three monoculture, two 2- yr rotations, and …

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Tiller Recruitment Patterns And Biennial Tiller Production In Prairie Sandreed, J. R. Hendrickson, Lowell E. Moser, Patrick E. Reece Sep 2000

Tiller Recruitment Patterns And Biennial Tiller Production In Prairie Sandreed, J. R. Hendrickson, Lowell E. Moser, Patrick E. Reece

Department of Agronomy and Horticulture: Faculty Publications

Tiller recruitment is an essential process for ensuring the perenniality of grasses. The timing and extent of tiller recruitment and the role of biennial tillers must be documented for key range species. Prairie sandreed [Calamovilfa longifolia (Hook) Scribn.] is an important grass in the Nebraska Sandhills for both ecological functioning and as a forage. The objective of this study was to document tiller recruitment patterns and the occurrence and contribution of current year and biennial tillers to biomass production in prairie sandreed at 2 locations in Nebraska. Tiller recruitment was monitored at 2-week periods throughout the growing season during …

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Before You Say Yes: A Planning Guide For Speakers, Charles A. Francis, Heidi Carter, Cris Carusi, James W. King Aug 2000

Before You Say Yes: A Planning Guide For Speakers, Charles A. Francis, Heidi Carter, Cris Carusi, James W. King

Department of Agronomy and Horticulture: Faculty Publications

We need guidelines to help us decide whether to accept invitations to speak, whether to a class on campus or a special interest group outside. As educators and workshop organizers, we could also use suggestions on how to approach potential speakers. This article describes a single-page format that can be used to guide the planning process. Essential elements include contact information, location and organization of the activity, audience, learning goals, expected content, conclusions, and evaluation. Use of this planning sheet can give organization to an often haphazard process of planning, and enhance the potential of achieving the learning goals of …

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Reversal Of Rice Yield Decline In A Long-Term Continuous Cropping Experiment, Achim Dobermann, David Dawe, Reimund P. Roetter, Kenneth G. Cassman Jul 2000

Reversal Of Rice Yield Decline In A Long-Term Continuous Cropping Experiment, Achim Dobermann, David Dawe, Reimund P. Roetter, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

In a long-term continuous cropping experiment at Los Baños, Philippines, three rice (Oryza sativa L.) crops were grown each year with the goals of maximum annual grain production and high N use efficiency. Our objective was to identify the factors responsible for the restoration of yields occurring after 1991. From 1968 to 1991, grain yields declined at an annual rate of 1.4 to 2.0%. From 1991 to 1995, dry season (DS) yields in the highest N treatment increased to within 80 to 100% of the simulated yield potential; yields in the unfertilized control did not increase. Increased solar radiation, …

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Changes In Soil Microbial Community Structure With Tillage Under Long-Term Wheat-Fallow Management, Rhae A. Drijber, John W. Doran, Anne M. Parkhurst, D. J. Lyon Jun 2000

Changes In Soil Microbial Community Structure With Tillage Under Long-Term Wheat-Fallow Management, Rhae A. Drijber, John W. Doran, Anne M. Parkhurst, D. J. Lyon

Department of Agronomy and Horticulture: Faculty Publications

Fatty acid methyl esters (FAMEs) were used to `fingerprint' soil microbial communities that evolved during 25 years of wheat-fallow cropping following native mixed prairie sod at Sidney, Nebraska, USA. Total ester-linked FAMEs (EL-FAMEs) and phospholipid-linked FAMEs (PL-FAMEs) were compared for their ability to discriminate between plots remaining in sod and those cropped to wheat or left fallow under no-till, sub-till or plow management. Cropped plots were higher in microbial biomass than their fallowed counterparts, and did not differ significantly with tillage for the 0±15 cm depth. Under fallow, microbial biomass was greatest in no-till and least in plow. Both cluster …

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Soil Health And Sustainability: Managing The Biotic Component Of Soil Quality, John W. Doran, Michael R. Zeiss Jun 2000

Soil Health And Sustainability: Managing The Biotic Component Of Soil Quality, John W. Doran, Michael R. Zeiss

Department of Agronomy and Horticulture: Faculty Publications

Soil health is the capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Anthropogenic reductions in soil health, and of individual components of soil quality, are a pressing ecological concern. A conference entitled ‘Soil Health: Managing the Biological Component of Soil Quality’ was held was held in the USA in November 1998 to help increase awareness of the importance and utility of soil organisms as indicators of soil quality and determinants of soil health. To …

