Plant Sciences Commons^™

Interplanting Annual Ryegrass, Wheat, Oat, And Corn To Mitigate Iron Deficiency In Dry Beans, Emmanuel Chiwo Omondi, Andrew R. Kniss

Agricultural and Environmental Sciences Faculty Research

This study evaluated whether grass intercropping can be used to alleviate Fe deficiency chlorosis in dry beans (Phaseolus vulgaris L.) grown in high pH, calcareous soils with low organic matter. Field studies were conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center in 2009 and 2010. Black- and navy beans were grown alone or intercropped with annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), corn (Zea mays L.), or spring wheat (Triticum aestivum L.) in a two-factor factorial strip-plot randomized complete block design. All four grass species increased chlorophyll intensity in dry beans. However, grass species …

Changes In Corn Residue Quality Throughout The Grazing Period And Effect Of Supplementation Of Calves Grazing Corn Residue, Amanda J. Burken

Department of Animal Science: Dissertations, Theses, and Student Research

Corn residue is an abundant feed source in Nebraska that can be utilized as an alternative winter feed. Calves were backgrounded on corn residue in order to determine gain and estimate forage intake when supplemented with distillers grains (DGS). Calves grazing the non-irrigated field gained more (1.03 kg/calf daily) when compared to those grazing the irrigated field (0.90 kg/calf daily; P < 0.01). In year 1, a quadratic effect for intake of DGS was present (P < 0.01) while year 2 observed a linear effect for increasing level of DGS (P < 0.01). The nutritional quality of corn residue was evaluated over time in order to determine changes in blade/sheath, cob, husk/shank and stem. Minimal changes in DM of the forage components occurred was grain reached 15.5% moisture. Digestibility of the blade/sheath declined linearly over time (P < 0.01) while the husk remained constant (P = 0.40). Cob digestibility decreased quadratically (P < 0.01) throughout the sampling period with few changes once grain reached 15.5% moisture. Differences observed in the digestibility of the blade/sheath were attributed to the effects of weathering. A third set of trials was conducted to evaluate the effects of by-product supplementation of calves grazing irrigated corn residue and supplemented with DGS or continuous access to lick tubs. The DGS treatment gained more (0.62 kg/calf daily) than the lick tub treatment (0.38 kg/calf daily; P < 0.01). Calves offered DGS consumed more supplement as a percentage of BW (0.52%) when compared with calves offered lick tubs (0.36%; P < 0.01) on a DM basis. Calves supplemented with DGS had a higher supplement efficiency (46.3% to 42.9%, DM basis) although no differences were present between treatments (P = 0.49). When analyzed on an OM basis, however, calves offered lick tubs had a numerically higher supplement efficiency (50.4%) in comparison to calves …

Soil Carbon And Nitrogen Mineralization And Crop Parameters In Typical Maize-Bean Intercropping In Western Kenya, Judith A. Odhiambo, Urszula Norton, Emmanuel C. Omondi, Dennis Ashilenje, Jay B. Norton

Agricultural and Environmental Sciences Faculty Research

Smallholder farmers in western Kenya who plant maize (Zea mays L.) intercropped with beans (Phaseolus vulgaris L.) face many challenges associated with nutrient-poor soils and weather-related crop failures. In regions where temperatures are favorable, crops are grown twice per year during long and short rainy seasons and in other regions, once per year during one long growing season. Growing crops two times per year necessitates frequent land preparation using inversion-type tillage. Little is known about the impact of current tillage-intensive crop management on annual soil organic matter (SOM) recovery. The aim of this study was to assess changes to soil …

Metabolic Engineering Of Oilseed Crops To Produce High Levels Of Novel Acetyl Glyceride Oils With Reduced Viscosity, Freezing Point And Calorific Value, Jinjie Liu, Adam Rice, Kathleen Mcglew, Vincent Shaw, Hyunwoo Park, Thomas E. Clemente, Mike Pollard, John Ohlrogge, Timothy P. Durrett

Department of Agronomy and Horticulture: Faculty Publications

Seed oils have proved recalcitrant to modification for the production of industrially useful lipids. Here, we demonstrate the successful metabolic engineering and subsequent field production of an oilseed crop with the highest accumulation of unusual oil achieved so far in transgenic plants. Previously, expression of the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene in wild-type Arabidopsis seeds resulted in the accumulation of 45 mol% of unusual 3-acetyl-1,2- diacyl-sn-glycerols (acetyl-TAGs) in the seed oil (Durrett et al., 2010 PNAS 107:9464). Expression of EaDAcT in dgat1 mutants compromised in their ability to synthesize regular triacylglycerols increased acetyl-TAGs to 65 mol%. Camelina and soybean …

