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Living Mulch For Sustainable Maize Stover Biomass Harvest, Cynthia A. Bartel, Chumki Banik, Andrew W. Lenssen, Kenneth J. Moore, David A. Laird, Sotirios V. Archontoulis, Kendall R. Lamkey 2017 Iowa State University

Living Mulch For Sustainable Maize Stover Biomass Harvest, Cynthia A. Bartel, Chumki Banik, Andrew W. Lenssen, Kenneth J. Moore, David A. Laird, Sotirios V. Archontoulis, Kendall R. Lamkey

Kendall R Lamkey

The Renewable Fuels Standard mandate provides enhanced opportunity for maize (Zea mays L.) stover use as a bioenergy feedstock. Living mulch (LM) offers a possible solution for the natural resources constraints associated with maize stover biomass harvest. A two site-year study was conducted near Boone and Kanawha, IA, in both maize following maize (MM) and maize following soybean [Glycine max (L.) Merr.] (SM) sequences to evaluate the impact of established and chemically suppressed Kentucky bluegrass (Poa pratensis L.) (KB) ‘Ridgeline’, ‘Wild Horse’, ‘Oasis’, and ‘Mallard’ blend and creeping red fescue (Festuca rubra L.) (CF) ‘Boreal’ as LM on three maize ...


Validation Of A Hairy Roots System To Study Soybean-Soybean Aphid Interactions, Stephanie C. Morriss, Matthew E. Studham, Gregory L. Tylka, Gustavo C. Macintosh 2017 Iowa State University

Validation Of A Hairy Roots System To Study Soybean-Soybean Aphid Interactions, Stephanie C. Morriss, Matthew E. Studham, Gregory L. Tylka, Gustavo C. Macintosh

Gregory Tylka

The soybean aphid (Aphis glycines) is one of the main insect pests of soybean (Glycine max) worldwide. Genomics approaches have provided important data on transcriptome changes, both in the insect and in the plant, in response to the plant-aphid interaction. However, the difficulties to transform soybean and to rear soybean aphid on artificial media have hindered our ability to systematically test the function of genes identified by those analyses as mediators of plant resistance to the insect. An efficient approach to produce transgenic soybean material is the production of transformed hairy roots using Agrobacterium rhizogenes; however, soybean aphids colonize leaves ...


Evaluating The Impact Of Two Contrasting Tillage Practices On Soil Properties In Central Kentucky, Emily Cook 2017 Murray State University

Evaluating The Impact Of Two Contrasting Tillage Practices On Soil Properties In Central Kentucky, Emily Cook

Posters-at-the-Capitol

Farming practices such as no tillage and plowing can institute change on soil physical and chemical characteristics. In this research, the effects of long-term conventional and no-tillage systems on the selected soil properties were determined in a continuous corn system on a farm with Maury silt loam soil. These samples were taken from University of Kentucky's Research Farm (Spindletop Farm). The field used was tilled in 1969 from bluegrass sod and the first time research was conduced was in 1970. Each plot is 20 ft. by 40 ft. and for many years each plot was split with winter cover ...


A Pectin Methylesterase Zmpme3 Is Expressed In Gametophyte Factor1-S (Ga1-S) Silks And Maps To That Locus In Maize (Zea Mays L.), Adrienne N. Moran Lauter, Michael G. Muszynski, Ryan D. Huffman, M. Paul Scott 2017 U.S. Department of Agriculture

A Pectin Methylesterase Zmpme3 Is Expressed In Gametophyte Factor1-S (Ga1-S) Silks And Maps To That Locus In Maize (Zea Mays L.), Adrienne N. Moran Lauter, Michael G. Muszynski, Ryan D. Huffman, M. Paul Scott

M. Paul Scott

The ga1 locus of maize confers unilateral cross incompatibility, preventing cross pollination between females carrying the incompatible Ga1-s allele and males not carrying a corresponding compatible allele. To characterize this system at the molecular level, we carried out a transcript profiling experiment in which silks from near isogenic lines carrying the Ga1-sand ga1 alleles were compared. While several differentially expressed genes were identified, only one mapped to the known location of ga1. This gene is a pectin methylesterase (PME), which we designated as ZmPme3, and is present and expressed only in Ga1-s genotypes. While a functional ZmPME3 is ...


