Agricultural Science Commons^™

Improving Nitrogen Management And Corn Productivity Through Enhanced Efficiency Fertilizer And Cover Crop Integration In Nebraska Cropping Systems, Madhusudhan Adhikari

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

Effective nitrogen (N) management is vital for sustaining corn yield and reducing environmental impacts in Nebraska cropping systems. Three field studies were conducted to evaluate the impact of 1) fertilizer type (anhydrous ammonia [AA] with nitrification inhibitor: enhanced efficiency fertilizer [EEF] or AA without EEF) and N application timing (pre-plant vs. split with side-dress UAN) on in-season soil N availability, crop response, nitrous oxide (N₂O) emissions, residual soil N and N use efficiencies (NUEs); 2) winter cover crop (CC) species and crop rotation variability on CC biomass production, N uptake, soil N dynamics, and cash crop performance in …

Extending Cover Crop Growing Window To Improve The Health Of Environmentally Sensitive Soils, Noshin Ara Tunazzina

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

Sloping and sandy soils are highly susceptible to degradation. The health of these soils could be improved with cover crops (CCs). However, CC effectiveness in improving soil health mainly depends on CC biomass production, which is often low in temperate regions. The question is: how can we increase CC biomass production? Lengthening the CC growing window can be a potential strategy. This study assessed how 1) interseeded and terminated early (2-3 weeks before crop planting) CC, 2) interseeded and terminated late (at crop planting) CC, 3) drilled (after harvest) and terminated early CC, 4) drilled and terminated late CC, and …

Evaluation Of Thermotherapy On Potato Tubers To Control Tuber-Borne Nematodes, Meloidogyne Spp, Wawan Kurniawan, Supramana, Abdul Munif, Giyanto

Jurnal Kultivasi

Root knot nematodes (Meloidogyne spp.) are significant plant-parasitic nematodes frequently transmitted through potato tubers and are a major factor contributing to the decline in both crop quality and yield. This study aims to evaluate the effectiveness of thermotherapy for eliminating Meloidogyne spp. from potato tubers and its impact on sprouting viability. Thermotherapy was conducted by immersing potato tubers and second-stage juveniles (J2) of Meloidogyne spp. in water at temperatures of 50 °C, 52.5 °C, 55 °C, and 60 °C for durations ranging from 5 to 75 minutes, depending on the treatment. Parameters observed included the mortality rate of Meloidogyne spp. …

Evaluation Of Field Grown Grapevine Grafts For Drought Tolerance Under Water Deficit Irrigation In The Arid Regions Of Uae, Sonu Krishankumar

Thesis/ Dissertation Defenses

Grapevines, among the most commercially significant fruit crops, are valued for their use in table grapes, raisins, and winemaking but are highly vulnerable to abiotic stresses such as drought, heat, and salinity. This study investigated the morphological, physiological, biochemical, and transcriptomic responses of grafted grapevines to drought stress, emphasizing rootstock-scion interactions. Grafting experiments were conducted with three rootstocks (Ramsey, RU140, and Paulsen) and table grape varieties (Thomson Seedless, Crimson Seedless, and Flame Seedless), with five combinations as Flame seedless × Ramsey (V1), Thompson seedless × Ramsey (V2), Crimson seedless × R110 (V3), Crimson seedless × Ramsey (V4) and Thompson seedless …

Evaluation Of The Global Durum Panel (Triticum Turgidum Ssp. Durum) For Wheat Streak Mosaic Virus Resistance, Winter Survival, And Seed Characteristics, Megan Engel

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

The majority of durum wheat (Triticum turgidum spp. durum; AABB; 2n=4x=28) is predominantly grown in the northern Great Plains of the United States, and is used in the production of semolina, a coarse flour that makes pasta and couscous. Durum has been widely regarded for being more tolerant to abiotic stress, due to its ability to withstand drought and high temperatures. In this thesis, we conducted greenhouse, field, and lab studies, for the traits wheat streak mosaic virus (WSMV), winter survival, and single kernel characteristics of the Global Durum Panel version 2 (GDPv2 n = 976), a panel …

