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2016

Maize

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Full-Text Articles in Life Sciences

Physiological Aspects Of Relative Changes In Nitrogen And Plant Density Stress Tolerances Over A 38-Year Period Of Us Maize Hybrid Introductions, Keru Chen Dec 2016

Physiological Aspects Of Relative Changes In Nitrogen And Plant Density Stress Tolerances Over A 38-Year Period Of Us Maize Hybrid Introductions, Keru Chen

Open Access Dissertations

Incremental gains in grain yield of maize hybrids over the decades are the consequence of genotype, environment and management interactions. Historically, genetic improvements in newer hybrids have included longer active grain filling periods (achieved by advancing silking and extending functional stay green in maize leaves); stronger source and sink during grain filling; enhanced tolerance to higher density; and canopy architecture changes. Newer hybrids were known to accumulate more dry matter and nitrogen in the post-silking period, but achieving a more comprehensive knowledge of pre-silking and post-silking dynamics required further understanding of dry matter and nitrogen partitioning in individual organs, as …


Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis Nov 2016

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis

John E. Sawyer

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) compare crop …


Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Ranae Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter J. Thorburn, Sotirios V. Archontoulis Nov 2016

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Ranae Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter J. Thorburn, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) …


Lessons From The Far End: Caterpillar Frass-Induced Defenses In Maize, Rice, Cabbage, And Tomato, Swayamjit Ray, Saumik Basu, Loren J. Rivera-Vega, Flor E. Acevedo, Joe Louis, Gary W. Felton, Dawn S. Luthe Oct 2016

Lessons From The Far End: Caterpillar Frass-Induced Defenses In Maize, Rice, Cabbage, And Tomato, Swayamjit Ray, Saumik Basu, Loren J. Rivera-Vega, Flor E. Acevedo, Joe Louis, Gary W. Felton, Dawn S. Luthe

Department of Entomology: Faculty Publications

Plant defenses to insect herbivores have been studied in response to several insect behaviors on plants such as feeding, crawling, and oviposition. However, we have only scratched the surface about how insect feces induce plant defenses. In this study, we measured frass-induced plant defenses in maize, rice, cabbage, and tomato by chewing herbivores such as European corn borer (ECB), fall armyworm (FAW), cabbage looper (CL), and tomato fruit worm (TFW). We observed that caterpillar frass induced plant defenses are specific to each host-herbivore system, and they may induce herbivore or pathogen defense responses in the host plant depending on the …


From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza Jul 2016

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and …


More Crop Per Drop: Benchmarking On-Farm Irrigation Water Use For Crop Production., Katherine Elizabeth Boone Gibson Jul 2016

More Crop Per Drop: Benchmarking On-Farm Irrigation Water Use For Crop Production., Katherine Elizabeth Boone Gibson

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

Efficient use of irrigation is essential to meet food production needs of growing global populations while ensuring long-term sustainability of freshwater resources. However, lack of on-farm irrigation data constrains understanding of irrigation variation and no framework exists to benchmark irrigation use using actual irrigation data. The following work investigates variation in irrigation using a database of ca. 1400 maize and soybean fields over 9 years in Nebraska and presents a framework to benchmark irrigation use using a separate database of ca. 1000 maize and soybean fields in Nebraska as proof of concept. “State-of-the-art” crop models estimated yield potential and irrigation …


Irrigated And Rainfed Crops Zea Mays L. (Maize) And Glycine Max (Soybean) Acting As A Source Or Sink For Atmospheric Warming At Mead, Nebraska, Jane A. Okalebo Dr., Kenneth G. Hubbard, Andy Suyker May 2016

Irrigated And Rainfed Crops Zea Mays L. (Maize) And Glycine Max (Soybean) Acting As A Source Or Sink For Atmospheric Warming At Mead, Nebraska, Jane A. Okalebo Dr., Kenneth G. Hubbard, Andy Suyker

