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Fertilizer Nitrogen Uptake Efficiency In Soft Red Winter Wheat And The Ability Of N-Star To Detect Alkaline Hydrolyzable Nitrogen In Crop Residues, Lana Aubrey Clark

Graduate Theses and Dissertations

Soil testing methods such as the Illinois Soil Nitrogen Test (ISNT) and Direct Steam Distillation (DSD) have been developed which measure alkaline hydrolyzable-N (AH-N) as a means of estimating potentially mineralizable-N. Crop residues play an important role in N cycling. However, the ability of the ISNT and DSD methods to determine AH-N within crop residues is unknown. Therefore, the first objective of this study was to determine the ability of the ISNT and DSD to quantify potentially mineralizable-N within five different crop residues common to Arkansas. Corn (Zea mays L.), soybean (Glycine max, L.), wheat, rice (Oryza sativa, L.), and …

Methane Emissions And Ammonia Volatilization From Drill-Seeded, Delayed-Flood Rice On A Silt-Loam Soil In Arkansas, Christopher Wade Rogers

Graduate Theses and Dissertations

The Environmental Protection Agency (EPA) currently uses a single methane (CH4) emissions factor of 160 kg CH4-C ha-1 for a primary rice (Oryza sativa L.) crop. The emissions factor is based on studies that do not adequately represent current management practices in Arkansas. Another concern is pre-flood fertilizer nitrogen (N) management, as the common N source, urea, is prone to loss via ammonia (NH3) volatilization. Thus, the objective of this research was to investigate trace gas emissions from rice on a silt-loam soil, including CH4 emissions as influenced by nitrogen (N) fertilization (i.e., optimal N and no N) in 2011, …

Milling And Functional Properties Of Co-Mingled Rice Cultivars, Nikhil N. Basutkar

Graduate Theses and Dissertations

Differences have been observed in the milling and functional properties of different rice cultivars, particularly between hybrid and pureline cultivars. Co-mingling of rice cultivars commonly occurs during harvest, storage and drying operations. Thus, there is a need to study the effect of co-mingling on the milling and functional properties of rice cultivars. Two long-grain, hybrid (H) cultivars CL XL745 and CL XL729 and two long-grain, pureline (P) cultivars CL 151 and Wells were used to prepare CL XL745/CL 151 (H/P), CL XL745/CL XL729 (H/H) and Wells/CL 151 (P/P) co-mingles, mixed in various proportions. Milled rice yield (MRY), head rice yield …

Impact Of Early Infestation Of Two-Spotted Spider Mites (Tetranychus Urticae) On Cotton Growth And Yield, Luis Orellana Jimenez

Graduate Theses and Dissertations

Two-spotted spider mites (Tetranychus urticae Koch, 1836) are pests of vegetables, ornamentals, and row crops around the world. Two-spotted spider mites have become an important long-season pests of cotton, causing injury to cotton from an early vegetative stage. In the past eight years, Arkansas cotton acreage treated for spider mites has more than doubled and most of the increase has been attributed to early season infestations. Yield losses of up to 30% have been observed in other studies where spider mite infestation started at third true leaf. Because of the apparent change in this pest's population dynamics, particularly at …

Biophysically-Based Measurement Of Plant Water Status Using Canopy Temperature, Christopher K. Parry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Precision irrigation scheduling is one approach that can conserve water by supplying crops with the minimum amount of water needed for sufficient vegetative growth and final crop yield. Improved methods for irrigation scheduling are needed for arid regions that rely mainly on irrigation for crop water needs, and humid regions that supplement water received from precipitation with added irrigation. Methods that directly determine plant physiological responses to water availability have potential to be significantly more sensitive and accurate than indirect approaches like soil moisture measurement. Stomatal conductance is a rapid physiological response to leaf water potential.

Stomatal conductance in single …

An Affinity–Effect Relationship For Microbial Communities In Plant–Soil Feedback Loops, Yi Lou, Sharon A. Clay, Adam S. Davis, Anita Dille, Joel Felix, Analiza H. M. Ramirez, Christy L. Sparague, Anthony C. Yannarell

Agronomy, Horticulture and Plant Science Faculty Publications

Feedback loops involving soil microorganisms can regulate plant populations. Here, we hypothesize that microorganisms are most likely to play a role in plant–soil feedback loops when they possess an affinity for a particular plant and the capacity to consistently affect the growth of that plant for good or ill. We characterized microbial communities using whole-community DNA fingerprinting from multiple "home-and-away" experiments involving giant ragweed (Ambrosia trifida L.) and common sunflower (Helianthus annuus L.), and we looked for affinity–effect relationships in these microbial communities. Using canonical ordination and partial least squares regression, we developed indices expressing each microorganism's affinity …

