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Using Values To Communicate Agricultural Science: An Elaboration Likelihood Model Approach, Allison Arp Jan 2018

Using Values To Communicate Agricultural Science: An Elaboration Likelihood Model Approach, Allison Arp

Iowa State University Summer Symposium on Science Communication

This study looked at how preexisting values influence audience processing of scientific information focusing on the topic of GMOs and how that may affect the audience’s interpretation of the message regardless of the communicator’s credibility or trustworthiness. Research found that attitude accessibility, agricultural identity and in some cases a biospheric value orientation were the most important predictors for a number of constructs related to GMO attitudes. Agricultural identity did not correlate with other value orientations, yet was the strongest predictor of many related attitudes. These results support previous ELM research and emphasize the complex nature of science and ...


Implementation Of Teaching Methods To Develop Plant Identification Mastery Among College Students, Sarah Striegel Dec 2017

Implementation Of Teaching Methods To Develop Plant Identification Mastery Among College Students, Sarah Striegel

Honors Projects and Posters

Students enrolled in Agronomy 330: Crop and Seed Identification Laboratory work to master the skill of plant identification of several crops, forages, and weeds. Prior to the beginning of the Fall 2017 semester, the course content was reorganized by taxonomic families and revised to stress vegetative identification. Adjustments were made to promote mastery by setting an expected performance level each student must achieve before proceeding to new material. Additionally, new course materials were developed weekly to facilitate learning with an emphasis on anatomical drawing. Students were required to achieve a passing score of 90% on each quiz. A supplemental quiz ...


Dicamba Injury And Insurance, Ray Massey Dec 2017

Dicamba Injury And Insurance, Ray Massey

Proceedings of the Integrated Crop Management Conference

Multiperil crop insurance, such as Revenue Protection and Yield Protection, and General Liability Insurance have both been involved in cases where 3rd party damage from herbicide applications occurs.


Nitrogen Management For Corn, Emerson Nafziger Dec 2017

Nitrogen Management For Corn, Emerson Nafziger

Proceedings of the Integrated Crop Management Conference

As pressure continues to reduce production costs, to manage risks, and to reduce loss of N to the environment, managing nitrogen remains a major challenge to Corn Belt corn producers. Major considerations include N rate, form of nitrogen, use of stabilizers, and method and timing of application.


Status Of Bacterial Leaf Streak Of Corn In The United States, Kirk Broders Dec 2017

Status Of Bacterial Leaf Streak Of Corn In The United States, Kirk Broders

Proceedings of the Integrated Crop Management Conference

The bacterial pathogen Xanthomonas vasicola pv vasculorum (Xvv), which causes the disease bacterial leaf streak (BLS), was officially reported on maize in the U.S. in 2016 (Korus et al. 2017). This represents the first report of this disease in North American and is the only report of the disease anywhere in the world outside of South Africa. The disease was observed in 51 counties in Nebraska as well as 6 counties in eastern Colorado and 16 counties in western Kansas. The disease has continued to expand in 2016 reaching epidemic proportion in regions of Colorado, Kansas and Nebraska with ...


Update On Soybean Diseases, Daren Mueller Dec 2017

Update On Soybean Diseases, Daren Mueller

Proceedings of the Integrated Crop Management Conference

Although parts of Iowa experienced dry conditions during the 2017 growing season, several important diseases were observed. Early season diseases were not common, but by late July prevalence increased. White mold was the most damaging disease in the northern part of the state. There was also limited, late development of sudden death syndrome and pod and stem blight (Diaporthe). Tobacco ringspot was found across much of Iowa very late in the season. This presentation will focus on these specific diseases and provide management updates for soybean diseases in general.


Nitrogen Dynamics With A Rye Cover Crop, John E. Sawyer, Swetabh Patel, Jose Pantoja, Daniel W. Barker, John P. Lundvall Dec 2017

Nitrogen Dynamics With A Rye Cover Crop, John E. Sawyer, Swetabh Patel, Jose Pantoja, Daniel W. Barker, John P. Lundvall

Proceedings of the Integrated Crop Management Conference

Winter cereal rye continues to be promoted as a viable cover crop within Iowa for corn and soybean production systems. Several environmental benefits accrue with use of cover crops, including reduction of nitrate in drainage water, soil erosion control, and reduced phosphorus (P) runoff loss. In the Iowa Nutrient Reduction Strategy, a rye cover crop is estimated to reduce nitrate-N concentration by 31%, a sizeable impact. However, questions remain about rye cover crop effects on corn nitrogen (N) fertilization requirement, N supply from the cover crop, and crop yield. To help answer these questions, a series of studies were conducted ...


