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Iowa State University

Plant Sciences

2010

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Extension Offers Cca Exam Prep Class, Brent A. Pringnitz Dec 2010

Extension Offers Cca Exam Prep Class, Brent A. Pringnitz

Integrated Crop Management News

The Iowa State University Extension Agribusiness Education Program is offering a review session for the upcoming Certified Crop Adviser (CCA) exam. The two-day review session will be held on Jan. 11 from 8:30 a.m. to 5:45 p.m. and Jan. 12 from 8:00 a.m. to 4:00 p.m. in the South Ballroom of the Memorial Union on the Iowa State University campus.


New Information On Herbicide Labels, Robert G. Hartzler Dec 2010

New Information On Herbicide Labels, Robert G. Hartzler

Integrated Crop Management News

Herbicide labels now include a standardized system to inform users of the product’s mechanism of action (MOA). A box labeled ‘Herbicide Group’ is present near the top of the label. The number in the box represents MOA of the active ingredient, based on a system developed by the Weed Science Society of America. Premixes containing more than one mode of action will have multiple numbers listed. Following is an example of the new logo.


Isu Extension Offers Soil Fertility Short Course, Brent A. Pringnitz Dec 2010

Isu Extension Offers Soil Fertility Short Course, Brent A. Pringnitz

Integrated Crop Management News

With high input costs and volatile nutrient prices it is more important than ever to make sound management soil fertility decisions. ISU Extension will be offering a two-day short course focusing on principles of soils, soil fertility and nutrient management to help crop production professionals make informed decisions. In addition to classroom work, attendees will visit the ISU Soil and Plant Analysis Laboratory.


Crop Advantage Series Provides Latest Crop Production Information, Brent A. Pringnitz Dec 2010

Crop Advantage Series Provides Latest Crop Production Information, Brent A. Pringnitz

Integrated Crop Management News

Anyone involved in Iowa crop production should plan to attend a 2011 Crop Advantage Series meeting. The meetings provide information to help producers make profitable decisions for the upcoming growing season. Sponsored by Iowa State University Extension, the meetings will be held at 14 locations across Iowa in January.


Winter Application Of Manure: Regulations And Common Sense, Angela M. Rieck-Hinz Dec 2010

Winter Application Of Manure: Regulations And Common Sense, Angela M. Rieck-Hinz

Integrated Crop Management News

In 2009, the Iowa Legislature passed a bill pertaining to winter application of manure on snow-covered and frozen ground. The rules enforcing that legislation were completed earlier this year and went into effect on Sept. 15, 2010. This law applies to liquid manure from confinement feeding operations that have more than 500 animal units in confinement. This law does not apply to:

  • manure from open feedlots
  • dry manure (frozen manure is not dry manure)
  • liquid manure from small animal feeding operations (confinements with 500 animal units or less)
  • liquid manure that can be appropriately injected or incorporated on the same ...


Update Sds Management After 2010 Outbreaks, Xiao-Bing Yang Dec 2010

Update Sds Management After 2010 Outbreaks, Xiao-Bing Yang

Integrated Crop Management News

The 2010 outbreak of sudden death syndrome (SDS) showed that many SDS management recommendations need more thought. I received several reports suggesting that the way SDS occurred were inconsistent with text books. At Iowa State’s Integrated Crop Management Conference, people shared their unique observations and asked some excellent questions. Below is summary of what we learned from 2010.