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Plant Community Patterns On Upland Prairie In The Eastern Nebraska Sandhills, Walter H. Schacht, Jerry D. Volesky, Dennis Bauer, Alexander Smart, Eric Mousel Mar 2000

Plant Community Patterns On Upland Prairie In The Eastern Nebraska Sandhills, Walter H. Schacht, Jerry D. Volesky, Dennis Bauer, Alexander Smart, Eric Mousel

Department of Agronomy and Horticulture: Faculty Publications

Topography is an important factor in determining vegetation patterns in grasslands. We collected frequency of occurrence data from transects on dune tops, south-facing slopes, north-facing slopes, and interdunal valleys in the eastern Sandhills of Nebraska to determine the effect of topographical position on plant species composition. We used canonical discriminant analysis to separate the four topographical positions based on frequency of occurrence of the 18 principal planttaxa. Topographic position played an important role in plant distribution on upland prairie with interdunal transects strongly separated from transects on other topographical positions. Bluegrasses (Poa L. spp.), switchgrass (Panicum virgatum L.), …

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Grain Yield Of Rice Cultivars And Lines Developed In The Philippines Since 1966, S. Peng, R. C. Laza, R. M. Visperas, A. L. Sanico, Kenneth G. Cassman, G. S. Khush Mar 2000

Grain Yield Of Rice Cultivars And Lines Developed In The Philippines Since 1966, S. Peng, R. C. Laza, R. M. Visperas, A. L. Sanico, Kenneth G. Cassman, G. S. Khush

Department of Agronomy and Horticulture: Faculty Publications

Genetic improvement in grain yield has been intensively studied in wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oat (Avena sativa L.), maize (Zea mays L.), and soybean [Glycine max (L.) Merr.]. Such information is limited in rice (Oryza sativa L.). The objective of this study was to determine the trend in the yield of rice cultivars–lines developed since 1966. Twelve cultivars–lines were grown at the International Rice Research Institute (IRRI) farm and the Philippine Rice Research Institute farm during the dry season of 1996. Seven cultivars–lines were grown at IRRI farm in the …

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Establishment Of Big Bluestem And Illinois Bundleflower Mixtures With Imazapic And Imazethapyr, Daniel D. Beran, Robert A. Masters, Roch E. Gaussoin, Fernando Rivas-Pantoja Jan 2000

Establishment Of Big Bluestem And Illinois Bundleflower Mixtures With Imazapic And Imazethapyr, Daniel D. Beran, Robert A. Masters, Roch E. Gaussoin, Fernando Rivas-Pantoja

Department of Agronomy and Horticulture: Faculty Publications

Weeds interfere with establishment of native grasses and legumes. A study was conducted to determine the influence of imazapic1 [(±)- 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]- 5-methyl-3-pyridinecarboxylic acid] and imazethapyr [2-[4,5-dihydro- 4-methyl -4 - (1- methylethyl) -5 -oxo-1H- imidazol -2 - yl]5- ethyl -3- pyridinecarboxylic acid] on weed control and establishment of ‘Pawnee’ big bluestem (Andropogon gerardii Vitman var. gerardii Vitman) and Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMill.] planted in three binary mixtures of 220:110, 165:165, and 110:220 pure live seed (PLS) m-2. Mixtures were seeded at cropland sites near Clay Center, Mead, and Lincoln, NE. Imazapic and imazeth- apyr …

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Parasitoids Of The Bean Leaf Beetle (Coleoptera: Chrysomelidae) Found In Nebraska Soybean Fields, Stephen D. Danielson, James R. Brandle, Laurie Hodges Jan 2000

Parasitoids Of The Bean Leaf Beetle (Coleoptera: Chrysomelidae) Found In Nebraska Soybean Fields, Stephen D. Danielson, James R. Brandle, Laurie Hodges

Department of Agronomy and Horticulture: Faculty Publications

The bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is the major insect pest of soybean in Nebraska and throughout much of the midwestern United States. Natural enemies of the bean leaf beetle have been reported in other states, but none have been reported in Nebraska. In this study, bean leaf beetle adults were obtained by aspirating those found on soybean plants early in the season and by sweep net once plants were in the V4 stage (approximately 0.33 meter tall). Sampling was done in 1997 and 1998 in soybean fields at the University of Nebraska Agricultural Research and Development …

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Ethylene Production, Cluster Root Formation, And Localization Of Iron(Iii) Reducing Capacity In Fe Deficient Squash Roots, Brian M. Waters, Dale G. Blevins Jan 2000