Fungicide Use On Corn, Alison Robertson Dec 2017

Fungicide Use On Corn, Alison Robertson

Proceedings of the Integrated Crop Management Conference

Over the past decade, the use of foliar fungicides on hybrid corn has become more commonplace. Reasons for this include increased foliar disease, new fungicides becoming available, and promoted plant health benefits. Both the public and private sector have done small plot and on-farm field trials evaluating the effect of foliar fungicides on disease severity and yield.


View From The Sky: Mapping Corn Nitrogen Status At The Watershed Level, Chris Wilkins, Suzanne Fey, Bra Wirt, Peter Kyveryga Dec 2017

View From The Sky: Mapping Corn Nitrogen Status At The Watershed Level, Chris Wilkins, Suzanne Fey, Bra Wirt, Peter Kyveryga

Proceedings of the Integrated Crop Management Conference

To make informed decisions of how to better manage nitrogen (N) fertilizer, farmers and agronomists need the best and most reliable data about performance of fertilization systems. Regardless of the method used to determine N fertilizer requirements, users need to know whether past fertilization decisions were cost effective (too little or too much N) through feedback assessments.


Back To The Basics: Integrating Weed Biology Into Weed Management Plans, Jared Goplen, Lisa Behnken, Ryan Miller, Liz Stahl Dec 2017

Back To The Basics: Integrating Weed Biology Into Weed Management Plans, Jared Goplen, Lisa Behnken, Ryan Miller, Liz Stahl

Proceedings of the Integrated Crop Management Conference

Herbicide-resistant giant ragweed and waterhemp continue to spread across the midwestern U.S. and are occurring more frequently in the same fields, making control with herbicides especially difficult. Weed biology is one of the most important factors to consider when developing a successful weed management program, with three main factors influencing success: 1) weed emergence patterns, 2) the weed seed bank, and 3) incorporating sound agronomic practices.


What Is Soil Health, How Do We Measure It, And Why The Emphasis On Soil Biology?, Marshall Mcdaniel Dec 2017

What Is Soil Health, How Do We Measure It, And Why The Emphasis On Soil Biology?, Marshall Mcdaniel

Proceedings of the Integrated Crop Management Conference

The current interest in soil health is largely due to increased awareness of the importance of soil biology. While there are a variety of biological soil health indices, there is currently no consensus among scientists. The current soil health tests are relatively expensive and show inconsistent results amongst management practices. Further research into calibrating and validating all soil health indicators is needed, especially for biological indicators.


Meeting The Nitrate Reduction Goal: What Will It Take?, Jamie Benning, Matt Helmers, Mark Licht Dec 2017

Meeting The Nitrate Reduction Goal: What Will It Take?, Jamie Benning, Matt Helmers, Mark Licht

Proceedings of the Integrated Crop Management Conference

The Iowa Nutrient Reduction Strategy is a science and technology-based framework developed to assess and reduce nutrient loss to Iowa waters and the Gulf of Mexico. The strategy addresses methods and practices to reduce total loads of nitrogen and phosphorus from both municipal and industrial point sources and agricultural nonpoint sources by a combined 45% (INRSSA, 2013). The approach was developed in response to the 2008 Gulf Hypoxia Action Plan that calls for Iowa and other states in the Mississippi River watershed to develop strategies to reduce nutrient loadings to the Gulf of Mexico and ultimately reduce the size of ...


Where Do We Stand With Soybean Cyst Nematode, Resistance, And Seed Treatments?, Gregory Tylka Dec 2017

Where Do We Stand With Soybean Cyst Nematode, Resistance, And Seed Treatments?, Gregory Tylka

Proceedings of the Integrated Crop Management Conference

The soybean cyst nematode (SCN), Heterodera glycines, is a major yield-limiting factor of soybean in the United States and Canada (table 1). One thing contributing to the large amount of damage caused by SCN is its widespread distribution. The nematode has been found in every soybean-producing state in the United States except West Virginia and in all Iowa counties (figure 1) (Tylka and Marett 2017). And results of repeated random surveys of Iowa done in the 1990s (Workneh et al. 1999) and in the mid 2000s and in 2017 (Tylka unpublished) indicate SCN is present in 60% to 70% or ...


