Plant Sciences Commons^™

Residual Effects Of Nitrogen Fertilization On Soil Nitrogen Pools And Corn Growth, Meghan E. Moser

Open Access Theses

Given the dynamic nature of soil nitrogen (N), inorganic N fertilization to corn (Zea mays L.) has potential to alter N pool balance by creating an accumulation or depletion of soil N. Current corn N recommendations in the common corn-soybean rotation of Indiana strive to find the best N rate that maximizes producer profit. Increasing our understanding of soil N will inform producers if they should adjust fertilizer rates for corn to influence maintenance of organic N and Carbon. Our objective was to determine residual N effects from fertilized corn in a corn-soybean rotation by measuring (1) soil N …

Forest Industry Byproducts Improve Soil Quality And Increase Pepper Growth In Three Soils Infested With Phythophthora Blight, Xiaojun Zhao

Open Access Theses

Phytophthora blight is a serious threat to the Midwest vegetable industry, because the oomycete pathogen responsible for this disease, Phytophthora capsici, has a wide host range, can spread quickly in fields, and produces resilient oospores that can survive in soil for years. Phytophthora capsici has become resistant to commonly used fungicides and resistant crop varieties are rare. Amending soil with complex organic substrates has potential to improve soil quality and suppress soil-borne pathogens including P. capsici. Indiana has a significant forest industry with many residual products that could be used as locally available amendments to meet this goal. …

The Biology And Management Of Waterhemp In Indiana, Joseph M. Heneghan

Open Access Theses

Waterhemp is a dioecious weed species indigenous to the Midwestern United states yet it has only recently become problematic in agronomic crop production in Indiana. Waterhemp is a small-seeded broadleaf which has increased in prevalence in conjunction with an increase in conservation tillage practices. Waterhemp germinates and emerges from the top 3 cm of soil and is known to exhibit extended periods of continual emergence, longer than most other summer annual weed species that are typically present in agronomic production settings. As a C4 species, waterhemp then grows rapidly and is capable of producing thousands of seeds, while effectively competing …

Mapping And Analyzing Energy Use And Efficiency In A Modified Hydroponic Shipping Container, Rachel E. Sparks

Open Access Theses

In urban centers today, vertical farming is becoming a popular alternative to conventional agriculture in an effort to increase local food production and improve urban food security by growing crops using hydroponic methods in controlled environment spaces. More specifically, one vertical method involves growing crops inside refurbished shipping containers, or a “farm-in-a-box” concept, which offers a flexible, mobile, and scalable means of year-round food production in a variety of climates. Despite benefits of producing food locally, some of the concerns associated with these vertical farming systems include high energy consumption from climate control and electric lighting systems as well as …

Manipulating Air And Root-Zone Temperature For Energy-Efficient Floriculture Crop Production, Madeline W. Olberg

Open Access Theses

Given the high energy costs for greenhouse floriculture production, growers are constantly searching for more energy-efficient methods of production. For example, some growers will lower greenhouse air temperature set points or grow crops in unheated high tunnels (HTs) or outdoors in order to minimize or eliminate heating costs. Unfortunately, development can be delayed and morphology can be altered if the mean daily air temperature (MDT) is reduced. We proposed that reducing MDT in combination with root-zone heating (RZH) could be an energy-efficient method for producing high-quality floriculture crops without significant delays. Unheated HT and unprotected outdoor production are very low-cost …

Effect Of Volunteer Corn Density On Deoxynivalenol Production By Fusarium Graminearum In Hybrid Corn, Gaelle Florence Hollandbeck

Open Access Theses

Fusarium graminearum causes Gibberella ear rot in corn and produces mycotoxins such as deoxynivalenol (DON). Volunteer corn is a weed resulting from uncollected kernels from the previous harvest and is very difficult to control once established. An experiment was established in Porter County, IN from 2013 to 2015 to examine the impact of volunteer corn density on Gibberella ear rot severity and DON levels in hybrid corn. Five densities of volunteer corn were established within plots of each hybrid (0, 0.5, 2, 4, and 8 volunteer plants/m2). Disease severity and DON were assessed for both hybrid and volunteer ears collected …

The Effect Of Adjuvants On Apple Disease Management, Chelsi Patricia Abbott

Open Access Theses

The management of common apple diseases such as apple scab ( Venturia inaequalis) and bitter rot (Colletotrichum spp.) relies heavily on effective fungicide applications. However, the development of fungicide resistance to newer fungicides has resulted in management failures and significant economic losses. This has led to a greater reliance on captan, an older fungicide, because there is a low risk of pathogens developing resistance. Label restrictions limit growers to 18 kg of captan per season, which may not provide sufficient control of both apple scab and bitter rot in wet years. Consequently, apple growers are faced with two …

