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2006

Agricultural Science

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Switchgrass For Biomass Feedstock In The Usa, Matt Sanderson, Paul Adler, Akwasi Boateng, Michael Casler, Gautam Sarath Dec 2006

Switchgrass For Biomass Feedstock In The Usa, Matt Sanderson, Paul Adler, Akwasi Boateng, Michael Casler, Gautam Sarath

Publications from USDA-ARS / UNL Faculty

Switchgrass has received much study for biomass feedstock production and conversion through research funded by the US-DOE and USDA during the past two decades. We have an improved understanding of the adaptation of existing cultivars and new cultivars with yield and adaptation improvements are now appearing. We also have a good understanding of the agronomics of switchgrass production, mainly from its use as a forage crop. There remain several constraints to switchgrass use in bioenergy cropping systems, including reliable establishment methods to obtain productive stands in the first year, targeted fertilization and nutrient management techniques to efficiently use nitrogen fertilizer ...


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 ...


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 ...


Intsormil’S Global Impact: A Revolution In West African Sorghum Production, Intsormil Dec 2006

Intsormil’S Global Impact: A Revolution In West African Sorghum Production, Intsormil

INTSORMIL Impacts and Bulletins

Sorghum and pearl millet are the staple grains for millions of people around the world, especially those residing in the semiarid margins of agricultural sustainability. For this reason, INTSORMIL has been working in the semiarid regions of Africa and Central America where it has been helping sorghum and millet farmers achieve the status of surplus grain production and the economic, social and health benefits thus provided. What impact has INTSORMIL had on the lives of these sorghum and millet farmers?

To determine the global impact of the USAID funded INTSORMIL program, Battelle, an independent agency, was chosen to conduct an ...


Bovine Immune Response To Shiga-Toxigenic Escherichia Coli O157:H7, Mark A. Hoffman, Christian Menge, Thomas A. Casey, William Laegreid, Brad T. Bosworth, Evelyn A. Dean-Nystrom Dec 2006

Bovine Immune Response To Shiga-Toxigenic Escherichia Coli O157:H7, Mark A. Hoffman, Christian Menge, Thomas A. Casey, William Laegreid, Brad T. Bosworth, Evelyn A. Dean-Nystrom

Publications from USDA-ARS / UNL Faculty

Although cattle develop humoral immune responses to Shiga-toxigenic (Stx+) Escherichia coli O157:H7, infections often result in long-term shedding of these human pathogenic bacteria. The objective of this study was to compare humoral and cellular immune responses to Stx+ and Stx- E. coli O157:H7. Three groups of calves were inoculated intrarumenally, twice in a 3-week interval, with different strains of E. coli: a Stx2- producing E. coli O157:H7 strain (Stx2+O157), a Shiga toxin-negative E. coli O157:H7 strain (Stx-O157), or a nonpathogenic E. coli strain (control). Fecal shedding of Stx2+O157 was significantly higher than that ...


Agronomic And Quality Effects In Winter Wheat Of A Gene Conditioning Resistance To Wheat Streak Mosaic Virus, L. A. Divis, R. A. Graybosch, C. J. Peterson, P. Stephen Baenziger, G. L. Hein, B. B. Beecher, T. J. Martin Nov 2006

Agronomic And Quality Effects In Winter Wheat Of A Gene Conditioning Resistance To Wheat Streak Mosaic Virus, L. A. Divis, R. A. Graybosch, C. J. Peterson, P. Stephen Baenziger, G. L. Hein, B. B. Beecher, T. J. Martin

Publications from USDA-ARS / UNL Faculty

Wheat streak mosaic virus (WSMV) is one of the most important diseases limiting winter wheat (Triticum aestivum L.) production in the western Great Plains of North America. There is no known effective WSMV resistance within the primary gene pool of wheat. However, a resistance gene (Wsm1) has been transferred to wheat from a perennial relative, intermediate wheat-grass [Thinopyrum intermedium (Host) Barkworth & DR Dewey]. Nebraska-adapted winter wheat lines carrying Wsm1 were used to characterize the effects of this alien introgression on agronomic and quality traits. Sister-lines from six breeding populations were evaluated under virus-free conditions, and under a naturally ...


More About Early Seed Discounts, Jim R. Rouse, Roger W. Elmore, Lori Abendroth Nov 2006

More About Early Seed Discounts, Jim R. Rouse, Roger W. Elmore, Lori Abendroth

Integrated Crop Management News

We received a great deal of feedback from our article in the October 9, 2006, issue of the ICM newsletterconcerning early seed discounts. Most of it was very positive and congratulated us for tackling an issue that is important to every grower. There were also a few readers who felt the article missed the mark, so we want to clarify some of the points.