Seed Production In Corn And Soybean, Kendall Lamkey 2017 Iowa State University

Seed Production In Corn And Soybean, Kendall Lamkey

Kendall R Lamkey

Seed production is one of the least visible yet most important aspects of food and feed production. This part of the system is often taken for granted, even by the farmers who plant the seed. One of the reasons is that much of the seed in the United States is provided by the private sector, particularly for corn and soybean. Also, seed production is a technical process that requires in-depth knowledge of the reproductive mechanisms in plants.


Surface Waters: Ammonium Is Not Ammonia – Part 3, John E. Sawyer, Matthew J. Helmers 2017 Iowa State University

Surface Waters: Ammonium Is Not Ammonia – Part 3, John E. Sawyer, Matthew J. Helmers

Matthew J. Helmers

Two previous ICM News articles outlined the difference between ammonium and ammonia, the relationship between the two nitrogen forms, and the implication of a combined (ammonium-N plus ammonia-N) analysis related to water quality criteria for aquatic life and chlorination treatment for drinking water.This article focuses on the potential sourcing of ammonium and ammonia in surface waters. Ammonium and ammonia in surface water systems can originate from many sources, and are naturally occurring forms of nitrogen. Predominant sources will vary on a watershed or sub-watershed basis. Also, sources and concentrations are greatly influenced by hydrology, including timing and volume of ...


What Does It Take To Detect A Change In Soil Carbon Stock? A Regional Comparison Of Minimum Detectable Difference And Experiment Duration In The North Central United States, Magdalena Necpálová, Robert P. Anex Jr., Alexandra N. Kravchenko, Lori J. Abendroth, Stephen J. Del Grosso, Warren A. Dick, Matthew J. Helmers, Daryl E. Herzmann, Joseph G. Lauer, Emerson D. Nafziger, John E. Sawyer, Peter C. Scharf, Jeffrey S. Strock, Maria B. Villamil 2017 University of Wisconsin–Madison

What Does It Take To Detect A Change In Soil Carbon Stock? A Regional Comparison Of Minimum Detectable Difference And Experiment Duration In The North Central United States, Magdalena Necpálová, Robert P. Anex Jr., Alexandra N. Kravchenko, Lori J. Abendroth, Stephen J. Del Grosso, Warren A. Dick, Matthew J. Helmers, Daryl E. Herzmann, Joseph G. Lauer, Emerson D. Nafziger, John E. Sawyer, Peter C. Scharf, Jeffrey S. Strock, Maria B. Villamil

Matthew J. Helmers

Variability in soil organic carbon (SOC) results from natural and human processes interacting across time and space, and leads to large variation in the minimum difference in SOC that can be detected with a particular experimental design. Here we report a unique comparison of minimum detectable differences (MDDs) in SOC, and the estimated times required to observe those MDDs across the north central United States, calculated for the two most common SOC experiments: (1) a comparison between two treatments, e.g., moldboard plow (MP) and no-tillage (NT), using a randomized complete block design experiment; and (2) a comparison of changes ...


Impact Of Liquid Swine Manure Application And Cover Crops On Ground Water Quality, Carl H. Pederson, Rameshwar S. Kanwar, Matthew J. Helmers, Antonio P. Mallarino 2017 Iowa State University

Impact Of Liquid Swine Manure Application And Cover Crops On Ground Water Quality, Carl H. Pederson, Rameshwar S. Kanwar, Matthew J. Helmers, Antonio P. Mallarino

Matthew J. Helmers

The primary design of this project was to determine the impact of appropriate rates of swine manure applications to corn and soybeans based on nitrogen and phosphorus requirements on crop yields, soil phosphorus accumulation, and nitrate and phosphorus leaching to groundwater. Another purpose of this design was to develop and recommend appropriate manure and nutrient management practices to producers to minimize the water contamination potential and enhance the use of swine manure as inorganic fertilizer. A third component was to determine the potential effects of rye as a cover crop to reduce nitrate loss to shallow ground water.