Plant Community Development Of Isle Royale's Moose-Spruce Savannas, Michael C. Rotter

All NMU Master's Theses

On Isle Royale National Park, heavy moose browsing over the past 100 years has suppressed the regeneration of many tree species, gradually resulting in a shift towards more open forests and savannas. By 1996, 16% of the forests at the southwest end of Isle Royale had become savanna and another 20% were starting to break-up. The changes in understory vegetation brought about by savanna formation have received little attention, even though the future of moose and wolf populations on Isle Royale are tied to these vegetation changes. This study examined the vegetation of savannas ranging in age (date since formation) …

Variation In Vegetation And Microbial Linkages With Slope Aspect In A Montane Temperate Hardwood Forest, Frank S. Gilliam, Radim Hédl, Markéta Chudomelová, Rebecca L. Mcculley, Jim A. Nelson

Plant and Soil Sciences Faculty Publications

Plant ecologists have long been interested in aspect-related contrasts of montane forests. Few studies have assessed correlation (linkage) among vegetation strata; fewer have included soil microbial communities. This study assessed contrasts in overstory, spring herbaceous, and soil microbial communities between northeast (NE) - and southwest (SW) -facing slopes in a second-growth West Virginia hardwood forest. We addressed three questions: (1) how do soil microbial, herbaceous layer, and overstory communities vary with slope aspect? (2) do forest vegetation strata and soil microbial communities exhibit linkage? (3) do biotic relationships and linkage vary with slope aspect? Moisture, organic matter, pH, soil NO …

Spreading The Char: The Importance Of Local Compatibility In The Diffusion Of Biochar Systems To The Smallholder Agriculture Community Context, Laura C. V. Munoz

Pomona Senior Theses

This thesis enters the context of smallholder agriculture communities in the developing world. It explores the potentials of biochar and what biochar systems could bring to the smallholder communities while simultaneously bringing environmental benefits. It then acknowledges the challenges of diffusion –the spreading of an unfamiliar innovation. It seeks to answer the question of what will make diffusion of biochar systems more successful in the smallholder context, fixating on the characteristic of compatibility as well as the role local community members can play in making a new biochar system more visible to the rest of the communities.

Stacking Of A Stearoyl-Acp Thioesterase With A Dual-Silenced Palmitoyl-Acp Thioesterase And Δ12 Fatty Acid Desaturase In Transgenic Soybean, Hyunwoo Park, George L. Graef, Yixiang Xu, Patrick Tenopir, Thomas E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max (L.) Merr) is valued for both its protein and oil, whose seed is composed of 40% and 20% of each component, respectively. Given its high percentage of polyunsaturated fatty acids, linoleic acid and linolenic acid, soybean oil oxidative stability is relatively poor. Historically food processors have employed a partial hydrogenation process to soybean oil as a means to improve both the oxidative stability and functionality in end-use applications. However, the hydrogenation process leads to the formation of trans-fats, which are associated with negative cardiovascular health. As a means to circumvent the need for the hydrogenation process, genetic …

Variation In Vegetation And Microbial Linkages With Slope Aspect In A Montane Temperate Hardwood Forest, Frank S. Gilliam, Radim Hedl, Marketa Chudomelova, Rebecca L. Mcculley, Jim Nelson

Biological Sciences Faculty Research

Plant ecologists have long been interested in aspect-related contrasts of montane forests. Few studies have assessed correlation (linkage) among vegetation strata; fewer have included soil microbial communities. This study assessed contrasts in overstory, spring herbaceous, and soil microbial communities between northeast (NE) - and southwest (SW) -facing slopes in a second-growth West Virginia hardwood forest. We addressed three questions: (1) how do soil microbial, herbaceous layer, and overstory communities vary with slope aspect? (2) do forest vegetation strata and soil microbial communities exhibit linkage? (3) do biotic relationships and linkage vary with slope aspect? Moisture, organic matter, pH, soil NO …

Restoring The Longleaf Pine (Pinus Palustris) Forests Using Pineywoods Cattle Grazing In Conjunction With Prescribed Burning, L. Tyler Albin