Water Availability, Root Depths And 2017 Crop Yields, Sotirios Archontoulis, Mark Licht, Mike Castellano, Raziel Ordonez, Javed Iqbal, Rafael Martinez-Feria, Pat Edmonds, Emily Wright, Mitch Baum, Ashlyn Kessler, Huber Isaiah, Aaron M. Sassman, Matt Liebman, Matt Helmers Dec 2017

Water Availability, Root Depths And 2017 Crop Yields, Sotirios Archontoulis, Mark Licht, Mike Castellano, Raziel Ordonez, Javed Iqbal, Rafael Martinez-Feria, Pat Edmonds, Emily Wright, Mitch Baum, Ashlyn Kessler, Huber Isaiah, Aaron M. Sassman, Matt Liebman, Matt Helmers

Proceedings of the Integrated Crop Management Conference

During 2016 and 2017, June-July precipitation was below normal in many parts of Iowa creating midseason concerns about potential yield loss due to water stress. However, these concerns were not realized. In contrast, 2016 and 2017 crop yields over-performed yields obtained in many years with average of above average June-July precipitation. In Iowa, deep root systems, high soil water storage capacity, and shallow water tables are common explanations for high yields in years with below normal precipitation. How deep can roots grow? How much does groundwater contribute to the yields? To answer these questions and more, the Forecast and Assessment ...


Weed Management Update For 2018 And Beyond: The More Things Change, Micheal D. K. Owen Dec 2017

Weed Management Update For 2018 And Beyond: The More Things Change, Micheal D. K. Owen

Proceedings of the Integrated Crop Management Conference

Again there are no new herbicides with novel mechanisms of action and none are anticipated in the near future. Weed management issues were very evident in 2017 and weed populations with evolved resistance(s) to herbicides continued to escalate statewide. Palmer amaranth populations have been identified in many new Iowa counties and it is likely that populations will eventually be identified in all Iowa counties. Weed management remains a major concern for Iowa agriculture and addressing these burgeoning problems requires greater diversity of tactics beyond herbicides.


Weather Outlook 2018 And Understanding Inversions, Elwynn Taylor Dec 2017

Weather Outlook 2018 And Understanding Inversions, Elwynn Taylor

Proceedings of the Integrated Crop Management Conference

Colorado is known for mountains. The temperature at the city of Colorado Springs was 80 degrees, the sky was clear, the air almost still. We took our jackets and boarded the train to the summit of Pike’s Peak (we were aware that “Pike’s Peak the first” was in Iowa and General Pike actually reached the summit of the Iowa version of the peak). The elevation of downtown Colorado Springs is 6,035 feet above sea level and the summit of the peak is 14,115 feet above sea level. We did not need to be told that the ...


Key Management Practices That Explain Soybean Yield Gaps Across The North Central Us, Shawn Conley Dec 2017

Key Management Practices That Explain Soybean Yield Gaps Across The North Central Us, Shawn Conley

Proceedings of the Integrated Crop Management Conference

To date identification of causes of yield gaps (difference between maximum yield potential and measured yield in producer yields) has been restricted to small geographic areas. In this study, we developed a novel approach that combines producer-reported data and a spatial framework to identify explanatory causes of yield gap over large geographic regions with diversity of climate, soils, and water regimes (rainfed and irrigated).


Is There Loss Of Corn Dry Matter In The Field After Maturity?, Mark Licht, Charles Hurburgh, Matthew Kots, Philip Blake, Mark Hanna Dec 2017

Is There Loss Of Corn Dry Matter In The Field After Maturity?, Mark Licht, Charles Hurburgh, Matthew Kots, Philip Blake, Mark Hanna

Proceedings of the Integrated Crop Management Conference

Mystery yield loss, phantom yield loss, and now invisible yield loss – all are terms used for the concept that dry matter (yield) is being lost in-field between maturity (at about 28% moisture) and harvest (approximately 15% moisture). Popular press articles continue to indicate up to 1% dry matter loss per 1% grain moisture decrease. If this amount of dry matter loss occurs, it would be significant in marketing terms. Some believe that this loss is caused by seed respiration.


