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New Strategies To Enhance Sustainability Of Apple Orchards, Mark Gleason, Donald R. Lewis, Matthew Z. Liebman, Paul A. Domoto, Gaile R. Nonnecke, Michael Duffy, Lester Wilson, Cheryl A. Reitmeier Aug 2017

New Strategies To Enhance Sustainability Of Apple Orchards, Mark Gleason, Donald R. Lewis, Matthew Z. Liebman, Paul A. Domoto, Gaile R. Nonnecke, Michael Duffy, Lester Wilson, Cheryl A. Reitmeier

Donald Lewis

Three years of experiments were conducted to help increase profit margins for apple growers, cope with new regulations on pesticide use, and deal with increased pesticide resistance by major apple pests and diseases.


Performance Of Scn-Resistant Soybean Varieties In Iowa In 2016, Greg Tylka Apr 2017

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

Gregory Tylka

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.


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.


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.


Corn Following Corn In 2008, Mahdi Al-Kaisi, Roger W. Elmore, Antonio P. Mallarino, Palle Pedersen, Alison E. Robertson, John E. Sawyer, Jon J. Tollefson Jul 2016

Corn Following Corn In 2008, Mahdi Al-Kaisi, Roger W. Elmore, Antonio P. Mallarino, Palle Pedersen, Alison E. Robertson, John E. Sawyer, Jon J. Tollefson

John E. Sawyer

Corn following corn is in rough shape in areas across Iowa. Many wonder what is happening. The crop’s condition in general is not normal for this time of year. For example, last Sunday the USDA rated this year’s Iowa corn crop as 54 percent in ‘Good’ to ‘Excellent’ condition and 15 percent is ‘Poor’ or ‘Very Poor.’ Last year 72 percent was rated ‘Good’ to ‘Excellent’ and 5 percent was in ‘Poor’ or ‘Very Poor’ condition during the same week. Average plant height as of Sunday was 24 inches compared to 40 inches at end of the same ...


Storing Fungicides Safely, Alison E. Robertson, Richard O. Pope Feb 2016

Storing Fungicides Safely, Alison E. Robertson, Richard O. Pope

Alison Robertson

Growers who stocked up on fungicides for the 2005 growing season due to the threat of Asian soybean rust will likely be facing fungicide storage issues this winter, especially since it is likely that most products cannot be returned. The good news is that most fungicides have a shelf life of at least two years--and probably longer--assuming they are stored correctly. Optimum storage conditions are cool, dry conditions, away from sunlight. Storage temperatures should not go below freezing; however, if a fungicide does freeze, then slowly thaw it out at room temperature.


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.


Summary Of 2009 Western Bean Cutworm Trapping Program, Laura C.H. Jesse, Erin W. Hodgson, Adam Sisson, Richard Pope Feb 2010

Summary Of 2009 Western Bean Cutworm Trapping Program, Laura C.H. Jesse, Erin W. Hodgson, Adam Sisson, Richard Pope

Integrated Crop Management News

The western bean cutworm (WBC), once a pest of the High Plains, has been on the move since at least 2000. (See map below.) This native caterpillar pest of dry beans and corn has been expanding its range to the east through the Corn Belt. WBC spread across Iowa during 2000-2003 and was first recorded in Illinois and Missouri in 2004.


New Strategies To Enhance Sustainability Of Apple Orchards, Mark Gleason, Donald R. Lewis, Matthew Z. Liebman, Paul A. Domoto, Gaile R. Nonnecke, Michael Duffy, Lester Wilson, Cheryl A. Reitmeier Jan 2010

New Strategies To Enhance Sustainability Of Apple Orchards, Mark Gleason, Donald R. Lewis, Matthew Z. Liebman, Paul A. Domoto, Gaile R. Nonnecke, Michael Duffy, Lester Wilson, Cheryl A. Reitmeier

Leopold Center Completed Grant Reports

Three years of experiments were conducted to help increase profit margins for apple growers, cope with new regulations on pesticide use, and deal with increased pesticide resistance by major apple pests and diseases.


Considerations For Soybean Insecticides And Fungicides, Alison E. Robertson, Daren S. Mueller, Nate Bestor, Matthew E. O'Neal, Rebekah Ritson Jul 2009

Considerations For Soybean Insecticides And Fungicides, Alison E. Robertson, Daren S. Mueller, Nate Bestor, Matthew E. O'Neal, Rebekah Ritson

Integrated Crop Management News

Several Iowa agribusinesses are offering soybean growers pest management plans that include applications of fungicide and insecticide. Although combining an insecticide and fungicide may be convenient, the results from our 2008 Pesticide Stewardship trials suggest this is a convenience that may not pay off.