Honors Theses

The longleaf pine (Pinus palustris) is major forest constituent of the Southern Coastal Plains of the United States. Ecologically, a virgin longleaf pine forests supports increased species richness. Since the 1800s, longleaf pine forests have been exploited as a massive source of commercial products (e.g., lumber, pulp, and naval stores). A decrease in species richness has been recorded following this vast decrease in longleaf pine presence. Rebuilding the longleaf pine ecosystem is essential for restoring species richness and maintaining the ecological health of many Costal Plains habitats. Presently, the most popular restoration and management method utilized is prescribed burning. Prescribed …

Advancing Digital Soil Mapping And Assessment In Arid Landscapes, Colby W. Brungard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil information is required for arid and semi-arid land management decisions such as permitting livestock grazing or planning vegetation restoration projects. However, traditional soil mapping methods may not provide adequate soil information, because the scale of mapping often requires dissimilar soils to be grouped together and there are no estimates of map uncertainty. Traditional methods are also often too costly or impractical to implement in large, remote, public arid and semi-arid rangelands. Digital soil mapping (DSM) may be able to overcome these limitations. Digital soil mapping is the creation of pixel-based soil maps using quantitative statistical models that relate easily …

Stem Development, Seeding Rate, And Establishment Of Birdsfoot Trefoil (Lotus Corniculatus) For Organic, Grazing-Based Dairies, Sara Hunt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Birdsfoot trefoil (BFT, Lotus corniculatus L.) is a non-bloating, productive forage legume well suited to grazing-based ruminant production. This thesis presents three studies conducted in the Mountain West applicable to organic management and cultivation of BFT. The first is an analysis of lignification in BFT stems that supports recommendations to harvest BFT at approximately 6 weeks of regrowth, or early bloom. Lignification decreases digestibility and is correlated with high shear force required for grazing animals to break BFT stems. The process of stem lignification was observed by harvesting increasingly mature stems; cutting thin sections of the sixth stem internode, which …

Monitoring Citrus Nutrition In The Rio Grande Valley For Fertilizer Recommendations, Iram Lopez

Theses and Dissertations - UTB/UTPA

Soil fertility and plant nutrition is crucial for a better yield and consistent harvest in the Rio Grande Valley for local farmers growing citrus trees. A field of oranges and a field of grapefruits were monitored and nutrition deficiencies were noticed that played an important role during fruit set. Soil samples that were taken throughout the year were analyzed via a carbon dioxide extraction method that mimics the way plants naturally take up nutrients or extract nutrients from every soil type. Macronutrients such as the N, P, K, Na, Ca, Mg and some of the micronutrients (Zn, Fe, Mn, and …

Primocane-Fruiting Blackberry: Optimum N-Fertilization, Jose Carlos Reynoso Campos

Graduate Theses and Dissertations

This study was conducted in 2011 at the University of Arkansas, Fayetteville to determine the optimum rate and time of nitrogen (N) application for `Prime-Ark® 45' primocane-fruiting (PF) blackberries under high tunnel conditions. There were four N treatments: Control (0), 10, 10-split, and 20 kg*ha-1 (Treatments 1, 2, 3, 4, respectively). In a randomized complete block (RCB) design, the following variables were compared: total and marketable yield, fresh weight of plant above ground, and cane diameter. Total fruit yields for Treatments 2 and 3 (2.5 and 2.5 kg, respectively) were highest and significantly different from the other treatments (p< 0.05). Marketable yield had a similar trend as total fruit yield, although not significantly different. Cane diameter and plant fresh weight were not significantly affected by fertilizer treatments. There were not significant differences in N content in leaves among treatments. Results indicated that either a single or split N application of 10 kgN*ha-1 could result in better yields.

Four …

Habitat Assessment Of Two Narrowly Endemic Plant Species, Ozark Spiderwort (Tradescantia Ozarkana) E. S. Anderson And Woods. And Newton's Larkspur (Delphinium Newtonianum) D. M. Moore, Autumn Lynn Coffey Olsen

Graduate Theses and Dissertations

The threat of biodiversity loss is upon us with the onset of climate change and our ever-demanding needs of the Earth's resources for a rapidly growing human population. Species highly vulnerable to loss are those limited in abundance and distribution, or those with reduced genetic diversity. Efforts to actively conserve a sensitive species require effectual data on the probable causes of their vulnerability. Two species of concern, Delphinium newtonianum and Tradescantia ozarkana, are globally rare endemic vascular plant species found only in the Interior Highlands of North America. In an attempt to understand the causes for their endemism, habitat …