Impact Of Drainage Water Management On Crop Yield, Drainage Volume, And Nitrate Loss, Linda Schott, Matt Helmers, Carl Pederson, Greg Brenneman, Myron Rees 2017 Iowa State University

Impact Of Drainage Water Management On Crop Yield, Drainage Volume, And Nitrate Loss, Linda Schott, Matt Helmers, Carl Pederson, Greg Brenneman, Myron Rees

Matthew J. Helmers

The objectives of this study were to determine the impact of shallow, controlled, conventional, and no drainage on crop yields, subsurface drainage volumes, and nitrate loss through subsurface drainage. This research investigates whether drainage water management reduces nitrate loadings to downstream surface waters.


Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Josh Sievers 2017 Iowa State University

Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Josh Sievers

Matthew J. Helmers

Corn Belt corn and soybean producers are increasingly challenged to maximize crop production while addressing the contributions farm practices make to Gulf hypoxia. Based on the need for nitrate-N reductions to meet water quality goals, new management practices are needed to reduce nitrate-N losses at minimal cost and maximum economic benefits. This three-year field research and demonstration project is evaluating various promising N management methods and technologies by documenting the nitrate-N export and crop yield from various systems.


Heavy Rain, Soil Erosion And Nutrient Losses, Mahdi Al-Kaisi, Matthew J. Helmers 2017 Iowa State University

Heavy Rain, Soil Erosion And Nutrient Losses, Mahdi Al-Kaisi, Matthew J. Helmers

Matthew J. Helmers

As we write this article spring rains are coming hard and fast causing substantial soil erosion when soils are most vulnerable because of degraded crop residue cover, soil preparation by tillage and no crop canopy. The soil profiles in most of Iowa are now filled to capacity with water. The profiles are at or near saturation. Therefore, the intensity and amount of rain we received have exceeded the soil capacity to filter water and minimize surface runoff even in fields with the most adequate conservation practices.


Nation’S Premier Site For Water Quality Drives Progress, Matt J. Helmers 2017 Iowa State University

Nation’S Premier Site For Water Quality Drives Progress, Matt J. Helmers

Matthew J. Helmers

A farm just outside the north-central Iowa town is home to Iowa State University’s Agriculture Drainage Research and Demonstration Site, a facility that has been working to further Iowa State University’s water conservation efforts since 1990. The site was born out of the Iowa Groundwater Protection Act, a piece of legislation passed in 1987 that generated funds from fees on pesticide manufacturing registrations, pesticide dealer licensing and a tax on fertilizer sales. A portion of the funds were used to create the 11-acre research site, with Iowa State University partnering with the Iowa Department of Agriculture and Land ...


Impact Of Liquid Swine Manure Application And Cover Crops On Nitrate In Subsurface Drainage Water, Carl Pederson, Matt Helmers, Michelle Soupir, Ramesh Kanwar, Antonio Mallarino 2017 Iowa State University

Impact Of Liquid Swine Manure Application And Cover Crops On Nitrate In Subsurface Drainage Water, Carl Pederson, Matt Helmers, Michelle Soupir, Ramesh Kanwar, Antonio Mallarino

Matthew J. Helmers

The primary objective of this project was to determine the impact of appropriate rates of swine manure applications to corn and soybeans based on nitrogen requirements of crops and the potential of nitrate leaching to groundwater. Another purpose of this longterm experimental study was to develop and recommend appropriate manure and nutrient management practices to producers to minimize the water contamination potential and enhance the use of swine manure as an organic fertilizer. A third component of this study was to determine the potential effects of rye as a cover crop to reduce nitrate loss to shallow ground water.


