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2006

Iowa State University

Plant Sciences

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New Extension Corn Production Web Site, Lori Abendroth, Roger W. Elmore Dec 2006

New Extension Corn Production Web Site, Lori Abendroth, Roger W. Elmore

Integrated Crop Management News

We've designed a new Web site for Iowa State University Extension corn production that has current and relevant management information for producing corn in Iowa. The Web site provides research-based recommendations and diagnostic tools for producers and agribusinesses. The largest section of the Web site is devoted to "Corn Management," which is broken into categories based on whether the topic addresses overarching production issues, such as cropping systems and rotations, or if the topic can be isolated to a certain time of the growing season (planting, early-season, mid-/late-season, harvest). For example, in the "Planting" category, users can find ...


A Response To Phenomenon In 2006: Multiple Ears Per Node, Roger W. Elmore, Lori Abendroth Dec 2006

A Response To Phenomenon In 2006: Multiple Ears Per Node, Roger W. Elmore, Lori Abendroth

Integrated Crop Management News

Corn hybrids from several companies expressed more than one ear at a single node from Iowa to Indiana in 2006. Multiple ears are not unexpected, but they typically occur at different nodes (as with prolific hybrids), not on the same node. This trait was expressed in different ways in Iowa. In the most extreme cases, up to eight ears occurred at a single node. Some have called these "bouquets." Ears on these plants were usually barren. In one case, a field with bouquet ears yielded 50 bu/acre.


How To Interpret Scn Soil Test Results, Gregory L. Tylka Dec 2006

How To Interpret Scn Soil Test Results, Gregory L. Tylka

Integrated Crop Management News

Soybean yield loss due to the soybean cyst nematode (SCN) occurred throughout much of Iowa in 2006. Damage from this pest was particularly noticeable in areas of the state that were very dry. There seems to be increased interest in testing for and managing SCN in Iowa this fall, and there likely has been more fields sampled for SCN this fall than in recent years. Following are some commonly asked questions and answers that illustrate things to consider when interpreting SCN soil sample results. This information is excerpted from Iowa State University Extension publication IPM 61, Interpreting SCN Soil Sample ...


Crop Performance Test Bulletins Now Available, Keven Arrowsmith Dec 2006

Crop Performance Test Bulletins Now Available, Keven Arrowsmith

Integrated Crop Management News

Results of the 2006 Iowa Crop Performance Tests for alfalfa, barley, corn, oat, soybean, triticale, and winter wheat are now available. For those wanting to download a copy of the bulletins, visit the Iowa Crop Improvement Association (ICIA) Web site or the Iowa State University (ISU) Extension Distribution Center (EDC) online store. Published bulletins may be requested by contacting ICIA at (515) 294-6921 or EDC at (515) 294-5247.


Aphids In The Air: What Is The Risk For 2007?, Wayne Ohnesorg, Matthew E. O'Neal, Marlin E. Rice Dec 2006

Aphids In The Air: What Is The Risk For 2007?, Wayne Ohnesorg, Matthew E. O'Neal, Marlin E. Rice

Integrated Crop Management News

The 2006 growing season has come to a close and with it another year's worth of experience with the soybean aphid. For many, it was a quiet, "low aphid" year with few reports of economic outbreaks within Iowa. Reflecting these low populations in the field, we observed fewer aphids within our suction traps (Figure 1) compared to the 2005 growing season when the traps collected nearly 100 times more aphids (Figure 2). For the last two years, the Iowa suction trap network (Figure 3) has been part of a larger network of suction traps located in nine states throughout ...


Disaster Recovery—Managing Immature Crops For Grain Or Silage, Stephen K. Barnhart, Roger W. Elmore, Palle Pedersen, H. Mark Hanna Dec 2006

Disaster Recovery—Managing Immature Crops For Grain Or Silage, Stephen K. Barnhart, Roger W. Elmore, Palle Pedersen, H. Mark Hanna

Agriculture and Environment Extension Publications

Tips on managing crops that may not mature before the first killing freeze of fall.


Impact Of Trap Design, Windbreaks, And Weather On Captures Of European Corn Borer (Lepidoptera: Crambidae) In Pheromone-Baited Traps, Brendon James Reardon, Douglas V. Sumerford, Thomas W. Sappington Dec 2006

Impact Of Trap Design, Windbreaks, And Weather On Captures Of European Corn Borer (Lepidoptera: Crambidae) In Pheromone-Baited Traps, Brendon James Reardon, Douglas V. Sumerford, Thomas W. Sappington

Entomology Publications

Pheromone-baited traps are often used in ecological studies of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). However, differences in trap captures may be confounded by trap design, trap location relative to a windbreak, and changes in local weather. The objectives of this experiment were, first, to examine differences in O. nubilalis adult (moth) captures among the Intercept wing trap, the Intercept bucket/funnel UNI trap, and the Hartstack wire-mesh, 75-cm-diameter cone trap (large metal cone trap) as well as among three cone trap designs. Second, we examined the influence of the location of the large metal cone trap ...


