CSCAP-USB Partnership Report 2013

This publication is produced as part of a regional collaborative project supported by the USDA-NIFA,
Award No. 2011-68002-30190 “Cropping Systems Coordinated Agricultural Project: Climate Change,
Mitigation, and Adaptation in Corn-based Cropping Systems.” The 11 institutions comprising the
project team include: Iowa State University, Lincoln University, Michigan State University, The Ohio
State University, Purdue University, South Dakota State University, University of Illinois, University of
Minnesota, University of Missouri, University of Wisconsin, and USDA-ARS Columbus, Ohio.
Publication No. CSCAP-0151-2013
Integrated Pest Management
Research Report to
The United Soybean Board
A Partnership of Climate & Corn-based Cropping Systems CAP
and the United Soybean Board
April 2013

Table of Contents
CSCAP & USB Partnership Overview ....................................................................... 2-4
Research Network and IPM Data Overview ....................................................................... 5-6
Research Spotlight: Ed Zaworski, Iowa State University Graduate Student ........................ 7
Research Spotlight: Gang Han, Iowa State University Graduate Student ........................ 8
Research Spotlight: Rebecca Redline, University of Wisconsin Graduate Student .............. 9
Research Spotlight: Mike Dunbar, Iowa State University Graduate Student ...................... 10
Going Forward ........................................................................ 11
Integrated Pest Management Team Members
Name Position University E-Mail
Entomologists
Mike Dunbar
*Mary Gardiner
Aaron Gassmann
*Andy Michel
Matt O’Neal
PhD Graduate Student
Assistant Professor
Assistant Professor
Assistant Professor
Associate Professor
Iowa State University
The Ohio State University
The Ohio State University
dunbar17@gmail.com
gardiner.28@osu.edu
aaronjg@iastate.edu
michel.70@osu.edu
oneal@iastate.edu
Plant Pathologists
*Nate Bestor
*Marty Chilvers
*Darin Eastburn
*Paul Esker
*Gang Han
*Leonor Leandro
*Dean Malvick
Daren Mueller
*Alison Robertson
*Greg Tylka
*Kiersten Wise
*Ed Zaworski
Assistant Coordinator
Assistant Professor
Associate Professor
Affiliate
MS Graduate Student
Associate Professor
Associate Professor
Assistant Professor
Associate Professor
Professor
Associate Professor
MS Graduate Student
Michigan State University
University of Illinois
Universidad de Costa Rica
University of Minnesota
Purdue University
bestor@iastate.edu
chilvers@msu.edu
eastburn@illinois.edu
paul.esker@ucr.ac.cr
gangh@iastate.edu
lleandro@iastate.edu
dmalvick@umn.edu
dsmuelle@iastate.edu
alisonr@iastate.edu
gltylka@iastate.edu
kawise@purdue.edu
zaworski@iastate.edu
Weed Scientists
*Kevin Bradley
*Vince Davis
*Rebecca Redline
Associate Professor
Assistant Professor
MS Graduate Student
University of Missouri
University of Wisconsin
University of Wisconsin
bradleyke@missouri.edu
vmdavis@wisc.edu
rredline@wisc.edu
* Funded by the United Soybean Board. Others are funded by Climate and Corn-based Cropping Systems
CAP.
2

