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Evaluating Herbicide Injury On Soybean, Robert G. Hartzler May 2017

Evaluating Herbicide Injury On Soybean, Robert G. Hartzler

Integrated Crop Management News

The potential for herbicide injury with preemergence herbicides is greater with soybean than corn. The risk increases with environmental conditions that reduce crop vigor and growth rate, and also with heavy rain that moves the herbicide to the depth of the germinating seed or emerging seedling. Much of the state has experienced these conditions, thus it is likely symptoms will be found in many fields as people return to the field with the improved weather.


Preemergence Herbicide Options For Planted Soybean Fields, Bob Hartzler May 2017

Preemergence Herbicide Options For Planted Soybean Fields, Bob Hartzler

Integrated Crop Management News

The spread of multiple herbicide resistant weeds brought an end to the era of total postemergence programs in soybean. Unfortunately, a prolonged rainy period prevented applications of preemergence treatments on many planted soybean fields in certain areas of the state. By the time fields are fit for field operations soybeans likely will be emerging and limit herbicide options in those fields. Without careful management and a bit of good fortune, this situation will make it difficult to stay ahead of the weeds for the remainder of the season. Controlling emerged weeds and applying an effective residual herbicide in these fields ...


The Economics Of Soil Health, Mahdi Al-Kaisi May 2017

The Economics Of Soil Health, Mahdi Al-Kaisi

Integrated Crop Management News

The term “economics of soil health” has been used frequently in an attempt to quantify and validate the value of improving soil health. The traditional thinking about assigning dollar values to soil health metrics, which are many, can be very challenging and it is easier said than done.


A Pest Of The Past: Have You Seen Hop Vine Borer?, Erin W. Hodgson May 2017

A Pest Of The Past: Have You Seen Hop Vine Borer?, Erin W. Hodgson

Integrated Crop Management News

A common caterpillar we include in our ISU field guides is hop vine borer (Figure 1), but I can’t even remember the last time I saw one. I’m wondering if it’s an early-season pest of the past? Archived ICM News articles tell me it was most commonly observed in northeastern Iowa and states to the east. It was considered an occasional pest that caused stand loss in corn, particularly in fields with grassy weeds. Have you seen it lately?


Worker Protection Standard Training Video For Workers And Handlers Now Available, Elizabeth J. Buffington, Kristine Schaefer May 2017

Worker Protection Standard Training Video For Workers And Handlers Now Available, Elizabeth J. Buffington, Kristine Schaefer

Integrated Crop Management News

The Pesticide Safety Education Program (PSEP) at Iowa State University and the Iowa Department of Agriculture and Land Stewardship (IDALS), Pesticide Bureau announce a new EPA-approved PowerPoint and narrated video to train workers and handlers under the 2015 revised Worker Protection Standard (WPS).


Black Cutworm Monitoring 2017, Adam Sisson, Erin Hodgson May 2017

Black Cutworm Monitoring 2017, Adam Sisson, Erin Hodgson

Integrated Crop Management News

This is the time of year when calls about black cutworm (BCW) scouting dates start to roll in, especially when Corn Belt states to the east have reported high moth numbers in traps. Despite what is being observed in states to the east (Illinois, Wisconsin and Indiana), there have been relatively few captures in Iowa. Minnesota has also reported few captures this year, so Iowa is not the only state avoiding major moth flights so far in 2017.


Update On Palmer Amaranth In Conservation Plantings, Bob Hartzler May 2017

Update On Palmer Amaranth In Conservation Plantings, Bob Hartzler

Integrated Crop Management News

The 2016 growing season will be remembered by many for the widespread detections of Palmer amaranth across Iowa. While native seed mixes contaminated with Palmer amaranth seed used in Conservation Reserve Program (CRP) fields were the largest source of introduction, it is important to recognize that the weed was also found in at least 7 counties in areas other than CRP fields. Palmer amaranth seed can be transported by machinery, in feed or bedding and by wildlife, thus all fields in Iowa are at risk of being invaded by Palmer amaranth.


Scouting For Pests In Iowa Cover Crops, Erin W. Hodgson Apr 2017

Scouting For Pests In Iowa Cover Crops, Erin W. Hodgson

Integrated Crop Management News

Landscape diversification, including the use of cover crops, can provide habitat and forage for beneficial insects. This is especially true in the spring when there is a lack of food. Alternatively, cover crops can also support field crop pests, including moths, beetles, flies and slugs. The early spring vegetation, sometimes called a “green bridge,” provides resources until the row crops emerge. In the past, several green bridge pests have become common in Iowa.