Regional Extreme Monthly Precipitation Simulated By Narccap Rcms, William J. Gutowski Jr., Raymond W. Arritt, Sho Kawazoe, David M. Flory, Eugene S. Takle, Sébastien Biner, Richard G. Jones, René Laprise, L. Ruby Leung, Linda O. Mearns, Wilfran Moufouma-Okia, Ana M. B. Nunes, Yun Qian, John O. Roads, Lisa C. Sloan, Mark A. Snyder Dec 2010

Regional Extreme Monthly Precipitation Simulated By Narccap Rcms, William J. Gutowski Jr., Raymond W. Arritt, Sho Kawazoe, David M. Flory, Eugene S. Takle, Sébastien Biner, Richard G. Jones, René Laprise, L. Ruby Leung, Linda O. Mearns, Wilfran Moufouma-Okia, Ana M. B. Nunes, Yun Qian, John O. Roads, Lisa C. Sloan, Mark A. Snyder

Geological and Atmospheric Sciences Publications

This paper analyzes the ability of the North American Regional Climate Change Assessment Program (NARCCAP) ensemble of regional climate models to simulate extreme monthly precipitation and its supporting circulation for regions of North America, comparing 18 years of simulations driven by the National Centers for Environmental Prediction (NCEP)–Department of Energy (DOE) reanalysis with observations. The analysis focuses on the wettest 10% of months during the cold half of the year (October–March), when it is assumed that resolved synoptic circulation governs precipitation. For a coastal California region where the precipitation is largely topographic, the models individually and collectively replicate ...


Quantifying Corn Nitrogen Deficiency And Application Rate With Active Canopy Sensors, J. E. Sawyer, D. W. Barker Dec 2010

Quantifying Corn Nitrogen Deficiency And Application Rate With Active Canopy Sensors, J. E. Sawyer, D. W. Barker

Proceedings of the Integrated Crop Management Conference

Precision agriculture technologies are an integral part of many crop production operations. However, implementation for N application has lagged, primarily due to lack of a viable system for variable N rate decisions. Active canopy sensors have been developed as a tool to determine plant N stress deficiency and provide an on-the-go decision for implementing variable rate. Two general approaches could be implemented. One is to plan on conducting canopy sensing each year, with a reduced N rate applied preplant, at planting, or early sidedress and then sensing conducted at mid-vegetative growth to determine additional application need. A second is to ...


Understanding Corn Development: A Key For Successful Crop Management, Lori J. Abendroth, Roger W. Elmore, Matthew J. Boyer, Stephanie K. Marlay Dec 2010

Understanding Corn Development: A Key For Successful Crop Management, Lori J. Abendroth, Roger W. Elmore, Matthew J. Boyer, Stephanie K. Marlay

Proceedings of the Integrated Crop Management Conference

The new publication, Corn Growth and Development, will be released January 2011 (Abendroth et al., 2011) and replaces How a Corn Plant Develops, Special Report 48 by Iowa State University (Ritchie et al., 1986). Corn Growth and Development (CGD) highlights include: Text based on new corn growth and development research; Images of the plant above- and below-ground; Timelines showcasing crop development across large periods of time; and Season-long nutrient and biomass accumulation curves derived from ISU research conducted during 2007 and 2008.


Influence Of The Rag1 And Rag2 Genes On Aphid Resistance And Agronomic Performance Of Soybean Lines, Shaylyn L. Wiarda, Walter R. Fehr, Matthew E. O'Neal Dec 2010

Influence Of The Rag1 And Rag2 Genes On Aphid Resistance And Agronomic Performance Of Soybean Lines, Shaylyn L. Wiarda, Walter R. Fehr, Matthew E. O'Neal

Proceedings of the Integrated Crop Management Conference

Aphids have been causing economic damage to soybean in the United States since 2000 (Hartman et al., 2001). High aphid density on soybeans causes the yield to decrease due to plant damage including leaf puckering, plant stunting, reduced pod and/or seed counts, and smaller seeds (Rice et al., 2008). In addition, the black sooty mold fungus that grows on aphid honeydew has a negative influence on soybean performance by reducing photosynthesis (Beckendorf et al., 2008).