Climate scientists widely agree the global climate is changing. This is evidenced by variations in
temperature and precipitation, as well as seasonality shifts; these changes are expected to continue.
There is a lack of research and subsequent information regarding how these global climate changes
will impact local and regional cropping systems. As such, the US agricultural base needs to be
strengthened and made more resilient to potential changes. One of the first steps is to identify adaptive
and mitigative strategies that have the potential for implementation by farmers and industry and that
will be supported through policy.
The team seeks to investigate complex carbon, nitrogen, and water cycles to increase the efficiency
and productivity of corn- and soybean-based cropping systems while simultaneously decreasing
the environmental footprint under extreme and variable long-term weather conditions. An integrated
approach is used across research locations to capture crop and environmental responses under a
suite of management practices including: corn-soybean rotation, cover crops within a corn-soybean
rotation, extended crop rotations, organic management, drainage water management, nitrogen fertilizer
management, tillage management, and landscape position. Within this diverse set of practices, team
members measure carbon, nitrogen, greenhouse gas, water quality and flow, pest populations, and
agronomic indicators.
A set of local, regional, and national scale models utilize the field research data to examine current
and predicted implications of the various practices on carbon, nitrogen, and water under different
climate conditions. Additionally, the social and economic behavior of farmers, as related to climate
change, is examined. This includes their perceptions of impacts to their production systems. This
unique research and analysis drives the team’s education and extension components as information
is distributed outward to empower and equip students and citizens with greater knowledge and ways
to actively engage.
Achanging climate will impact the Midwest environment and is expected to influence pest populations,
migration patterns, severity, and farmer recommendations. Climate changes that will impact insects,
diseases, and weeds include:
• Longer growing season (shifted frost dates)
• Warmer winters
• Warmer nights
• More frequent severe precipitation events
• Increased humidity within canopy
Integrated Pest Management Effort
The IPM team supported through CSCAP funding includes three faculty and a graduate student.
This limited number of personnel could not adequately address the complex challenges facing pest
management in corn and soybean systems. Significant funding by the United Soybean Board allowed
for the addition of 12 faculty and 3 graduate students. The combined IPM team has developed
standardized protocols for use across 8 Midwestern states and are collecting soil-borne pests, foliar
disease incidence and severity, insect populations, and weed populations.
CSCAP Vision
3

USB Funding: 2012 & 2013
4
Graduate Student
Salary
$105,946
Undergraduate
Student Salary
$55,978
Staff Salary
$23,942
Materials &
Supplies
$23,310
Travel
$37,173
Other Direct
Costs
$17,251
Total Funding: $263,600

Research Network
5
Decagon Soil Moisture Sensors
Measuring Greenhouse Gas
Emissions with Photoacoustic
Spectroscopy

Measurements and Samples Collected
IPM Measurements Nathan Bestor
Dr. Daren Mueller
The CSCAP research network is leveraged with pest management data
collected from plots that also have a suite of agronomic, soil, and water
measurements taken. Pest data were collected from field locations in 7 states
in 2012. Pests were assessed visually in corn and soybean fields.
Corn
• Foliar disease was visually assessed as a percentage of total leaf area
infected.Ten to 15 plants per plot were rated by assessing the ear leaf and
the second leaf above the ear leaf.
• Nine to 15 ears in each plot were rated for ear rots by visually assessing the
percentage of the total ear infected.
• Stalk rots were assessed on 5 consecutive plants in three rows using the
push test (30 degrees). Incidence of lodging and type of stalk rot also were
recorded.
• Insects populations were assessed using sticky traps, pit fall traps, and
sweep netting. Mike Dunbar, graduate student at Iowa State University, is
currently identifying insects collected from each location.
Soybean
• Foliar disease was visually assessed as a percentage of total leaf area
infected. Twenty to 25 leaves in the upper and lower canopy were rated in
each plot.
• Stem diseases such as white mold and sudden death syndrome were
assessed at the plot level when present.
• Insects populations were assessed using sticky traps, pitfall traps, and
sweep netting. Mike Dunbar is currently identifying insects collected from
each location.
Observations from 2012 Data
• Disease levels were extremely low (<5% severity) throughout the region for
both soybean and corn.
• Diseases expected to be seen in drought conditions such as Aspergillus ear
rot and charcoal rot did occur, but were not as problematic as expected in a
drought year.
• Insects collected from traps are still being identified by Mike Dunbar (see
page 10).
Looking Forward
The value of collecting pest data to complement the larger project is two-fold.
First, if any damaging pests are present at a particular location, the subsequent
impacts on yield may be taken into account in crop models. Second, if any
pest trends do occur in the multistate scouting, these may trigger specific
modeling efforts. However, because the plots are set up to address non-pest
related research, the pest data collected by the IPM team will most likely be
used for identifying possible pest outbreaks at each location.
6

