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2006

Iowa State University

Agricultural Science

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Sudden Death Syndrome Prevalent This Summer, X. B. Yang Sep 2006

Sudden Death Syndrome Prevalent This Summer, X. B. Yang

Integrated Crop Management News

As the summer ended, sudden death syndrome (SDS) of soybean has been found in many fields in Iowa. Widespread infestation has been reported by producers and agronomists in eastern and central Iowa, and the disease also has been found in western Iowa. This year, the disease showed up in early July with many reports before the first week of July. Cooler temperatures this summer may have contributed to its occurrence. In central Iowa, the incidence of infested fields is high, but the severity is not. In most fields where SDS is spotted, the disease occurs in small areas with limited ...


Halverson Receives I-Cash Hall Of Fame Award, Keven Arrowsmith Sep 2006

Halverson Receives I-Cash Hall Of Fame Award, Keven Arrowsmith

Integrated Crop Management News

Iowa's Center for Agricultural Safety and Health (I-CASH) has named Charlotte Halverson of Dubuque the 2006 recipient of its Agricultural Safety and Health Hall of Fame Award. Halverson is a highly trained and skilled occupational health nurse who has served the farming community for more than 25 years. She is the rural health training coordinator at the National Educational Center for Agricultural Safety and rural health and parish health coordinator at Mercy Medical Center--Dubuque.


Sentinel Plots At End Of The 2006 Season, Ralph Von Qualen, X. B. Yang Sep 2006

Sentinel Plots At End Of The 2006 Season, Ralph Von Qualen, X. B. Yang

Integrated Crop Management News

We are completing our second crop season since Asian soybean rust (ASR) was found in the United States. We can breathe a sigh of relief and give thanks that ASR did not make its way to Iowa. Indeed, this potentially devastating disease has not plagued the entire north-central United States. Had conditions been favorable for this disease, we were ready to give producers fair warning.


Pest Management And The Environment Program Announces Fall Pesticide Training, Keven Arrowsmith Sep 2006

Pest Management And The Environment Program Announces Fall Pesticide Training, Keven Arrowsmith

Integrated Crop Management News

During fall 2006, Iowa State University's Extension Pest Management and the Environment (PME) program in cooperation with the Iowa Department of Agriculture and Land Stewardship (IDALS) will provide 10 continuing instructional courses (CIC) at sites across Iowa for certified commercial applicators. A "commercial applicator" is a person, corporation, or employee of a person or corporation who enters into a contract or an agreement for the sake of monetary payment and agrees to perform a service by applying a pesticide but does not include a farmer trading work with another, a person employed by a farmer not solely as a ...


Moisture Basis Conversions For Grain Composition Data, Charles R. Hurburgh Jr. Sep 2006

Moisture Basis Conversions For Grain Composition Data, Charles R. Hurburgh Jr.

Agriculture and Environment Extension Publications

Weight percentages change with variations in moisture content. Dry samples have larger percentages of protein, oil, starch, and fiber than wet samples. Calculation of these percentages on a moisture basis other than the actual moisture at the time of test is strictly a mathematical formula.


A New Greenhouse Method To Assay Soybean Resistance To Brown Stem Rot, G. A. Tabor, S. R. Cianzio, G. L. Tylka, R. Roorda, C. R. Bronson Sep 2006

A New Greenhouse Method To Assay Soybean Resistance To Brown Stem Rot, G. A. Tabor, S. R. Cianzio, G. L. Tylka, R. Roorda, C. R. Bronson

Plant Pathology and Microbiology Publications

Greenhouse, growth chamber, and field experiments were conducted to develop a method to assess resistance of soybeans to Cadophora gregata (Phialophora gregata), causal agent of brown stem rot (BSR). In the new method, C. gregata is introduced at the base of the stems of 2-week-old soybeans, and the presence of the fungus is assessed in the tips of the stems 5 weeks later. To test the effectiveness of the method, two populations of soybeans and 10 checks were inoculated at the stem base and then assayed for fungal colonization of the stem tips, percentage of symptomatic leaflets, and percent internal ...


August Angst, Richard O. Pope Aug 2006

August Angst, Richard O. Pope

Integrated Crop Management News

August 2006 began where the rest of the season left off, warm and fairly dry. Sporadic thundershowers were the rule, with considerable local variation in rainfall. A storm system rolled through northwest and north-central Iowa, dropping 4 to 5 inches of rain in some areas. However, straight-line winds leveled corn and some soybeans in a narrow band from Plymouth to Dickinson County. Rain concerns continue in nearly all parts of Iowa. Aphid populations can be found in nearly all counties, but to date the only populations nearing threshold are located along the border with Minnesota.


Corn Production Field Day, Keven Arrowsmith Aug 2006

Corn Production Field Day, Keven Arrowsmith

Integrated Crop Management News

Who should attend: Farmers and agronomists

Where: Iowa State University Bruner Farm (located 1 mile south of U.S. Highway 30 on "W" Avenue and 1/2 mile east on 240th Street)

When: Thursday, August 24, 10 a.m. to 3 p.m.


Kanawha Research Farm Celebrates 75 Years, Keven Arrowsmith Aug 2006

Kanawha Research Farm Celebrates 75 Years, Keven Arrowsmith

Integrated Crop Management News

In 1931, a group of farmers started the Northern Iowa Research Association to work on problems specific to northern Iowa farmers. The Northern Iowa Research Association purchased a farm on the southern edge of Kanawha and has encouraged Iowa State University researchers to conduct work there. Since its beginning, this farm has conducted research in flax production, sugar beet production, small grain management, corn and soybean breeding, weed management, nutrient management (nitrogen, phosphorus, potassium), soybean cyst nematode, tillage, replant decisions, and rotations.


