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Plant Sciences

Department of Agronomy and Horticulture: Faculty Publications

Series

2000

Articles 1 - 17 of 17

Full-Text Articles in Life Sciences

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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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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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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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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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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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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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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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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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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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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