Glyphosate Interactions With Micronutrients And Plant Diseases, Bob Hartzler Dec 2010

Glyphosate Interactions With Micronutrients And Plant Diseases, Bob Hartzler

Proceedings of the Integrated Crop Management Conference

Glyphosate is the most widely used pesticide in the world. As has happened with other pesticides that attained widespread use, concerns over unintended consequences resulting from glyphosate use have arisen. In addition to articles appearing in trade journals and the popular press, an entire issue of a scientific journal (J. European Agronomy) was devoted to this topic: Glyphosate interactions with physiology, nutrition, and diseases of plants: Threat to agricultural sustainability? (Yamada et al. 2009). This paper will provide an overview of the controversy regarding negative impacts of glyphosate on crop production.


Fifty Years Of Atrazine In Iowa: Benefits, Impacts, And Current Status, Richard S. Fawcett Dec 2010

Fifty Years Of Atrazine In Iowa: Benefits, Impacts, And Current Status, Richard S. Fawcett

Proceedings of the Integrated Crop Management Conference

Atrazine was first registered for use in the U.S. in 1958. It quickly became the preferred herbicide of corn growers, controlling both grasses and broadleaf weeds and being used either as a postemergence or preemergence application, unlike the primary alternative herbicide of the time, 2,4-D (Muller 2008). Over 50 years later, atrazine is still an important weed management tool for corn growers, and was the most widely used herbicide until recently when only glyphosate was used on more acres.


Virus-Phomopsis Interactions On Soybean And The Effects Of Insect And Disease Management Practices, J. P. Soto-Arias, Alison Robertson, Matthew E. O'Neal, Gary Munkvold Dec 2010

Virus-Phomopsis Interactions On Soybean And The Effects Of Insect And Disease Management Practices, J. P. Soto-Arias, Alison Robertson, Matthew E. O'Neal, Gary Munkvold

Proceedings of the Integrated Crop Management Conference

Soybean (Glycine max (L.) Merr.) is affected by several seed-borne pathogens that reduce seed quality, affecting both marketability (Gergerich, 1999; Koning et al. 2001) and germination (Sinclair, 1999). One of the most common seedborne diseases is Phomopsis seed decay, primarily caused by Phomopsis longicolla T. W. Hobbs, a member of the Diaporthe-Phomopsis complex (Sinclair, 1999). Fungi of this complex are widespread throughout most of the soybean producing areas around the world, and the biggest impacts on seed and grain quality are physical damage, reduction in germination, alteration in protein content and reduction of oil quality (Meriles et al., 2004; Sinclair ...


Tillage, Cropping, Harvest, And Nutrient Management Systems Impacts On Phosphorus Loss With Surface Runoff: A Research Update, Antonio P. Mallarino, Mazhar U. Haq, Matthew J. Helmers, Aaron A. Andrews, Carl Pederson, Ryan Rusk Dec 2010

Tillage, Cropping, Harvest, And Nutrient Management Systems Impacts On Phosphorus Loss With Surface Runoff: A Research Update, Antonio P. Mallarino, Mazhar U. Haq, Matthew J. Helmers, Aaron A. Andrews, Carl Pederson, Ryan Rusk

Proceedings of the Integrated Crop Management Conference

Eroded soil and phosphorus (P) impair several Iowa lakes and streams, and exported P contributes to hypoxia in the Gulf of Mexico. Most of the sediment and P originate from agricultural fields and stream banks. Phosphorus is lost from fields mainly by surface and subsurface transport processes, although delivery through water erosion and surface runoff accounts for the vast majority of the P reaching surface water bodies. The P lost with runoff can be classified into particulate P, dissolved reactive P (DRP), and bioavailable P (BAP). Particulate P includes forms in or attached to soil mineral and organic particles (sediment-bound ...


Agronomic Responses Of Corn To Stand Reducation At Vegetative Growth Stages, Jeffrey A. Coulter, Emerson D. Nafziger, Lori J. Abendroth, Peter R. Thomison Dec 2010

Agronomic Responses Of Corn To Stand Reducation At Vegetative Growth Stages, Jeffrey A. Coulter, Emerson D. Nafziger, Lori J. Abendroth, Peter R. Thomison

Proceedings of the Integrated Crop Management Conference

Yield loss charts for hail associated with stand reduction assume that remaining plants lose the ability to compensate for lost plants by mid-vegetative growth. Yield losses and stand losses after V8 – leaf collar system – and throughout the remaining vegetative stages are 1:1 according to the current standards.