Research Spotlight Ed Zaworski
Dr. Greg Tylka and Dr. Daren Mueller
Research Description
Discoveries To-Date
Soybean cyst nematode (SCN) is a major concern for soybean farmers. It is likely that with imminent global
climate change, the frequency of extreme weather patterns such as drought could increase. Thus, it becomes
important to understand how the lifecycle of major diseases such as SCN might be affected during these
extreme weather conditions. In order to examine lifecycle changes, I am altering the amount of water a soybean
receives under greenhouse settings. I am also looking at a new seed treatment and how it will affect SCN and
sudden death syndrome (SDS). Data from the seed treatment study are not presented here.
The first of two experiments conducted
examines the difference in SCN
reproduction between plants watered
daily with two different amounts of water
(10 and 20 ml). The second experiment
explores SCN reproduction between
plants watered daily and plants watered
only when they begin to wilt. To measure
soybean cyst nematode reproduction,
females are collected from soil or roots.
Eggs of SCN are also counted by
releasing the eggs from cysts.
In the first experiment, 20 ml of water was applied per day to half of the plants and 10 ml was applied to the
other half. There was no significant difference in SCN eggs among these two watering regimes. However, a
trend existed in which the number of SCN eggs was higher for plants receiving the 20 ml treatment. This was
opposite of what we expected to see. Thus, for the second experiment, the protocol was changed to increase
water stress on plants, rather than only reducing water amount. This was accomplished by applying 10 ml
water per day to half of the plants, watering the others only when they began to wilt. In this experiment, SCN
eggs were significantly higher for plants allowed to reach wilting than for those with water applied daily. These
results may indicate that soil moisture is a less important factor in SCN reproduction than is plant stress. Re-
testing for confirmation of results will occur; however, it appears water stress to a soybean plant can influence
SCN reproduction.
Looking Forward
As my research progresses, I will begin to
examine the combined effect of SCN and
SDS infection on soybean grown in various
moisture regimes under greenhouse settings.
This will be challenging, as both pathogens
require slightly different optimal environmental
conditions for development, making it difficult to
get both to infect a plant substantially. Another
graduate student will be continuing the above
mentioned SCN water regime research as I
focus on the combined SCN/SDS experiment.
Main Effect Watering Regime
Eggs (per gram wet root); Run #2
7

Research Spotlight Gang Han
Dr. Daren Mueller and Dr. Leonor Leandro
Discoveries To-Date
Soybean root rot and seedling diseases can lead to significant stand loss and yield reduction. Several soil
microorganisms are able to infect soybean plants early in the season, especially in soils with excessive soil
moisture. My research, which started in May 2012, mainly focuses on how drainage systems and cover crops
affect soil microorganisms over time, specifically focusing on soybean soilborne pathogens such as Fusarium
spp., Alternaria spp., and Aspergillus spp. My hypothesis is that drainage systems and cover crops do not have
long-term effects on soil microbial activity.
Four drainage regimes (conventional, controlled, shallow, and no drainage) and four cover crop regimes
(tillage-cover crop [T-C], tillage-no cover crop [T-NC], no tillage-cover crop [NT-C], and no tillage-no cover crop
[NT-NC]) were examined in this study. Root rot severity of V2 stage soybean seedlings was visually evaluated
and root pieces were plated to determine frequency of root pathogens. Diseased and healthy root pieces
were plated onto water agar, V8 agar, and corn meal agar. Root pieces on water agar were incubated under
continuous light, and V8 and corn meal agar were incubated under dark. Fungi were identified to genus based.
Root rot severity was not significantly different among
drainage regimes. Frequency of pathogen
isolation differed among drainage regimes,
but repetitiveness was poor. The severe
drought in Iowa in 2012 may explain the lack of
drainage effects in this trial. Among cover crop
regimes, the most severe root infection occurred in
the NT-NC treatment based on root ratings. T-C and
T-NC treatments had the least severe symptoms,
while the T-NC treatment had the largest disease
rating variance among four replications. The most
frequently isolated fungi in both experiments were
Fusarium spp.
As 2013 approaches, I am very interested in
examining these drainage and cover crop regimes
under non-drought conditions, as well as to determine
treatment consistency from year to year. In addition,
greenhouse work is ongoing to investigate how soils
from different drainage regimes affect root rots at
three moisture gradients.
Looking Forward
Photographs L to R:
Plants showing root rot;
fungi growing on media;
fungal growth used for
identification
Severity Rating on Roots
Germination Rate on V8 Plates
Fusarium spp. Ratio
8