Insect-Mediated Seed-Set Evaluation Of 21 Soybean Lines Segregating For Male Sterility At 10 Different Loci, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer Dec 2006

Insect-Mediated Seed-Set Evaluation Of 21 Soybean Lines Segregating For Male Sterility At 10 Different Loci, E. Ortiz-Perez, Harry T. Horner, S. J. Hanlin, R. G. Palmer

Genetics, Development and Cell Biology Publications

The first requirement to establish a successful hybrid soybean program is the availability of a stable male-sterile, female-fertile system. Male sterility has been an important tool in soybean breeding programs to improve traits such as yield, seed-protein and seed-oil content, and seed size. However, improvement of seed-set per se on male-sterile plants has not been an important breeding objective. The evaluation of the out-crossing potential of the available male-sterile, female-fertile soybean lines is crucial to determine the future of hybrid soybean. The objective of this study was to evaluate seed-set among 21 soybean lines segregating for male sterility at 10 ...


Restoring Perennial Cover And Ecological Function To Corn Belt Landscapes: The Iowa Farmer's Perspective, Ryan C. Atwell, Lisa A. Schulte, Lynne M. Westphal Dec 2006

Restoring Perennial Cover And Ecological Function To Corn Belt Landscapes: The Iowa Farmer's Perspective, Ryan C. Atwell, Lisa A. Schulte, Lynne M. Westphal

Natural Resource Ecology and Management Publications

The tallgrass prairie ecosystem of the North American Corn Belt region has experienced major alteration of hydrologic systems, nearly complete loss of natural perennial vegetation, and concomitant decline in species due to agricultural intensification. In this working landscape, restoration to pre-European settlement conditions is doubtful. However, current research posits that restoring strategically placed patches of perennial cover across agricultural watersheds, such as stream buffers, wetlands and prairies, as well as instituting more diverse cropping rotations, could bolster current ecological function and enhance the conservation of species. These studies also suggest that such restoration might increase socio-economic resilience in the region ...


Analysis Of Bulked And Redundant Accessions Of Brassica Germplasm Using Assignment Tests Of Microsatellite Markers, Von Mark V. Cruz, John D. Nason, Richard Luhman, Laura F. Marek, Randy C. Shoemaker, E. Charles Brummer, Candice A. C. Gardner Dec 2006

Analysis Of Bulked And Redundant Accessions Of Brassica Germplasm Using Assignment Tests Of Microsatellite Markers, Von Mark V. Cruz, John D. Nason, Richard Luhman, Laura F. Marek, Randy C. Shoemaker, E. Charles Brummer, Candice A. C. Gardner

Ecology, Evolution and Organismal Biology Publications

This study was conducted to determine if Brassica germplasm bulks created and maintained by the USDA-ARS North Central Plant Introduction Station (NCRPIS) were made with genetically indistinguishable component accessions and to examine newly identified putative duplicate accessions to determine if they can be bulked. Using ten microsatellite primer pairs, we genotyped two bulks of B. rapa L. ssp. dichotoma (Roxb.) Hanelt comprising four accessions and three bulks of B. rapa L. ssp. trilocularis (Roxb.) Hanelt comprising fourteen accessions, as well as four pairs of putatively duplicate accessions of B.␣napus L. Assignment tests on ten individual plants per accession were ...


Determining The Extent Of Frost Damage In Maize Seed Using The Tetrazolium Test, Mindy Devries, A. Susana Goggi Dec 2006

Determining The Extent Of Frost Damage In Maize Seed Using The Tetrazolium Test, Mindy Devries, A. Susana Goggi

Agronomy Publications

Frost damage in seed corn causes a significant decrease in seed quality. The tetrazolium (TZ) test has been used to identify types of physiological damage in several plant species, including frost damage in corn. Quantifying the amount of seed damaged by frost and the consequent loss of seed vigor are important for making management decisions. The current tetrazolium test procedures provide seed viability information but do not estimate seed vigor. In our project, the tetrazolium staining procedure was modified to allow separation of viable seeds into vigor categories. Vigor categories were defined based on Association of Official Seed Analysts (AOSA ...