Ethylene Production, Cluster Root Formation, And Localization Of Iron(Iii) Reducing Capacity In Fe Deficient Squash Roots, Brian M. Waters, Dale G. Blevins

Department of Agronomy and Horticulture: Faculty Publications

Dicots and non-graminaceous monocots have the ability to increase root iron(III) reducing capacity in response to iron (Fe) deficiency stress. In squash (Cucurbita pepo L.) seedlings, Fe(III) reducing capacity was quantified during early vegetative growth. When plants were grown in Fe-free solution, the Fe(III) reducing capacity was greatly elevated, reached peak activity on day 4, then declined through day 6. Root ethylene production exhibited a temporal pattern that closely matched that of Fe(III) reducing capacity through day 6. On the 7th day of Fe deficiency, cluster root morphology developed, which coincided with a sharp increase in the root Fe(III) …

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Crop Quality And Utilization: A Twelve-Hour In Vitro Procedure For Sorghum Grain Feed Quality Assessment, Jeffrey F. Pedersen, Todd Milton, R. A. Mass Jan 2000

Crop Quality And Utilization: A Twelve-Hour In Vitro Procedure For Sorghum Grain Feed Quality Assessment, Jeffrey F. Pedersen, Todd Milton, R. A. Mass

Department of Agronomy and Horticulture: Faculty Publications

Improvedmethods for assessing cereal crop feed value are a prerequisite for the genetic improvement of sorghum [Sorghum bicolor (L.) Moench] feed value. Rate of starch digestion is now commonly believed to be the limiting factor in sorghum utilization by cattle (Bos taurus). However, techniques to assess this trait are not useful to sorghum breeders because of high labor inputs, lab error associated with starch measurement, and need for high numbers of replications. The objective of this study was to develop a simple technique capable of identifying differences in digestion between sorghum and corn (Zea mays L.) …

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‘Weihing’ Great Northern Disease-Resistant Dry Bean, Dermot P. Coyne, D.S. Nuland, Dale T. Lindgren, James R. Steadman, D.W. Smith, J. Gonzales, J. Schild, J. Reiser, Lisa Sutton, Clay Carlson, J.R. Stavely, P. Miklas Jan 2000

‘Weihing’ Great Northern Disease-Resistant Dry Bean, Dermot P. Coyne, D.S. Nuland, Dale T. Lindgren, James R. Steadman, D.W. Smith, J. Gonzales, J. Schild, J. Reiser, Lisa Sutton, Clay Carlson, J.R. Stavely, P. Miklas

Department of Agronomy and Horticulture: Faculty Publications

Nebraska is the leading provider in the United States of Great Northern (GN) dry beans (Phaseolus vulgaris L.). Rust [(Uromyces appendiculatus (Pers.) Unger], common bacterial blight [(Xanthomonas campestris pv. phaseoli (Smith) Dye] (Xcp), and white mold [Sclerotinia sclerotiorum (Lib.) de Bary] diseases cause serious reductions in bean yield and seed quality in Nebraska. Halo blight (Pseudomonas syringae pv. syringae van Hall) has been observed in some years, but is not considered a major problem. Diseaseresistant cultivars should ensure improved seed yields and yield stability, and seed quality, and reduce pesticide application. Upright growth habit, combined …

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Using A Nitrate Specific Ion Electrode To Determine Stalk Nitrate–Nitrogen Concentration, Wallace Wilhelm, S.L. Arnold, James S. Schepers Jan 2000

Using A Nitrate Specific Ion Electrode To Determine Stalk Nitrate–Nitrogen Concentration, Wallace Wilhelm, S.L. Arnold, James S. Schepers

Department of Agronomy and Horticulture: Faculty Publications

The end-of-season stalk NO3 test has been used to determine N sufficiency in corn (Zea mays L.). Nitrate concentration is commonly determined with flow-injection analysis (FIA), which is accurate but uses hazardous chemicals and is time-consuming. Use of a simpler method of NO3 determination, such as the NO3 specific ion electrode (SIE), may save time and costs, and reduce hazards. The objective of this study was to compare estimates of stalk NO3 concentration by FIA and NO3 SIE. For FIA, NO3 was extracted with 2 M KCl, and the extract was filtered before analysis. …

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Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance In Soybean Fields Protected And Unprotected By Shelterbelts, Stephen D. Danielson, James R. Brandle, Laurie Hodges, P. Srinivas Jan 2000

Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance In Soybean Fields Protected And Unprotected By Shelterbelts, Stephen D. Danielson, James R. Brandle, Laurie Hodges, P. Srinivas