Automatic Extraction Of Plots From Geo-Registered Uas Imagery Of Crop Fields With Complex Planting Schemes, Anthony A. Hearst

Open Access Theses

Complex planting schemes are common in experimental crop fields and can make it difficult to extract plots of interest from high-resolution imagery of the fields gathered by Unmanned Aircraft Systems (UAS). This prevents UAS imagery from being applied in High-Throughput Precision Phenotyping and other areas of agricultural research. If the imagery is accurately geo-registered, then it may be possible to extract plots from the imagery based on their map coordinates. To test this approach, a UAS was used to acquire visual imagery of 5 ha of soybean fields containing 6.0 m2 plots in a complex planting scheme. Sixteen artificial targets …

Analyzing The Importance Of Diversifying Beyond Tobacco For Small-Scale Farmers In Malawi, Mphatso Charity Mbulukwa

Open Access Theses

This thesis analyses potential agricultural alternatives to production and marketing of tobacco in Malawi. I study existing patterns of crop and income diversification and factors that limit crop diversification. I also provide an analysis of the current profitability of different important cash crop alternatives that are commonly grown among smallholder farmers and compare their profitability to that of tobacco.

Following a review and synthesis of available literature on alternatives to tobacco, analysis is presented that relies upon data collected in 2009 from 380 households in Kasungu and Machinga districts of Malawi. Simpsons Index of diversification was used to measure the …

Defining Management Strategies To Maximize Net Soil Carbon And Nitrogen Retention In Turfgrass Systems, Quincy D. Law

Open Access Theses

Soil carbon (C) sequestration has been proposed as a method to reduce atmospheric carbon dioxide (CO2 ). Managed turf areas are both a source and a sink for greenhouse gases (GHGs) including CO 2 , methane (CH4 ), and nitrous oxide (N2 O), among others. Management practices, including turfgrass selection and mowing, influence the amount of C and N stored in the soil, as well as the direct and indirect GHG emissions. Thus, the objective of this research was to determine how turfgrass selection (both species and cultivar) and mowing practices (such as frequency and grass clipping management) influence the …

Creating Initial Digital Soil Properties Map Of Afghanistan, Shams R. Rahmani

Open Access Theses

Afghanistan is a country with a population of more than 31 million people and is located in south central Asia. The total arable land in the country is 12%, 5% is irrigated and the remaining 7% is rainfed. Due to the lack of available soil information, poor farming practices and land management planning severely affect the yield of agriculture products. In order to ensure sustainable agriculture and prevent land degradation problems, understanding spatial variability of soil is crucial. The overall objective of this research study was to use digital soil mapping techniques to identify the soil resources and generate a …

Effect Of Post-Anthesis Fungicide Applications To Manage Fusarium Head Blight In Winter Wheat, Anna Noversoke

Open Access Theses

Fusarium head blight (FHB) of wheat, caused by the fungus Fusarium graminearum, is currently considered one of the most economically important diseases on wheat in the North Central United States. The fungus causes light-weight "tombstone" grains to form and produces the mycotoxin deoxynivalenol (DON), reducing the yield and quality of the grain. Currently, farmers rely heavily on the sterol demethylase Inhibitor (DMI) triazole fungicide Prosaro (Bayer CropScience) to protect their crop from this disease. The optimal fungicide application timing is traditionally believed to be early anthesis - Feekes Growth Stage (FGS) 10.5.1. However, environmental conditions and uneven flowering across a …

Invasive Silver Carp (Hypophthalmichthys Moltrix) Protein Hydrolysates And Their Efficacy In Increasing Seedling Vigor And Reducing Seed Borne Pathogen Growth, Shanleigh Pauline Thomson

Open Access Theses

Silver carp are an invasive fish species introduced into the United States within the last forty years. Unable to be effectively eradicated or commercialized as a source of food, other methods must be developed to control and/or use these fish. Fish protein hydrolysates (FPH) are products derived from the proteins inherent within fish. Development of FPH from Silver carp for a variety of uses could aid in controlling their expanding population and provide organic produces with a seed treatment option which is not available to them currently.

In the first study, FPH were used as a seed vigor treatment for …

Liquid Swine Manure Application Timing And Instincttm Impacts On Net Soil Nitrogen Mineralization And Corn Yield, Min Xu

Open Access Theses

Nitrogen (N) is one of the most expensive variable input costs for corn production. Optimized manure management is essential to ensure maximum crop N utilization and to reduce the risk of N loss. A field study was conducted in central Indiana from 2011-2013 to assess liquid swine ( Sus scrofa L.) manure N availability when applied at different times or co-applied with InstinctTM , a microencapsulated form of nitrapyrin. Soil inorganic N contents, soil N mineralization, corn yield, grain N content, whole plant N concentrations of corn at the V6 growth stage, and ear leaf N concentrations of corn at …