Alfalfa Weevils Active Throughout Southern And Central Iowa, Erin W. Hodgson Apr 2017

Alfalfa Weevils Active Throughout Southern And Central Iowa, Erin W. Hodgson

Integrated Crop Management News

Adult alfalfa weevils become active and start laying eggs as soon as temperatures exceed 48°F. Alfalfa weevil eggs develop based on temperature, or accumulating degree days, and hatching can start around 200-300 degree days. Start scouting alfalfa fields south of Interstate 80 at 200 degree days and fields north of Interstate 80 at 250 degree days. Based on accumulated temperatures since January, weevils could be active throughout southern and central Iowa (Figure. 1).


Bean Leaf Beetle Mortality Predictions, Erin Hodgson, Adam Sisson Apr 2017

Bean Leaf Beetle Mortality Predictions, Erin Hodgson, Adam Sisson

Integrated Crop Management News

Bean leaf beetle adults (Photo 1) are susceptible to cold weather and most will die when the air temperature falls below 14°F (-10°C). However, they have adapted to winter by protecting themselves under plant debris and loose soil. Each spring, adult beetles emerge from overwintering habitat and migrate to available host plants, such as alfalfa, tick trefoil, and various clovers. As the season progresses, bean leaf beetles move to more preferred hosts, like soybean. While initial adult activity can begin well before soybean emergence, peak abundance often coincides with early vegetative soybean growth.


Plan To Scout Alfalfa Stands For Winter Survival, Brian Lang Mar 2017

Plan To Scout Alfalfa Stands For Winter Survival, Brian Lang

Integrated Crop Management News

A warm weather pattern in late February caused soil temperatures across most of Iowa to rise above 40 degrees Fahrenheit (F). This warm period was likely long enough for alfalfa and some forage grasses (most ryegrass varieties and less winter-hardy orchardgrass and tall fescue varieties) to break dormancy. When low temperatures resume, alfalfa plants can reharden to a degree, but only to the extent that it still has stored carbohydrates available. Winter injury occurs either when frequent warm-cold cycles deplete carbohydrates, or if the temperature drops so rapidly that the plant does not have time to sufficiently reharden


Resistance Management Plan For Soybean Aphid, Erin W. Hodgson Feb 2017

Resistance Management Plan For Soybean Aphid, Erin W. Hodgson

Integrated Crop Management News

Soybean aphid remains the most important soybean insect pest in Iowa, and management over the last fifteen years has primarily relied on using foliar insecticides. The economic injury level was defined in 2007, and is approximately 675 aphids per plant or 5,560 cumulative aphid days. From that multi-state 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 is increased with regular scouting and applications made after exceeding the economic threshold. The ...


Last County In Iowa Found Infested With Scn, Greg Tylka, Brian Lang Jan 2017

Last County In Iowa Found Infested With Scn, Greg Tylka, Brian Lang

Integrated Crop Management News

More than 100 fields throughout Iowa were surveyed for the presence of the soybean cyst nematode (SCN) in 2016 in a project sponsored by the ISU Soybean Research Center and the Iowa Soybean Association (ISA). Soil samples were collected by Iowa State University Extension and Outreach field agronomists and ISA staff and interns and sent to the ISU Plant and Insect Diagnostic Clinic for processing.


Wind Speed And Herbicide Application, Robert G. Hartzler Jan 2017

Wind Speed And Herbicide Application, Robert G. Hartzler

Integrated Crop Management News

The anticipated increase in dicamba and 2,4-D use associated with XtendTM and EnlistTM crops will require enhanced stewardship to prevent problems with off-target movement. While many factors influence herbicide drift, high wind speeds pose the greatest threat of moving herbicides off the intended target.


Performance Of Scn-Resistant Soybean Varieties In Iowa In 2016, Greg Tylka Dec 2016

Performance Of Scn-Resistant Soybean Varieties In Iowa In 2016, Greg Tylka

Integrated Crop Management News

Soybean varieties that are resistant to the soybean cyst nematode (SCN) are essential tools for managing the pest. Resistance to SCN requires multiple genes, and soybean varieties bred to be resistant may not contain all of the resistance genes necessary to provide maximum nematode control. Consequently, SCN control can vary greatly among resistant soybean varieties, just as yield.

Iowa State University evaluates the SCN control and yield of SCN-resistant soybean varieties in field experiments conducted throughout Iowa annually. The effort is supported, in part, by soybean checkoff funds from the Iowa Soybean Association.


What’S The Situation With Scn In Your Fields?, Greg Tylka Oct 2016

What’S The Situation With Scn In Your Fields?, Greg Tylka

Integrated Crop Management News

The soybean cyst nematode (SCN) is capable of causing serious yield loss on soybeans every year and is widespread throughout Iowa and much of the Midwest. In the “good ole days,” a farmer was “good to go” with SCN management if he or she knew what fields were infested with the nematode and then grew SCN-resistant soybean varieties in rotation with the nonhost crop corn. Nowadays, though, things are a little more complicated.