The Science Of Cover Crops In Iowa, Liz Juchems, Stefan Gailans Dec 2017

The Science Of Cover Crops In Iowa, Liz Juchems, Stefan Gailans

Proceedings of the Integrated Crop Management Conference

Iowa Cover Crop Working Group (ICCWG) is under the leadership of the Iowa Learning Farms program and includes core members from the following agencies and organizations: Practical Farmers of Iowa (PFI), Iowa State University Extension and Outreach (ISUEO), USDA-Agricultural Research Service-National Laboratory for Agriculture and the Environment (USDA-ARS-NLAE), Iowa Department of Agriculture and Land Stewardship (IDALS).


Watch Potassium Management—It Also Effects Corn Response To Nitrogen And Soybean Diseases, Antonio P. Mallarino Dec 2017

Watch Potassium Management—It Also Effects Corn Response To Nitrogen And Soybean Diseases, Antonio P. Mallarino

Proceedings of the Integrated Crop Management Conference

Potassium (K) fertilization effects on corn and soybean grain yield have been studied for many years in Iowa. Research results summarized for this and other conferences included calibration of soil-test methods and study of soil-test K spatial and temporal variability, recycling with crop residues, K placement methods for various tillage systems, soil sampling methods, and variable-rate fertilization. The research has shown the importance of proper K fertilization practices for profitable crop production, which mainly include appropriate use of soil sampling and testing, fertilizing low-testing soils, maintaining soil-test K levels in the optimum interpretation category, and avoiding fertilization of high-testing soils ...


Dicamba: Past, Present, And Future, Bob Hartzler Dec 2017

Dicamba: Past, Present, And Future, Bob Hartzler

Proceedings of the Integrated Crop Management Conference

Dicamba has been an important component of Iowa weed management systems for more than 50 years. The history of its use is somewhat unique in that its popularity has ebbed and flowed over time. The increase in herbicide resistant weeds combined with the introduction of dicamba-resistant soybean (Xtend) promises a large increase in dicamba use in both corn and soybean. This article will review the characteristics of dicamba that differentiate it from other herbicides, provide an overview of problems observed in 2017, and describe how risks can be minimized in 2018.


Corn Planting Decisions: What’S Changed And What’S The Same?, Mark Licht, Emily Wright, Mitch Baum, Nick Upah Dec 2017

Corn Planting Decisions: What’S Changed And What’S The Same?, Mark Licht, Emily Wright, Mitch Baum, Nick Upah

Proceedings of the Integrated Crop Management Conference

Corn planting is arguably the most important field operation. Wide sweeping decisions from hybrid selection, row spacing, and seeding rates to planter adjustments, seed depth, and field conditions all come together the day planting occurs. It is a perfect storm where all these decisions align to achieve ideal stand establishment and set the stage for high yield potential.


Disease Risks Associated With Cover Crops And Soybean Production, Alison Robertson, Tom Kaspar, Leonor Leandro, Daren Mueller, Jyotsna Acharya Dec 2017

Disease Risks Associated With Cover Crops And Soybean Production, Alison Robertson, Tom Kaspar, Leonor Leandro, Daren Mueller, Jyotsna Acharya

Proceedings of the Integrated Crop Management Conference

Cover crops have numerous environmental benefits, for example reducing erosion, improving infiltration, mitigating nutrient loading in surface waters, and improving soil health (Kaspar et al 2001, Kaspar and Singer 2011, Schnepf and Cox 2006). Still, some farmers are reluctant to introduce cover crops into their production systems. In a 2016 Cover Crop Survey, approximately 30 percent of the respondents stated that “increased disease potential” was a minor or major challenge to using cover crops on their farm (SARE, 2016). Of the respondents, 20 percent had been growing cover crops for 2-3 years, 30% for 4-5 years, and 19% for more ...


Genetically Modified Crops: Marvel Or Malady?, Peter Goldsbrough Dec 2017

Genetically Modified Crops: Marvel Or Malady?, Peter Goldsbrough

Proceedings of the Integrated Crop Management Conference

The first transgenic plants were produced in 1983 by three different groups of scientists in the United States and Europe. The successful transfer of genes from other species into petunia and tobacco plants was a major technological achievement that led to important advances in our understanding of how plants grow and develop. This technology also led to the development of genetically modified (GM) agronomic crop plants that were planted by farmers for the first time in 1996. This technology has generated more controversy than any other advance in agriculture in the last twenty years. Further scientific advances made during the ...