Assessing Positional Accuracy And Correcting Point Data For Digital Soil Mapping At Varying Scales, Minerva J. Dorantes

Open Access Theses

Accuracy, timeliness, and the effect of scale of soil maps are rarely assessed. The recent increase in the use of GIS technologies and modelling software in natural resources and land management, has increased the demand for soil information at a finer resolution worldwide. Most of the world's developing countries rely on soils information at a scale that is too coarse for practical planning, and have obstacles impeding collection of new data, such as civil war and a lack of collection resources. The United States has an exhaustive collection of soils data at a fine scale. However, its location information is …

Using Energy-Efficient Technologies To Produce Bedding Plants And Microgreens In Protected And Controlled Environments, Joshua R. Gerovac

Open Access Theses

Gerovac, Joshua R. M.S., Purdue University, December 2014. Using Energy-Efficient Technologies to Produce Bedding Plants and Microgreens in Protected and Controlled Environments. Major Professor: Roberto G. Lopez. Production of bedding plants in commercial greenhouses (GHs) located in northern latitudes begins in late winter and continues through late spring when low outdoor temperatures generally necessitate active heating to maintain temperatures suitable for growth and development. Meanwhile, year-round production of microgreens using multi-layer systems requires sole-source (SS) photosynthetic lighting for production. Energy used to provide active heating in commercial GHs or SS lighting in multi-layer systems is second only to labor as …

Agronomic And Genetic Characterization Of Aluminum Tolerance In A Recombinant Inbred Population Of Sorghum [Sorghum Bicolor (L.) Moench], Amanda Christine Easterly

Open Access Theses

Acid soils are estimated to cover up to 30% of arable soils globally and lead to significant limitations on agricultural productivity, primarily through aluminum toxicity. In sorghum [Sorghum bicolor (L.) Moench], significant genetic variation exists for tolerance to phytotoxic species of aluminum; tolerance is conferred through the exudation of citrate at the root tip, binding aluminum in the soil rhizosphere. A gene in the multidrug and toxic compound extrusion (MATE) family is the primary tolerance locus in sorghum. The purpose of this research was to evaluate a recombinant inbred line (RIL) population of sorghum segregating for SbMATE to establish …

Managing Swine Manure In Double-Crop Soybean, Donald Joseph Graper

Open Access Theses

Animal production, especially swine (Sus scrofa domesticus ) and poultry, has increased in the United States prompting the need to manage the larger volume of manure beyond land applications to supply nitrogen (N) for corn (Zea mays ) production. Applying swine manure to soybean (Glycine max ) has been shown to increase grain yield due to N supply. The goal of this research was to determine if swine manure applications to double-crop soybean following wheat can limit manure N loading to the soil by extending management options, increase soybean biomass and grain production, and increase N removal …

Spatial And Temporal Distribution Of Fungicides Applied To Creeping Bentgrass, Kurt Ronald Hockemeyer

Open Access Theses

Turf managers often rely on fungicides to limit damage caused by root diseases. Since fungicides do not move basipetally, they are effective only when fungitoxic concentrations are delivered to the rhizosphere. This research focused on the distribution of modern fungicides in verdure, thatch, sand, and roots of creeping bentgrass (Agrostis stolonifera L. var. palustris (Huds.) Farw.) maintained as a putting green. Fungicides (azoxystrobin (methyl (E)-2-[2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl]-3-methoxyacrylate), propiconazole (1,2,4-Triazole, 1-((2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl)methyl), pyraclostrobin (carbamic acid, [2-[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]methoxy-,methyl ester), and thiophanate-methyl (dimethyl 4,4'-o-phenylenebis[3-thioallophanate]) were applied to replicate field plots in a water volume of 815 L ha-1. Plots were sampled over time (0, 3, 7, 10, …

Quality Changes In Hermetically Stored Corn Caused By Fungi And Sitophilus Zeamais, Nda-Agyima Addae-Mensah K

Open Access Theses

Hermetic storage has been shown to be effective in controlling insect pests and maintaining grain quality of dry grains at 13% moisture and below. However, the feasibility and use of hermetic storage for grains at intermediate mid-moisture levels under the influence of the sub-Saharan African weather conditions is relatively unknown. Hermetic storage experiments were conducted on grade 1 "6297 and 6333 VT RIB" hybrid corn under controlled temperature conditions at 10 degrees centigrade and 25 degrees centigrade at target approximate moisture content levels of 11, 15, 18 and 21% wet basis for a total storage period of 6 months. Corn …

Towards The Development Of Ash Varieties Resistant To Emerald Ash Borer, Lindsay Ann Kolich

