Agricultural Science Commons^™

Recoupling Fire And Grazing Reduces Wildland Fuel Loads On Rangelands, Heath D. Starns, Samuel D. Fuhlendore, R. Dwayne Elmore, Dirac L. Twidwell Jr, Eric T. Thacker, Torre J. Hovick, Barney Luttbeg

Department of Agronomy and Horticulture: Faculty Publications

Fire suppression and exclusion, the historically dominant paradigm of fire management, has resulted in major modifications of fire-dependent ecosystems worldwide. These changes are partially credited with a recent increase in wildfire number and extent, as well as more extreme fire behavior. Fire and herbivory historically interacted, and research has shown that the interaction creates a unique mosaic of vegetation heterogeneity that each disturbance alone does not create. Because fire and grazing have largely been decoupled in modern times, the degree to which the interaction affects fuels and fire regimes has not yet been quantified. We evaluated effects of fire-only and …

Modeling The Response Of Black Walnut -Dominant Mixed Hardwoods To Seasonal Climate Effects With Uav-Based Hyperspectral Sensor And Aerial Photogrammetry, Tyler G. Bradford

Graduate Theses/Dissertations

The development of compact sensors in recent years has inspired the use of UAS-based hyperspectral and aerial imaging techniques for small-scale remote sensing applications. With increasing concerns about climate change, spectrally-derived vegetation indices (VIs) have proven useful for quantifying stress-induced vegetation response. The goal of this study was to develop predictive models and assess methodology for modeling the biological response of a black walnut -dominant mixed hardwood stand to seasonal climate events using UAV-based hyperspectral remote-sensing. The derived VIs were evaluated against the means of four seasonal measures of climate calculated for a two-week period prior to the flight date. …

Arkansas Soybean Research Studies 2017, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Understanding Spatial Dynamics Of Tallgrass Prairie Dominated By Tall Fescue, Callie Griffith

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

This study was conducted on restored tallgrass prairie and invaded tallgrass prairie located in the Grand River Grasslands of southern Iowa to determine differences in heterogeneity of plant structure and functional group composition at different scales. Restored tallgrass prairies were seeded with a species-rich seeding mixture and managed by burning the entire prairie, every three years. Data were collected in August 2014 and 2015 to compare heterogeneity of restoration of native plant structure and functional group composition to the heterogeneity of invaded tallgrass prairies that were managed with patch burning and conventionally grazed. Invaded tallgrass prairies were managed with patch-burning …

Generation And Evaluation Of Modified Opaque-2 (O2) Popcorn Suggests A Route To Quality Protein Popcorn (Qpp), Ying Ren

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

I have been working on a Quality Protein Popcorn breeding project where QPM conversion is carried out simultaneously for several elite popcorn germplasms. During my study in the graduate program, I led the following aspects of the Quality Protein Popcorn Breeding Project:

1. Identified suitable QPMs as opaque-2 allele donors.

2.Examined the feasibility of quick introgression of the opaque-2 allele into popcorn lines via marker-assisted selection.

3. Monitored modification by SDS-PAGE zein profiling and light box phenotypic selection to make sure multiple modifier loci for opaque-2 were incorporated each time generation advancement was carried out.

4. Carried out high throughput …

Grazing Strategy Effects On Utilization, Animal Performance, Aboveground Production, Species Composition, And Soil Properties On Nebraska Sandhills Meadow, Aaron Shropshire

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

Ultrahigh stocking density (a.k.a., mob grazing) is proposed as a management tool that results in greater harvest efficiency, animal performance, aboveground plant production, species richness, and soil carbon content. The study objective was to determine grazing treatment, haying, or non-defoliated control effects on forage utilization, aboveground production, animal performance, and soil properties. In 2010, 25 ha of Sandhills meadow were divided into 2 replications of 3 grazing, a hay, and control treatment. Grazing treatments were a 120-pasture rotation with one grazing cycle (mob), a 4-pasture rotation with one cycle (4PR1), and a 4-pasture rotation with two cycles (4PR2) at stocking …

Impacts Of Cover Crop Mixtures On Productivity Of Cropping Systems, Brionna Lee West

Graduate Theses/Dissertations

A field study and a meta-analysis were conducted to compare the impact of cover crops on carbon and nitrogen dynamics and cash crop yield. The field study included six treatments: winter cereal rye, winter cereal rye-Austrian winter pea at two seeding rates, cereal rye-Austrian winter pea-radish at two seeding rates, and a no cover control. Meta-analysis data sets were compiled from studies published between 1994 and 2017. Treatments were grouped into the following classifications: monoculture, binary mix, polyculture, or control. In both the field study and meta-analysis, cover crops did not affect cash crop yield. However, plant biomass and plant …

Effects Of Irrigation On Forage Growth Rates On Rotational Grazing Dairies, Zachary Davis

Graduate Theses/Dissertations

The amount and timing of rainfall in Missouri can be very irregular. This causes issues for producers of agronomic products in the state who rely on forages for income. The most sensible approach to the problem is the use of irrigation. But there is little useful information to reference when implementing this management decision. By studying three different styles of irrigation (center pivot, spider, and k-line) on 4 species of forages native to Missouri (alfalfa, crabgrass, perennial ryegrass, and tall fescue/clover), this study provides valuable insight as to the cost and benefit of irrigation. The main goal is to produce …

Arkansas Corn And Grain Sorghum Performance Tests 2018, R. D. Bond, J. A. Still, J. F. Carlin

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.