Genetic And Soil Influences On The Grapevine Rhizosphere Microbiome, Lauren M. Quackenbush

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

In vineyard cropping systems, the rhizosphere microbiome arises through recruitment and filtering of the bulk soil microbiome shaped over time by soil carbon and nitrogen, climate, pH and historical legacies of vineyard management. The recruitment and filtering steps occur under the genetic influences of rootstock and scion that together drive variability in rhizosphere microbiome diversity and composition.

This study compares rhizosphere microbiomes of four Pinot Noir blocks under two rootstocks (101-14 and 420A) and four scions (777, 828, Calera, Mt. Eden). Core microbiomes were consistent across all replicates. The most abundant bacterial phyla were Actinobacteriota, Proteobacteria, and Acidobacteriota …

Arkansas Cotton Variety Tests 2024, F. Bourland, J. Gann, B. Lovelady, B. Guest Jr., J. Mcalee, L. Martin, Z. Treadway, C. Henderson

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Tests is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant. These annual evaluations will then facilitate the inclusion of new, improved genetic material in Arkansas cotton production. Adaptation of varieties is determined by evaluating the lines at five University of Arkansas System Division of Agriculture research sites (Manila, Keiser, Judd Hill, Marianna, and Rohwer). The 2024 tests at Keiser were adversely affected …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2024, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Citrus Fruits Maturity Parameters 2025-2026, Department Of Primary Industries And Regional Development, Western Australia

Viticulture research reports

Under Biosecurity and Agricultural Management (Agricultural Standards) Regulations 2013 Part 5.

Arkansas Soybean Performance Tests 2024, J. F. Carlin, R. D. Bond, T. C. Swanson, J. C. Mccoy

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.

Arkansas Soybean Research Studies 2023, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

The 2023 Arkansas Soybean Research Studies includes research reports on topics pertaining to soybean across several disciplines from breeding to post-harvest processing. Research reports contained in this publication may represent preliminary or only data from a single year or limited results; therefore, these results should not be used as a basis for long-term recommendations.

Several research reports in this publication will appear in other University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station publications. This duplication is the result of the overlap in research coverage between disciplines and our effort to inform Arkansas soybean producers of the research …

Arkansas Corn And Grain Sorghum Performance Tests 2024, J. F. Carlin, R. D. Bond, J. C. Mccoy, T. C. Swanson

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.

The 2024 corn performance tests contained 44 hybrids and were conducted at the Northeast Rice Research and Extension Center (NERREC) at Harrisburg, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. The 2024 grain sorghum performance tests contained 16 …

Performance Of Eight Lettuce Cultivars In A Water Culture System, Ricky C. Young, Hudson M. Cox, Jacob D. Frodge, Mollie K. Mayabb, Brycen C. Shephard, Alireza Rahemi

Posters-at-the-Capitol

Lettuce (Lactuca sativa L.) is one of the most well-known vegetables in the world. About 27 million tons of lettuce were produced in the world in 2022 and global demand for lettuce is increasing steadily, driven by the importance of fiber consumption. Lettuce can be grown in multiple media, including hydroponic systems in a controlled environment agriculture (CEA) system. Growing lettuce in hydroponic systems is an alternative to lettuce production optimization. Since little information is available about lettuce cultivar trials in hydroponic systems, a research project was developed and executed to study the ability of different types of lettuce …

Research Report: Cold-Hardy Hydrangeas For Landscape And Cut Flowers, Rebecca G. Sideman, Kaitlyn Orde, Ella Lukacz, Cathy Neal

Faculty Publications

This research report describes the performance of several cold-hard “panicle” (H. paniculata), “smooth” (H. arborescens), and “oakleaf” (H. quercifolia) hydrangea as landscape plants and for cut flower production in Durham, NH. We established a replicated planting of sixteen newer hydrangea cultivars at Woodman Farm in summer 2020. Preliminary data from these young shrubs indicates that there are wide differences in flower production, stem quality, flowering time and duration, and postharvest floral quality – among other traits.