Plant Nutrition Science For Sustaining Public Trust, Tom Bruulsema Dec 2017

Plant Nutrition Science For Sustaining Public Trust, Tom Bruulsema

Proceedings of the Integrated Crop Management Conference

When M. K. Hubbert wrote his Science paper on peak oil in 1949, he noted with concern projections that world population could possibly hit 9 billion within 200 years. The actual increase has been more than twice that fast. And it’s projected to continue further. Sustainable intensification of agriculture will be an essential part of our future. Attaining it will require plant nutrition science that sustains public trust.


Integrating Strips Of Native Prairie Into Rowcrop Agriculture Fields, Timothy Youngquist Dec 2017

Integrating Strips Of Native Prairie Into Rowcrop Agriculture Fields, Timothy Youngquist

Proceedings of the Integrated Crop Management Conference

Tallgrass prairie once covered over 85% of the total land area of the state of Iowa. Currently, less than .01% of that original ground cover remains; the remnant prairies largely exist in small blocks along railroad right-of-ways, cemetery edges, and other marginal locations. As of today, almost 75% of the total area of Iowa is planted to corn and soybeans. Those rowcrop acres are necessary for the economy of the state. Prairie provides necessary ecological benefits for soil retention, water quality, and habitat for a wide range of native birds, mammals, pollinators, and other beneficial insects. STRIPS (Science-based Trials of ...


Twin Sectors Caused By Alternative Transpositions In Maize, Jeremy Schuster Apr 2017

Twin Sectors Caused By Alternative Transpositions In Maize, Jeremy Schuster

Symposium on Undergraduate Research and Creative Expression

During development of the maize ear, mutations may occur during cell division. These mutations can form twin sectors, or a sector of the maize ear that has a different coloration or pattern in the pericarp, seed coat, of the maize ear.

We studied the effects of Activator (Ac) transposon (a chromosomal segment that can undergo transposition) in the development of twin sectors on maize ears containing the allele P1-ovov454. This allele conditions orange-variegated pericarp and cob due to the presence of the Ac transposon in the p1 gene which controls kernel pericarp color. We screened for ears with multi-kernel dark ...


Bridging The Gap Between College Algebra And Agronomic Math, Haleigh Nicole Summers Apr 2017

Bridging The Gap Between College Algebra And Agronomic Math, Haleigh Nicole Summers

Honors Projects and Posters

Practitioners of agronomy are often faced with scenarios involving math during their daily activities. Students studying agronomy are required to take college algebra but often miss the opportunity to bridge the gap between general algebra and agronomic math. The purpose of this research was to evaluate the effectiveness of two delivery methods for teaching agronomic math. Videos and posters were created to demonstrate: fertilizer application, unit conversions, irrigation, yield estimation, and growing degree day calculation. We predicted using videos to teach agronomic math would be more effective by providing both auditory and visual teaching methods, while posters only provide visual ...


Tillage Effects On Soil In Southern Guatemala: A Case Study Using Remote Analyses, Sarah Irene Leichty Apr 2017

Tillage Effects On Soil In Southern Guatemala: A Case Study Using Remote Analyses, Sarah Irene Leichty

Honors Projects and Posters

Guatemala lacks soils information, yet soils knowledge is essential in order to reduce environmental impacts, improve food security, determine best farming practices, and increase crop yields. Reasons for the lack of information include lack of personnel and difficulty accessing equipment. This study's objective is to remedy those shortcomings via (a) the creation and sending of a soil testing kit, (b) corresponding manual written for non-soil scientist use, and (c) mechanisms to send data to ISU for thorough analysis. The soil testing kit included basic laboratory materials used to test essential soil characteristics such as soil aggregate stability, aggregate size ...


Effect Of Soybean Cyst Nematodes On Soybean Gene Expression, Pierre Guzman Apr 2017

Effect Of Soybean Cyst Nematodes On Soybean Gene Expression, Pierre Guzman

Honors Projects and Posters

Soybean Cyst Nematodes are a recurring parasite that can drastically afflict yield. Further understanding of the interaction between the pest and its soybean host is essential to working towards increased plant resistance. Utilizing current molecular biology techniques, the plant response to parasitical exposure was analyzed, focusing on the effect on gene expression due to the presence and damage caused by the nematode, homozygous screening and western blot was also used to determine the genetic change in the samples. Through observing the stages of growth of the plant in conjunction with exposure to nematodes, affected phenotype of the plant samples was ...