Late Movement Of Soybean Rust, Daren S. Mueller Nov 2006

Late Movement Of Soybean Rust, Daren S. Mueller

Integrated Crop Management News

After a hot, dry summer with very little movement, soybean rust made a late push both up the East Coast and into the Ohio River Valley. After the dust settled from the excitement in October, rust was reported in 159 new counties, including seven new states (Arkansas, Illinois, Indiana, Kentucky, Missouri, Tennessee, and Virginia). Soybean rust season totals to date are 230 counties in 15 states on soybean and 262 counties total (including kudzu). Last year at this time, there were only 130 counties in seven states positive for soybean rust. No rust was found in Iowa despite extensive scouting ...


Scn-Resistant Soybean Varieties For 2007: Many Choices, Few Sources Of Resistance, Gregory L. Tylka Nov 2006

Scn-Resistant Soybean Varieties For 2007: Many Choices, Few Sources Of Resistance, Gregory L. Tylka

Integrated Crop Management News

The soybean cyst nematode (SCN) is a major yield-limiting pest of soybeans throughout the Midwest that can be managed very effectively through use of SCN-resistant soybean varieties. Resistant varieties reduce the amount of SCN reproduction (and population density buildup) that occurs while producing significantly greater soybean yields than non-resistant (susceptible) varieties in fields infested with the nematode. The Iowa State University Extension publication titled Soybean cyst nematode-resistant soybean varieties for Iowa has recently been updated, is now available, and lists SCN-resistant soybean varieties available to Iowa growers in late maturity group 0 and maturity groups 1, 2, and 3.


Ethanol Webcast Archived Online, Jean Mcguire Nov 2006

Ethanol Webcast Archived Online, Jean Mcguire

Integrated Crop Management News

The Perspectives on Present and Future Corn-Based Ethanol Industry webcast was presented by Iowa State University (ISU) Extension on Monday, November 13. An archive of the program is available athttp://www.extension.iastate.edu/webcast/archive.htm. Seven Iowa State University economists presented economic information on several aspects of the industry during the 3-hour, 15-minute program. Links to papers offering additional information on each topic and the PowerPoint each presenter used are available at http://www.extension.iastate.edu/ag/ethanol.html.


What's Your Type?: An Hg Type Test For Scn Populations, Gregory L. Tylka Nov 2006

What's Your Type?: An Hg Type Test For Scn Populations, Gregory L. Tylka

Integrated Crop Management News

SCN-resistant soybean varieties reduce the amount of SCN reproduction that occurs when soybeans are grown. But if resistant soybean varieties are grown repeatedly, an SCN population capable of reproducing readily on the resistant varieties can develop. This is because resistant varieties are not immune; they allow some low level of SCN reproduction. The possibility of SCN populations building up on resistant varieties is especially a concern because almost all resistant soybean varieties have SCN resistance genes from the soybean breeding line PI88788 (see article on newly published list of SCN-resistant soybean varieties for 2007 in this issue).


Bt Rootworm Corn Failures: Understanding The Issues, Jon J. Tollefson, Marlin E. Rice Nov 2006

Bt Rootworm Corn Failures: Understanding The Issues, Jon J. Tollefson, Marlin E. Rice

Integrated Crop Management News

Genetically engineered corn that produces a Bt toxin effective against corn rootworms is now readily available and was widely planted in Iowa during 2006. Several seed companies have registrations, or will have shortly, and they will add additional Bt events and varieties to the choices for corn rootworm management. Does that mean that our corn rootworm management decisions are over, and we don't have to worry about rootworm injury? No. Bt corn rootworm hybrids are another insect management tool that must be thoughtfully incorporated into corn production practices.


The Circuitous Path To The Comparison Of Simulated Values From Crop Models With Field Observations, Albert Weiss, Wally Wilhelm Nov 2006

The Circuitous Path To The Comparison Of Simulated Values From Crop Models With Field Observations, Albert Weiss, Wally Wilhelm

Publications from USDA-ARS / UNL Faculty

The Journal of Agricultural Science, Cambridge has been a fixture in dissemination of crop simulation models and the concepts and data upon which they are built since the inception of computers and computer modeling in the mid-20th century. To quantify the performance of a crop simulation model, model outputs are compared with observed values using statistical measures of bias, i.e. the difference between simulated and observed values. While applying these statistical measures is unambiguous for the experienced user, the same cannot always be said of determining the observed or simulated values. For example, differences in accessing crop development can ...