Introduction To Hydroponics- 2025-2026 Workshop Handbook, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Hydroponically grown plants grow faster than traditional production systems, with greater productivity, greater palatability, and having optimal visual character. Three principal components of a system include the plant support platform, a nutrient solution reservoir, and an interface for the root-solution. This publication provides in-depth explanation to system design, evaluation of water quality, nutrient formulation, and prototype systems that can be easily constructed for those wanting to explore hydroponics, such as educators, organizational leaders, or home enthusiasts.

Effects Of Round-Up On The Environment, Sandra J. Marcu

Journal of Earth and Life Science

Many people around the world have used and still currently use Roundup but are unaware of the effects it has on the environment. Roundup is a spray on application weedkiller that is widely used around the world today both residentially and commercially. It enables its user to grow a garden or a field of crops with a no-tilling approach to eliminate weeds. It is a well-known and popular choice for killing weeds that has been around since the mid 1970’s (Oca, 2017). John Franz, a Monsanto scientist discovered that glyphosate (main ingredient in Roundup) was an herbicide or weedkiller, and …

Modeling The Impact Of Climate Change On Plant Hardiness Zones Across The Contiguous United States Using Empirical Bayesian Kriging Regression Prediction, Daniel Donkor

Graduate Theses/Dissertations

Mapping plant hardiness zones is crucial to understanding and predicting the spatial distribution of plants in response to climatic conditions. The United States Department of Agriculture (USDA) developed the plant hardiness zones based on the average of annual extreme minimum temperatures using the Parameter elevation Regression on Independent Slope Model (PRISM). While the USDA’s 2012 and 2023 Plant Hardiness Zone maps remain standard references, they offer limited geostatistical transparency that causes more complications in replicating. This study applies Empirical Bayesian Kriging Regression Prediction (EBKRP) method to generate Plant Hardiness Zone maps, analyze spatial and temporal shifts in the plant hardiness …

Greenhouse Management For The Smaller Structure--Educational And Hobby, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Greenhouses used for teaching or by hobbyist are smaller than those used for commercial production or found in the retail environment. Structural materials, covering, mechanical equipment, and control systems often are packaged as a kit made available through greenhouse suppliers. Supplier construction services may not be available, in which buyers must use local contractors to complete the installation. Greenhouses are unique structures that differ greatly from sheds or other outbuildings. They have coverings that allow maximum light transmittance, protected from UV degradation, and can handle wide inside to outside temperature extremes. This extension circular provides valuable information on the character, …

Addressing Food Security In Cameroon, Stacy A. Adams, Ruth Abunaw Besong

Department of Agronomy and Horticulture: Faculty Publications

Cameroon Africa has experience a period of nearly a decade of unrest as militants fight for independence for two Anglophone regions within a predominantly Francophone country. The English-speaking minority have felt aggrieved for continued erosion of rights by the central government. Protests have rapidly spread since 2016, causing closure of schools, businesses, and medical facilities. People have lost homes and been displaced, negatively affecting food production and crop availability. The United States Department of State leads an effort of diplomacy beyond emergency food relief through the Mandela Washington Fellowship that connects American professionals to innovative and impactful young African leaders. …

Terrarium- An Ecosystem In A Jar, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

STEM education is supported through hand's-on activities in the classroom. Content understanding and reaffirmation of knowledge is supported through this informative STEM-Quick card that teachers or extension educators can distribute to participants for reference. Terrariums provide an example of a closed ecosystem where water and carbon cycling is demonstrated and plant growth can be observed. This card presents the steps to building and caring for an easy to create terrarium.

