Horticulture Commons^™

Extension Agriculture And Natural Resources In The U.S. Midwest: A Review And Analysis Of Challenges And Future Opportunities, Mahdi M. Al-Kaisi, Roger Wesley Elmore, Gerald A. Miller, David Kwaw-Mensah

Department of Agronomy and Horticulture: Faculty Publications

This review addresses key changes in U.S. agricultural extension and future opportunities. Agricultural extension has been a part of the land-grant university (LGU) system for more than 100 years. The Morrill Act of 1862 established the LGU system by authorizing states access to federally controlled land and funding for public institutions offering educational opportunities focusing on agriculture and mechanical arts for farmers and the working class. Current surveys in Iowa reveal changing trends in extension: more than 90% of farmers identified private-sector crop advisers as their primary source for recommendations, whereas more than 80% of those advisors identified Iowa State …

Soybean Yield And Nodulation Response To Crop History And Inoculation, Stephen Mason, Tomie Galusha, Zaher Kmail

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] inoculation was imposed on a long-term continuous grain sorghum [Sorghum bicolor (L.) Moench] and soybean cropping systems study with and without manure application at Mead, NE. The objective was to determine the influence of 28-yr history of continuous grain sorghum and soybean production, inoculation, and manure on soybean yield and nodulation. Average 2-yr soybean grain yield was 0.5 Mg ha^–1 greater on plots with continuous grain sorghum crop history rather than soybean history, even after this history was broken by 2-yr crop rotation with grain sorghum in the 2 yr previous to …

Soil Moisture Affects Growing-Season Wildfire Size In The Southern Great Plains, Erik S. Krueger, Tyson E. Ochsner, David M. Engle, J. D. Carlson, Dirac L. Twidwell, Samuel D. Fuhlendorf

Department of Agronomy and Horticulture: Faculty Publications

The increasing availability of soil moisture data presents an opportunity for its use in wildfire danger assessments, but research regarding the influence of soil moisture on wildfires is scarce. Our objective was to identify relationships between soil moisture and wildfire size for Oklahoma wildfires during the growing (May-October) and dormant seasons (November-April). We hypothesized that soil moisture influences wildfire size when vegetation is growing but is less important when most vegetation is dead or dormant. Soil moisture, as fraction of available water capacity (FAW), and commonly measured weather variables were determined for 38,419 wildfires from 2000–2012. Wildfires were grouped by …

Arkansas Soybean Performance Tests 2015, R. D. Bond, J. A. Still, D. G. Dombek

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’s 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.

The Effects Of Foliar Nutrient Applications On Split, Yield, And Internal Fruit Quality Of 'Wonderful' Pomegranate (Punica Granatum L.), John Matthew Chater

Master's Theses

Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. Additionally, investigations into putative health benefits of pomegranate fruit have increased interest in its production but limited evidence exists regarding effects of agricultural practices such as foliar fertilizer applications on internal fruit quality. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO_{4 …}

Distribution Of Herbicide-Resistant Shattercane And Johnsongrass Populations In Sorghum Production Areas Of Nebraska And Northern Kansas, Rodrigo Werle, Amit J. Jhala, Melinda K. Yerka, J. Anita Dille, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Overreliance on acetolactate synthase (ALS)-inhibiting herbicides for weed control during the 1990s resulted in selection of ALS-resistant shattercane [Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet ex Davidse] biotypes in Nebraska. The objective of this study was to assess the baseline presence of ALS-resistance in 190 shattercane and 59 johnsongrass [Sorghum halepense (L.) Pers.] populations collected across northern Kansas, northwestern Missouri, and southern Nebraska in 2013. In 2014, a preliminary field experiment was conducted to evaluate the presence of herbicide resistance in the aforementioned populations. Treatments consisted of four herbicides (clethodim {2-[1-[[(E)-3-chloroprop-2-enoxy]amino] propylidene]-5-(2-ethylsulfanylpropyl)cyclohexane-1,3-dione}, glyphosate [N-(phosphonomethyl) …

Genetic Control Of Morphometric Diversity In The Maize Shoot Apical Meristem, Samuel Leiboff, Xianran Li, Heng-Cheng Hu, Natalie Todt, Jinliang Yang, Xiao Li, Xiaoqing Yu, Gary J. Muehlbauer, Marja C.P. Timmermans, Jianming Yu, Patrick S. Schnable, Michael J. Scanlon

Department of Agronomy and Horticulture: Faculty Publications

The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate …

Residue Harvest Effects On Irrigated, No-Till Corn Yield And Nitrogen Response, Charles S. Wortmann, Charles A. Shapiro, Marty R. Schmer