Models And Applications For Risk Assessment And Prediction Of Asian Soybean Rust Epidemics, Emerson M. Del Ponte, Cláudia V. Godoy, Marcelo G. Canteri, Erlei M. Reis, X. B. Yang Nov 2006

Models And Applications For Risk Assessment And Prediction Of Asian Soybean Rust Epidemics, Emerson M. Del Ponte, Cláudia V. Godoy, Marcelo G. Canteri, Erlei M. Reis, X. B. Yang

Plant Pathology and Microbiology Publications

Asian rust of soybean [Glycine max (L.) Merril] is one of the most important fungal diseases of this crop worldwide. The recent introduction of Phakopsora pachyrhiziSyd. & P. Syd in the Americas represents a major threat to soybean production in the main growing regions, and significant losses have already been reported. P. pachyrhizi is extremely aggressive under favorable weather conditions, causing rapid plant defoliation. Epidemiological studies, under both controlled and natural environmental conditions, have been done for several decades with the aim of elucidating factors that affect the disease cycle as a basis for disease modeling. The recent spread of ...


Harina De Sorgo En La Industria Panificadora De El Salvador, Intsormil Nov 2006

Harina De Sorgo En La Industria Panificadora De El Salvador, Intsormil

INTSORMIL Impacts and Bulletins

La industria panificadora de El Salvador depende de las importaciones de trigo, lo cual ocasiona una pérdida considerable de divisas. En respuesta a esto, los investigadores del Centro Nacional de Tecnología Agropecuaria y Forestal (CENTA) con ayuda del INTSORMIL han venido produciendo variedades de sorgo con cualidades físicas y químicas adecuadas para sustituir parcialmente la harina de trigo, reduciendo de esta manera los costos de producción de las panaderías. La Señora Fidelia Herrera, técnologa del CENTA fue la primera en tomar el liderazgo sobre la necesidad del uso de la harina de sorgo en El Salvador, al ayudar durante los ...


Sorghum Flour In The El Salvador Baking Industry, Intsormil Nov 2006

Sorghum Flour In The El Salvador Baking Industry, Intsormil

INTSORMIL Impacts and Bulletins

The El Salvador baking industry is dependent on imported wheat which results in a loss of valuable foreign exchange. In response, CENTA (Centro Nacional de Tecnologia Agropecuaria y Forestal) scientists with support from INTSORMIL have produced sorghum varieties which have the physical and chemical qualities making them suitable for flour which can be used as a partial substitute for wheat flour in the baking industry, thus decreasing the cost of baked goods. CENTA food technician, Fidelia Herrera pioneered the use of sorghum flour in El Salvador and began helping village bakers utilize sorghum flour back in the 70’s.

To ...


University Research Program Sees Drop In Funding, Zach Pluhacek Nov 2006

University Research Program Sees Drop In Funding, Zach Pluhacek

INTSORMIL Impacts and Bulletins

A program headquartered at the University of Nebraska-Lincoln that uses science to assist economically stressed nations will receive $9 million throughout five years through a cooperative agreement with the U.S. Agency for International Development.

The agreement, announced Friday morning by the UNL Office of Research and Graduate Studies, will significantly decrease the annual funding the International Sorghum and Millet Collaborative Research Support Program, or INTSORMIL, has received in recent years.


Convergence Of Agriculture And Energy: Implications For Research And Policy, Kenneth Cassman, Vernon Eidman, Eugene Simpson, Larry Berger, Robert Loomis, Marie Walsh, Todd A. Peterson, Edward Runge Nov 2006

Convergence Of Agriculture And Energy: Implications For Research And Policy, Kenneth Cassman, Vernon Eidman, Eugene Simpson, Larry Berger, Robert Loomis, Marie Walsh, Todd A. Peterson, Edward Runge

Publications from USDA-ARS / UNL Faculty

Access to an adequate energy supply at reasonable cost is crucial for sustained economic growth. Unfortunately, oil prices and the need to import from politically unstable countries lowers the reliability of the U.S. energy supply and hinders economic development. Although biofuels have been identified as an important component of the national strategy to decrease U.S. dependence on imported oil, the ability to sustain a rapid expansion of biofuel production capacity raises new research and policy issues. This document seeks to identify the most critical of these issues to help inform the policy development process. The goal is to ...


Grazing Management Effects On Sediment And Phosphorus In Surface Runoff, Matthew M. Haan, James R. Russell, Wendy J. Powers, John L. Kovar, Jamie L. Benning Nov 2006

Grazing Management Effects On Sediment And Phosphorus In Surface Runoff, Matthew M. Haan, James R. Russell, Wendy J. Powers, John L. Kovar, Jamie L. Benning

Publications from USDA-ARS / UNL Faculty

Sediment and phosphorus (P) in runoff from pastures are potential non–point-source pollutants in surface waters that may be influenced by surface cover, sward height, treading damage, surface slope, soil moisture, and soil P. The objectives of the current study were to quantify sediment and total P loads in runoff produced during simulated rainfall from pastures and to evaluate their relationships with the physical and chemical characteristics of the soil and sward. Five forage management treatments— ungrazed (U), hay harvest/fall stockpile grazing (HS), continuous stocking to a sward height of 5 cm (5C), and rotational stocking to sward heights ...