Department of Agronomy and Horticulture: Faculty Publications

The bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is a major insect pest of soybean in Nebraska and throughout much of the Midwest. This insect overwinters in the adult stage in litter in wooded areas such as shelterbelts. Historically, crop producers have been unsure of the merits of shelterbelts, especially if nearby crops are more likely to be infested by insect pests as a result. In this study, bean leaf beetle adults were sampled during the season by visually counting the number of beetles found on soybean plants early in the season and by sweep net sampling once plants …

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Shoot And Root Characterization Of Rudbeckia Hirta L. Mowed At Different Heights, Amy L. Neigebauer, Garald L. Horse, Don Steinegger, Greg L. Davis Jan 2000

Shoot And Root Characterization Of Rudbeckia Hirta L. Mowed At Different Heights, Amy L. Neigebauer, Garald L. Horse, Don Steinegger, Greg L. Davis

Department of Agronomy and Horticulture: Faculty Publications

Significant research has been conducted on wildflower sod, but the reasoning behind the production system methods is not clear. The purpose of this research was to determine the influence of mowing height on the subsequent leaf growth and root biomass distribution in a wildflower sod production system. Rudbeckia hirta was grown in sand in polyvinyl chloride (PVC) tubes in simulating field conditions. Plants were either not mowed (control) or hand-clipped to 5.1, 7.6, or 10.2 cm to simulate mowing. After the initial mowing, plants were mowed at ≈7-day intervals. Total root depth, number of root axes in the top 2.5 …

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Post–Green Revolution Trends In Yield Potential Of Temperate Maize In The North-Central United States, D. N. Duvick, Kenneth G. Cassman Nov 1999

Post–Green Revolution Trends In Yield Potential Of Temperate Maize In The North-Central United States, D. N. Duvick, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

This paper addresses the question of whether there has been an increase in yield potential of maize (Zea mays L.) hybrids released in the north-central United States since the advent of the “Green Revolution” that began in the late 1960s. Because there are few published data about hybrid growth rates and yield-determining plant traits when grown at yield potential levels, we attempt to address this issue indirectly by evaluation of maize breeding efforts, changes in plant traits of commercial hybrids, and by comparison of statewide average yield trends and yield trends in sanctioned yield contests. On the basis of …

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Yield Potential Trends Of Tropical Rice Since The Release Of Ir8 And The Challenge Of Increasing Rice Yield Potential, S. Peng, Kenneth G. Cassman, S. S. Virmani, J. Sheehy, G. S. Khush Nov 1999

Yield Potential Trends Of Tropical Rice Since The Release Of Ir8 And The Challenge Of Increasing Rice Yield Potential, S. Peng, Kenneth G. Cassman, S. S. Virmani, J. Sheehy, G. S. Khush

Department of Agronomy and Horticulture: Faculty Publications

Since the release of IR8 in 1966, 42 additional indica rice (Oryza sativa L.) cultivars developed by the International Rice Research Institute (IRRI) for the irrigated and favorable rainfed lowlands have been released in the Philippines. The maximum yield of IR8 has been reduced by about 2 Mg ha-1 during the past 30 yr. Empirical breeding for population improvement within the indica germplasm has in the maintenance of rice yield potential in the tropics of about 10 Mg ha-1. To break the yield barrier, several approaches are being explored. These include development of a new plant …

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An Integrated Genetic Linkage Map Of The Soybean Genome, P.B. Cregan, T. Jarvik, A.L. Bush, R.C. Shoemaker, K.G. Lark, A.L. Kahler, N. Kaya, T.T. Vantoai, D.G. Lohnes, J. Chung, James E. Specht Aug 1999

An Integrated Genetic Linkage Map Of The Soybean Genome, P.B. Cregan, T. Jarvik, A.L. Bush, R.C. Shoemaker, K.G. Lark, A.L. Kahler, N. Kaya, T.T. Vantoai, D.G. Lohnes, J. Chung, James E. Specht

Department of Agronomy and Horticulture: Faculty Publications

A number of molecular genetic maps of the soybean [Glycine max (L.) Merr.] have been developed over the past 10 yr. These maps are primarily based on restriction fragment length polymorphism (RFLP) markers. Parental surveys have shown that most RFLP loci have only two known alleles. However, because the soybean is an ancient polyploid, RFLP probes typically hybridize and map to more than one position in the genome. Thus, the polymorphic potential of an RFLP probe is primarily a function of the frequency of the two alleles at each locus the probe detects. In contrast, simple sequence repeat (SSR) …

