Digital Commons Network^™

Evaluation Of A Cool-Season Grass-White Clover Mixture For Low-Nitrogen Input Lawns, Gabriel Adam Macke

Open Access Theses

Turfgrass lawns require supplemental nitrogen (N) to maintain green color and seasonal shoot density. Improper lawn fertilization with excess N or phosphorus has the potential to contaminate both surface and groundwater. Thus, to reduce the reliance on supplemental N fertilization, alternative strategies or novel turf systems like grass-legume mixtures need explored. White clover ( Trifolium repens L.) is a stoloniferous legume that biologically fixes N from the atmosphere and adds N into the soil via mineralization. The objective of this field study was to evaluate the persistence and feasibility of a cool-season grass-clover lawn mixture. A lawn grass mixture with …

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 …

Cereal Rye Cover Crop Effects On Soil Physical And Chemical Properties In Southeastern Indiana, Joseph D. Rorick

Open Access Theses

Cover crops are growing in popularity in the Midwest, although questions remain about how to include them most effectively in a corn-soybean ( Zea mays L. - Glycine max L.) rotation. This study was conducted to determine the effects of cereal rye ( Secale cereale L.) on soil bulk density and water retention, soil organic carbon, soil nitrogen, and water stable aggregate mean weight diameter after four years of cover crop growth and the effects on soil moisture over a five year period. The study was conducted at the Southeast Purdue Agricultural Center (SEPAC) on silt loam soils. A 14 …

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. …

Genetic Study Of Carotenoids In Maize Grain (Zea Mays L.), Oscar Rafael Espejel Venado

Open Access Theses

Pro-Vitamin A (proVA) carotenoids, which are converted into retinol (Vitamin A) in the human body, have been the subject of human nutrition studies and are a target for biofortification of staple crops. Historically, β-carotene has been the principal target for enhancing levels of proVA, yet there is recent interest in enhancing the proVA carotenoid β-cryptoxanthin. Studies have shown that β-cryptoxanthin has excellent bioavailability, and its use in maize may be nearly as effective as β-carotene in providing retinol. The primary aim of this study was to gain a better understanding of the genetic control of levels of β-cryptoxanthin, conversion of …

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 …

Cover Crop And No-Till Effects On Soil Health Properties In Indiana, Sara Alford

Open Access Theses

A growing concern of soil health and long-term sustainability has increased interest in no-till and cover crops in the Midwest. Some of the challenges with no-till in the Midwest can be higher soil moisture and lower soil temperatures at cash crop planting in the spring, planter adjustment issues, and lack of immediate economic benefit. Cover crops also have some of the same issues along with extra cost of seed and termination, mismanagement of cover crops, and lack of knowledge on the benefits and costs. This project was begun in order to quantify the effects of no-till and cover crops on …

Genetic Analysis Of Tocochromanol Variation In Maize Using High-Density Linkage Mapping, Megan E. Fenton

Open Access Theses

Vitamin E is an essential nutrient in the human diet and refers to eight distinct compounds that are collectively known as tocochromanols. Tocochromanols are grouped into two classes: tocotrienols and tocopherols. Tocochromanols are the major lipid-soluble antioxidants in maize (Zea mays L.) grain. Enhancing the tocochromanol content of maize derived foods through plant breeding has important nutritional and health implications. Chapter one is a literature review that provides a foundational understanding of the biosynthesis, function and genetic control of tocochromanols in plants, with specific attention to maize (Zea mays L.). Upon this foundation two research objectives were developed that work …

Eco-Evolutionary Factors Drive Herbivore-Induced Plant Volatiles, Which Intercept Plant Defense, Elizabeth K. Rowen

Open Access Theses

Herbivore-induced plant volatiles (HIPVs) mediate a wide variety of interactions in ecosystems. However, many volatile compounds are found across plant taxa, and some are exploited to attract natural enemies for biological control. Subtle changes in HIPV blends can produce profound changes in the behavior of predators, parasitoids and herbivores, and may also alter the defensive processes of neighboring plants. I investigated different ecological and evolutionary factors to understand how plant volatile emissions are affected by feeding guild, herbivore diet breadth and domestication. I meta-analyzed 109 studies and found that specialists induce more total volatiles than generalists. Domesticated species have stronger …

Growth Parameters Of 'Golden Delicious' Apple Trees (Malus X Domestica Borkh), Biying Shi

