Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 84

Full-Text Articles in Entire DC Network

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Sep 2019

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Agronomy Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset containing ...


A Statistical Analysis Of Zea Mays Grain Yield Response To Nitrification-Inhibitor Amendments Under Field Conditions Utilizing Parametric And Non-Parametric Techniques, Elliot H. Sully Jan 2019

A Statistical Analysis Of Zea Mays Grain Yield Response To Nitrification-Inhibitor Amendments Under Field Conditions Utilizing Parametric And Non-Parametric Techniques, Elliot H. Sully

Graduate Theses and Dissertations

Nitrification is a matter of economic and ecological importance in nitrogen-tensive agricultural practices such as corn (Zea mays) grain production. When ammonium is bacterially oxidized into nitrate it becomes more susceptible to leaching and denitrification as nitrous oxide. The nitrification process not only adds to water and air pollution but also impacts on farm productivity by reducing grains yields and increasing fertilizer demands. Nitrification inhibiting fertilizer amendments can potentially improve grain yields by retarding the growth of nitrifying soil bacteria. Multiple field studies conducted across various locations and timespans have generated mixed results regarding the grain yield difference attributed to ...


Uhf Band Attenuation Through A Corn Canopy With Crop Growth, Richard Jay Cirone Jan 2019

Uhf Band Attenuation Through A Corn Canopy With Crop Growth, Richard Jay Cirone

Graduate Theses and Dissertations

Soil moisture and vegetation remote sensing measurements can be inaccurate and/or misinterpreted in the US Corn Belt, specifically when considering seasonal variation in standing vegetation. A direct crop water measurement method was employed to assist in correction of satellite measurements, specifically to SMOS and SMAP. A 433 MHz radio link was installed in a central Iowa cornfield, shortly after planting, across a distance of 50 meters, for the purpose of measuring attenuation by crop water. This experiment ran until mid grain fill, development stage R3. Vegetation water column density increased from essentially 0 at planting to just above 4 ...


Comparing The Effect Of Cropping Sequence, Planting Date And Seed Treatment On Seedling Diseases Of Corn Caused By Pythium Species, Rebecca K. Vittetoe Jan 2019

Comparing The Effect Of Cropping Sequence, Planting Date And Seed Treatment On Seedling Diseases Of Corn Caused By Pythium Species, Rebecca K. Vittetoe

Creative Components

Pythium species (spp.) are one of the major pathogens known to cause seedling diseases in corn in Iowa. Fungicide seed treatments can help provide protection for a window of time. Not all fungicide seed treatment active ingredients are effective against Pythium. Active ingredients that specifically target Pythium include metalaxyl, mefenoxam, ethaboxam, and picarbutrazox. Trials were established in 2017 and 2018 to examine the effect environmental conditions at planting, seed treatments, and previous crop residues (corn (Zea mays L.), soybean (Glycine max L.), and winter rye (Secale cereal L.) have on early corn stand establishment, plant vigor (2018 only), seedling diseases ...


A Systems Modeling Approach To Forecast Corn Economic Optimum Nitrogen Rate, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Peter J. Thorburn, Michael J. Castellano, Kenneth J. Moore, Andy Vanloocke, Emily A. Heaton, Sotirios V. Archontoulis Apr 2018

A Systems Modeling Approach To Forecast Corn Economic Optimum Nitrogen Rate, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Peter J. Thorburn, Michael J. Castellano, Kenneth J. Moore, Andy Vanloocke, Emily A. Heaton, Sotirios V. Archontoulis

Agronomy Publications

Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the ...


Foliar Fertilization Of Corn In Northeast Iowa, Jay Matthews Jan 2018

Foliar Fertilization Of Corn In Northeast Iowa, Jay Matthews

Creative Components

Corn (Zea mays L.) is one of the most widely grown crops in the world and is the largest crop grown in Iowa. In contrast to research on foliar fertilization of soybean (Glycine max L. Merr.), research on foliar fertilization for corn with macronutrients and secondary nutrients has been scarce in Iowa and the upper Midwest region. As corn yields have continued to increase growers have questioned the capacity of the soil to provide all the nutrients needed to maximize corn yield. One solution that has been offered is the application of a foliar fertilizer. As new foliar fertilizer products ...