Decision Support Tools To Address Climate Change: Climate Model - Land Surface Models, Zea Mays L. (Corn) Phenology And Evapotranspiration-Yield Sensitivity Models For Nebraska, Usa., Jane A. Okalebo

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska's climate is highly variable and is expected to change in the future with anthropogenic global warming (AGW), resulting in warmer spring and summer temperatures coupled with more erratic rainfall events. This has strong implications for agriculture in the region, yet it is not clear that current modeling and decision-support tools are adequate to address these looming changes and provide planning, mitigation and adaptation strategies. To address climate change and its implications to agriculture in Nebraska, a set of robust decision support tools are very crucial. This study herein are divided into three chapters, with each chapter addressing a specific …

Arkansas Soybean Performance Tests 2014, R. D. Bond, D. G. Dombek, J. A. Still

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/or marketing seed within the State, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Functional Genomics And Microbiome Profiling Of The Asian Longhorned Beetle (Anoplophora Glabripennis) Reveal Insights Into The Digestive Physiology And Nutritional Ecology Of Wood Feeding Beetles, Erin D. Scully, Scott M. Geib, John E. Carlson, Ming Tien, Duane Mckenna, Kelli Hoover

Department of Agronomy and Horticulture: Faculty Publications

Background: Wood-feeding beetles harbor an ecologically rich and taxonomically diverse assemblage of gut microbes that appear to promote survival in woody tissue, which is devoid of nitrogen and essential nutrients. Nevertheless, the contributions of these apparent symbionts to digestive physiology and nutritional ecology remain uncharacterized in most beetle lineages.

Results: Through parallel transcriptome profiling of beetle- and microbial- derived mRNAs, we demonstrate that the midgut microbiome of the Asian longhorned beetle (Anoplophora glabripennis), a member of the beetle family Cerambycidae, is enriched in biosynthetic pathways for the synthesis of essential amino acids, vitamins, and sterols. Consequently, the midgut …

Carbohydrate Metabolism And The Trehalose Biosynthetic Pathway In Maize Kernels Grown In Vitro Under Sucrose Starvation Stress, Samuel W. Bledsoe

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Drought is an increasing issue that many farmers encounter especially in hot arid climates with little rainfall. High temperatures and inadequate rainfall at certain stages in crop development can have disastrous consequences to yield. In maize, drought occurring near or during the flowering stage often causes significant kernel abortion that greatly impacts potential yield. The trehalose biosynthetic pathway has recently been found to be important in plant metabolism in response to stress in higher order plants. Trehalose is currently known throughout the plant and animal kingdoms as an osmoprotectant, high energy fuel source, structural component, and involved in pathogen response. …

Establishment And Spread Of A Single Parthenogenic Genotype Of The Mediterranean Arundo Wasp, Tetramesa Romana1, In The Variable Climate Of Texas, John A. Goolsby, John F. Gaskin, Daniel V. Tarin, Alan E. Pepper, Don C. Henne, Allan Auclair, Alexis Racelis, Kenneth R. Summy, Patrick J. Moran, Donald B. Thomas

Biology Faculty Publications and Presentations

As part of a biological control program for the invasive weed, Arundo donax L., several genotypically unique populations of the parthenogenetic stemgalling wasp, Tetramesa romana Walker (Hymenoptera: Eurytomidae), from Spain and France were released in an infested riparian zone along the Rio Grande from Brownsville to Del Rio, TX. An adventive population of the wasp of unknown origin with limited distribution in Texas was also discovered, evaluated, and released as part of the program. More than 1.2 million wasps representing the mixture of genotypes were aerially released from 2009 to 2011. Wasps dispersed from their original release locations and now …

2015 Spring Seed Guide, Teshome Regassa, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

NEBRASKA CORN HYBRID TESTS CROP PRODUCTION SUMMARY: According to the National Agricultural Statistics Service, there were 8.75 million acres of corn harvested in Nebraska in 2014 producing approximately 1.58 billion bushels of grain. The total average corn yield for Nebraska in 2014 was a record 181 bushels per acre (bu/a). Total corn yields from the previous 10 years are reported below.