Open Access Theses

High yield and high quality of tree fruit result from appropriate orchard design and management practices. This requires an accurate knowledge of vegetative growth, branching, and flowering processes of fruit trees. Tree development knowledge is the fundamental information necessary to build functional-structural tree models, which have various applications in agriculture. To build such models, information is needed on the distributions of growth parameters, not merely means as are often reported. The objective of this study was to quantitatively analyze shoot development and examine the correlations between fruit quality and light distribution in apple trees. This study was conducted in 2014, …

Application And Implications Of Rule-Based Pruning Of Apple Trees, Jacob B. Franzen

Open Access Theses

Labor is one of the largest operating costs associated with tree fruit production in the United States. Pruning and harvest can easily eclipse over a quarter of an orchard's operating budget. Additionally, labor sources are becoming increasingly difficult to find while worker pay keeps going up. As a result, it appears that labor costs will continue to rise for the foreseeable future. Work on developing mechanized alternatives to pruning is seen as one of the key areas to reduce an orchard's dependence on human labor. The objective of this study was to test a set of simplified pruning rules (RUL), …

Framework For Functional Tree Simulation Applied To 'Golden Delicious' Apple Trees, Marek Fiser

Open Access Theses

This research aims to develop a framework to model realistic and functional trees. Our modular framework is easily controllable and extensible by the user. The framework provides powerful features such as per-leaf light simulation and a source-sink based resources transport model. Our novel 3D reconstruction algorithm generates realistic tree models with a good 3D polygon topology. ^ The second part of this research is a functional model of a Golden Delicious apple tree. We use our simulation framework and data collected in Purdue Meigs farm over the year 2014 to create a realistic data-driven model. The model reacts on temperature …

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 …

Management Of Root Knot Nematode (Meloidogyne Incognita ) In Indiana Soybeans, David Edgardo Perla Martinez

Open Access Theses

The aim of this project was to evaluate different strategies for management of Root Knot Nematode (RKN) on soybean and tomato in Indiana. Seed treatments were evaluated under field and greenhouse conditions, but no effect on RKN populations was observed. Soybean lines evaluated for resistance to RKN under greenhouse conditions showed that six lines may be resistant to RKN. Four different commercial mustard cover crops were evaluated for their bio-fumigant impact on RKN populations in the production of tomato. Euruca sativa, Cv. Nemat was a poor host of RKN. A positive impact on the vigor of the tomato plants followed …

Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer

Open Access Theses

Auxin transport is essential for the architecture and development of erect plants. In a network of transporters directing auxin flows, ATP-Binding Cassette (ABC) transporters are a ubiquitous family of proteins that actively transport important substrates, including auxins, across the plasma membrane. ABCB1 and ABCB19 have been shown to account for the majority of rootward auxin transport, but residual fluxes to the root tip in Arabidopsis b1b19 double mutants implies the involvement of at least one additional auxin transporter in this process. Of specific interest, the severe dwarfism seen in abcb1abcb19 is strikingly reminiscent of that seen in mutants defective in …

Ems Induced Mutations In Dhurrin Metabolism And Their Impacts On Sorghum Growth And Development, Jenae Lavon Skelton

Open Access Theses

Sorghum is the fifth most important grain crop in the world. It is a staple food, feed, and silage crop in many developing countries in the semi-arid tropics. One factor that can impact sorghum forage quality is dhurrin content. Dhurrin is a cyanogenic glucoside naturally produced in the plant. When tissues containing dhurrin are crushed, hydrogen cyanide (HCN) is released during dhurrin decomposition. HCN is toxic to humans and livestock. While there is natural genetic diversity for the concentration of dhurrin within sorghum lines, there have been no naturally occurring dhurrin-free genotypes identified to date. ^ We have identified ethyl …

Refining Phylogenetic Hypotheses Using Chloroplast Genomics And Incomplete Data Sets In Lasthenia (Madieae, Asteraceae), Joseph Frederic Walker

Open Access Theses

The genus Lasthenia (Madieae, Asteraceae), consists of predominantly annual plant species that are largely endemic to the California Floristic Province of western North America and occupy a large range of habitat types. With high levels of morphological and ecological diversity, Lasthenia is a robust tool, capable of providing a natural non-model organism for answering a diverse array of ecological and evolutionary questions. Future studies would benefit greatly from a strong phylogenetic hypothesis and more molecular resources, such as the whole plastome sequence for a representative species in the genus. Over a decade ago there was a study that laid a …

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 …