The fact is, your SCN numbers may be building up unbeknownst to you. This buildup can go unrecognized because a soybean crop often does not appear stressed ...


More Scn-Resistant Soybean Varieties Than Ever, But Diversity Of Resistance Is Lacking, Greg Tylka Oct 2016

More Scn-Resistant Soybean Varieties Than Ever, But Diversity Of Resistance Is Lacking, Greg Tylka

Integrated Crop Management News

Nearly 40 years after its discovery in the upper Midwest, the soybean cyst nematode (SCN) continues to be a highly damaging pathogen of soybeans in Iowa and surrounding soybean-producing states. SCN is most damaging in hot, dry growing seasons, but yield losses of 10% to 25% or more can occur in years when temperatures are moderate and rainfall is average or above average. Growing SCN-resistant soybean varieties can slow the build-up of SCN population densities (numbers) in the soil and produce profitable soybean yields in SCN-infested fields.


Cold Temperatures And Burndown Herbicides, Robert G. Hartzler Apr 2016

Cold Temperatures And Burndown Herbicides, Robert G. Hartzler

Integrated Crop Management News

The weather forecast appears to be favorable for field activities so people will be anxious to get into the field. A concern for many will be the effect of the widespread freeze on the performance of burndown herbicides. Unfortunately, there is no simple blanket statement that can be made since the plant response will vary depending on weed species, weed size, and the herbicides used.


2015 Evaluation Of Commercial Seed Treatments On Soybean At Three Locations In Iowa, Alison E. Robertson, Mauricio Serrano, Stith N. Wiggs Apr 2016

2015 Evaluation Of Commercial Seed Treatments On Soybean At Three Locations In Iowa, Alison E. Robertson, Mauricio Serrano, Stith N. Wiggs

Integrated Crop Management News

In 2015, 13 currently available commercial seed treatments were evaluated at three locations in Iowa. Seed treatments that reduce the risk of seedling diseases, soybean cyst nematode (SCN) and sudden death syndrome (SDS) were included in the trial. The goal of the trials is to provide information of the effect of commercial seed treatments on stand count, disease incidence and severity, and yield of soybean. Funding is provided by Iowa Soybean Association.


Fine-Tune Oat Seeding Rate This Spring, Margaret Smith, Mary H. Wiedenhoeft, David Weisberger Mar 2016

Fine-Tune Oat Seeding Rate This Spring, Margaret Smith, Mary H. Wiedenhoeft, David Weisberger

Integrated Crop Management News

It’s time to plant small grains. When planting oats, spring wheat, and barley, farmers typically plant two to three bushels of small grains per acre, but there is a better way to optimize plant populations and grain yields. Farmers calculate corn and soybean rates by seed count and should do the same for small grains.


Terminating Cover Crops - What's Your Plan?, Meaghan J. B. Anderson, Rebecca K. Vittetoe, Robert G. Hartzler Mar 2016

Terminating Cover Crops - What's Your Plan?, Meaghan J. B. Anderson, Rebecca K. Vittetoe, Robert G. Hartzler

Integrated Crop Management News

Take time now to get a plan in place for terminating a cover crop. Whether termination will be done with a herbicide, rolling/crimping, or tillage, it is important to know not just the advantages, but also the limitations with a termination method. Regardless of termination choice, it is important to have a plan in place to minimize problems this spring.


Dicamba And Dicamba-Resistant Soybean Varieties, Robert G. Hartzler, Michael D. Owen Mar 2016

Dicamba And Dicamba-Resistant Soybean Varieties, Robert G. Hartzler, Michael D. Owen

Integrated Crop Management News

On February 3, 2016, Monsanto announced commercial launch plans for soybean varieties resistant to dicamba and glyphosate (designated Roundup Ready 2 Xtend varieties). This announcement followed China’s decision to approve grain from these varieties for import. Many weed management practitioners hope the use of this new technology will improve control of challenging weeds, including those with evolved resistance to glyphosate and herbicides from other groups. Weed science programs across the United States have evaluated this technology for several years, conducting field research to better understand the technology and how it might be best utilized in soybean production systems.


Approaches For Managing Corn Rootworm In Iowa, Erin W. Hodgson, Aaron J. Gassmann Mar 2016

Approaches For Managing Corn Rootworm In Iowa, Erin W. Hodgson, Aaron J. Gassmann

Integrated Crop Management News

Corn rootworm is a persistent and economically important pest in Iowa, with yield loss caused primarily by larval feeding on corn roots. Genetically modified corn with Bt traits kills western and northern rootworm larvae, and Bt-rootworm corn has been available since 2003. However, some Iowa farmers have observed severe root injury to Bt hybrids in continuous cornfields, and there has been documented resistance of western corn rootworm in Iowa to Cry3Bb1 corn and mCry3A corn since 2009 and 2011, respectively.