Quantitative And Quality Losses Caused By Rodents In On-Farm Stored Maize: A Case Study In The Low Land Tropical Zone Of Kenya, Kukom Edoh Ognakossan, Christopher M. Mutungi, Tobias O. Otieno, Hippolyte D. Affognon, Daniel N. Sila, Willis O. Owino

All Peer-Reviewed Publications

Rodents are one of the major storage pests in on-farm maize storage in the tropics. However, information on actual magnitude of weight and quality losses caused by rodents in maize stores and species of rodent associated with the losses is scarce and if available would help to improve maize postharvest management. Maize stores of small-scale farmers in the lowland tropical zone of Kenya were monitored for actual weight losses caused by rodents and rodent trapping was conducted to determine species and estimate population of the rodents associated with the losses. Moulds and total aflatoxin contamination and nutritional value of rodent-damaged …

Evaluation Of Biorational Insecticides And Dna Barcoding As Tools To Improve Insect Pest Management In Lablab Bean (Lablab Purpureus) In Bangladesh, Margaret R. Douglas, Jan Chang, Kohinoor Begum, Sevgan Subramanian, John F. Tooker, Syed Nurul Alam, Srinivasan Ramasamy

All Peer-Reviewed Publications

Lablab bean (Lablab purpureus) is a popular vegetable crop in Bangladesh, but farmers growing this crop experience significant losses to insect pests despite heavy reliance on conventional insecticides. We conducted field studies to improve pest management in lablab bean by testing biorational insecticides as alternatives to conventional insecticides for the control of pod borers (Maruca vitrata) and aphids (Aphis craccivora), and characterizing flower-inhabiting thrips as an emerging pest in this crop. In field experiments, spinosad was the most promising biorational we tested, suppressing pod-boring caterpillars more effectively than thiamethoxam or quinalphos. In contrast, azadirachtin (neem) did not significantly suppress any …

Soil Responses To One-Season Winter Cover Crops, Mckenna Morgan, Iin Handayani

Posters-at-the-Capitol

Soil Responses to One-Season Winter Cover Crops

McKenna Morgan and I. P. Handayani

Hutson School of Agriculture Murray State University, KY, USA

Abstract

In regions like western Kentucky where wooded lots are common there is a growing interest in how to utilize them so that land profits can be maximized. The frequently poor soils in wooded areas due to erosion and lack of ground cover vegetation often cause complications in the creation of pasture areas. Therefore, the objective of this study was to assess the effect of growing winter cover crops on soils to prepare for pasture systems in the …

Hybridisation-Based Target Enrichment Of Phenology Genes To Dissect The Genetic Basis Of Yield And Adaptation In Barley, Camilla Beate Hill, Tefera Angessa, Lee-Anne Mcfawn, Debbie Wong, Josquin Tibbits, Xiao-Qi Zhang, Kerrie Forrest, David Moody, Paul Telfer, Sharon Westcott, Dean A. Diepeveen, Yanhao Xu, Cong Tan, Matthew Hayden, Chengdao Li

Grain and Other Field Crops Research Articles

Barley (Hordeum vulgare L.) is a major cereal grain widely used for livestock feed, brewing malts and human food. Grain yield is the most important breeding target for genetic improvement and largely depends on optimal timing of flowering. Little is known about the allelic diversity of genes that underlie flowering time in domesticated barley, the genetic changes that have occurred during breeding, and their impact on yield and adaptation. Here, we report a comprehensive genomic assessment of a worldwide collection of 895 barley accessions based on the targeted resequencing of phenology genes. A versatile target-capture method was used to …

Investigation Of Alternative Hosts And Agronomic Factors Affecting Xanthomonas Vasicola Pv. Vasculorum, Causal Agent Of Bacterial Leaf Streak Of Corn, Terra Marie Hartman

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

Xanthomonas vasicola pv. vasculorum, causal agent of bacterial leaf streak of corn, was first reported in the U.S. in 2016 on Nebraska corn leaf samples. Prior to this report, the pathogen had only been reported on corn in South Africa. After the Nebraska report, the pathogen was reported on corn in Argentina, Brazil, and several U.S. states. This pathogen has an extensive host range, which includes sugarcane (Saccharum officinarum), grain sorghum (Sorghum bicolor), palm species (Dictyosperma album, Roystonea regia, and Areca catechu) and broom bamboo (Thysanolaena maxima). Plants commonly found in …