Estimating Nitrogen Credits From Poultry Litter On Silt Loam Soils In Arkansas Using The Nitrogen-Soil Test For Rice: N-Star, Chester Eugene Greub

Graduate Theses and Dissertations

Rice (Oryza sativa L.) is one of the most important global cereal crops and is grown on a substantial number of hectares in Arkansas each year. Consequently, Arkansas is the leading rice producing state in the United States accounting for almost half of domestic production. The development and release of N-STaR (Nitrogen-Soil Test for Rice) allows producers to predict site-specific N fertilizer needs for rice production in Arkansas, with N-STaR being a predictor of potentially mineralizable-N. Furthermore, poultry production is a thriving commodity in Arkansas, producing a substantial amount of poultry litter (PL) annually. Rice producers are applying PL to …

Traversing Swanton Road, 15th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …

Mechanical Mastication Of Utah Juniper Encroaching Sagebrush Steppe Increases Inorganic Soil N, Kert R. Young, Bruce A. Roundy, Dennis L. Eggett

Articles

Juniper (Juniperus spp.) has encroached on millions of hectares of sagebrush (Artemisia spp.) steppe. Juniper mechanical mastication increases cover of understory species but could increase resource availability and subsequently invasive plant species. We quantified the effects of juniper mastication on soil resource availability by comparing total C, total N, C : N ratio, Olsen extractable P, sulfate S, and pH using soil samples and inorganic N (NO₃^-+NH₄⁺) using ion exchange membranes. We compared resource availability in paired masticated and untreated areas in three juniper-dominated sagebrush and bunchgrass ecosystems in the Utah portion …

Antimicrobial And Antiinsectan Phenolic Metabolites Of Dalea Searlsiae, Gil Belofsky, Mario Aronica, Eric Foss, Jane Diamond, Felipe Santana, Jacob Darley, Patrick F. Dowd, Christina M. Coleman, Daneel Ferreira

All Faculty Scholarship for the College of the Sciences

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A–D (1–4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1–5, 7 …

Noncanonical Role For The Host Vps4 Aaa+ Atpase Escrt Protein In The Formation Of Tomato Bushy Stunt Virus Replicase, Daniel Barajas, Isabel Fernández De Castro Martín, Judit Pogany, Cristina Risco, Peter D. Nagy

Plant Pathology Faculty Publications

Assembling of the membrane-bound viral replicase complexes (VRCs) consisting of viral- and host-encoded proteins is a key step during the replication of positive-stranded RNA viruses in the infected cells. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the involvement of eleven cellular ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. The ESCRT proteins are involved in endosomal sorting of cellular membrane proteins by forming multiprotein complexes, deforming membranes away from the cytosol and, ultimately, pinching off vesicles into the lumen of the endosomes. In this paper, we show an …

Variation In Sex Allocation And Floral Morphology In An Expanding Distylous Plant Hybrid Complex, Jennifer Rhode Ward, M. Leigh Cowart, Julie Clifford, Mieko Camp, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Premise of research. Sex allocation, the relative energy devoted to producing pollen, ovules, and floral displays, can significantly affect reproductive output and population dynamics. In this study, we investigated floral morphology and gamete production in bisexual, distylous plants from a self-incompatible hybrid complex (Piriqueta cistoides ssp. caroliniana Walter [Arbo]; Turneraceae). Sampling focused on two parent types (C, V) and their stable hybrid derivative (H). Since H morphotypes are heterotic for growth and fruit production, we hypothesized that they would produce larger flowers with more gametes. We also anticipated that plants with long styles (long morphs) would produce less …

Comparison Of Five Major Trichome Regulatory Genes In Brassica Villosa With Orthologues Within The Brassicaceae, Naghabushana K. Nayidu, Sateesh Kagale, Ali Taheri, Thushan S. Withana-Gamage, Isobel A. P. Parkin, Andrew G. Sharpe, Margaret Y. Gruber

Agricultural and Environmental Sciences Faculty Research

Coding sequences for major trichome regulatory genes, including the positive regulators GLABRA 1(GL1), GLABRA 2 (GL2), ENHANCER OF GLABRA 3 (EGL3), and TRANSPARENT TESTA GLABRA 1 (TTG1) and the negative regulator TRIPTYCHON (TRY), were cloned from wild Brassica villosa, which is characterized by dense trichome coverage over most of the plant. Transcript (FPKM) levels from RNA sequencing indicated much higher expression of the GL2 and TTG1 regulatory genes in B. villosa leaves compared with expression levels of GL1 and EGL3 genes in either B. villosa or the reference genome species, glabrous B. oleracea; however, cotyledon TTG1 expression was high in …