Department of Agronomy and Horticulture: Faculty Publications

Crop residue harvest occurs on about 40% of Nebraska’s 3,700,000 ha of corn (Zea mays L.) land, primarily for feeding of beef cattle. Immobilization of applied N is expected to be less with residue harvest due to reduced microbial activity for digestion of high C/N ratio organic material. Residue reduction may affect subsequent crop yield and response to applied N. Field research was conducted at three locations over 2 yr in eastern Nebraska for irrigated, no-till corn following corn to determine residue harvest effects on yield and the economically optimal nitrogen rate (EONR). Study sites had deep silt loam …

Herbicides Applied At Or Shortly After Seeding Are Effective For Weed Control In Seedling Buffalograss, Luqi Li, Matthew D. Sousek, Zachary Reicher

Department of Agronomy and Horticulture: Faculty Publications

Herbicides applied shortly after seeding of buffalograss [Buchloe dactyloides (Nutt.) Engelm.] can help reduce weed pressure and maximize establishment of buffalograss. This study evaluated 12 relatively recently developed herbicides for turf safety and weed control when applied at seeding or 0 or 2 weeks after emergence (WAE) of ‘Bowie’ or ‘Sundancer’ buffalograss. Primary weed species on the site were common purslane (Portulaca oleracea L.), redroot pigweed (Amaranthus retroflexus L.), and/or yellow foxtail [Setaria lutescens (Weigel ex Stuntz) F.T. Hubb.]. Regardless of cultivar, untreated checks had53% weed cover by 6 WAE, whereas most of the herbicide treatments resulted …

Synfind: Compiling Syntenic Regions Across Any Set Of Genomes On Demand, Haibao Tang, Matthew D. Bomhoff, Evan Briones, Liangsheng Zhang, James C. Schnable, Eric Lyons

Department of Agronomy and Horticulture: Faculty Publications

The identification of conserved syntenic regions enables discovery of predicted locations for orthologous and homeologous genes, evenwhennosuchgeneispresent.Thiscapabilitymeansthatsynteny-basedmethodsarefarmoreeffectivethansequencesimilaritybased methods in identifying true-negatives, a necessity forstudying gene loss and gene transposition. However, the identification of syntenicregionsrequirescomplexanalyseswhichmustberepeatedforpairwisecomparisonsbetweenanytwospecies.Therefore,as the number of published genomes increases, there is a growing demand for scalable, simple-to-use applications to perform comparative genomic analyses that cater to both gene family studies and genome-scale studies. We implemented SynFind, a web-based tool that addresses this need. Given one query genome, SynFind is capable of identifying conserved syntenic regions in any set of targetgenomes.SynFindiscapableofreportingper-geneinformation,usefulforresearchersstudyingspecificgenefamilies,aswellas genome-wide data sets of syntenic gene and predicted gene …

A Population Structure And Genome-Wide Association Analysis On The Usda Soybean Germplasm Collection, Nonoy Bandillo, Diego Jarquin, Qijian Song, Randall L. Nelson, Perry Cregan, James Specht, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

Population structure analyses and genome-wide association studies (GWAS) conducted on crop germplasm collections provide valuable information on the frequency and distribution of alleles governing economically important traits. The value of these analyses is substantially enhanced when the accession numbers can be increased from ~1,000 to ~10,000 or more. In this research, we conducted the first comprehensive analysis of population structure on the collection of 14,000 soybean accessions [Glycine max (L.) Merr. and G. soja Siebold & Zucc.] using a 50KSNP chip. Accessions originating from Japan were relatively homogenous and distinct from the Korean accessions. As a whole, both Japanese and …

Arkansas Corn And Grain Sorghum Performance Tests 2015, R. D. Bond, J. A. Still, D. G. Dombek

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.

Adding Genetically Distant Individuals To Training Populations Reduces Genomic Prediction Accuracy In Barley, Aaron Lorenz, Kevin P. Smith

Department of Agronomy and Horticulture: Faculty Publications

One of the most important factors affecting genomic prediction accuracy appears to be training population (TP) composition. The objective of this study was to evaluate the effect of genomic relationship on genomic prediction accuracy and determine if adding increasingly unrelated individuals to a TP can reduce prediction accuracy. To accomplish this, a population of barley (Hordeum vulgare L.) lines from the University of Minnesota (lines denoted as MN) and North Dakota State University (lines denoted as ND) breeding programs were used for model training. Predictions were validated using two independent sets of progenies derived from MN  MN crosses …

Community Seed Banks: Origins, Evolution, And Prospects, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

As a survey of contemporary community-level seed banks, this is an excellent compilation and instructive guide. The first section provides an overview of how seed banks originated, their varied goals and activities, several contrasting forms of management, and how they organize and perform to meet these goals. An intriguing claim in the book is that the concept of “seed banks is only some three decades old,” while in fact the practice of saving, preserving, and exchanging seed within a community is probably as old as human communities themselves.