We conducted field experiments from 2006 to 2009 at twelve site-years in Illinois, Iowa, and Ohio to determine responses of corn to stand reduction at the fifth, eighth, eleventh, and fifteenth leaf collar stages (V5, V8, V11, and V15, respectively). We also wanted to know whether these responses varied between uniform and ...


Establishing Forages, Stephen K. Barnhart Dec 2010

Establishing Forages, Stephen K. Barnhart

Proceedings of the Integrated Crop Management Conference

A key element in profitable forage production is good stand density. Inadequate stands can be the result of poor initial establishment, mismanagement during grazing or harvest, fertility limitations, or any of a number of ‘natural calamities’ such as freeze, flood or just long periods of wet (or dry!) weather.


Nematodes That Feed On Corn—What To Make Of It All, Gregory L. Tylka Dec 2010

Nematodes That Feed On Corn—What To Make Of It All, Gregory L. Tylka

Proceedings of the Integrated Crop Management Conference

Nematodes are microscopic worms that live in soil and water. Many nematode species feed on decaying organic matter, bacteria, fungi, and even other nematodes. But some nematodes, including many that live in the soil, feed on plants and are called plant-parasitic nematodes.


The Increase In Scn Reproduction On Resistant Soybean Varieties—What Does It Mean?, Gregory L. Tylka Dec 2010

The Increase In Scn Reproduction On Resistant Soybean Varieties—What Does It Mean?, Gregory L. Tylka

Proceedings of the Integrated Crop Management Conference

The soybean cyst nematode (SCN), Heterodera glycines, is a consistent threat to profitable soybean production in the Midwest each year. In years of adequate to excess rainfall, like 2010 in Iowa, the short-term effect of SCN on soybean yields may be reduction of only a few bushels per acre. But in hot, dry years, yield loss can approach 50 percent or more. And no matter the extent of yield loss, SCN population densities (numbers) can increase dramatically during a growing season if susceptible soybean varieties are grown. And high SCN population densities increase the chances of soybean yields being greatly ...


Selecting Corn Hybrids For Performance And Profit, Peter Thomison Dec 2010

Selecting Corn Hybrids For Performance And Profit, Peter Thomison

Proceedings of the Integrated Crop Management Conference

One of the most important management decisions a corn grower makes each year is the selection of corn hybrids for spring planting. During the past 40 to 50 years, there has been continuous improvement in the genetics of corn hybrids which has contributed to steady increases in grain yield potential ranging from 0.7 to 2.6% per year. To stay competitive growers must introduce new hybrids to their acreage on a regular basis.


Nitrogen Additives: What Is What, And Do They Work?, Robert W. Mullen Dec 2010

Nitrogen Additives: What Is What, And Do They Work?, Robert W. Mullen

Proceedings of the Integrated Crop Management Conference

Increases in nitrogen prices and environmental pressures have caused many corn producers to reevaluate nitrogen (N) management to determine if they can improve use efficiency. One potential avenue of improving N use efficiency is to allow applied N the ability to avoid volatilization losses when utilizing urea-based fertilizers and to lengthen the amount of time ammonium is present since it is much less susceptible to loss than nitrate. This obviously means considering either a urease inhibitor or a nitrification inhibitor. The goal of this proceedings article is to discuss various urease and nitrification inhibitors, examine modes of action, and evaluate ...