Heat Stress Risk Factors Of Feedlot Heifers, Tami M. Brown-Brandl, Roger A. Eigenberg, John A. Nienaber Oct 2006

Heat Stress Risk Factors Of Feedlot Heifers, Tami M. Brown-Brandl, Roger A. Eigenberg, John A. Nienaber

Publications from USDA-ARS / UNL Faculty

Heat stress in cattle results in millions of dollars in lost revenue each year due to production losses, and in extreme cases, death. Death losses are more likely to result from animals vulnerable to heat stress. A study was conducted to determine risk factors for heat stress in feedlot heifers. Over two consecutive summers, a total of 256 feedlot heifers (32/ breed/ year) of four breeds were observed. As a measure of stress, respiration rates and panting scores were taken twice daily (morning and afternoon) on a random sample of 10 heifers/ breed. Weights, condition scores, and temperament scores were ...


Comparison Of Heat Tolerance Of Feedlot Heifers Of Different Breeds, T. M. Brown-Brandl, J. A. Nienaber, Roger A. Eigenberg, Terry L. Mader, J. L. Morrow, J. W. Dailey Oct 2006

Comparison Of Heat Tolerance Of Feedlot Heifers Of Different Breeds, T. M. Brown-Brandl, J. A. Nienaber, Roger A. Eigenberg, Terry L. Mader, J. L. Morrow, J. W. Dailey

Publications from USDA-ARS / UNL Faculty

Heat stress in cattle causes decreases in feed intake and feed efficiency; in extreme cases, it can cause death. These losses amount to millions of dollars each year. A study was designed to determine severity of heat stress among four breeds of cattle. Throughout two summers, 256 feedlot heifers of four different breeds were observed. Respiration rates, panting scores, and surface temperatures were taken twice each day on 10 animals/breed for several weeks during the summers of 2002 and 2003. Twenty-four-hour behavior measurements were recorded for four heat-stress and four thermoneutral days. Results showed during the afternoon, Angus cattle ...


Heat Stress Risk Factors Of Feedlot Heifers, T. M. Brown-Brandl, Roger A. Eigenberg, J. A. Nienaber Oct 2006

Heat Stress Risk Factors Of Feedlot Heifers, T. M. Brown-Brandl, Roger A. Eigenberg, J. A. Nienaber

Publications from USDA-ARS / UNL Faculty

Heat stress in cattle results in millions of dollars in lost revenue each year due to production losses, and in extreme cases, death. Death losses are more likely to result from animals vulnerable to heat stress. A study was conducted to determine risk factors for heat stress in feedlot heifers. Over two consecutive summers, a total of 256 feedlot heifers (32/ breed/ year) of four breeds were observed. As a measure of stress, respiration rates and panting scores were taken twice daily (morning and afternoon) on a random sample of 10 heifers/ breed. Weights, condition scores, and temperament scores were ...


Icm Conference Registration Opens Soon, Brent A. Pringnitz Oct 2006

Icm Conference Registration Opens Soon, Brent A. Pringnitz

Integrated Crop Management News

The 2006 Integrated Crop Management Conference and Agribusiness Expo will be held November 29-30, 2006, at the Iowa State Center complex in Ames. The conference will once again feature a program packed with the latest information on crop production and protection brought to you by Iowa State University specialists and invited speakers from around the Midwest. Returning this year is the Agribusiness Expo, held in Hilton Coliseum on Wednesday, November 29.


Check Fields For Scn To Prepare For 2007, Gregory L. Tylka Oct 2006

Check Fields For Scn To Prepare For 2007, Gregory L. Tylka

Integrated Crop Management News

The soybean cyst nematode (SCN) continues to be an extremely damaging and widespread pest of soybean in Iowa and many other Midwestern states. The nematode infests more than 70 percent of the fields in Iowa and more than 80 percent of the fields in Illinois. Often there is no obvious stunting or yellowing of soybean plants in infested fields. Consequently, many SCN-infested fields in Iowa have not been diagnosed.


Rural And Ag Safety And Health Forum November 16, Keven Arrowsmith Oct 2006

Rural And Ag Safety And Health Forum November 16, Keven Arrowsmith

Integrated Crop Management News

Iowa's Center for Agricultural Safety and Health (I-CASH) and the Great Plains Center for Agricultural Health are cosponsoring the Midwest Rural and Agricultural Safety and Health Forum on November 16, 2006, at the Holiday Inn and Conference Center in Coralville, IA.


Grain Quality And Handling Issues For 2006, Charles R. Hurburgh Oct 2006

Grain Quality And Handling Issues For 2006, Charles R. Hurburgh

Integrated Crop Management News

The erratic rainfall patterns across Iowa have affected both yield and quality for corn and soybeans. Because more corn is likely to be stored for local use through the entire crop year, attention to harvest and storage management details will be very important.