Utilization Of Polyanhydride Nanoparticle Encapsulated Fungicide Seed Treatments Against Seedborne And Soilborne Fusarium Graminearum On Maize, Lauren Alicia Washington Jan 2017

Utilization Of Polyanhydride Nanoparticle Encapsulated Fungicide Seed Treatments Against Seedborne And Soilborne Fusarium Graminearum On Maize, Lauren Alicia Washington

Graduate Theses and Dissertations

Fusarium graminearum is a soilborne and seedborne fungus that can cause significant losses on maize through a variety of different diseases, including seedling blight. Seedling blight is usually managed by utilizing fungicide seed treatments, but unfavorable germination environments and high levels of inoculum can still cause significant losses. Therefore, improved seed treatment efficacy is needed. Amphiphilic polyanhydride nanoparticles (PAN) have been used to enhance efficacy and provide sustained release of several active ingredients in animal systems and have potential for use in crop production.

To assess the potential benefits of PANs in seed treatment formulations, we performed two types of ...


Targeted Subfield Switchgrass Integration Could Improve The Farm Economy, Water Quality, And Bioenergy Feedstock Production, Elke Brandes, Gabe S. Mcnunn, Lisa A. Schulte, David J. Muth, Andy Vanloocke, Emily A. Heaton Jan 2017

Targeted Subfield Switchgrass Integration Could Improve The Farm Economy, Water Quality, And Bioenergy Feedstock Production, Elke Brandes, Gabe S. Mcnunn, Lisa A. Schulte, David J. Muth, Andy Vanloocke, Emily A. Heaton

Agronomy Publications

Progress on reducing nutrient loss from annual croplands has been hampered by perceived conflicts between short-term profitability and long-term stewardship, but these may be overcome through strategic integration of perennial crops. Perennial biomass crops like switchgrass can mitigate nitrate-nitrogen (NO3-N) leaching, address bioenergy feedstock targets, and – as a lower-cost management alternative to annual crops (i.e., corn, soybeans) – may also improve farm profitability. We analyzed publicly available environmental, agronomic, and economic data with two integrated models: a subfield agroecosystem management model, Landscape Environmental Assessment Framework (LEAF), and a process-based biogeochemical model, DeNitrification-DeComposition (DNDC). We constructed a factorial combination of profitability ...


Nitrogen Pools And Fluxes In Diversified Cropping Systems, William Robert Osterholz Jan 2016

Nitrogen Pools And Fluxes In Diversified Cropping Systems, William Robert Osterholz

Graduate Theses and Dissertations

Achieving high crop yields requires a large supply of plant available nitrogen (N), yet losses of inorganic N from agriculture are deleterious to environmental quality. A significant portion of agricultural N losses could be prevented if large soil inorganic N pools were not needed to satisfy crop N demand. Alternative N management strategies that consider N fluxes like gross N mineralization in addition to N pools should be investigated, as they could conceivably reduce the size of soil inorganic N pools while still providing sufficient N for crop production. Diversified cropping systems may be able to utilize such alternative N ...


Rye Cover Crop Biomass, Nutrient Composition And Crop Management Practices To Enhance Corn Yield, Swetabh Patel Jan 2016

Rye Cover Crop Biomass, Nutrient Composition And Crop Management Practices To Enhance Corn Yield, Swetabh Patel

Graduate Theses and Dissertations

Winter cereal rye (Secale cereal L.), a commonly used cover crop in corn (Zea mays L.) systems has potential to scavenge soil NO3–N through a fibrous root system. The objective of this study was to quantify root and shoot biomass, C, and N partitioning in rye cover crop at the time of termination in spring. This was a one–year study conducted at a site with a no-till corn–soybean [Glycine max (L.) Merr.] rotation, rye drilled following grain crop harvest, and three N rates applied to corn (0, 135, and 225 kg N ha–1). Rye root biomass ...