I am in the preliminary stages of the experiment and have not begun data analysis, but I can share the hypothesis
being testing and what I expect to find. Research on N2
O emissions from weeds is extremely limited. However,
there are similarities between the utilization of N and water between cover crops and weed management in
POST herbicide control systems. Cover crops reduce N2
O emissions because they uptake excess soil N and
reduce soil moisture. When cover crops are terminated, their residues break down and release N, and their
presence on the surface generally increases soil moisture. This favors denitrification and the release of N2
O.
Using what is known about cover crops as a framework, my hypothesis is that treatments with growing weeds
will have reduced N2
O emissions compared to treatments without weeds. However, once the weeds are killed
they will create surface residues before they start to break down and therefore generate higher N2
O emissions
as weed densities increase. Overall, I expect that total N2
O emissions will be comparable for plots with the same
N treatment (independent of weed density), but the magnitude and timing of N2
O fluxes will differ.
I’m excited to analyze the data from
this greenhouse study and compare
the results to a similar non-crop field
study I’ll be conducting this summer.
Additionally, I’ll have a field study
investigating how N2
O emissions
are affected by weed competition
for N and soil moisture with corn,
and another study measuring N2
O
emissions in soybean plots with
different row spacings and levels of
weed management.
Research Spotlight Rebecca Redline
Dr. Vince Davis
University of Wisconsin-Madison
Looking Forward
Discoveries To-Date
My research will determine how nitrogen (N) use and early-season weed management influence nitrous oxide
(N2
O) emissions in Midwest corn and soybean production. Weeds compete with these crops for water and soil
available nitrogen, and soil moisture and N fertility are major contributors to N2
O emissions in crops. Moreover,
plant residues on the soil surface encourage N cycling and emissions. My research seeks to answer to following
questions: What effect does early-season weed competition have on N2
O emissions? Do dead weed residues
in crops increase N2
O emissions? Are cumulative emissions (before and after postemergence weed control)
the same for a given rate of N independent of weed density?
A non-crop greenhouse study is underway that compares the
effects of N rate and weed density on N2
O emissions. Nitrogen
is applied when the weeds are seeded, and when weeds are
10-15 cm tall they are killed with glyphosate and residue is left
on the soil surface. Gas samples and soil moisture data are
collected starting at the time of weed seeding until four weeks
after the glyphosate application. Static gas chambers are used
in each treatment and four gas samples are removed from
each chamber over the course of one hour twice each week.
Samples are analyzed with gas chromatography to determine
the concentration of N2
O and gas fluxes for each treatment are
determined by regression analysis over the four sample timings.
Figure. Anticipated results of N2O fluxes over time for various N rates and weed
densities based on our stated hypothesis. This graph does not represent actual date,
just our hypothetical expectation.
Powell amaranth in our static
gas sampling chambers,
just prior to glyphosate
application, at equivalent field
density of 100 plants m-2
. At
the glyphosate application
timing, weeds are harvested
in one chamber to determine
biomass accumulation and
gas samples are continually
collected over the dead
weed residue in the second
chamber following the
application.
9