Crop Quality From 2009/2010 And Grain Storage Management Needs, Charles Hurburgh, Shawn Shouse, Greg Brenneman, Kelvin Leibold Dec 2010

Crop Quality From 2009/2010 And Grain Storage Management Needs, Charles Hurburgh, Shawn Shouse, Greg Brenneman, Kelvin Leibold

Proceedings of the Integrated Crop Management Conference

Corn in 2009 was extremely wet and had low test weights (often 52 lb/bu and less) that did not increase significantly after drying. The situation was caused by a wet, cold growing season that was 20-25% short on heat units, followed by a cloudy, humid fall, with just enough heat to put field molds in their optimal growing conditions. This was the source of higher-than-normal damaged (moldy) kernel levels out of the field, with progressively higher risk of vomitoxin, zearalenone, and fumonisin from west to east in the Corn Belt. Mycotoxins do not go away in storage; they will ...


Weeds 2011: What Is New, Herbicide-Resistant Weeds And Management Tactics, Micheal D. K. Owen Dec 2010

Weeds 2011: What Is New, Herbicide-Resistant Weeds And Management Tactics, Micheal D. K. Owen

Proceedings of the Integrated Crop Management Conference

Weeds have a major impact on global agricultural profitability and represent the most important pest complex to the well-being of mankind. In 2004, the ubiquitous nature of weeds impacted U.S. agriculture representing a $20 billion cost to the growers (Basu et al., 2004; Bridges, 1994). Currently, herbicide-resistant weeds likely represent an even greater economic threat to U.S. agriculture.


Impacts Of Crop, Biomass Harvest Systems, And Nutrient Management On Field And Subsurface Drainage Water Quality, Matthew J. Helmers, Antonio Mallarino, Carl Pederson, Mazhar Haq Dec 2010

Impacts Of Crop, Biomass Harvest Systems, And Nutrient Management On Field And Subsurface Drainage Water Quality, Matthew J. Helmers, Antonio Mallarino, Carl Pederson, Mazhar Haq

Proceedings of the Integrated Crop Management Conference

Grain-crop biomass and perennial grass biomass are of particular interest for their use in bioenergy production systems. Nutrient needs, particularly nitrogen and phosphorus, change with varying cropping systems, harvest systems, and rates of fertilizer application. Furthermore, manure generated from livestock production can be a viable nutrient source for cropping systems, reducing the need for commercial fertilizers. The primary focus of this study was to investigate nutrient loss, primarily nitrate-nitrogen loss, in subsurface drainage water under a variety of cropping, nutrient management, and harvest scenarios. Overall crop yields and biomass production were also evaluated.


New Corn Research Findings And Implications: Performance Of Era And Modern Hybrids; Hybrids For Corn Following Corn; Impact Of Late Vegetative Stand Reduction, Roger W. Elmore, Matt J. Boyer, Wade A. Kent, Lori J. Abendroth Dec 2010

New Corn Research Findings And Implications: Performance Of Era And Modern Hybrids; Hybrids For Corn Following Corn; Impact Of Late Vegetative Stand Reduction, Roger W. Elmore, Matt J. Boyer, Wade A. Kent, Lori J. Abendroth

Proceedings of the Integrated Crop Management Conference

Research is never done. New questions remain as soon as we address the old ones. With that in mind, our corn research program at Iowa State moves in step with our extension program. In most cases, our research results feed directly into our extension programming. In this article, we present draft abstracts and data from three of our nearly-completed projects. We welcome your comments on these as well as the next research questions that need addressed!


Soil-Test Interpretations And Phosphorus Management Approaches For Profitable Crop Production, Antonio P. Mallarino Dec 2010

Soil-Test Interpretations And Phosphorus Management Approaches For Profitable Crop Production, Antonio P. Mallarino

Proceedings of the Integrated Crop Management Conference

Careful phosphorus (P) management planning is very important these days because of volatile grain/fertilizer price ratios and public concerns about water quality impairment due to excess P loss from fields. Largely unpredictable crop and fertilizer price fluctuations complicate fertilization decisions, however, and encourage producers to cut fertilization rates. Reducing P fertilization rates sometimes also is seen as an effective way of reducing P loss from fields and improving water quality, especially when manure is applied. Reducing P application rates across all conditions is not a good management or environmental decision, however, because it may not increase producers’ returns to ...