Can Ground Eggshells Be Used As A Liming Source?, John Holmes, Paul Kassel Nov 2006

Can Ground Eggshells Be Used As A Liming Source?, John Holmes, Paul Kassel

Proceedings of the Integrated Crop Management Conference

Iowa has become the leading egg producing state in the U.S. It's common to see large-scale egg-laying units in many parts of Iowa. Although most plants ship the eggs intact, some facilities have begun to ship liquid eggs. One egg-breaking operation in northern Iowa produces approximately 15 tons of ground eggshells daily. Several other egg-breaking facilities are also operating in Iowa. The eggshells at most locations are ground, stockpiled, and applied to farm fields. Farmers want to know if the eggshells have any value as a liming source, and if so, at what rate they should be applied.


Row Spacing Is Critical For High Yielding Soybeans, Palle Pedersen Nov 2006

Row Spacing Is Critical For High Yielding Soybeans, Palle Pedersen

Proceedings of the Integrated Crop Management Conference

There are fundamental management decisions that give the best opportunity to maintain high yield. Understanding how a soybean plant develops through the season will provide insight into selection of management decisions that should lead to maintaining the soybean genetic yield potential. Row spacing is the third most important variable for maximizing soybean yield after variety selection and planting date. Most research from the Midwest documents that narrows (less than 30 inch) yield greater than wide rows (30 inch or greater). Despite this, the majority of the acres in Iowa are still planted in wide rows. Why7 There are many reasons ...


Production And Use Of Flax And Field Peas In Iowa, Margaret Smith, Mary Wiedenhoeft, Sarah Carlson, Jim Fawcett Nov 2006

Production And Use Of Flax And Field Peas In Iowa, Margaret Smith, Mary Wiedenhoeft, Sarah Carlson, Jim Fawcett

Proceedings of the Integrated Crop Management Conference

Most Iowa crop producers now rely on only two crops, corn and soybeans, for their livelihood. This has led to many challenges, including increased pest problems, such as bean leaf beetles and soybean aphids, a skewed distribution of labor throughout the year, and vulnerability to adverse weather and poor prices. It has also become increasingly difficult to compete in the world market when these commodities can be produced at a lower cost in other countries, such as Brazil. Crop producers are continually looking for a third crop to include in their rotation, but either the economics are not favorable or ...


Brown Stem Rot And Its Interaction With The Soybean Cyst Nematode, G. M. Tabor, G. L. Tylka, C. R. Bronson Nov 2006

Brown Stem Rot And Its Interaction With The Soybean Cyst Nematode, G. M. Tabor, G. L. Tylka, C. R. Bronson

Proceedings of the Integrated Crop Management Conference

Brown stem rot (BSR) of soybeans is caused by the fungal vascular pathogen Cadophora gregata (previously named Phialophora gregata). BSR is an economically important disease of soybeans in the north central United States, being prevalent in 68 to 73% of the soybean fields of Illinois, Iowa, and Minnesota (Workneh et al. 1999). There are two genetic types (called genotypes) of C. gregata that differ in their ability to cause foliar symptoms on susceptible soybeans (Chen et al. 2000). Infection by genotype A of the fungus can result in mild to severe brown discoloration of the pith and severe foliar symptoms ...


Cost-Effective, Performance-Based Environmental Management, John Rodecap, Chad Ingels Nov 2006

Cost-Effective, Performance-Based Environmental Management, John Rodecap, Chad Ingels

Proceedings of the Integrated Crop Management Conference

Iowa has over 19,000 miles of interior rivers and streams, numerous lakes and other natural resources and considerable agricultural production capacity. With such an extensive network of water bodies running through the state it is no surprise that experts have estimated that 90% of Iowa water quality issues are attributed to agricultural land and related activities. This nonpoint source contamination often results from long term actions and will take a long time for measurable outcomes.


Crop Management Practices In Indiana Soybean Production Systems?, Shawn P. Conley, Judith B. Santini Nov 2006

Crop Management Practices In Indiana Soybean Production Systems?, Shawn P. Conley, Judith B. Santini

Proceedings of the Integrated Crop Management Conference

To meet the current and future needs of today's soybean producer it is vital that agricultural researchers and Extension specialists clearly understand the production concerns of our clientele. The objective of this research was to characterize the current management practices of Indiana soybean (Glycine max (L.) Merr.) growers, to identify specific educational needs, and to provide a framework for directing applied soybean research efforts. This assessment was conducted through a direct-mail survey. The results of this survey define distinct similarities and differences among growers of different farm operation size. Large acreage growers (>1000 acres) were more likely to plant ...