Identification Of Genes/Genomic Regions Controlling Resistance To Biotic And Abiotic Stresses In Synthetic Hexaploid Wheat, Madhav Bhatta

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

Synthetic hexaploid wheat (SHW; 2n=6x=42, AABBDD, Triticum aestivumL.) is produced from an interspecific cross between durum wheat (2n=4x=28, AABB, T. turgidumL.) and goat grass (2n=2x=14, DD, AegilopstauschiiCoss.). It is reported to have a considerable amount of genetic diversity and is a potential source of novel alleles controlling abiotic and biotic stresses resistance and improving wheat quality. Therefore, the first study was to understand the genetic diversity and population structure of SHWs and compare the genetic diversity of SHWs with elite bread wheat (BW) cultivars. The result of this study identified a wide range of genetic diversity within …

Response Of Common Bean (Phaseolus Vulgaris L.) To Nitrogen, Phosphorus And Rhizobia Inoculation Across Variable Soils In Zimbabwe, Vongai Chekanai, Regis Chikowo, Bernard Vanlauwe

All Peer-Reviewed Publications

Common bean is an important crop with potential to curb malnutrition in poor Sub-Saharan African populations. Yields of common bean (Phaseolus vulgaris L.) are, however poor, limited by low soil phosphorus (P), nitrogen (N) and poor biological N2-fixation. On-farm experiments were carried out to study the effect of N, P and rhizobia inoculation on common bean yield and yield components during the 2014/2015 and 2015/2016 cropping seasons in Eastern Zimbabwe. Experiments were conducted on five farmers’ fields located in two agroecologies; three fields were considered to be degraded with soil organic carbon (SOC) < 4 g kg−1 and available P < 6 mg kg−1, while the two non–degraded sites had SOC > 7 g kg−1 and available P > 15 …

Canavalia Gladiata And Dolichos Lablab Extracts For Sustainable Pest Biocontrol And Plant Nutrition Improvement In El Salvador, Carlos Martinez

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

Botanical repellents and pesticides are now being rediscovered as new tools for integrated pest management in order to reduce the use of toxic chemicals in crop production. Canavalia gladiata and Dolichos lablab are two Fabaceae very well adapted to farmlands of El Salvador, effective as living barriers and mostly as cover crops, however, they are not yet very well disseminated. This document describes the potential for using the liquid extracts and the dry flour of raw seeds of those plants for economic benefit and practical convenience for pest management in Salvadorian agriculture under field conditions. Seed extracts were useful when …

Assessment Of Soil Fertility Under Different Land-Use Systems In Dhading District Of Nepal, Sudarshan Kharal, Babu Ram Khanal, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

Unscientific land use and cropping techniques have led high soil erosion and degradation of soil quality in the mid-hills of Nepal. To understand the effects of land use systems for selected soil chemical properties in mid-hills, composite soil samples at 0 cm to 20 cm depth were collected from five different land-use systems: Grassland, forest land, upland, lowland, and vegetable farms from Dhading district of Nepal in 2017. Soil samples were analyzed for soil fertility parameters: Soil pH, organic matter (OM), total nitrogen (N), available phosphorus (P), available potassium (K) and its effect due to different land use systems were …

Research Report: Prevalence And Mechanism Of Atrazine Resistance In Waterhemp From Nebraska, Rodrigo Werle, Mithila Jugulam, Greg Kruger, Amaranatha Vennapusa, Felipe Faleco, Bruno Viera, Spencer Samuelson

Department of Agronomy and Horticulture: Faculty Publications

Waterhemp is a troublesome summer annual broadleaf weed species that has evolved resistance to glyphosate and other herbicide sites of action (SOA) in Nebraska, including to groups 2 (i.e., Classic, Pursuit, FirstRate), 4 (i.e., 2, 4-D), 5(i.e., atrazine) and 27 (e.g., Callisto, Laudis). The overall objectives of this study were to

1. Evaluate the eficay of PRE applied atrazine, metribuzin and sulfentrazone to control Nebraska waterhemp populations;
2. Evaluate the efficacy of POST applied atrazine to control Nebraska waterhemp populations; and
3. Determine the mechanism of atrazine resistance in Nebraska waterhemp populations.

Digital Soil Mapping In The Bara District Of Nepal Using Kriging Tool In Arcgis, Dinesh Panday, Bijesh Maharjan, Devraj Chalise, Ram Kumar Shrestha, Bikesh Twanabasu

Department of Agronomy and Horticulture: Faculty Publications

Digital soil mapping has been widely used to develop statistical models of the relationships between environmental variables and soil attributes. This study aimed at determining and mapping the spatial distribution of the variability in soil chemical properties of the agricultural floodplain lands of the Bara district in Nepal. The study was carried out in 23 Village Development Committees with 12,516 ha total area, in the southern part of the Bara district. A total of 109 surface soil samples (0 to 15 cm depth) were collected and analyzed for pH, organic matter (OM), nitrogen (N), phosphorus (P, expressed as P_{2 …}