Fusarium Root Rot Of Soybean—Occurrence, Impact, And Relationship With Soybean Cyst Nematode, Mercedes Diaz Arias, Gregory L. Tylka, Alison Robertson, Leonor Leandro, Gary Munkvold Dec 2010

Fusarium Root Rot Of Soybean—Occurrence, Impact, And Relationship With Soybean Cyst Nematode, Mercedes Diaz Arias, Gregory L. Tylka, Alison Robertson, Leonor Leandro, Gary Munkvold

Proceedings of the Integrated Crop Management Conference

Fusarium species are ubiquitous soilborne pathogens that can cause devastating and difficult-to-manage damping-off, root rot, wilt, or sudden death syndrome (SDS) in soybeans (Armstrong, 1950; French and Kennedy, 1963; Rupe, 1989). At least 12 different species of Fusarium have been reported to be associated with soybean roots (McGee, 1992); among these species and the diseases they cause, the economic impact is widely recognized only for SDS; economic impacts of Fusarium wilt and root rot are much less well documented. Fusarium root rot is widespread in US (Yang and Feng, 2001). F. oxysporum complex and F. solani complex are generally believed ...


Manure Management Issues For 2011 And Beyond, Angela Rieck-Hinz Dec 2010

Manure Management Issues For 2011 And Beyond, Angela Rieck-Hinz

Proceedings of the Integrated Crop Management Conference

The title of this talk should be “Here We Go Again.” Increased regulatory pressure and policy-driven programs developed in the name of protecting water quality are driving manure management issues. This session will look at some of the potential new requirements and possible impacts on manure nutrient management planning in Iowa.


Profitable Corn Disease Management In Iowa, Alison Robertson Dec 2010

Profitable Corn Disease Management In Iowa, Alison Robertson

Proceedings of the Integrated Crop Management Conference

Over the past few years, diseases of corn have increased in incidence and severity in Iowa. Several factors have likely contributed to increased disease development and they include favorable weather conditions, disease susceptible hybrids on the market, an increase in continuous corn acres, and reduced tillage practices.


Managing Soybean Aphid In Iowa: An Economic Analysis, Rebekah Ritson, Alison Robertson, Matthew O'Neal, Daren Meuller, Nathan Bestor Dec 2010

Managing Soybean Aphid In Iowa: An Economic Analysis, Rebekah Ritson, Alison Robertson, Matthew O'Neal, Daren Meuller, Nathan Bestor

Proceedings of the Integrated Crop Management Conference

The introduction of soybean aphid and soybean rust to North America led to numerous insecticides and fungicides becoming available for use on soybean. Frequent outbreaks of soybean aphid along with reports of increased yields due to fungicide application, even in the absence of foliar disease, has resulted in widespread use of tank mixes. The popularity of tank mixes (a co-application of insecticide and fungicide) as a management tool is increasing. Many pest management programs that recommend this strategy apply pesticides based on soybean growth stage.


Managing Poultry Manure Nitrogen For Optimum Corn Yields And Minimum Environmental Loss, Dorivar Ruiz Diaz, John Sawyer Dec 2010

Managing Poultry Manure Nitrogen For Optimum Corn Yields And Minimum Environmental Loss, Dorivar Ruiz Diaz, John Sawyer

Proceedings of the Integrated Crop Management Conference

Appropriate poultry manure management is essential to ensure maximum crop nitrogen (N) utilization and reduce risk of negative environmental impact. Poultry manure sources can provide a significant supply of nutrients for corn (Zea mays L.) production. While the main focus is usually on N and phosphorus (P), poultry manure is also an excellent source of other nutrients like potassium (K) as well as secondary and micronutrients where needed (Brock et al., 2006). Field application is typically based on P due to high concentration relative to N in the manure, and application may be limited to avoid over application of P ...