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Canopy Analysis As A Technique To Characterize Defoliation Intensity On Sandhills Range, M. S. Miller-Goodman, Lowell E. Moser, Steven S. Waller, J. E. Brummer, P. E. Reece Jul 1999

Canopy Analysis As A Technique To Characterize Defoliation Intensity On Sandhills Range, M. S. Miller-Goodman, Lowell E. Moser, Steven S. Waller, J. E. Brummer, P. E. Reece

Department of Agronomy and Horticulture: Faculty Publications

Characterization of relationships between grazing and vegetation responses is difficult. Rapid and accurate measurement of pasture canopy characteristics would help clarify these relationships if canopy changes are directly related to grazing variables. The objectives of this study were (1) to evaluate use of the LI-COR LAI-2000 for quantification of changes in canopy density and architecture in response to defoliation by cattle, (2) to determine if changes in leaf area index (LAI) measured with the LAI-2000 are related to stocking rate, and (3) to determine advantages and drawbacks of the LAI-2000 for monitoring grazing impacts on canopy density and architecture. Leaf …

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Field And Laboratory Evaluation Of Soil Quality Changes Resulting From Injection Of Liquid Sewage Sludge, S. Stamatiadis, John W. Doran, Timothy A. Kettler May 1999

Field And Laboratory Evaluation Of Soil Quality Changes Resulting From Injection Of Liquid Sewage Sludge, S. Stamatiadis, John W. Doran, Timothy A. Kettler

Department of Agronomy and Horticulture: Faculty Publications

Soil quality changes resulting from repeated or single injection of liquid municipal sewage sludge were evaluated in terraced cropland in eastern Nebraska, USA. Differences in soil properties among sampling locations were explained primarily by two factors, landscape position and sludge injection. Selected chemical properties (pH, EC, NO 3-N) did not generally differ between landscape positions, but soil organic matter (organic C and N) and microbial activity indices (soil respiration, biomass N, available N, mineralization and nitrification rates) were more sensitive indicators of change. Values of these indicators generally increased down-slope from the upper terrace to the grassed waterway on …

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Ecological Intensification Of Cereal Production Systems: Yield Potential, Soil Quality, And Precision Agriculture, Kenneth G. Cassman May 1999

Ecological Intensification Of Cereal Production Systems: Yield Potential, Soil Quality, And Precision Agriculture, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply. Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation. Meeting future food demand while minimizing expansion of cultivated area primarily …

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Genetic\ Agronomic And Quality Comparisons Of Two 1al.1rs. Wheat-Rye Chromosomal Translocations, Robert A. Graybosch, J.-H. Lee, C. J. Peterson, D. R. Porter, O. K. Chung Apr 1999

Genetic\ Agronomic And Quality Comparisons Of Two 1al.1rs. Wheat-Rye Chromosomal Translocations, Robert A. Graybosch, J.-H. Lee, C. J. Peterson, D. R. Porter, O. K. Chung

Department of Agronomy and Horticulture: Faculty Publications

The 1AL.1RS wheat-rye chromosomal translocation originally found in ‘Amigo’ wheat possesses resistance genes for stem rust, powdery mildew and greenbug biotypes B and C, but also has a negative effect on wheat processing quality. Recently, a second 1AL.1RS translocation carrying Gb6 a gene conferring resistance to greenbug biotypes B, C, E, G and I, was identified in the wheat germplasm line ‘GRS1290’. Protein analytical methods, and the DNA polymerase chain reaction were used to identify markers capable of differentiating the 1RS chromosome arms derived from ‘Amigo’ and ‘GRS1201’. The secalin proteins encoded by genes on 1RS chromosome arms differed in …

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Switchgrass Seedling Development As Affected By Seed Size, Alexander J. Smart, Lowell E. Moser Mar 1999

Switchgrass Seedling Development As Affected By Seed Size, Alexander J. Smart, Lowell E. Moser

Department of Agronomy and Horticulture: Faculty Publications

Seed size has been associated with early seedling vigor (i.e., germination rate, emergence rate, and growth) in grasses. This study was conducted to compare seedling development over a 60-d period in the field as affected by heavy seed (HS) (0.19 to 0.21 g 100 seed-1) and light seed (LS) (0.13 to 0.16 g 100 seed-1) of 'Blackwell' and 'Trailblazer' switchgrass (Panicum virgatum L.). The experiment was conducted in 1995 and 1996 at Lincoln, NE, on a Kennebec silt loam (fine-silty, mixed, superactive, mesic Cumnlic Hapludolls). The experimental design was a randomized complete block with four …