NEBRASKA SOYBEAN VARIETY TESTS - 2014 - CROP PRODUCTION SUMMARY: According to the National Agricultural Statistics Service, there were 5.4 million acres of soybeans planted in Nebraska in 2014. 5.35 million acres were harvested producing around 288 million bushels. …

An Economic Analysis Of Wild Bee Pollination In Lowbush Blueberry Production, Francis A. Drummond

University of Maine Office of Research Administration: Grant Reports

The purpose of this project is to determine the relative economic values of wild bee pollinators and commercial honeybees in lowbush blueberry production for individual Maine farms. The lowbush blueberry requires insect pollination in order to set fruit. Most farmers rent colonies of the non-native honeybee for pollination services, but wild, native bees are also effective pollinators. This project aims to provide growers with the means to assess the pollination needs of individual fields and to understand the levels of pollination possible if honeybees are not available. In order to achieve these goals, the relative abundance and species diversity of …

Comprehensive Characterization And Rna-Seq Profiling Of The Hd-Zip Transcription Factor Family In Soybean (Glycine Max) During Dehydration And Salt Stress, Vikas Belamkar, Nathan T. Weeks, Arvind K. Bharti, Andrew Farmer, Michelle A. Graham, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

Background:

The homeodomain leucine zipper (HD-Zip) transcription factor family is one of the largest plant specific superfamilies, and includes genes with roles in modulation of plant growth and response to environmental stresses. Many HD-Zip genes are characterized in Arabidopsis (Arabidopsis thaliana), and members of the family are being investigated for abiotic stress responses in rice (Oryza sativa), maize (Zea mays), poplar (Populus trichocarpa) and cucumber (Cucmis sativus). Findings in these species suggest HD-Zip genes as high priority candidates for crop improvement.

Results:

In this study we have identified members of …

Arkansas Corn And Grain Sorghum Performance Tests 2014, R. D/ Bond, D. G. Dombek, J. A. Still

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state, and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers.

Control Of Herbicide-Resistant Volunteer Corn In Herbicide-Resistant Soybean, Parminder Chahal

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Volunteer corn is a problem weed in soybean fields because it reduces yield and seed quality, and potentially harbors insects, pests, and diseases. Several pre-packaged herbicides have been registered in soybean in recent years, but response of volunteer corn to these herbicides has not yet been documented. Therefore, the first objective of this study was to evaluate the response of glufosinate-, glyphosate-, and imidazolinone-resistant volunteer corn to 20 pre-emergence (PRE) and 17 post-emergence (POST) soybean herbicides. The results indicated that PRE soybean herbicides partially controlled (< 80%) volunteer corn except clomazone, while acetyl CoA carboxylase (ACCase) inhibiting herbicides provided ≥ 85% control. Germination and emergence are critical stages in weed seed establishment and persistence. Scientific literature is not available about the factors affecting germination and emergence of volunteer corn. The second objective was to determine the effects of different environmental and agronomic factors on the germination and emergence of glyphosate-resistant hybrid and volunteer corn. The results indicated that response of hybrid and volunteer corn to majority of the variables tested was similar, suggesting that volunteer corn can germinate and emerge in a wide range of climatic conditions. Majority of growers control volunteer corn when it is visible above the soybean canopy, but this can results in early season competition with soybean. The third objective was to evaluate the impact of different densities of glyphosate-resistant volunteer corn at different control timings, and late season volunteer corn emergence on soybean yields. Late season volunteer corn emergence had no significant effect on soybean yield. Yield did not decrease with all volunteer corn densities, except with the highest density (10,000 plants and 500 clumps ha^-1) at all control timings. Soybean growers are looking for alternative herbicides, such …

Economic Contribution Of Agriculture And Food To Arkansas' Gross Domestic Product 1997-2012, Leah English, Jennie Popp, Wayne Miller

Research Reports and Research Bulletins

Agricultural production, processing, and retail industries are major contributors to the Arkansas economy in terms of GDP. Agriculture contributes to the economy through direct agricultural production, value-added processing, and agricultural retail activities, and it also plays an important role through its interactions with other sectors. The use of non-agricultural goods and services as inputs into the agricultural sector promotes diversified growth in Arkansas’ economy; thus agriculture remains a vital part of Arkansas’ economy. This report: 1) compares the relative size of the Agriculture and Food Sector in Arkansas with those of neighboring states, the Southeastern region of the United States, …

Selection And Genetic Drift In North American Maize, Collin Lamkey

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Characterizing the impact of selection and genetic drift in the formation of heterotic groups and patterns in maize can reveal important insights into the mechanism underlying adaptation, and the relative importance of each force in defining population structure. The objectives were to characterize the role selection for hybrid performance had in defining population structure in both a reciprocal full-sib selection (RFS) program and a large collection of historically important inbred lines.

