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

Digital Commons Network

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

Articles 1 - 30 of 666

Full-Text Articles in Entire DC Network

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 ...


Update On Soybean Diseases And Their Management, Daren Mueller Dec 2016

Update On Soybean Diseases And Their Management, Daren Mueller

Proceedings of the Integrated Crop Management Conference

There were several diseases that appeared in soybean fields in 2016. While diseases were not common early in the season, by late July they became more prevalent. Some of the most prevalent diseases during the 2016 season were bacterial pustule, frogeye leaf spot, sudden death syndrome (SDS), and white mold. This talk will focus on these specific diseases and provide updates on management of soybean diseases in general.


Understanding And Increasing Soybean Yields, Ryan J. Van Roekel, Larry C. Purcell Dec 2016

Understanding And Increasing Soybean Yields, Ryan J. Van Roekel, Larry C. Purcell

Proceedings of the Integrated Crop Management Conference

An understanding of the main factors influencing grain yield in soybean can provide key insights for making management decisions to increase yield. Seed number is determined by the amount of photosynthate produced between R1 and R5 that is allocated to the seeds, divided by the minimum amount of photosynthate needed to keep a single seed from aborting. Stresses or improvements in crop growth prior to flowering should not have a significant impact on final yield, provided that >95% light interception is achieved by R1. Seed weight is determined by the seed growth rate and the length of the seed fill ...


Nitrogen Myths And Realities, Michael Castellano, Sotirios Archontoulis, Carolina Cordova, Ranae Dietzel Dec 2016

Nitrogen Myths And Realities, Michael Castellano, Sotirios Archontoulis, Carolina Cordova, Ranae Dietzel

Proceedings of the Integrated Crop Management Conference

More than 1/3 of the nitrogen in human bodies is derived from industrially synthesized nitrogen fertilizer (Smil, 2004). Without nitrogen fertilizer, agriculture could not sustain the global population of 7 billion people living today, much less the 11 billion people expected to be living by 2100. There is no doubt: nitrogen fertilizer is critical to sustain human health and grow developing economies.


Iowa Soybean Association And Iowa State University Cooperative Soybean Cyst Nematode And Corn Rootworm Beetle Survey Results, Tristan Mueller, Clarke Mcgrath Dec 2016

Iowa Soybean Association And Iowa State University Cooperative Soybean Cyst Nematode And Corn Rootworm Beetle Survey Results, Tristan Mueller, Clarke Mcgrath

Proceedings of the Integrated Crop Management Conference

In cooperation with industry partners, Iowa Soybean Association and Iowa State University (ISU) conducted soybean cyst nematode and corn rootworm surveys across the state. With nearly every county in the state included in the surveys, the results have been informative.


Understanding The 2016 Yields And Interactions Between Soils, Crops, Climate And Management, Sotirios Archontoulis, Mark Licht, Mike Castellano, Ranae Dietzel, Andy Van Loocke, Raziel Ordonez, Javed Iqbal, Laila Puntel, Carolina Cordova, Kaitlin Togliatti, Rafael A. Martinez-Feria, Huber Isaiah, Matt Helmers Dec 2016

Understanding The 2016 Yields And Interactions Between Soils, Crops, Climate And Management, Sotirios Archontoulis, Mark Licht, Mike Castellano, Ranae Dietzel, Andy Van Loocke, Raziel Ordonez, Javed Iqbal, Laila Puntel, Carolina Cordova, Kaitlin Togliatti, Rafael A. Martinez-Feria, Huber Isaiah, Matt Helmers

Proceedings of the Integrated Crop Management Conference

Several technologies to forecast crop yields and soil nutrient dynamics have emerged over the past years. These include process-based models, statistical models, machine learning, aerial images, or combinations. These technologies are viewed as promising to assist Midwestern agriculture to achieve production and environmental goals, but in general, most of these technologies are in their initial stages of implementation. In June 2016 we launched a web-tool (http://crops.extension.iastate.edu/facts/) that provided real-time information and yield predictions for 20 combinations of crops and management practices. Our project, which is called FACTS (Forecast and Assessment of Cropping sysTemS), takes a ...


What Happens During Pathogen Infections In Crop Plants?, Steve Whitham Dec 2016

What Happens During Pathogen Infections In Crop Plants?, Steve Whitham

Proceedings of the Integrated Crop Management Conference

Plants have sophisticated immune systems that provide protection against most microorganisms. However, pathogens that are able cause disease have the ability to disrupt plant defenses. Recent research has shown that there is extensive communication between plants and microorganisms, and that there are multiple layers to effective disease resistance. This presentation will introduce the audience to concepts in plant disease resistance and the offensive weapons that pathogens use as they attempt to overcome plant defenses.