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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.


Impacts Of 4r Nitrogen Management On Drainage Water Quality, Matthew J. Helmers Dec 2017

Impacts Of 4r Nitrogen Management On Drainage Water Quality, Matthew J. Helmers

Proceedings of the Integrated Crop Management Conference

Much of the U.S. Corn Belt is characterized by relative flat, poorly-drained areas which with extensive subsurface drainage, have become some of the most valuable and productive agricultural land in the world. However, this is not without consequences. Nitrate-N loss from these systems is of particular concern due to its potential adverse impacts on both public health and ecosystem function. In addition to the potential local impacts on receiving waters in the Corn Belt, nitrogen loads from the region are suspected as a primary contributor to hypoxia in the Gulf of Mexico. For nearly 30 years Iowa State University ...


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.


The Iowa Nutrient Reduction Strategy Farmer Survey: Tracking Knowledge, Attitudes, And Behaviors, Laurie Nowatzke Dec 2017

The Iowa Nutrient Reduction Strategy Farmer Survey: Tracking Knowledge, Attitudes, And Behaviors, Laurie Nowatzke

Proceedings of the Integrated Crop Management Conference

In 2013, the state of Iowa released the Iowa Nutrient Reduction Strategy (NRS) (http://www.nutrientstrategy.iastate.edu). The NRS is a science and technology-based approach to guide actions that reduce the amount of nutrients delivered to Iowa waterways and the Gulf of Mexico. The NRS was developed through a collaboration between Iowa State University (ISU), the Iowa Department of Agriculture and Land Stewardship (IDALS), and the Iowa Department of Natural Resources, with support from the USDA Agricultural Research Serviceand the USDA Natural Resources Conservation Service (NRCS). The strategy outlines opportunities and recommendations for voluntary efforts to reduce nutrients in ...


Searching For The Bottom, Chad Hart Dec 2017

Searching For The Bottom, Chad Hart

Proceedings of the Integrated Crop Management Conference

Looking back over the last ten years, crop agriculture has swung between two regimes. The years 2007 to 2012 were characterized by strong crop prices, driven in the beginning by record building demand and at the end by a drought. The years 2013 to 2017 are characterized by strong crop production, a consistent string of large harvests that have been more than enough to meet and exceed demand. The outlook for 2018, based on the information we have today, suggests that pattern will continue for at least another year.


Resistance Management Plan For Soybean Aphid, Erin Hodgson Dec 2017

Resistance Management Plan For Soybean Aphid, Erin Hodgson

Proceedings of the Integrated Crop Management Conference

Soybean aphid remains the most important soybean insect pest in Iowa, and management over the last fifteen years has primarily relied on foliar insecticides. The economic injury level was defined by Ragsdale et al. (2007), and is approximately 675 aphids per plant or 5,560 cumulative aphid days. From that multistate research, a conservative economic threshold was developed to protect yield: 250 aphids per plant with 80% of the plants infested through the seed set plant growth stage (R5.5). The odds of making a profitable treatment decision are increased with regular scouting and applications made after exceeding the economic ...


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.


Rootworm Behavior And Resistance In Bt Cornfields, Joseph L. Spencer, Sarah A. Hughson Dec 2017

Rootworm Behavior And Resistance In Bt Cornfields, Joseph L. Spencer, Sarah A. Hughson

Proceedings of the Integrated Crop Management Conference

The western corn rootworm (Diabrotica virgifera virgifera LeConte, WCR) is the most economically important U.S. corn pest (Gray et al. 2009). Together with the northern corn rootworm (Diabrotica barberi Smith and Lawrence, NCR), it was estimated that these pests annually cost producers $1 billion in yield losses and control costs (Metcalf 1986). Today the cost is thought to be much greater (Dun et al. 2010; Tinsley et al. 2013).


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).


Current Legal Issues Impacting Crop Production, Kristine A. Tidgren Dec 2017

Current Legal Issues Impacting Crop Production, Kristine A. Tidgren

Proceedings of the Integrated Crop Management Conference

On March 16, 2015, the Des Moines Board of Water Works Trustees (DMWW) filed a federal Clean Water Act (CWA) lawsuit agand Calhoun). The lawsuit, which was filed in the United States District Court for the Northern District of Iowa, al leged that the supervisors, in their capacity as trustees for the drainage districts. The lawsuit, among its many demands, asked the federal court to order the drainage districts to cease “all discharges of nitrate that are not authorized by an NPDES or state operating permit.”


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 ...


The Iowa Pest Resistance Management Plan: A Community-Based Approach To Address Pest Resistance In Iowa, Evan Sivesind Dec 2017

The Iowa Pest Resistance Management Plan: A Community-Based Approach To Address Pest Resistance In Iowa, Evan Sivesind

Proceedings of the Integrated Crop Management Conference

Pest resistance to chemical, genetic, and agronomic management practices is a widespread and increasing problem in Iowa. Evolution of pest resistance to current management technologies is occurring at a faster rate than new technologies are being developed. Though many resistance management practices (RMPs) are well described and validated, their adoption has been slow. This project aims to bridge the gap between knowledge and adoption by engaging all sectors of Iowa agriculture utilizing a community-based approach, a tactical imperative when dealing with mobile pests that cross field boundaries. By increasing adoption of RMPs, valuable pest management tools will be preserved and ...


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 ...


Recent Developments In China And Impacts On Us Agricultural Trade, Wendong Zhang Dec 2017

Recent Developments In China And Impacts On Us Agricultural Trade, Wendong Zhang

Proceedings of the Integrated Crop Management Conference

There is never short of changes and surprises in China. The past two years have been extremely interesting for producers and policymakers watching Chinese agricultural markets. In particular, China’s President Xi promised to extend all farmland contracts by another 30 years, China ended the costly $9-$10/bu corn support price program in 2016 and unveiled a new nationwide mandate of E10 fuel. This article introduces several key points of these policy changes, their motivations and impacts on the US agricultural trade.