The Illumina GoldenGate Assay was used to genotype the University of Nebraska-Lincoln Replicated Recurrent Selection (UNL-RpRS) program. Eight cycles of S1-progeny and RFS selection were conducted for an index …

Economic Contribution Of The Agricultural Sector To The Arkansas Economy In 2012, Leah English, Jennie Popp, Wayne Miller

Research Reports and Research Bulletins

This report is the ninth in a series of reports examining agriculture’s economic contribution on the Arkansas economy. Utilizing data from the United States Bureau of Economic Analysis (BEA), USDA Economic Research Service (ERS), USDA National Agricultural Statistics Service (NASS), and IMPLAN Group, LLC , the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2012.

Msh1-Induced Non-Genetic Variation Provides A Source Of Phenotypic Diversity In Sorghum Bicolor, Roberto De La Rosa Santamaria, Mon-Ray Shao, Guomei Wang, David O. Nino-Liu, Hardik Kundariya, Yashitola Wamboldt, Ismail M. Dweikat, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

MutS Homolog 1 (MSH1) encodes a plant-specific protein that functions in mitochondria and chloroplasts. We showed previously that disruption or suppression of the MSH1 gene results in a process of developmental reprogramming that is heritable and non-genetic in subsequent generations. In Arabidopsis, this developmental reprogramming process is accompanied by striking changes in gene expression of organellar and stress response genes. This developmentally reprogrammed state, when used in crossing, results in a range of variation for plant growth potential. Here we investigate the implications of MSH1 modulation in a crop species. We found that MSH1-mediated phenotypic variation in Sorghum bicolor …

Cold Frames, High Tunnels, And Greenhouses: Choose A Growing Structure Best For You, Stacy A. Adams, Kim A. Todd

Department of Agronomy and Horticulture: Faculty Publications

Cold frames, high tunnels, and greenhouses are plant growth structures that can be used to extend the growing season or allow for use year around for growing high value specialty crops. This publication discusses the various attributes and applications of each so that plant producers in teaching, research, extension, commercially or as a hobby can determine the best structure to meet individual needs.

Cold frames, high tunnels, and greenhouses are structures that provide hobbyists and growers with options for plant protection and season extension. They vary in cost, size, structural complexity, and ability for year-round usage. The small cold frame …

The Trehalose Pathway In Maize: Conservation And Gene Regulation In Response To The Diurnal Cycle And Extended Darkness, Clémence Henry, Samuel W. Bledsoe, Allison Siekman, Alec Kollman, Brian M. Waters, Regina Feil, Mark Stitt, L. Mark Lagrimini

Department of Agronomy and Horticulture: Faculty Publications

Energy resources in plants are managed in continuously changing environments, such as changes occurring during the day/night cycle. Shading is an environmental disruption that decreases photosynthesis, compromises energy status, and impacts on crop productivity. The trehalose pathway plays a central but not well-defined role in maintaining energy balance. Here, we characterized the maize trehalose pathway genes and deciphered the impacts of the diurnal cycle and disruption of the day/night cycle on trehalose pathway gene expression and sugar metabolism. The maize genome encodes 14 trehalose-6-phosphate synthase (TPS) genes, 11 trehalose-6-phosphate phosphatase (TPP) genes, and one trehalase gene. Transcript abundance of most …

Contrasting Metabolism In Perenniating Structures Of Upland And Lowland Switchgrass Plants Late In The Growing Season, Nathan Palmer, Aaron J. Saathoff, Christian M. Tobias, Paul Twigg, Yuannan Xia, Kenneth P. Vogel, Soundararajan Madhavan, Scott E. Sattler, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Background: Switchgrass (Panicum virgatum L.) is being developed as a bioenergy crop for many temperate regions of the world. One way to increase biomass yields is to move southern adapted lowland cultivars to more northern latitudes. However, many southerly adapted switchgrass germplasm can suffer significant winter kill in northerly climes.

Materials and Methods: Here, we have applied next-generation sequencing in combination with biochemical analyses to query the metabolism of crowns and rhizomes obtained from two contrasting switchgrass cultivars. Crowns and rhizomes from field-grown lowland (cv Kanlow) and upland (cv Summer) switchgrass cultivars were collected from three randomly selected post-flowering …

Production Of Minitubers From Potato Seedlings And Advanced Selections, Benildo G. De Los Reyes

University of Maine Office of Research Administration: Grant Reports

This cooperation between the University of Maine and USDA-ARS was aimed at providing the infrastructure and manpower support for the propagation and advancement of tetraploid potato breeding materials for the USDFA-ARS-Beltsville Potato Breeding Program (K. Haynes, PI).