Cover Crop Options And Mixes For Upper Midwest Corn-Soybean Systems, Seth R. Appelgate Jan 2016

Cover Crop Options And Mixes For Upper Midwest Corn-Soybean Systems, Seth R. Appelgate

Graduate Theses and Dissertations

The implementation of cover crops in Iowa has the potential to decrease soil erosion, weed density, and nitrate leaching while increasing soil organic carbon. This study investigated nine potential cover crops; winter rye (Secale cereale L.), winter triticale (Triticale hexaploide Lart.), two winter canola (Brassica napus L.) varieties, winter camelina [Camelina sativa (L.) Crantz], spring barley (Hordeum vulgare L.), spring oat (Avena sativa L.), purple top turnip (Brassica rapa L.), and hairy vetch (Vicia villosa Roth). Cover crops were planted as sole crops and selected binary and trinary mixtures. A control treatment of no cover crop was included. Cover crops ...


Candidate Perennial Bioenergy Grasses Have A Higher Albedo Than Annual Row Crops, Jesse N. Miller, Andy Vanloocke, Nuria Gomez-Casanovas, Carl J. Bernacchi Jan 2016

Candidate Perennial Bioenergy Grasses Have A Higher Albedo Than Annual Row Crops, Jesse N. Miller, Andy Vanloocke, Nuria Gomez-Casanovas, Carl J. Bernacchi

Agronomy Publications

The production of perennial cellulosic feedstocks for bioenergy presents the potential to diversify regional economies and the national energy supply, while also serving as climate ‘regulators’ due to a number of biogeochemical and biogeophysical differences relative to row crops. Numerous observational and model-based approaches have investigated biogeochemical trade-offs, such as increased carbon sequestration and increased water use, associated with growing cellulosic feedstocks. A less understood aspect is the biogeophysical changes associated with the difference in albedo (a), which could alter the local energy balance and cause local to regional cooling several times larger than that associated with offsetting carbon. Here ...


Emerging Issues In The U.S. Corn Belt: Infection Of Corn By Clavibacter Michiganensis Subsp. Nebraskensis And Use Of Foliar Fungicides To Protect Yield, Salome Mallowa Obura Jan 2015

Emerging Issues In The U.S. Corn Belt: Infection Of Corn By Clavibacter Michiganensis Subsp. Nebraskensis And Use Of Foliar Fungicides To Protect Yield, Salome Mallowa Obura

Graduate Theses and Dissertations

Currently two major issues pertaining to disease management in corn production in the US Corn Belt are the spread of Goss's wilt and leaf blight caused by Clavibacter michiganensis subsp. nebraskensis (Cmn), and the use of foliar fungicides on corn for `plant health' benefits. This dissertation presents data regarding infection of corn by Cmn, and fungicide effects on disease management and yield.

Greenhouse and laboratory research was undertaken to determine if infection of corn by Cmn may occur without severe wounding, such as that caused by hail, sand blasting or wind damage. Corn plants with no obvious wounding were ...


Biosynthetically Produced Amino Acid Byproducts Can Replace Nitrogen Fertilizers For Corn Production, Juan Carlos Quezada Rivera Jan 2015

Biosynthetically Produced Amino Acid Byproducts Can Replace Nitrogen Fertilizers For Corn Production, Juan Carlos Quezada Rivera

Graduate Theses and Dissertations

Commercial biosynthesis of the amino acids tryptophan (TRP) and lysine (LYS) results in byproducts that are rich in both organic and inorganic compounds. Their nitrogen (N) content may have value as fertilizer N replacement in corn (Zea mays L.) production. We conducted a two-year field study where soil applied pure TRP, its biosynthesis byproduct and LYS byproduct were evaluated as replacements for synthetic N fertilizers in corn production. In-season plant measurements leaf area index , normalized difference vegetation index, grain quality (grain protein and oil concentration) and total N accumulation were not affected by N treatments. Additionally, TRP and LYS biosynthesis ...


Winter Rye Cover Crop Effect On Corn Seedling Pathogens, Lara Ann Schenck Jan 2015

Winter Rye Cover Crop Effect On Corn Seedling Pathogens, Lara Ann Schenck

Graduate Theses and Dissertations

Cover crops are a valuable management tool to reduce soil and nutrient losses while retaining moisture, improving soil organic matter content, and stabilizing soil N during the winter months when the ground is normally left fallow. Cereal rye (Secale cereale L.) is commonly used as a winter cover crop in the Midwest due to its ability to withstand cold temperatures, reduce soil erosion, and scavenge soil N. However, it has been found that a cereal rye cover crop can sometimes reduce performance and yields in the following corn (Zea mays) crop. Past studies have suggested that reduced corn growth and ...