Nitrogen Fertilizer Rate Effects On Soil Organic Carbon In Iowa Continuous Corn And Corn-Soybean Systems, Hanna J. Poffenbarger, Daniel W. Barker, Matthew J. Helmers, Fernando E. Miguez, John E. Sawyer, Johan Six, Michael J. Castellano 2017 Iowa State University

Nitrogen Fertilizer Rate Effects On Soil Organic Carbon In Iowa Continuous Corn And Corn-Soybean Systems, Hanna J. Poffenbarger, Daniel W. Barker, Matthew J. Helmers, Fernando E. Miguez, John E. Sawyer, Johan Six, Michael J. Castellano

Matthew J. Helmers

Nitrogen fertilizer rate is a key factor affecting soil organic C (SOC) in corn-based cropping systems. The objective of this study was to determine the change in SOC in response to long-term N rates for continuous corn and corn-soybean cropping systems at two sites in Iowa. Soil samples were collected to a depth of 15 cm in 1999 and again in 2014 after 15 years of corn N rate treatments ranging from 0 to 269 kg ha-1. The soil samples were analyzed for total C and N concentrations. For continuous corn at both sites, the average annual change in ...


A Pectin Methylesterase Zmpme3 Is Expressed In Gametophyte Factor1-S (Ga1-S) Silks And Maps To That Locus In Maize (Zea Mays L.), Adrienne N. Moran Lauter, Michael G. Muszynski, Ryan D. Huffman, M. Paul Scott 2017 U.S. Department of Agriculture

A Pectin Methylesterase Zmpme3 Is Expressed In Gametophyte Factor1-S (Ga1-S) Silks And Maps To That Locus In Maize (Zea Mays L.), Adrienne N. Moran Lauter, Michael G. Muszynski, Ryan D. Huffman, M. Paul Scott

Agronomy Publications

The ga1 locus of maize confers unilateral cross incompatibility, preventing cross pollination between females carrying the incompatible Ga1-s allele and males not carrying a corresponding compatible allele. To characterize this system at the molecular level, we carried out a transcript profiling experiment in which silks from near isogenic lines carrying the Ga1-sand ga1 alleles were compared. While several differentially expressed genes were identified, only one mapped to the known location of ga1. This gene is a pectin methylesterase (PME), which we designated as ZmPme3, and is present and expressed only in Ga1-s genotypes. While a functional ZmPME3 is ...


A Small Cysteine-Rich Protein From The Asian Soybean Rust Fungus, Phakopsora Pachyrhizi, Suppresses Plant Immunity, Mingsheng Qi, Tobias I. Link, Manuel Müller, Daniela Hirschburger, Ramesh N. Pudake, Kerry F. Pedley, Edward Braun, Ralf T. Voegele, Thomas J. Baum, Steven A. Whitham 2017 Iowa State University

A Small Cysteine-Rich Protein From The Asian Soybean Rust Fungus, Phakopsora Pachyrhizi, Suppresses Plant Immunity, Mingsheng Qi, Tobias I. Link, Manuel Müller, Daniela Hirschburger, Ramesh N. Pudake, Kerry F. Pedley, Edward Braun, Ralf T. Voegele, Thomas J. Baum, Steven A. Whitham

Steven Whitham

The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate biotrophic pathogen causing severe soybean disease epidemics. Molecular mechanisms by which P. pachyrhizi and other rust fungi interact with their host plants are poorly understood. The genomes of all rust fungi encode many small, secreted cysteine-rich proteins (SSCRP). While these proteins are thought to function within the host, their roles are completely unknown. Here, we present the characterization of P. pachyrhizi effector candidate 23 (PpEC23), a SSCRP that we show to suppress plant immunity. Furthermore, we show that PpEC23 interacts with soybean transcription factor GmSPL12l and that ...