Organized seed banks often serve specific functions: preserving seeds, providing seed access …

Switchgrass Germplasm Resources, Michael D. Casler, Kenneth P. Vogel, Melanie Harrison

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) is an important native grass and dominant member of the tallgrass prairie ecosystem. It is used for conservation, restoration, livestock feed production, and bioenergy feedstock production. The purpose of this review is to describe the biological and geographical basis for switchgrass germplasm diversity and to provide a resource for scientists and outreach personnel to find switchgrass germplasm to meet their needs. Upland and lowland ecotypes represent the most important polymorphism in switchgrass, with distinct but overlapping geographic distributions. Variation in ploidy exists within both ecotypes, with 2n = 4x = 36 the dominant ploidy …

Engaging Many Minds: Nurturing Collaboration In A Steam Context, Mark Dzula

The STEAM Journal

This field note describes a recent interdisciplinary project facilitated by Jeremy Gercke, an art teacher at the Bishop's School in La Jolla, California. The project creates ceramic tile markers for flora around the Bishop's School campus. The markers feature QR codes linking to websites populated with student content, including: drawings, information, and oral histories. In this project, Mr. Gercke synthesizes his interests as an artist; maximizes his social connections to mentors, peers and students; and bridges disciplines to create opportunities for interdisciplinary (STEAM) inquiry.

Summaries Of Arkansas Cotton Research 2014, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

The Enhancement Of Wild Bees (Hymenoptera: Apoidea) For Pollination Security, Eric M. Venturini

Electronic Theses and Dissertations

The acreage of pollinator-dependent crops continues to expand across the globe. Simultaneously, honey bee hives – an annually rented commodity that growers rely on – are more expensive every year and in some cases, scarce. In response, pollinator-dependent growers seek alternative pollinators. One approach is installing bee pasture on farms, a strategy that enables systems-based farmers to become in-situ farm-scale habitat managers. This thesis first presents a review of the literature on bee pasture plantings and provides a brief overview of some methods for assessing their impacts on the pollinator community. There are three major gaps in current bee pasture …

Arkansas Wheat Cultivar Performance Tests 2014-2015, R. E. Mason, R. G. Miller, D. E. Moon, J. P. Kelley

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 2014, R. J. Norman, K.A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Occurrence Of An Herbicide-Resistant Plant Trait In Agricultural Field Margins, Karla L. Gag, David J. Gibson, Bryan G. Young, Julie M. Young, Joseph L. Matthews, Stephen C. Weller, Robert G. Wilson

Department of Agronomy and Horticulture: Faculty Publications

Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, Conyza canadensis. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR C. canadensis in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, …

Comparing Yield Monitors With Weigh Wagons For On-Farm Corn Hybrid Evaluation, Bjorn P. Nelson, Roger Wesley Elmore, Andrew W. Lenssen

Department of Agronomy and Horticulture: Faculty Publications

For many years, on-farm yield evaluations of corn (Zea mays L.) hybrids were done with weigh wagons, handheld moisture testers, and measuring wheels. Today, most combines have continuous flow yield and moisture sensors. Published research results comparing the accuracy of combine-mounted sensor systems with that of weigh wagons are limited for on-farm corn hybrid evaluation. This study examined the accuracy of combine-mounted yield sensors with traditional weigh wagon methodology in on-farm corn hybrid strip trials. Data from combine-mounted sensors for plot weight, moisture percentage, and yield were compared with weigh wagon weight, handheld moisture testers, and calculated yield …

Genetic Engineering Online Lessons Improve Teaching And Increase Knowledge And Accepting Attitudes Among Students, Grace Troupe

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

Genetic engineering has been used in the production of food in the U.S. for nearly three decades, however, science literacy in genetic engineering among consumers is still low. To address this problem, an online resource called The Journey of a Gene (passel.unl.edu/ge) was created to help incorporate genetic engineering education in high school and college curriculums. Here we report two studies conducted to evaluate the effectiveness of The Journey of a Gene in 1) improving student knowledge and attitudes about genetic engineering and 2) helping teachers increase their knowledge as well as quantity and quality of genetic engineering instruction. In …

Fishing For A Sustainable Future: Aquaponics As A Method Of Food Production, Richard Ramsundar

Student Theses 2015-Present

This thesis compares and explains the advantages aquaponics farming has over modern industrial intensive farming. Through a comparison natural capital usage, conservation, recycling and cost, the thesis advocates for the expansion of aquaponics usage in urban settings. The thesis also explains the history of intensive farming and aquaponics in America, the science of how aquaponics operates, the economic and environmental costs of modern intensive farming versus aquaponics farming, and the social implications of aquaponics. Lastly, I propose a policy that reallocates farm subsidies by modifying the Farm Bill. Then I propose policies that support creating a new standard of farm …