Size Restrictions For Postemergence Herbicides In Corn, Erin W. Hodgson, Richard O. Pope Jun 2009

Size Restrictions For Postemergence Herbicides In Corn, Erin W. Hodgson, Richard O. Pope

Integrated Crop Management News

Stalk borer is native to Iowa and has only one generation per year. Adult stalk borers are grayish-brown moths with white spots along the forewing with a 1-inch wingspan. Adults emerge in early August and lay eggs in grasses and broadleaf weeds until October. Larvae hatch in late April and early May, or when 500 degree days (base 41°F) have accumulated.


Alfalfa Weevil Hatch Is Upon Us, Richard O. Pope, Jon J. Tollefson Apr 2009

Alfalfa Weevil Hatch Is Upon Us, Richard O. Pope, Jon J. Tollefson

Integrated Crop Management News

The map below indicates the accumulated degree days for each of the nine Iowa crop reporting districts. Degree-day information indicates that alfalfa weevil larvae should be hatching this week in southern Iowa. In central Iowa counties, weevils should be hatching by the third week of April; and in northern Iowa, weevils should hatch the last full week of April. That means that fields in southern Iowa should be scouted now.


A 2009 Prediction For Stewart’S Disease Of Corn, Forrest W. Nutter Jr., Alison E. Robertson, Jon J. Tollefson, Richard O. Pope Apr 2009

A 2009 Prediction For Stewart’S Disease Of Corn, Forrest W. Nutter Jr., Alison E. Robertson, Jon J. Tollefson, Richard O. Pope

Integrated Crop Management News

December, January and February temperatures were all colder than average across Iowa. As a result, the risk for Stewart’s disease of corn in 2009 is low to negligible throughout all of Iowa, based on two predictive models. Stewart’s disease, also known as Stewart’s wilt, is caused by the bacterium Pantoea stewartii. An insect vector, the corn flea beetle, plays a critical role in the plant-to-plant spread of this causal microorganism.


Fungicide-Insecticide Study On Soybeans, Nathan R. Bestor, Daren S. Mueller, Alison E. Robertson, Rebecca Ritson, Matthew E. O'Neal, Palle Pedersen Jan 2009

Fungicide-Insecticide Study On Soybeans, Nathan R. Bestor, Daren S. Mueller, Alison E. Robertson, Rebecca Ritson, Matthew E. O'Neal, Palle Pedersen

Iowa State Research Farm Progress Reports

This study was designed to optimize insecticide and fungicide usage on soybeans by comparing different products applied at different timings. To explain yield responses, foliar disease severity and aphid populations were assessed throughout the season.


Goss’S Wilt Prevalent In Western Iowa, Alison E. Robertson, Laura C.H. Jesse Aug 2008

Goss’S Wilt Prevalent In Western Iowa, Alison E. Robertson, Laura C.H. Jesse

Integrated Crop Management News

This past week several corn samples infected with Goss’s wilt were submitted to the Iowa State University Plant and Insect Diagnostic Clinic. Tamra Jackson at University of Nebraska, Lincoln has also reported an increase in the prevalence of Goss’s wilt in Nebraska this growing season (see Crop Watch, August 8, 2008).


Corn Following Corn In 2008, Mahdi Al-Kaisi, Roger W. Elmore, Antonio P. Mallarino, Palle Pedersen, Alison E. Robertson, John E. Sawyer, Jon J. Tollefson Jul 2008

Corn Following Corn In 2008, Mahdi Al-Kaisi, Roger W. Elmore, Antonio P. Mallarino, Palle Pedersen, Alison E. Robertson, John E. Sawyer, Jon J. Tollefson

Integrated Crop Management News

Corn following corn is in rough shape in areas across Iowa. Many wonder what is happening. The crop’s condition in general is not normal for this time of year. For example, last Sunday the USDA rated this year’s Iowa corn crop as 54 percent in ‘Good’ to ‘Excellent’ condition and 15 percent is ‘Poor’ or ‘Very Poor.’ Last year 72 percent was rated ‘Good’ to ‘Excellent’ and 5 percent was in ‘Poor’ or ‘Very Poor’ condition during the same week. Average plant height as of Sunday was 24 inches compared to 40 inches at end of the same ...


Iowa 2008 Prediction For Stewart’S Disease Of Corn, Forrest W. Nutter Jr., Lu Liu, Richard O. Pope, Marlin E. Rice Apr 2008

Iowa 2008 Prediction For Stewart’S Disease Of Corn, Forrest W. Nutter Jr., Lu Liu, Richard O. Pope, Marlin E. Rice

Integrated Crop Management News

Following an Iowa winter of ice, snow and cold temperatures, the predicted risk for Stewart’s disease of corn in 2008 is negligible throughout most of Iowa, with only the southeastern-most counties having a low risk. Stewart’s disease (also known as Stewart’s wilt), is caused by the bacterium Pantoea stewartii. In addition to the pathogen, an insect vector, the corn flea beetle, plays a critical role in the spread of this microorganism from plant-to-plant.