Substantial Contribution Of Genetic Variation In The Expression Of Transcription Factors To Phenotypic Variation Revealed By Erd-Gwas, Hung-ying Lin, Qiang Liu, Xiao Li, Jinliang Yang, Sanzhen Liu, Yinlian Huang, Michael J. Scanlon, Dan Nettleton, Patrick S. Schnable 2017 Iowa State University

Substantial Contribution Of Genetic Variation In The Expression Of Transcription Factors To Phenotypic Variation Revealed By Erd-Gwas, Hung-Ying Lin, Qiang Liu, Xiao Li, Jinliang Yang, Sanzhen Liu, Yinlian Huang, Michael J. Scanlon, Dan Nettleton, Patrick S. Schnable

Agronomy & Horticulture -- Faculty Publications

Background: There are significant limitations in existing methods for the genome-wide identification of genes whose expression patterns affect traits.

Results: The transcriptomes of five tissues from 27 genetically diverse maize inbred lines were deeply sequenced to identify genes exhibiting high and low levels of expression variation across tissues or genotypes. Transcription factors are enriched among genes with the most variation in expression across tissues, as well as among genes with higher-than-median levels of variation in expression across genotypes. In contrast, transcription factors are depleted among genes whose expression is either highly stable or highly variable across genotypes. We developed a ...


Recurrent Selection To Alter Grain Phytic Acid Concentration And Iron Bioavailability, Alyssa W. Beavers, A. Susana Goggi, Manju B. Reddy, Adrienne Moran Lauter, M. Paul Scott 2017 Michigan State University

Recurrent Selection To Alter Grain Phytic Acid Concentration And Iron Bioavailability, Alyssa W. Beavers, A. Susana Goggi, Manju B. Reddy, Adrienne Moran Lauter, M. Paul Scott

Manju B. Reddy

Iron is an important micronutrient and Fe deficiency is a global health concern. Phytic acid inhibits Fe absorption and cannot be digested by monogastric livestock or humans. High phytate concentration in staple crops may be one of the contributing factors for the high incidence of anemia in developing countries because of its inhibiting effect on Fe absorption. In seeds, it serves as the main storage compound for P. Low phytic acid mutants (lpa) in maize (Zea mays L.) have improved Fe bioavailability, but they have poor germination. Our objective was to develop both low phytic acid (LPA) and high phytic ...


Characterization Of Acaricide Resistance, Plant-Mediated Rnai Against Two-Spotted Spider Mites (Tetranychus Urticae Koch), And Assessing Off- And Non-Target Effects, Hooman Hosseinzadeh Namin 2017 The University of Western Ontario

Characterization Of Acaricide Resistance, Plant-Mediated Rnai Against Two-Spotted Spider Mites (Tetranychus Urticae Koch), And Assessing Off- And Non-Target Effects, Hooman Hosseinzadeh Namin

Electronic Thesis and Dissertation Repository

The two-spotted spider mite (TSSM), Tetranychus urticae (Koch), is one of the most damaging agricultural pests in the world. It feeds on over 150 crops, causing considerable yield losses in greenhouses and agricultural fields. Currently, using synthetic acaricides is the main method to control TSSM. However, it can develop resistance to acaricides with repeated exposure, and typically resistance can occur within two to four years. To understand the underlying mechanisms of spider mite adaptation to acaricides is an essential part of resistance management strategy. The resistance ratio of the pyridaben-selected strain compared with the pre-selection strain was estimated at greater ...


Predicted Gains From Recurrent Selection In The Bs11 Maize Population, P. S. Guzman, K. R. Lamkey 2017 Iowa State University

Predicted Gains From Recurrent Selection In The Bs11 Maize Population, P. S. Guzman, K. R. Lamkey

Kendall R Lamkey

Random genetic drift and inbreeding depression resulting from the use of small effective population size limit the gain of recurrent selection programs. The objectives of our study were to predict the gains of S2, S1, full-sib, and modified-ear-to-row recurrent selection methods in maize (Zea mays L.) with varying effective population sizes of 5, 10, 20, and 30 and to compare these predicted gains with the realized gains obtained in a related study. Using the variance estimates of the BS11C0 population, predicted gain cycle-1 was computed based on single trait selection and index selection. Predicted gain cycle-1 for S1-progeny selection method ...


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