Open Access Theses

The emerald ash borer (EAB; Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a destructive invasive beetle from Asia which has killed millions of ash trees (Fraxinus spp.) throughout North America. This phloem-feeding borer is capable of killing otherwise healthy trees and colonizes trees as small as saplings - most affected trees die within four years of colonization. Asian ash species (i.e., Manchurian and Chinese) appear to be more resistant to EAB than those native to North America (e.g., green, white, and black ash). In this project we use reciprocal and conspecific grafts of these five ash species to determine the …

Investigation Of Macrophomina Phaseolina On Soybeans From A Regional Perspective, Zachary Forbes Sexton

Open Access Theses

The fungal pathogen, Macrophomina phaseolina, causes the disease charcoal rot (CR), which greatly impacts soybean production. Host resistance to CR is the primary means of managing this disease, yet resistance in commercial soybean cultivars in Maturity Groups (MG) I-III is currently unknown. Thirty (30) and sixty-seven (67) entries to the 2012 Wisconsin (MG I-II) and Indiana (MG II-III) Soybean Variety Trials, respectively, were evaluated for resistance to CR using a cut-stem assay. Disease was characterized as an area under the disease progress curve (AUDPC) based on lesion development and resistance assessed in relation to the resistant check (DT97-4290). In each …

Biochar And Vermicompost Amendments In Vegetable Cropping Systems: Impacts On Soil Quality, Soil-Borne Pathogens And Crop Productivity, Nathan Lee Shoaf

Open Access Theses

Amending soils with biochar and vermicompost has the potential to provide multiple benefits for specialty crops including pathogen suppression and increased crop productivity. Oomycete pathogens such as Phytophthora capsici can devastate crop fields and they are difficult to control presenting significant management challenges for Midwestern growers. Soils amended with a microbially-inoculated softwood biochar increased carrot root growth relative to the control and corn stover biochar in 2011, while the corn stover biochar also increased carrot root growth relative to the control, but only in two varieties. Neither biochar treatment influenced carrot growth in 2012. In greenhouse trials, vermicompost amendments provided …

Application And Timing Effects Of Qoi And Dmi Fungicides And A Foliar Fertilizer On Overall Plant Health And Grain Yield In Corn, Jason Phillip Geis

Open Access Theses

The use of fungicides on corn has recently increased as a result of higher grain market prices, changes in cropping practices, higher disease incidence and severity, and the availability and marketing claims of new fungicides. Some of the marketed potential "plant health(TM)" benefits include improved tolerance to drought and heat, improved N utilization, and increased stalk strength. Previous studies have displayed delayed canopy senescence, changes in water use efficiency, and reduced ozone damage in controlled environments. Foliar fertilization has also increased in popularity in recent years due to an increase in grain prices, manufacturer claims, and product availability.

Large-scale field …

Effects Of Wheat Grain Moisture: Quality, Germination, And Relationship To Accumulated Growing Degree Days, Kirsten Thomas

Open Access Theses

Bread wheat (Triticum aestivum L.) is a cereal crop of global importance. As global demand increases, it is essential to increase the quality and efficiency of crop production. Harvesting wheat early provides an opportunity for increased grain quality, and it may also allow the grower to double-crop soybean ( Glycine max L.) after wheat more effectively. Our objectives were to determine if harvesting grain early, at high moisture would, 1) increase milling and baking quality and 2) improve germination potential. As a result of these objectives, we will develop a model to predict dry-down of wheat. Five soft red …

Quantifying Subsurface Hydrology Effects On Chemical Transport In Agriculture Drainage Ditches Using A 20 Meter Flume, Colton Eugene Yoder

Open Access Theses

Agriculture drainage ditches serve as the veins of the Midwestern agricultural landscapes. The transport of chemical fertilizers and pesticides in these ditches affects both local and downstream ecosystems. Although much research has already been conducted on chemical transport in streams and drainage ditches, as well as through drainage tiles, there has not been sufficient research on the effects of subsurface hydrology on nutrient storage and interactions between the stream water and the hyporheic zone. In this study, a 20-meter flume was filled with ditch sediment from Marshall Ditch at Purdue University's Agronomy Center for Research and Education in West Lafayette, …

Developing White Ash With Resistance To The Emerald Ash Borer, Kaitlin Joy Palla

Open Access Theses

Hypocotyls isolated from mature embryos germinated on Murashige and Skoog (MS) medium supplemented with 22.2 µM 6-benzyladenine (BA) and 0.5 µM thidiazuron (TDZ) were transformed using Agrobacterium tumefaciens strain EHA105 harboring the pBI121-8D2 vector containing the neomycin phosphotransferase (nptII) gene and a full length, codon-optimized Bacillus thuringiensis Cry8Da protoxin gene (cry8D2). Explants were transformed in a bacterial suspension with 100 µM acetosyringone using 90 s sonication and 10 min vacuum-infiltration. Four independent lines of transformed shoots were selectively regenerated on MS medium with 22.2 µM BA, 0.5 µM TDZ, 50 mg L^-1 adenine sulfate, 10% …