Research Spotlight Mike Dunbar
Dr. Aaron Gassmann and Dr. Matthew O’Neal
Discoveries To-Date
I investigate how different farm management practices, including the use of cover crops and extended rotations,
will impact arthropod communities. Arthropods are sampled multiple times throughout the growing season and
are also sampled at different locations within the crops (i.e., at ground and canopy level). Captured arthropods
are identified and then classified into categories such as beneficial or pest taxa. I expect that increasing levels
of polyculture will foster increasing abundance and/or diversity of beneficial arthropod taxa while decreasing
pest taxa abundance.
Arthropod communities are measured monthly throughout the growing season. To capture arthropods at the
ground level, pitfall traps are placed within fields. Arthropods that move throughout or above the crop canopy
are captured with sticky traps and sweep nets. Once captured, arthropods are identified to their taxonomic
family (though in some cases individuals may be identified to species) and categorized as being beneficial,
harmful (pests), or neutral to the cropping system. Once all the arthropods are identified, different ecological
indices can be calculated which measure the characteristics of the arthropod communities of interest.
I’ve focused on better understanding the influence of
farm management practices including cover crops over
the last two years. Differences between abundance of
beneficial and pest arthropod communities have rarely
been observed between fields planted with cover crops
and fields where cover crops are absent. However,
abundance data only tells one part of the story; how many
individuals were classified as beneficial, pest or neutral
taxa is also important. Understanding what taxa make up
communities of arthropods found in soybean fields grown
with cover crops compared to soybean fields grown in the
absence of cover crops will hopefully yield more interesting
results. It could be that arthropod communities in more
diverse planting schemes are themselves more diverse in
arthropod taxa than more conventional monoculture. I plan
to answer some part of that question as I move forward
with my research.
Mean species richness (or more accurately, family
richness) of research plots grown at the Iowa State
University Ag Research Site, Ames, IA 2012. These
data are taken from pitfall traps, and only include
taxa that are considered beneficial. Throughout the
season it appears that species richness is similar
between plots where cover crops were planted and
where they were not.
Looking Forward
I hope to see similar trends from our ecological indices over all three years of sampling (2011-2013). Hopefully,
regardless of an extreme drought year, increasing levels of polyculture will correspond to increasing levels of
beneficial arthropod diversity.
Overall June July Aug Sept
SpeciesRichness(±SEM)
0
2
4
6
8
10
SB
SB(Rye)
Corn
Corn(Rye)
10

Going Forward
The highlights of the first two years of funding are the three graduate student projects funded entirely
by USB. The students have been incorporated into the larger CSCAP project, gaining an important
awareness of transdisciplinary research. The IPM team also is collecting data to supplement Mike
Dunbar’s graduate research and pest-related data to complement the larger CSCAP project.
With three more years of funding from CSCAP, we will continue to leverage USB’s funding with the
$20 million from USDA-NIFA.
The vision moving forward is to build on the activities that currently exist – complementing the CSCAP
project with pest data and adding graduate students to answer peripheral questions related to the
larger project and IPM. With the next three years of funding, the existing three graduate students will
finish and we plan to add several more graduate students. As more faculty see the value in being part
of the larger CSCAP project, several graduate student projects have been discussed. These include:
• Understanding how changing climate may play a role in the distribution of charcoal rot on soybean
• Studying the effect of extreme weather events on green stem syndrome
• Studying how strobilurin fungicides will affect root growth, thus affecting how crops can survive
drier-than-normal growing conditions
• Study the impact of water management on weeds
• Continue to look at the effect of soil moisture on soybean cyst nematode
• Continue to investigate the effect of weeds on greenhouse gas emissions
• Effect of soybean on carbon and nitrogen footprint [Note: not IPM related, but can be incorporated
in the next three years.]
11

Please contact us with your questions or areas of interest:
Dr. Daren Mueller
Assistant Professor, Iowa State University
dsmuelle@iastate.edu | 515.460.8000
Lori Abendroth
Project Manager, CSCAP
labend@iastate.edu | 515.294.5692
Dr. Lois Wright Morton
Project Director, CSCAP
Professor, Iowa State University
lwmorton@iastate.edu | 515.294.2843
Climate and Corn-based Cropping Systems Coordinated Agricultural Project
www.sustainablecorn.org
Design Assistance from Gabrielle Glenister
CSCAP Project Management Undergraduate Assistant

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