Can We Sustain Corn Yield Trends?, Roger Elmore Nov 2006

Can We Sustain Corn Yield Trends?, Roger Elmore

Proceedings of the Integrated Crop Management Conference

Corn yields in Iowa continue at a rate of 2 bushels per acre per year. This is a trend that started back in the 1940's. Driven by hybrid genetic improvement and management the question we need to address is: Are these yield trends sustainable into the future? Will these yield trends continue to increase? If so, for how long7 We can think of yield in four different ways. Yield trends for two of these four are increasing while two are not:


The "Root" Of Drought Problems, Elwynn Taylor Nov 2006

The "Root" Of Drought Problems, Elwynn Taylor

Proceedings of the Integrated Crop Management Conference

Agricultural plants require moisture, but there is more to it than a simple need for rain or irrigation. Under conditions that depend on precipitation to replenish crop available soil moisture it is easy to conclude that the success of the crop depends upon the rain. This is in large measure true , yet considerable variations in yields are found in areas with like precipitation. The "law of limiting factors" holds that at any given moment there is only one factor limiting the growth of a plant. It may be some aspect of soil fertility, or temperature, or light, or carbon dioxide ...


Wisconsin Farmers Take The 2-Pass Challenge Against Weeds, Richard T. Proost, Daniel J. Heider, Chris M. Boerboom Nov 2006

Wisconsin Farmers Take The 2-Pass Challenge Against Weeds, Richard T. Proost, Daniel J. Heider, Chris M. Boerboom

Proceedings of the Integrated Crop Management Conference

Single pass herbicide programs have become the standard for most Wisconsin corn producers. The apparent time and cost savings in controlling weeds with a single pre or post-emergence herbicide application is the driving force behind this trend. While there are situations where a single pass program will work, it has weaknesses that can result in inconsistent performance.


Site-Specific Tillage Management And Crop Yield Response, Mahdi Al-Kaisi Nov 2006

Site-Specific Tillage Management And Crop Yield Response, Mahdi Al-Kaisi

Proceedings of the Integrated Crop Management Conference

Tillage decision is only one issue farmers have to make during fall. There are many factors that need to be considered in selecting a tillage system for any given field or region within the state. Those factors are soil conditions, which can include, soil slope, soil drainage, top soil depth or the A-horizon depth. Other factors need to be considered, which are equally important. They are management factors, such as, residue cover, type of residue (corn or soybean), soil moisture condition at the time of making the decision, timing of tillage operation, fertilizer management in conjunction with tillage operation, type ...


Weed Management Update - Who Cares?, Micheal D. K. Owen Nov 2006

Weed Management Update - Who Cares?, Micheal D. K. Owen

Proceedings of the Integrated Crop Management Conference

Despite the importance of glyphosate-based crop systems, there is a need for continued investigation and development of new tactics to manage weeds effectively and economically. It is interesting that larger farm size and higher percentage of income attributable to grain is associated with growers willingness to accept alternative weed management strategies and the adoption of integrated weed management programs (Hammond et al. 2006). The concern for timely weed management in order to protect crop yields becomes premiere in POST-based corn and soybean systems, whether based on glyphosate or any other herbicide (Halford et al. 200 l; Cox et al. 2006 ...


Strategies For Management Of Soybean Sudden Death Syndrome And White Mold, X. B. Yang, S. S. Navi Nov 2006

Strategies For Management Of Soybean Sudden Death Syndrome And White Mold, X. B. Yang, S. S. Navi

Proceedings of the Integrated Crop Management Conference

Soybean sudden death syndrome (SDS) caused by Fusarium solani f. sp. glycines and soybean white mold caused Sclerotinia sclerotiorum were two of the most prevalent diseases in 2006. The two diseases have become even year production problems for some producers. This workshop will review results of the latest studies from the past two years and discuss management strategies for the two diseases. The SDS has been recognized as a major disease of soybean (Glycine max (L.) Merrill) in the southern United States for nearly three decades. In 1995 Scherm and Yang using computer model predicted that the disease would become ...


A Postemergence Primer, Bob Hartzler Nov 2006

A Postemergence Primer, Bob Hartzler

Proceedings of the Integrated Crop Management Conference

Postemergence herbicides are the most widely used weed management tool in Iowa's corn and soybean acres. Application of the herbicide directly to the target bypasses the myriad of soil interactions that influence preemergence herbicides. However, killing weeds with postemergence products is not as simple as merely getting the herbicide onto the leaf of the weed. This paper will discuss the factors that influence the activity of postemergence weeds.