Bean Leaf Beetle: Predicted Peak First-Generation Dates, Marlin E. Rice, Richard O. Pope Jul 2007

Bean Leaf Beetle: Predicted Peak First-Generation Dates, Marlin E. Rice, Richard O. Pope

Integrated Crop Management News

Bean leaf beetle feeding on soybean pods can lead to significant reductions in seed quality and yield. Management during the pod setting and filling stages can be frustrating because beetles may feed on pods for a couple of weeks before the population reaches the economic threshold. In this situation, some loss in seed quality and quantity occurs before an insecticide application can be economically justified. Several years ago, Larry Pedigo and his students in the Department of Entomology developed research-based information to help make a management decision for second-generation bean leaf beetles based upon the population size of the first-generation ...


Fungicide Applications In Corn May Be Increasing, Alison E. Robertson, Daren S. Mueller, Carol Pilcher, Kristine J. P. Schaefer Jun 2007

Fungicide Applications In Corn May Be Increasing, Alison E. Robertson, Daren S. Mueller, Carol Pilcher, Kristine J. P. Schaefer

Integrated Crop Management News

In the past, fungicide applications on hybrid corn were mostly regarded as uneconomical. The increased corn-following-corn acres and associated increased disease risk, together with the higher price of corn and fungicide marketing, are responsible for changes in corn production practices. As a result, fungicide applications on corn may be more common in 2007. It is anticipated that most of these foliar fungicide applications will occur during corn tasseling stage and will be aerial applications.


Stalk Borers Moving Into Southern Iowa Corn, Marlin E. Rice, Richard O. Pope Jun 2007

Stalk Borers Moving Into Southern Iowa Corn, Marlin E. Rice, Richard O. Pope

Integrated Crop Management News

Stalk borers are notorious for killing or stunting corn rows next to fences, grassed waterways, and conservation terraces. This insect can be most troublesome in nonBt corn, which of course could include the Bt refuge acres. To stop this damage, fields must be scouted and an insecticide applied on a timely basis before the larvae have an opportunity to tunnel into the growing point of the young plants.


Black Cutworm 2007 Cutting Dates Predicted, Marlin E. Rice, Richard O. Pope May 2007

Black Cutworm 2007 Cutting Dates Predicted, Marlin E. Rice, Richard O. Pope

Integrated Crop Management News

Significant numbers of black cutworm adults (moths) were captured in pheromone traps during April across Iowa. This insect is an occasional pest of seedling corn that sometimes causes significant damage in a few fields. Pheromone trap cooperators reported catching moths across the state in late March and throughout April. Based upon these trap captures, we anticipate that first cutting of seedling corn should occur May 9-10 across southern Iowa, May 18-19 across central Iowa, and May 20-21 across northern Iowa.


Seed Treatments In Soybean: Managing Bean Pod Mottle Virus, Jeffrey D. Bradshaw, Marlin E. Rice, John H. Hill Apr 2007

Seed Treatments In Soybean: Managing Bean Pod Mottle Virus, Jeffrey D. Bradshaw, Marlin E. Rice, John H. Hill

Integrated Crop Management News

Bean leaf beetles are the principal vectors of bean pod mottle virus (BPMV). Last week we discussed the affects of seed-applied insecticides on bean leaf beetles and whether such insecticides can substitute for an early-season foliar application within a BPMV disease management program. Although there is a positive relationship between bean leaf beetles and BPMV, the effect of chemical control on the disease is different than that for the insect vector. As we discussed last week, a management program that included seed-applied insecticides resulted in improved yield but lower seed quality. Why does this happen and how is BPMV affected?


Bean Leaf Beetles: Predicted Winter Mortality, Marlin E. Rice, Richard O. Pope Apr 2007

Bean Leaf Beetles: Predicted Winter Mortality, Marlin E. Rice, Richard O. Pope

Integrated Crop Management News

During the last 17 years, the bean leaf beetle has undergone tremendous population changes in Iowa. From 1989 to 1996, the populations (both first generation and second generation) were relatively insignificant and the insect hardly could even be considered a serious pest. But in 1997, the population in central Iowa began to accelerate nearly yearly until it reached a historical high in 2002. Populations that year were nearly 400 times larger than those of the mid-1990s. Since that time, the population has returned to more normal levels and is similar to what we witnessed at the beginning of the beetle ...