Nutrient Management For Growing Dandelion (Taraxacum Officinale L.) In Nutrient Film And Deep Flow Hydroponics, Reetinder Gill

Graduate Theses and Dissertations

This research study was conducted to determine an optimal nutrient strategy for dandelion production in nutrient film technique (NFT) and deep flow technique (DFT) systems of hydroponics. It was achieved by growing dandelion at varying levels of nutrient solution concentration and pH in both NFT and DFT systems. Additionally, an optimal nutrient solution concentration and timing of application for dandelion seedling production was also determined.

Microsatellite Variations Of Elite Setaria Varieties Released During Last Six Decades In China, Guanqing Jia, Xiaotong Liu, James C. Schnable, Zhengang Niu, Chunfang Wang, Yuhui Li, Shujun Wang, Suying Wang, Jinrong Liu, Erhu Guo, Hui Zhi, Xianmin Diao

Department of Agronomy and Horticulture: Faculty Publications

Crop improvement is a multifaceted micro-evolutionary process, involving changes in breeding approaches, planting configurations and consumption preferences of human beings. Recent research has started to identify the specific genes or genomic regions correlate to improved agronomic traits, however, an apparent blank between the genetic structure of crop elite varieties and their improving histories in diverse modern breeding programs is still in existence. Foxtail millet (Setaria italica) was one of the earliest cereal crops to be domesticated and served as a staple crop for early civilizations in China, where it is still widely grown today. In the present trial, …

Maria Sibylla Merian (1647-1717): Pioneering Naturalist, Artist, And Inspiration For Catesby, Kay Etheridge, Florence F.J.M. Pieters

Biology Faculty Publications

Book Summary: While accessible to the interested general reader, it is a technical standard that is usable academically. Containing significant new information, this work is the most comprehensive and accurate book written about Catesby and is the legacy of the Catesby Commemorative Trust’s Mark Catesby Tercentennial symposium held in 2012.

Chapter Summary: Merian's books on European and Surinamese insects and plants provided new models for representing nature that were echoed in the work of artists and naturalists working in the eighteenth century and beyond. This chapter discusses how Mark Catesby, the subject of the book, was particularly influenced by Merian.

Evaluation And Association Mapping Of Resistance To Tan Spot And Stagonospora Nodorum Blotch In Adapted Winter Wheat Germplasm, Zhaohui Liu, Ibrahim El-Basyoni, Gayan Kariyawasam, Guorong Zhang, Allan Fritz, Jana Hansen, Francois Marais, Andrew Friskop, Shiaoman Chao, Eduard Akhunov, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Tan spot and Stagonospora nodorum blotch (SNB), often occurring together, are two economically significant diseases of wheat in the Northern Great Plains of the United States. They are caused by the fungi Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively, both of which produce multiple necrotrophic effectors (NE) to cause disease. In this work, 120 hard red winter wheat (HRWW) cultivars or elite lines, mostly from the United States, were evaluated in the greenhouse for their reactions to the two diseases as well as NE produced by the two pathogens. One P. nodorum isolate (Sn4) and four Pyrenophora tritici-repentis isolates (Pti2, …

Historical Common Names Of Great Plains Plants, With Scientific Names Index. Volume Ii: Scientific Names Index, Elaine Nowick

Zea E-Books Collection

Containing thousands of entries of both vernacular and scientific names of Great Plains plants, the literature that informs this exhaustive listing spans nearly 300 years. Author Elaine Nowick has drawn from sources as diverse as Linnaeus, Lewis and Clark, and local university extension publications to compile the gamut of practical, and often fanciful, common plant names used over the years. Each common name is accompanied by a definitive scientific name with references and authority information. Interspersed with scientifically-correct botanical line drawings, the entries are written in standard ICBN format, making this a useful volume for scholars as well as lay …

Historical Common Names Of Great Plains Plants, With Scientific Names Index. Volume I: Common Names, Elaine Nowick

Zea E-Books Collection

Containing thousands of entries of both vernacular and scientific names of Great Plains plants, the literature that informs this exhaustive listing spans nearly 300 years. Author Elaine Nowick has drawn from sources as diverse as Linnaeus, Lewis and Clark, and local university extension publications to compile the gamut of practical, and often fanciful, common plant names used over the years. Each common name is accompanied by a definitive scientific name with references and authority information. Interspersed with scientifically-correct botanical line drawings, the entries are written in standard ICBN format, making this a useful volume for scholars as well as lay …