Revolutionizing Grapevine Breeding Programs: A Mobile Genome Editing System For Perennial Crops, Bridget Bolt

Theses and Dissertations--Plant and Soil Sciences

Grapevine (Vitis vinifera) faces unprecedented challenges from climate change, with up to 90% of current growing regions potentially becoming unsuitable for production within decades. Traditional breeding approaches require 25-30 years for variety development, creating a time constraint incompatible with the pace of environmental change. This research establishes the approach for a novel mobile RNA-based gene editing platform that addresses longstanding bottlenecks in grapevine improvement while preserving cultivar identity and reducing breeding timelines.

This research developed a three-component system for transgene-free gene editing in grapevine. First, a mobile CRISPR/Cas9 system was established using Agrobacterium rhizogenes transformation and the cut-and-dip …

The Effect Of Seed Provenance And Organic Fertilizer Types On Growth And Yield Of G2 Potato (Solanum Tuberosum L. Cv. Medians) Seeds In Jatinangor Medium Plains, Mohammad Faisal Rafiif, Wawan Sutari, Jajang Sauman Hamdani

Jurnal Kultivasi

Potato growth is influenced by seed provenance and fertilization, but the availability of high-quality potato seeds is still limited. To overcome those challenges, solutions include using temperature-tolerant potato varieties from medium plains and applying organic fertilizers to improve potato growth and yield. The purpose of this research was to determine the effect of the interaction between seed provenance and application of organic fertilizers on the growth and yield of G2 potato seeds of the Medians cultivar in the Jatinangor medium plains. The research was conducted from June to October 2023 at the Ciparanje Experimental Farm, Faculty of Agriculture, Universitas Padjadjaran, …

Leveraging Within-Field Spatial Variability To Optimize Soybean Yield, Seed Quality, And Profitability, Marina Marly Dalla Betta

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

Optimizing yield and seed quality in soybean production is critical for both profitability and meeting market demands. However, within-field variability in soil properties poses a challenge in determining optimal management strategies to maximize soybean yield, seed quality, and profitability. This work aimed to evaluate the spatial variability of soybean fields to optimize soybean seeding rates, seed quality, and profitability. Two case studies were used to carry over this research. The first study looked at the optimal economical site-specific soybean seeding rates using 11 on-farm precision experiments across Nebraska. The second study looked at the protein and oil variability within 22 …

Developing Holistic And Reduced Fertilization Guidelines For Southeastern Peach (Prunus Persica (L.) Batsch) Orchards, Richardson Bien-Aime

All Theses

Peach production in the southeastern United States requires optimizing fertilization practices to balance economic sustainability and environmental health. Current guidelines may overlook rootstock-specific nutrient requirements and fail to align with orchard-specific conditions, often resulting in overfertilization, increased costs, and environmental risks. This study, conducted at Clemson University’s Musser Fruit Research Center during 2023 and 2024, aimed to refine fertilization practices through two complementary experiments. The first experiment investigated how three rootstocks, ’MP-29’, Lovell, and Guardian, influence nutrient dynamics of ‘Carored’ peach trees. Nutrient concentrations were measured in various tree organs, including leaves, pruned wood, thinned fruitlets, and harvested fruits, along …

Broad-Spectrum Resistance To Fungal Foliar Diseases In Wheat: Recent Efforts And Achievements, Amira M.I. Mourad, Asmaa A.M. Ahmed, P. Stephen Baenziger, Andreas Börner, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Wheat (Triticum spp.) is one of the most important cereal crops in the world. Several diseases affect wheat production and can cause 20-80% yield loss annually. Out of these diseases, stripe rust, also known as yellow rust (Puccinia striiformis f. sp. tritici), stem rust (Puccinia graminis f. sp. tritici), leaf rust (Puccinia recondita), and powdery mildew (Blumeria graminis f. sp. tritici) are the most important fungal diseases that infect the foliar part of the plant. Many efforts were made to improve wheat resistance to these diseases. Due to the continuous advancement in …