Plant Tissue Analysis To Assess Phosphorus And Potassium Nutritional Status Of Corn And Soybean In Iowa, Andrew John Stammer Jan 2015

Plant Tissue Analysis To Assess Phosphorus And Potassium Nutritional Status Of Corn And Soybean In Iowa, Andrew John Stammer

Graduate Theses and Dissertations

Interest in re-evaluating the value of tissue testing to assess P and K status in corn (Zea mays L.) and soybean (Glycine max L. Merr.) is increasing. The objective of this research was to study relationships between grain yield response to P and K and the concentration of these nutrients in plant tissue. Single-year and multi-year response trials were conducted in Iowa at 30 sites for P (32 sites-years with corn and 34 with soybean) and at 53 for K (67 sites years with corn and 52 with soybean) that encompassed 17 soil series. We sampled above-ground plant parts at ...


Active Sensor Strategies For In-Season Application Of Urea In Corn, Daniel W. Barker, John E. Sawyer Jan 2014

Active Sensor Strategies For In-Season Application Of Urea In Corn, Daniel W. Barker, John E. Sawyer

Agronomy Conference Proceedings and Presentations

Addition of N fertilizer during the midvegetative corn (Zea Mays L.) stage is being used in Iowa to protect yield potential. The objective of this experiment was to compare pre-plant and in-season N application strategies, and evaluate N use efficiency and grain yield of sensor-based N rate application.


Evaluation Of Optical Canopy Sensors For In-Season N Rate Management In Corn, Daniel W. Barker, John E. Sawyer Jan 2014

Evaluation Of Optical Canopy Sensors For In-Season N Rate Management In Corn, Daniel W. Barker, John E. Sawyer

Agronomy Conference Proceedings and Presentations

Optical canopy sensors are an emerging technology that can serve as a useful in-season N fertilizer management tool for corn (Zea mays L.) production. The sensors provide an estimate of plant biomass and N status at the time of sensing. These growth parameters can be used to make in-season N rate adjustments and variable rate N applications. Currently, a robust and accurate algorithm to determine the appropriate N rate based on canopy sensing is need in order to improve the effectiveness of active sensors in production fields. The objective of this study is to determine the ability of optical canopy ...


A Comparison Of Carbon Storage Potential In Corn- And Prairie-Based Agroecosystems, Ranae Dietzel Jan 2014

A Comparison Of Carbon Storage Potential In Corn- And Prairie-Based Agroecosystems, Ranae Dietzel

Graduate Theses and Dissertations

Increasing carbon (C) in the soil is important both for removing harmful C from the atmosphere and improving the health of the soil. In this dissertation, I set out to examine how planting and harvesting prairies on soils suitable for corn affected soil C storage potential when compared to corn-based systems. I addressed three questions designed to a) improve our understanding of the fundamental differences between how prairies and corn grow throughout the year, b) test how prairies and corn add C to the soil after establishment, and c) use our current understanding of prairie and corn growth and C ...


Optimizing Nitrogen Fertilizer Application In Corn Using Green Technology, Daniel W. Barker, John E. Sawyer Jan 2014

Optimizing Nitrogen Fertilizer Application In Corn Using Green Technology, Daniel W. Barker, John E. Sawyer

Agronomy Conference Proceedings and Presentations

The utilization of active canopy sensors in corn (Zea Mays L.) for in-season N fertilizer management has the potential to maintain optimal production and conserve fertilizer N resources. Canopy sensors can be considered a green technology in production agriculture by attempting equitable land stewardship and providing an economically viable N management practice. Robust and accurate algorithms to determine an appropriate N application rate based on canopy sensing is needed in order to effectively utilize sensors in Iowa production fields. The objective of this study was to develop N rate algorithms using active canopy sensors which can prescribe in-season N application ...