The Source Matters For Getting The Most Out Of Aerial Imagery, Matthew J. Darr, Zachery S. Vanderleest, Ryan William Bergman, Christopher J. Murphy Mar 2016

The Source Matters For Getting The Most Out Of Aerial Imagery, Matthew J. Darr, Zachery S. Vanderleest, Ryan William Bergman, Christopher J. Murphy

Integrated Crop Management News

As spring plans are finalized, don’t forget to consider aerial imaging as part of a continuous improvement plan. Remote sensing and the use of aerial imagery has been used for decades in agriculture but since 2010 we’ve seen the number of available imagery providers grow extensively. The use of imagery can vary from farm to farm but several common uses include variable rate fertility recommendations, assessing water management performance, quantifying soil compaction and machinery induced yield limiters, locating late season weed outbreaks, and generally evaluating the consistency of crop vigor across a field.


Research Shows Extra Cover Crop Growth Prior To Soybeans Provides Benefits, Daren S. Mueller, Michael J. Castellano Mar 2016

Research Shows Extra Cover Crop Growth Prior To Soybeans Provides Benefits, Daren S. Mueller, Michael J. Castellano

Integrated Crop Management News

This study, funded by the United Soybean Board (USB), was conducted to understand the potential for cover crops to perform in a corn and soybean rotation, and to collect data on the performance of cover crops in those rotations in relation to the timing of termination.


Selecting Nozzles For Postemergence Herbicides, Robert G. Hartzler, H. Mark Hanna Feb 2016

Selecting Nozzles For Postemergence Herbicides, Robert G. Hartzler, H. Mark Hanna

Integrated Crop Management News

An earlier ICM News article discussing affects of nozzle type and size on spray coverage prompted a question from a farmer regarding nozzle selection. In recent years there have been many advances in nozzle design. The primary improvement has been development of nozzles that minimize the formation of driftable droplets (< 200 micron) while still producing a droplet spectrum that provides the level of coverage required for consistent, postemergence weed control.


Managing Two Soybean Pests To Optimize Yield, Erin W. Hodgson, Gregory L. Tylka, Aaron J. Gassmann Feb 2016

Managing Two Soybean Pests To Optimize Yield, Erin W. Hodgson, Gregory L. Tylka, Aaron J. Gassmann

Integrated Crop Management News

Soybean cyst nematode (SCN) and soybean aphid (SBA) are important soybean pests in the north-central region. Soybean varieties with host plant resistance for SCN (PI88788) and SBA (Rag1) can suppress pest populations and subsequently protect yield. In addition, seed treatments are becoming widely adopted and now can include a nematacide, fungicides and insecticide. Combining host plant resistance with seed treatments could potentially further protect yield. This article summarizes a 3-year research effort, funded by the soybean checkoff through a grant from the Iowa Soybean Association, that evaluated interactions among these two pests, host plant resistance, and seed treatments.


Spray Volume Is Critical For Postemergence Herbicides, Robert G. Hartzler, H. Mark Hanna Feb 2016

Spray Volume Is Critical For Postemergence Herbicides, Robert G. Hartzler, H. Mark Hanna

Integrated Crop Management News

Proper herbicide application is critical to ensure products achieve their full potential for weed control. For postemergence herbicides, this includes application to appropriately sized weeds and equipping the sprayer to achieve uniform coverage of target weeds. Weed scientists at Purdue University recently reported on the influence of nozzle type and spray volume on target coverage within the soybean canopy. A traditional flat fan (XR) nozzle and three drift reduction nozzles were included in the study. The XR nozzle produced more driftable droplets than the other nozzles, and the two types of air induction nozzles had much less volume in small ...


A Call To Farmers To Assist With Soybean Yield Gap Project, Mark Licht Feb 2016

A Call To Farmers To Assist With Soybean Yield Gap Project, Mark Licht

Integrated Crop Management News

Soybean production is expected to rise to satisfy the increasing demand for food, biodiesel and livestock feed, both in the United States and globally. It is critical to reduce the yield gap, which is the difference between the attainable crop yield, as determined by the interactive effects of weather, soils and genetics, and the actual crop yield attained by the producer.


Nation’S Premier Site For Water Quality Drives Progress, Matt J. Helmers Jan 2016

Nation’S Premier Site For Water Quality Drives Progress, Matt J. Helmers

Integrated Crop Management News

A farm just outside the north-central Iowa town is home to Iowa State University’s Agriculture Drainage Research and Demonstration Site, a facility that has been working to further Iowa State University’s water conservation efforts since 1990. The site was born out of the Iowa Groundwater Protection Act, a piece of legislation passed in 1987 that generated funds from fees on pesticide manufacturing registrations, pesticide dealer licensing and a tax on fertilizer sales. A portion of the funds were used to create the 11-acre research site, with Iowa State University partnering with the Iowa Department of Agriculture and Land ...