Seed Treatments In Soybean: Managing Bean Leaf Beetles, Jeffrey D. Bradshaw, Marlin E. Rice, John H. Hill Apr 2007

Seed Treatments In Soybean: Managing Bean Leaf Beetles, Jeffrey D. Bradshaw, Marlin E. Rice, John H. Hill

Integrated Crop Management News

To date, our recommendation for the chemical control of bean leaf beetles and bean pod mottle virus has been for an early and a mid-season application of a pyrethroid insecticide (e.g., Asana®, Mustang®, or Warrior®). These insecticide applications should be timed such that fields are treated as soon as bean leaf beetles are first detected in the field (the early-season application) and again when the first generation emerges in early July (the mid-season application). These applications have been shown to improve yield and seed quality under high disease and beetle pressure.


Alfalfa Weevil Predictions For Iowa, 2007, Marlin E. Rice, Richard O. Pope Apr 2007

Alfalfa Weevil Predictions For Iowa, 2007, Marlin E. Rice, Richard O. Pope

Integrated Crop Management News

Degree-day information indicates that alfalfa weevil larvae should have started hatching in southern Iowa on March 30-31. In central Iowa counties, weevils should be hatching by the middle of April, and in southern Iowa, weevils should hatch the last full week of April. Proper management of this insect requires timely scouting, correct identification, determination of population levels, and if necessary, cutting the hay or spraying an insecticide. Alfalfa weevil larvae can be very destructive to first-cutting alfalfa, so fields should be scouted. Larvae remove leaf tissue, beginning with the new leaves at the top of the plant, then work down ...


Revisiting An Integrated Approach To Bean Leaf Beetle And Bean Pod Mottle Virus Management, Marlin E. Rice, Jeffrey D. Bradshaw, John H. Hill Mar 2007

Revisiting An Integrated Approach To Bean Leaf Beetle And Bean Pod Mottle Virus Management, Marlin E. Rice, Jeffrey D. Bradshaw, John H. Hill

Integrated Crop Management News

This article originally appeared in the 2005 ICM newsletter. However, the significance of the bean leaf beetle and bean pod mottle virus has not diminished in recent years. There is still the potential of economic damage from either or both pests. We have recently completed a three-year study that examines the complex issues of managing these two pests, but the data are still being analyzed. We also have identified potential field tolerance to virus disease. Growers are encouraged to query seed dealers regarding tolerance of varieties to virus disease. Ultimately, this will likely be the best management tool for disease ...


Recent Study Brings "Good News" About The Soybean Aphid, John H. Hill, Palle Pedersen, Craig R. Grau, Eileen Cullen Mar 2007

Recent Study Brings "Good News" About The Soybean Aphid, John H. Hill, Palle Pedersen, Craig R. Grau, Eileen Cullen

Integrated Crop Management News

Increased activity of bean leaf beetles and soybean aphids in Iowa soybean fields has challenged many of us over the last five years. Not just because of the sap feeding and leaf defoliation that can cause significant yield loss but also because we are dealing with another yield robber that we often can't see. Iowa soybean fields can be infected with bean pod mottle and soybean {m}osaic viruses that are transmitted by bean leaf beetles and soybean aphids, respectively. The challenge that we are dealing with is, first of all, we can't always see that we have ...


Soybean Pests In 2006: A Survey Of Corn And Soybean Initiative Partners, Richard O. Pope Mar 2007

Soybean Pests In 2006: A Survey Of Corn And Soybean Initiative Partners, Richard O. Pope

Integrated Crop Management News

ISU Corn and Soybean Initiative partner agronomists were surveyed in December about pest management issues in corn and soybean in the 2006 growing season. Here are summarized results of the survey concerning soybean pests. There were 17 usable responses from 28 companies polled, and responses geographically covered most parts of the state except extreme south-central Iowa.


Western Bean Cutworm Management In 2006, Richard O. Pope Feb 2007

Western Bean Cutworm Management In 2006, Richard O. Pope

Integrated Crop Management News

Western bean cutworm is a corn pest that has become an economic concern in some parts of Iowa in the past decade. Iowa State University led a pheromone trapping network to monitor the presence and timing of emergence of adults in Iowa. The map shows the reported data on moth captures for the season. ISU Corn and Soybean Initiative partner agronomists were surveyed in December about pest management issues in corn and soybean in the 2006 growing season.


Bean Pod Mottle Virus: Back With A Vengeance, John H. Hill, Palle Pedersen, Jeffrey D. Bradshaw Aug 2006

Bean Pod Mottle Virus: Back With A Vengeance, John H. Hill, Palle Pedersen, Jeffrey D. Bradshaw

Integrated Crop Management News

As stated in an earlier article in the ICM Newsletter (May 15, 2006), bean leaf beetles are back with a vengeance this year. Based on observations from agronomists across the state, this year seems to have the highest level of bean leaf beetles since 2002. This also has resulted in an apparent high incidence of bean pod mottle virus disease in Iowa fields. Infected plants can be characterized by the leaves, which show a yellow to green blotchy appearance called leaf mottle. Sometimes leaves have a raised or blistered appearance.