Emerging Issues In Integrated Pest Management Implementation And Adoption In The North Central Usa, Thomas W. Sappington Jan 2014

Emerging Issues In Integrated Pest Management Implementation And Adoption In The North Central Usa, Thomas W. Sappington

Entomology Publications

There is a long tradition of integrated pest management (IPM) in the North Central region of the USA. IPM is difficult to define precisely, and it means different things to different people. But in general it is a philosophy based on multiple tactics to prevent a population from building up to unacceptable damaging levels. If preventive tactics are determined or projected to be inadequate, then a rescue tactic is applied. There are a number of constraints on adoption of IPM by growers. The growth in farm size has put a premium on efficiency, whereas IPM can demand extra effort and ...


The Effects Of Starter Fertilizer On Root And Shoot Growth Of Corn Hybrids And Seeding Rates And Plant-To-Plant Variability In Growth And Grain Yield, Warren Pierson Jan 2013

The Effects Of Starter Fertilizer On Root And Shoot Growth Of Corn Hybrids And Seeding Rates And Plant-To-Plant Variability In Growth And Grain Yield, Warren Pierson

Graduate Theses and Dissertations

Starter fertilizer often increases early-season growth of corn; however, yield responses have varied. Yield responses often occur on soils with low soil fertility, however, have occurred on soils with high fertility. Currently, farmers are attempting to reduce plant-to-plant variability in growth and development to maximize grain yield. Farmers have asked if placing starter fertilizer near the seed could reduce plant-to-plant variability with the hypothesis that uniform fertility will result in uniform plants. We conducted two experiments near Ames, Iowa, and Nashua, Iowa with similar treatments and data collection. Starter fertilizer was banded 5 cm below the seed and 5 cm ...


Evaluation And Prediction Of Corn Stover Biomass And Composition From Commercially Available Corn Hybrids, Ty Jason Barten Jan 2013

Evaluation And Prediction Of Corn Stover Biomass And Composition From Commercially Available Corn Hybrids, Ty Jason Barten

Graduate Theses and Dissertations

ABSTRACT

High consumption of imported energy in the United States and other countries has increased the interest in bio-renewable sources of energy. This interest has fueled research into crop residues as one potential alternative fuel source. At issue is how to balance economic viability with the sustainability of the endeavor.

The objective of this project was two-fold. The first objective was to quantify the amount and distribution of dry matter, moisture, fiber, and minerals in corn stover from a number of corn hybrids, grown at varying population densities. In this multi-year study we found that of the stover material remaining ...


Corn Yield Variability On The Des Moines Lobe Of Iowa: Assessment Of Extent And Soil-Related Causes, Matthew Thomas Streeter Jan 2013

Corn Yield Variability On The Des Moines Lobe Of Iowa: Assessment Of Extent And Soil-Related Causes, Matthew Thomas Streeter

Graduate Theses and Dissertations

Precision agriculture techniques are an essential component to modern row crop agriculture in Iowa and can be used to create crop yield variability maps via geographic information systems. The first objective of this thesis was to explore the methodology that could be used to locate significant long-term corn yield variability on the Iowa Des Moines Lobe. A 158-ha site, consisting mainly of Clarion, Nicollet and Webster soil map units and containing multiple years of geo-referenced corn (Zea mays) yield data was selected. A cluster analysis tool was performed to locate spatially consistent corn yield variability (high, low and mean yield ...


Effects Of Deterioration Parameters On Storage Of Maize: A Review, Rashad A. Suleiman, Kurt A. Rosentrater, Carl J. Bern Jan 2013

Effects Of Deterioration Parameters On Storage Of Maize: A Review, Rashad A. Suleiman, Kurt A. Rosentrater, Carl J. Bern

Agricultural and Biosystems Engineering Publications

Maize (Zea mays L), commonly known as corn in the United States, is the third most important cereal grain worldwide, after wheat and rice. It is a basic staple grain for large groups of people in Africa, Latin America, and Asia. In tropical countries, a large proportion of the maize is harvested and stored under humid and warm climatic conditions, which subsequently results in rapid deterioration of the grains, mainly because of growth of molds and pests. This study reviewed the main factors that lead to deterioration of maize in tropical countries and suggests ways of preventing the identified causes ...