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Effect Of Leaf Phosphorus And Potassium Concentration On Chlorophyll Meter Reading In Rice, Shaobing Peng, Arnel L. Sanico, Felipe V. Garcia, Rebecca C. Laza, Romeo M. Visperas, Josue P. Descalsota, Kenneth G. Cassman Jan 1999

Effect Of Leaf Phosphorus And Potassium Concentration On Chlorophyll Meter Reading In Rice, Shaobing Peng, Arnel L. Sanico, Felipe V. Garcia, Rebecca C. Laza, Romeo M. Visperas, Josue P. Descalsota, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Chlorophyll meter (SPAD) is a convenient tool to estimate leaf nitrogen (N) concentration of rice plants. There is no information on the effects of leaf phosphorus (P) and potassium (K) concentration on SP AD readings and on the relationship between SPAD values and leaf N concentration in the literature. In 1996 dry season, cv IR72 was grown at the International Rice Research Institute (IRRI) and the Philippine Rice Research Institute (PhilRice) under various N, P and K fertilizer combinations. SPAD measurements were made on the topmost fully expanded leaves at mid-tillering and panicle initiation. The leaves were then detached, dried …

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Loci Controlling Resistance To High Plains Virus And Wheat Streak Mosaic Virus In A B73 × Mo17 Population Of Maize, A. Marçon, S. M. Kaeppler, S. G. Jensen, L. Senior, C. Stuber Jan 1999

Loci Controlling Resistance To High Plains Virus And Wheat Streak Mosaic Virus In A B73 × Mo17 Population Of Maize, A. Marçon, S. M. Kaeppler, S. G. Jensen, L. Senior, C. Stuber

Department of Agronomy and Horticulture: Faculty Publications

High Plains disease has the potential to cause significant yield loss in susceptible corn (Zea mays L.) and wheat (Triticum aestivum L.) genotypes, especially in the central and western USA. The primary causal agent, High Plains virus (HPV), is vectored by wheat curl mite (WCM; Aceria tossicheila Keifer), which is also the vector of wheat streak mosaic virus (WSMV). In general, the two diseases occur together as a mixed infection in the field. The objective of this research was to characterize the inheritance of HPV and WSMV resistance using B73 (resistant to HPV and WSMV) × Mo17 (moderately …

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The Response Of Muskmelon Growth And Development To Microclimate Modification By Shelterbelts, Dongsheng Zheng, James R. Brandle, Laurie Hodges, Entin Daningsih, Kenneth G. Hubbard Jan 1999

The Response Of Muskmelon Growth And Development To Microclimate Modification By Shelterbelts, Dongsheng Zheng, James R. Brandle, Laurie Hodges, Entin Daningsih, Kenneth G. Hubbard

Department of Agronomy and Horticulture: Faculty Publications

The relationships between shelterbelt (tree windbreak)-induced microclimate and muskmelon (Cucumis melo L.) growth and development were investigated at the Univ. of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Nebr., during the 1992 and 1993 growing seasons. Wind speed, wind direction, air and soil temperatures, relative humidity, and soil moisture were monitored in both sheltered and nonsheltered areas. Plant growth parameters (plant height, vine length, plant dry weight, and leaf area) were measured at various stages of development. Shelterbelts provided improved growing conditions for muskmelon transplants. Direct wind damage and duration of higher wind speeds were reduced 47% to …

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Notes: Evaluation Of A Filter Bag System For Ndf, Adf, And Ivdmd Forage Analysis, Kenneth P. Vogel, Jeffrey F. Pedersen, Steven D. Masterson, John J. Toy Jan 1999

Notes: Evaluation Of A Filter Bag System For Ndf, Adf, And Ivdmd Forage Analysis, Kenneth P. Vogel, Jeffrey F. Pedersen, Steven D. Masterson, John J. Toy

Department of Agronomy and Horticulture: Faculty Publications

A new method of determining in vitro dry matter digestibility (IVDMD) as recently developed in which the digestion is conducted with the forage samples in filter bags. Our objective was to compare the filter bag and conventional IVDMD analysis methods using smooth bromegrass (Bromus inermis Leyss.), switchgrass (Panicum virgatum L.), and forage sorghum [Sorghum bicolor (L.) Moench] samples. In addition, the filter bag analysis systems for determining non-sequential neutral and acid detergent fiber (NDF and ADF), respectively, were compared with the non-sequential conventional analysis systems. In the filter bag systems, the forage samples are sealed in filter bags and the …

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