Arkansas Wheat Cultivar Performance Tests 2013-2014, R. E. Mason, R. G. Miller, J. P. Kelley, E. A. Milus

Arkansas Agricultural Experiment Station Research Series

Wheat cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for small-grain producers.

B. R. Wells Arkansas Rice Research Studies 2013, R. J. Norman, K.A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Fall Seed Guide 2014, Teshome Regassa, P. Stephen Baenziger, Greg Kruger, Dipak Santra

Department of Agronomy and Horticulture: Faculty Publications

Crops include in this guide are winter wheat, winter barley, and triticale. You may receive this guide in the mail or through the University of Nebraska Extension network. The data and other information this guide is based on can be found at our web site: http://cropwatch.unl.edu/ varietytest/ and http://digitalcommons.unl.edu/ncia. Additional information is available at the wheat variety virtual tour web site http://cropwatch.unl.edu/wheat/virtual or the winter wheat variety selection tool page http://citnews.unl.edu/winter_wheat_tool/index.shtml.

Our rainfed plots in Keith County were lost to hail damage. Last season we had moist soil conditions at planting for the majority of the locations. There was good …

Summaries Of Arkansas Cotton Research 2013, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

An Evaluation Of Watermelon (Citrullus Spp.) Germplasm For Additional Sources Of Resistance To The Twospotted Spider Mite (Tetranychus Urticae Koch)., Hector Cantu Jr.

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Fourteen U.S plant introduction (PI) accessions of C. lanatus var. lanatus (4), C. lanatus var. citroides (5) C. colocynthis (5) and a known susceptible commercial cultivar ‘Sugar Baby’ were evaluated for resistance to the twospotted spider mite, Tetranychus urticae Koch, in a limited free-choice and free-choice bioassay under laboratory conditions. The limited free choice bioassay, involved nine Petri dish cages that held five randomly assigned leaves individually inoculated with two adult females and one adult male. Eggs, larva, and adults were counted over a nine day period. The free choice bioassay involved the even distribution of three mite infested …

Infiltration And Runoff Parameters For Tilled And No-Till Row Crops, Andrew J. Volkmer

Department of Biological Systems Engineering: Dissertations and Theses

Infiltration and runoff are hydrologic processes that effect the amount of water available to plants, for groundwater recharge, and for stream flow. No-till planting (NT) is a management practice used to reduce soil erosion, increase water infiltration, and reduce soil water evaporation, and can have great impact on infiltration and runoff. An investigation was conducted to determine the impact of NT on infiltration and runoff when compared to tilled conditions.

Runoff and precipitation data was gathered from sites at Fillmore County, NE, Phelps County, NE, the USDA-ARS North Appalachian Experimental Watersheds (NAEW) near Coshocton, OH, and the Lennoxville Research Station …

Ammonia-Oxidizing Bacteria And Archaea Under Continuous Maize: The Influence Of Tillage, N Input And Aggregation On Abundance And Community Composition, Lauren Segal

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrification involves the oxidation of ammonium (NH₄⁺) and is an important component of the overall N cycle. Nitrification occurs in two steps; first by oxidizing ammonium to nitrite, and then to nitrate. The first step is often the rate limiting step. Until recently ammonia-oxidizing bacteria (AOB) were thought to be the sole contributors to this process; however, the discovery of crenarchaeota, ammonia-oxidizing archaea (AOA), in marine environments has led to further study of their role in nitrification. Current literature supports the dominance of AOA over AOB in terrestrial ecosystems; however, little is known about what drives their …

Selection On Crop-Derived Traits And Qtl In Sunflower (Helianthus Annuus) Crop-Wild Hybrids Under Water Stress, Birkin R. Owart, Jonathan Corbi, John M. Burke, Jennifer M. Dechaine

All Faculty Scholarship for the College of the Sciences

Locally relevant conditions, such as water stress in irrigated agricultural regions, should be considered when assessing the risk of crop allele introgression into wild populations following hybridization. Although research in cultivars has suggested that domestication traits may reduce fecundity under water stress as compared to wild-like phenotypes, this has not been investigated in crop-wild hybrids. In this study, we examine phenotypic selection acting on, as well as the genetic architecture of vegetative, reproductive, and physiological characteristics in an experimental population of sunflower crop-wild hybrids grown under wild-like low water conditions. Crop-derived petiole length and head diameter were favored in low …