Disentangling Genotype And Environment Specific Latent Features For Improved Trait Prediction Using A Compositional Autoencoder, Anirudha Powadi, Talukder Zaki Jubery, Michael C. Tross, James C. Schnable, Baskar Ganapathysubramanian

Department of Agronomy and Horticulture: Faculty Publications

In plant breeding and genetics, predictive models traditionally rely on compact representations of high-dimensional data, often using methods like Principal Component Analysis (PCA) and, more recently, Autoencoders (AE). However, these methods do not separate genotype-specific and environment-specific features, limiting their ability to accurately predict traits influenced by both genetic and environmental factors. We hypothesize that disentangling these representations into genotype-specific and environment-specific components can enhance predictive models. To test this, we developed a compositional autoencoder (CAE) that decomposes high-dimensional data into distinct genotype-specific and environment-specific latent features. Our CAE framework employed a hierarchical architecture within an autoencoder to effectively separate …

Industrial Hemp Biomass Negatively Affected By Herbicide Drift From Corn And Soybean Herbicides, Milos Zaric, Bruno Canella Vieira, Barbara Houston, Guilherme Sousa Alves, Samuel E. Wortman, Julie A. Peterson, Greg R. Kruger

Department of Agronomy and Horticulture: Faculty Publications

The establishment of industrial hemp (Cannabis sativa L.) fields near row crops has raised concerns about the potential adverse effects of herbicide drift on hemp production. This study examined hemp susceptibility to drift of herbicides registered for use in corn and/or soybeans. Herbicide solutions (2,4-D, dicamba, glufosinate, glyphosate, imazethapyr, lactofen, mesotrione) were applied separately in the wind tunnel (3.6 m s⁻¹ airspeed), simulating drift scenarios, with conventional TP95015EVS (TP) and air inclusion AI95015EVS (AI) flat fan nozzles calibrated to deliver 140 L ha⁻¹ carrier volume at 230 kPa. Mylar cards and hemp plants (20–25 cm tall) were placed …

Excavated Tanks (Farm Dams), Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

Guidelines and information for planning, legal requirements, design, construction and management of excavated tanks for water storage on farm.

Excavated tanks (farm dams) provide effective water storage wherever surface water run-off can be harvested for livestock, crop spraying, irrigation and domestic use on rural properties.

Excavated tanks for rainfall storage are common in the southern agricultural areas of WA.

Well-designed and constructed dams are farm assets, safe and require little maintenance.

Poor design and construction can lead to poor water harvesting and storage, excessive costs, downstream erosion and risks to property and people.

DPIRD recommends that excavated tanks should be …

Designing A Decision-Support Tool For Fertilizer Recommendations In Oil Palm Smallholders, Rana Farrasati

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

Oil palm (Elaeis guineensis Jacq.), originally from West Africa, now accounts for 42% of global vegetable oil production and mainly includes key regions cultivated in tropical regions of Southeast Asia, West Africa, South America, and Central America. Despite its economic significance, the oil palm industry faces challenges of stagnant yields and large yield gaps, particularly among independent smallholders. These issues often stem from inadequate nutrient management practices and limited agronomic knowledge. Our objective was to quantify nutrient requirements for mature oil palm plantations as a basis to design a decision support tool (DST) for fertilizer recommendations. To do so, …

Bio-Based Sprayable Mulch For Weed Control In Row Crop Systems, Camila Chiaranda Rodrigues

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

Improving current crop productivity levels requires transformative advancements in management, engineering, and science. One of the main challenges is the increasing difficulty of weed management due to herbicide-resistant weeds. There is a growing need for alternative weed management methods to reduce pesticide use and improve environmental safety. An emerging technology that is being developed is spray-on films which could help address these challenges. Spray-on films are liquid solutions that after spraying on the soil will dry and form a physical barrier. The overall objective of this research was to evaluate the effectiveness of a chicken feather bio-based sprayable mulch film …