Using Resistant Soybean Varieties To Manage Soybean Cyst Nematode, Gregory L. Tylka Nov 2006

Using Resistant Soybean Varieties To Manage Soybean Cyst Nematode, Gregory L. Tylka

Proceedings of the Integrated Crop Management Conference

The soybean cyst nematode (SCN) was a serious yield-limiting pest of soybeans throughout Iowa in 2006. It caused severe damage in areas of Iowa that received less-than-normal rainfall. This nematode is widely distributed throughout the state and does not increase its numbers extraordinarily (i.e. does not flare up) in dry years. The nematode has excellent long-term survival and its population densities build up each year that susceptible soybeans are grown, regardless of the precipitation that occurs. Research in Iowa has shown that up to 40% yield loss can occur without the appearance of any above-ground symptoms.


Managing Nitrogen For High Corn Yields, John E. Sawyer Nov 2006

Managing Nitrogen For High Corn Yields, John E. Sawyer

Proceedings of the Integrated Crop Management Conference

The old saying still holds; yield is king. Producers are interested in high crop yields in order to pay for input costs, cover enterprise expenses, and provide profits. Demand for corn grain is increasing rapidly, with large need for expanding ethanol and livestock production. This demand is fueling interest in higher productivity and more continuous corn (CC). Yields are now commonly topping 200+ bu/acre, and risk of yield loss related to nitrogen (N) management weighs as heavily on the minds of producers as it ever has. What N management practices make sense to sustain high yield in corn following ...


Evaluation Of The Illinois Soil Nitrogen Test In The North Central Region, C. A. M. Laboski, J. E. Sawyer, D. T. Walters, L. G. Bundy, R. G. Hoeft, G. W. Randall, T. W. Andraski Nov 2006

Evaluation Of The Illinois Soil Nitrogen Test In The North Central Region, C. A. M. Laboski, J. E. Sawyer, D. T. Walters, L. G. Bundy, R. G. Hoeft, G. W. Randall, T. W. Andraski

Proceedings of the Integrated Crop Management Conference

Data from 96 locations across the North Central Region was complied to evaluate the usefulness of the Illinois soil nitrogen test (ISNT) in identifying fields where corn will not respond to additional N fertilizer and predicting the yield optimizing N rate (YONR) for each field. The ISNT could not accurately predict non-responsive sites, nor could it predict YONR. Sub-setting the data based on soil drainage class and previous crop did not improve the predictive capability of the ISNT. The ISNT was related to soil organic matter and was measuring a constant fraction of total soil N. The ISNT is not ...


Management Considerations For Continuous Corn Production, Lori Abendroth Nov 2006

Management Considerations For Continuous Corn Production, Lori Abendroth

Proceedings of the Integrated Crop Management Conference

Growing a corn crop after a previous crop of corn on the same ground requires special management. But we've done it before! In 1976, Iowa had around 14 million acres of corn and 6 1/2 million acres of soybean. That is about a 2:1 ratio. The ratio of corn to soybean in 2006 was 55:45 with nearly 13 million acres of corn. We can grow more corn. The question is how to do it without sacrificing yield. Although in some of the better years for growing corn and in some environments in those years yields are ...


Strike Two For Soybean Rust - 2006 In Review, Alison Robertson, X. B. Yang Nov 2006

Strike Two For Soybean Rust - 2006 In Review, Alison Robertson, X. B. Yang

Proceedings of the Integrated Crop Management Conference

Asian soybean rust is caused by the fungus Phakopsora pachyrhizi. This disease was first reported in November 2004 and survived the past two winters on kudzu in the south. Soybean rust can seriously reduce soybean yields and/or significantly increase the cost of soybean production when the disease occurs with high incidence and severity


Forage For Horses: But The Horse Isn't Really The Customer!, Steve Barnhart Nov 2006

Forage For Horses: But The Horse Isn't Really The Customer!, Steve Barnhart

Proceedings of the Integrated Crop Management Conference

Horses are natural grass eaters. Their mouth structure and digestive anatomy allow horses to successfully use forages as a primary source of nutrition and as an important part of normal digestive system function. This requirement for forages is most easily supplied by pasture and hay. Mature horses will generally consume 2 to 2.5 percent of their body weight in feed each day. Ideally, horses should consume l percent or more (as dry matter) of their body weight daily as hay or pastures. Forages can provide varying amounts of the nutrient requirements depending on the forage quality and amount consumed ...