Conference on Applied Statistics in Agriculture

Land Use and Land Cover Change (LULCC) influence the climate at a global and local scale. Using long term microclimate data (2002-2009, 2011-2012) from the Carbon Sequestration Project (CSP), Mead, NE, this study examines how crop selection and water management can mitigate heat in the atmosphere. Mitigation of global warming is dependent on the management of crop lands, and the amount and timing of rainfall during the growing season. Rainfed crops were found to heat the passing air. The irrigated maize crop was able to mitigate 20 to 62% of the sensible heat (H) compared to the rainfed maize counterpart, …


The Politics Of Maize In Zambia: Who Holds The Keys To Change The Status Quo?, Antony Chapoto, Olipa Zulu-Mbata, Barak D. Hoffman, Chance Kabaghe, Nicholas J. Sitko, Auckland Kuteya, Ballard Zulu Jan 2016

The Politics Of Maize In Zambia: Who Holds The Keys To Change The Status Quo?, Antony Chapoto, Olipa Zulu-Mbata, Barak D. Hoffman, Chance Kabaghe, Nicholas J. Sitko, Auckland Kuteya, Ballard Zulu

Zambia Social Science Journal

As both the national staple food and primary smallholder crop, maize occupies a central position in Zambia’s agricultural political economy. Despite the government’s large subsidies, maize productivity levels remain way below global averages, maize commercialisation in the smallholder sector remains highly concentrated, maize meal prices are highly volatile, and rural poverty remains high. This study uses a political economy framework to better understand the policy-making process, power structures and dynamics involved in the maize sector in order to get a better understanding of who holds the keys to change, and how to influence agricultural policy changes. Net-Map procedure was used …


Agrobacterium-Mediated Transformation Of Five Inbred Maize Lines With The Brittle 2 Gene, Thuy Ninh Nguyen, Thi Luong Tran, Duc Thanh Nguyen Jan 2016

Agrobacterium-Mediated Transformation Of Five Inbred Maize Lines With The Brittle 2 Gene, Thuy Ninh Nguyen, Thi Luong Tran, Duc Thanh Nguyen

Turkish Journal of Biology

The Brittle 2 (Bt2) gene encodes a small subunit of ADP-glucose pyrophosphorylase (AGPase) enzyme, one of the enzymes that play an important role in endosperm starch biosynthesis. We carried out a study to transfer the Bt2 gene into several inbred maize lines and regenerate transgenic maize plants possessing the transgene, which can be used to further study the role of the Bt2 gene in starch biosynthesis. Agrobacterium tumefaciens strains C58 and EHA105 harboring the transformation vector pCambia2300/Ubi-Bt2-Nos were used to transfer the Bt2 gene into five inbred maize lines, H14, H26, H240, H95, and N18. Transformed calli were selected on …


Morphologic And Transcriptomic Response To Weed Pressure In Multiple Maize (Zea Mays L.) Selections And Teosinte (Zea Mays L. Ssp Parviglumis) Lines, Stephanie A. Bruggeman Jan 2016

Morphologic And Transcriptomic Response To Weed Pressure In Multiple Maize (Zea Mays L.) Selections And Teosinte (Zea Mays L. Ssp Parviglumis) Lines, Stephanie A. Bruggeman

Electronic Theses and Dissertations

Sweet corn (Zea mays L. convar. saccharata var. rugosa) and modern dent variants (field maize, Zea mays L. indentata) have varying degrees of weed tolerance (ability to maintain yield under weed stress). Maize retains ~30% of its ancestral teosinte’s (Zea mays ssp parviglumis) genetic base. Transcriptomic response to weed pressure in maize and teosinte can lead to manipulation of the maize genome to minimize crop yield loss due to weed presence. In maize and teosinte under weed-free and weedstressed conditions, the objectives of this study were: 1) to evaluate transcriptomic responses of 2 teosinte lines; 2) …


Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding Jan 2016

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …


Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez Jan 2016

Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez

Department of Agronomy and Horticulture: Faculty Publications

It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize–soybean rotation offers multiple potential benefits that can reduce the impacts of higher temperatures and more variable rainfall; some of the anticipated changes for the Midwest. In this experiment we used the Agricultural Production Systems sIMulator (APSIM) to understand how winter rye cover crops impact crop production and environmental outcomes, given future climate change. We first tested APSIM …