B. Braunii, Race B Gene For A Triterpene Methyltransferase Enzyme And Uses Thereof, Joe Chappell, Okada Shigeru, Scott Kinison, Tom Niehaus

Plant and Soil Sciences Faculty Patents

Provided is an isolated polypeptide having triterpene methyltransferase activity. Also provided is an isolated nucleic acid molecule that encodes the triterpene methyltransferase polypeptides; a vector comprising the nucleic acid molecules that encode the triterpene methyltransferase polypeptides; and a host cell(s) transfected with the aforementioned nucleic acid molecule or vector. In another aspect, a method of producing a methylated triterpene is provided. The method comprises providing a metabolizable carbon source to a host cell transfected with a nucleic acid molecule that encodes a triterpene methyltransferase under conditions sufficient for production of a methylated triterpene. The method optionally further comprises isolating the …

Influence Of Ultraviolet Radiation On Cell Wall Constituents In Reduced-Lignin Mutants Of Corn And Sorghum, Brock Bermel

Undergraduate Research Symposium

Brown midrib mutants (BMR) of corn (Zea mays) and sorghum (Sorghum bicolor) have reduced lignin content and have recently gained popularity in Southern Minnesota as forage material for grazing animals. These mutants have lowered expression of cinnamyl alcohol dehydrogenase and caffeic O-methyltransferase enzymes in the phenylpropanoid pathway responsible for the construction of the cinnamyl alcohol subunits of lignin. Lignin is found in the secondary cell wall of higher plants, along with substantial amounts of cellulose and hemicellulose polysaccharides. Reduced lignin increases livestock digestibility of these plants, but may also increase susceptibility to environmental stress and lodging. …

Mechanical Removal Of Juniper And Its Effects On Plant Diversity, Kyle Van Vleet

Undergraduate Research Symposium

The increase in density and distribution of juniper (Juniperus spp.) in sagebrush communities throughout the Western United States, primarily as a result of fire suppression and historic over-grazing, has raised concerns among land managers and ranchers due to the detrimental effects of juniper on livestock forage species, and wildlife habitat. Juniper may dominate sagebrush communities because it may decrease understory plant cover and is more proficient in accessing deep soil waters than common competitors in the area. The main objective of this study was to examine how removal of juniper by mechanical means may affect species richness and abundance …

Effects Of Zinc Oxide Nanoparticles On Carrot Roots And Arbuscular Mycorrhizae, Brian Husler

College of Arts and Sciences Presentations

Increased use of engineered nanoparticles (NPs) is likely to result in their continued release into the environment. Some nanoparticles including zinc oxide nanoparticles (ZnO-NPs) can be toxic to eukaryotic cells, but presently little is known about ZnO-NPs effects on plants and organisms symbiotically associated them. Under in vitro conditions, we examined the effect of 4 nm ZnO-NPs on carrots roots and arbuscular mycorrhizal fungi (AMF), which are obligate biotrophs that play an essential role in mineral uptake. During 4 weeks of incubation, roots in the control treatment (0μg ml^-1 ZnO) grew 30 ± 8 cm, while growth was negligible …

Acetobixan, An Inhibitor Of Cellulose Synthesis Identified By Microbial Bioprospecting, Ye Xia, Lei Lei, Chad Brabham, Jozsef Stork, James R. Strickland, Adam Ladak, Ying Gu, Ian Wallace, Seth Debolt

Horticulture Faculty Publications

In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI), named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action …

Overview Of The Integrated Pest Management (Ipm) Terrain And Activities In Furtherance Of The Walmart Initiative To Purchase Fresh Vegetables From Local Growers In Alabama, Franklin Quarcoo, Conrad Bonsi

Professional Agricultural Workers Journal

Tuskegee University has been providing various types of technical expertise to limited resource farmers who have been supplying Walmart with collard greens, watermelons and purple hull peas. A number of pests bedevil the cultivation of these crops; cost-effective management methods for these pests are needed. The objectives of this paper are to document the IPM activities associated with supplying produce to Walmart; summarize pest problems encountered on the afore-stated crops; recommend IPM methods suitable for limited resource farmers; and suggest other activities that ensure that farmers incur even less pest-related crop losses. Anthracnose was the major pest encountered on watermelons. …