Current Challenges In Managing Corn Rootworm, Erin W. Hodgson, Aaron J. Gassmann Nov 2012

Current Challenges In Managing Corn Rootworm, Erin W. Hodgson, Aaron J. Gassmann

Agriculture and Environment Extension Publications

Corn rootworm is a major pest of corn in the United States. In the last decade, Iowa farmers have seen many changes for managing corn rootworm. With the commercial release of transgenic Bt-rootworm corn in 2003, many farmers reduced or eliminated soil-applied insecticides to manage larvae. Western corn rootworm is adapting to transgenic technologies throughout the Corn Belt. Some continuous cornfields have larvae that can now survive at high numbers and cause severe root injury to Bt corn. We encourage farmers to use multiple strategies to protect corn.


Selection Of Haploid Maize Kernels From Hybrid Kernels For Plant Breeding Using Near-Infrared Spectroscopy And Simca Analysis, Roger W. Jones, Tonu Reinot, Ursula K. Frei, Yichia Tseng, Thomas Lübberstedt, John F. Mcclelland Apr 2012

Selection Of Haploid Maize Kernels From Hybrid Kernels For Plant Breeding Using Near-Infrared Spectroscopy And Simca Analysis, Roger W. Jones, Tonu Reinot, Ursula K. Frei, Yichia Tseng, Thomas Lübberstedt, John F. Mcclelland

Ames Laboratory Publications

Samples of haploid and hybrid seed from three different maize donor genotypes after maternal haploid induction were used to test the capability of automated near-infrared transmission spectroscopy to individually differentiate haploid from hybrid seeds. Using a two-step chemometric analysis in which the seeds were first classified according to genotype and then the haploid or hybrid status was determined proved to be the most successful approach. This approach allowed 11 of 13 haploid and 25 of 25 hybrid kernels to be correctly identified from a mixture that included seeds of all the genotypes.


Post Applied Urea+Agrotain To V10 Corn Field Scale Strip Demonstrations, Daniel W. Barker, John E. Sawyer Jan 2012

Post Applied Urea+Agrotain To V10 Corn Field Scale Strip Demonstrations, Daniel W. Barker, John E. Sawyer

Agronomy Conference Proceedings and Presentations

The objectives are to apply N fertilizer when corn rapidly accumulates N and dry matter during the mid-vegetative growth stages and utilize active sensors as a remote sensing method of applying VRT nitrogen.


Corn Residue Harvesting Effects On Yield Response To N Fertilization, Jose L. Pantoja, John E. Sawyer, Daniel W. Barker, Mahdi Al-Kaisi Nov 2011

Corn Residue Harvesting Effects On Yield Response To N Fertilization, Jose L. Pantoja, John E. Sawyer, Daniel W. Barker, Mahdi Al-Kaisi

Agronomy Conference Proceedings and Presentations

Producers have many choices of diverse tillage practices for their corn (Zea mays L.) production systems. However, no-till has become an important soil management practice to help reduce water and wind erosion, as well as nutrient runoff, while conserving soil moisture for crop use. No-till systems also help farmers by saving labor and time, as well as reducing farm costs due to less equipment and fuel consumption. Nevertheless, no-till production is typically more successful and has higher crop yield on moderately to well drained medium-textured soils (Bitzer, 1998), compared to soils with poor internal drainage and high clay.


Did Recurrent Selection For Yield Affect Iowa Stiff Stalk Synthetic Maize Population Grain Fill Characteristics?, Steve James Eichenberger Jan 2011

Did Recurrent Selection For Yield Affect Iowa Stiff Stalk Synthetic Maize Population Grain Fill Characteristics?, Steve James Eichenberger

Graduate Theses and Dissertations

Hybrid maize yield increases, new product development, and increased stress tolerance can be more easily achieved with a better understanding of the physiological and genetic basis for phenotypic changes in response to recurrent selection for yield. The purpose of this study was to identify changes in grain fill characteristics and their interaction with plant density in a closed population and identify a model that accurately predicts grain fill in this population. We hypothesize that recurrent selection for increased yield indirectly impacted the grain fill characteristics of maize including final kernel weight, kernel fill duration, and kernel fill rate in the ...