Impact Of Derived Global Weather Data On Simulated Crop Yields, Justin Van Wart, Patricio Grassini, Kenneth Cassman Jan 2016

Impact Of Derived Global Weather Data On Simulated Crop Yields, Justin Van Wart, Patricio Grassini, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study’s objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve …


Improving Nitrogen-Use And Radiation-Use Efficiencies Of C4 Summer Cerealsby Split Nitrogen Applications Under An Irrigated Arid Environment, Shakeel Ahmad, Hakoomat Ali, Umair Farooq, Shahzad Usman Khan, Atique-Ur Rehman, Naeem Sarwar, Ahmad Naeem Shahzad, Hülya Doğan, Shabbir Hussain, Muhammad Tauseef Sultan, Abdul Waheed, Muhammad Zia Ul Haq, Khadim Hussain, Muhammad Azam Khan Jan 2016

Improving Nitrogen-Use And Radiation-Use Efficiencies Of C4 Summer Cerealsby Split Nitrogen Applications Under An Irrigated Arid Environment, Shakeel Ahmad, Hakoomat Ali, Umair Farooq, Shahzad Usman Khan, Atique-Ur Rehman, Naeem Sarwar, Ahmad Naeem Shahzad, Hülya Doğan, Shabbir Hussain, Muhammad Tauseef Sultan, Abdul Waheed, Muhammad Zia Ul Haq, Khadim Hussain, Muhammad Azam Khan

Turkish Journal of Agriculture and Forestry

Increasing resource-use efficiency is of prime importance in sustainable agriculture. A field study was carried out to improve nitrogen-use efficiency (NUE) and radiation-use efficiency (RUE) of three C4 summer cereals, i.e. Maize, millet, and sorghum, under an irrigated arid environment. The results showed that among various cultivars of cereals, cultivars Pearl (maize), 18 BY (millet), and Jumbo (sorghum) produced the highest aboveground total dry matters and grain yields. The highest NUE and RUE were obtained by splitting the nitrogen dose 3 times, i.e. At sowing and at first and second irrigation. The NUE for maize, millet, and sorghum varied from …


Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding Jan 2016

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …


Irrigated Zea Mays Response To Nitrogen And High Plant Population Density In Narrow Rows, Julie Baniszewski Jan 2016

Irrigated Zea Mays Response To Nitrogen And High Plant Population Density In Narrow Rows, Julie Baniszewski

Theses and Dissertations--Plant and Soil Sciences

Modern genetics have improved maize hybrids to better tolerate stress, use nutrients more efficiently and potentially yield higher. Management practices, such as narrow row technology and high plant population density (PPD) may further improve yields in modern maize under irrigated, non-limiting conditions. High PPD (74, 99, 124, 148 K seeds ha-1) were tested in narrow rows with up to four nitrogen (N) rates in three locations over two years in Kentucky with a modern maize hybrid in irrigated, non-limiting conditions. Results indicate that optimal seeding rates were 99,000 to 124,000 seeds ha-1, providing maximum yield and …


Regional Variations Of Optimal Sowing Dates Of Maize For The Southwestern U.S., Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos Jan 2016

Regional Variations Of Optimal Sowing Dates Of Maize For The Southwestern U.S., Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Sowing date (SD) is sensitive to regional climate characteristics; thus, it is critical to systematically examine the effects of SD on crop yields for various temperature regimes. We performed a sensitivity study of SD for maize in the southwestern U.S. using the regionally extended version of the Agricultural Production Systems sIMulator (APSIM) model. The model was run utilizing North American Regional Reanalysis at a 32 km resolution from 1991 to 2011, with an irrigation threshold at 95% of the soil water-holding capacity. Two types of SD optimizations maximizing yield potential (Yp), varying spatially or interannually, revealed that the optimal SD …