Update: Soybean Rust And Other Foliar Diseases, Daren S. Mueller Aug 2006

Update: Soybean Rust And Other Foliar Diseases, Daren S. Mueller

Integrated Crop Management News

Another growing season is passing and soybean rust remains confined to the southeastern United States. With drier-than-normal conditions throughout much of the southeastern United States early in the spring and well into summer, soybean rust has not been able to spread too far from the overwintering sites. To date for 2006, there are 28 counties in six states with soybean rust. In comparison to 2005, there were 21 counties with soybean rust in early August (see maps).


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.


The Heat (Has Been) On!, Richard O. Pope Jul 2006

The Heat (Has Been) On!, Richard O. Pope

Integrated Crop Management News

It should come as no surprise that the week of July 23 was a hot one in all of Iowa. We effectively gained an extra day and a half of heat compared with long-term averages in all parts of Iowa. Mind you that as corn and soybean are in the fill stage, degree days themselves aren't as important as they were in the leadup to pollination. Now we look at stresses on plants, and we do have variable moisture and accompanying heat stress in many parts of Iowa.


New Publication Offers Rationale For Nitrogen Use In Corn Production, Jean Mcguire Jul 2006

New Publication Offers Rationale For Nitrogen Use In Corn Production, Jean Mcguire

Integrated Crop Management News

A new publication is available through Iowa State University Extension that explores a recently developed regional Corn Belt approach to nitrogen rate guidelines. Concepts and Rationale for Regional Nitrogen Rate Guidelines for Corn was developed jointly by soil fertility specialists from University of Illinois, Iowa State University (ISU), University of Minnesota,The Ohio State University, Purdue University, and University of Wisconsin.


Corn Now Planted Earlier Than Ever Before!, Roger W. Elmore, Lori Abendroth Jul 2006

Corn Now Planted Earlier Than Ever Before!, Roger W. Elmore, Lori Abendroth

Integrated Crop Management News

The fact that corn is now planted earlier than ever before is not a surprise to most of you. Many have discussed this and have known intuitively that it has happened. Although we are still in the middle of the growing season, let's take a step back and investigate overall trends occurring in Iowa. In this article, we look at National Agricultural Statistics Service data on corn planting progress over the last three decades to add some actual numbers to the discussion. By comparing when 50 percent of the corn crop has been planted, it is clear that planting ...


Spider Mites, Soybean Aphids, And Summer Temperature, Marlin E. Rice Jul 2006

Spider Mites, Soybean Aphids, And Summer Temperature, Marlin E. Rice

Integrated Crop Management News

Temperatures in the high 90s and low 100s have prompted questions about how this will affect pests in soybeans. Spider mites typically flourish in hot, dry weather. Fungal pathogens that suppress spider mites during high humidity and mild temperatures are less effective against mites during very dry and hot conditions. Therefore, spider mites may be a greater concern this year during early August than soybean aphids.


Location, Location, Location!, Richard O. Pope Jul 2006

Location, Location, Location!, Richard O. Pope

Integrated Crop Management News

The biggest factor determining the crop condition in late July is not a new one. If your location has caught some of the sporadic rainfall in the past month, you are likely in reasonable shape. If not, your crops are beginning to struggle. The driest areas in terms of rainfall deficit from normal since May 1 are northwest, west-central and south-central, which are all around 50 percent of normal rainfall. That said, corn and soybean both are hanging in pretty well, and late July and August rainfall will work wonders--if and when it comes.


Soybean Aphids Down In July, Marlin E. Rice Jul 2006

Soybean Aphids Down In July, Marlin E. Rice

Integrated Crop Management News

Reports from extension field crops specialists across Iowa on July 24 indicate that soybean aphids have not reached the economic threshold of 250 aphids per plant in most fields. Soybean aphids can be found, but it appears that overall the populations range from just a few aphids per plant up to 30-50 per plant. There was a report of several fields being sprayed in northwest Iowa near Emmetsburg, but no aphid counts were given for these fields so the population size relative to the economic threshold is unknown.


Rotation-Resistant Corn Rootworms In Iowa, Patricia L. Prasifka, Jon J. Tollefson, Marlin E. Rice Jul 2006

Rotation-Resistant Corn Rootworms In Iowa, Patricia L. Prasifka, Jon J. Tollefson, Marlin E. Rice

Integrated Crop Management News

There are variants of both corn rootworm species in Iowa that are resistant to crop rotation. The northern corn rootworm overcame the annual rotation of corn with another crop by developing a two-year life cycle. This variety of the northern corn rootworm (known as extended diapause) became common and caused extensive damage to rotated corn in the late 1980s in northwest Iowa. Since then it has spread throughout Iowa and is probably found in every county.


Recent Soybean Yellowing May Be Symptom Of Scn, Gregory L. Tylka Jul 2006

Recent Soybean Yellowing May Be Symptom Of Scn, Gregory L. Tylka

Integrated Crop Management News

There have been many yellow spots in soybean fields throughout Iowa so far this season. In most cases, the yellowing is iron deficiency chlorosis. But since mid-July, additional yellowing of soybean fields has appeared, and it is likely that at least some of the newly appearing chlorosis is being caused by feeding of the soybean cyst nematode (SCN). SCN usually is present in fields for many years before population densities increase to a level that causes obvious stunting or yellowing.


These Are The Dog Days, Richard O. Pope Jul 2006

These Are The Dog Days, Richard O. Pope

Integrated Crop Management News

The traditional dog days of summer roughly range from July 4 through about August 10. Although they were named for the time when the dog star, Sirius, rose with the sun, dog days for us is the time when row crops are pollinating and the first half of grain fill. The week starting July 10 was about average in degree day accumulation, and especially in the southern two-thirds of Iowa, some welcome rain fell. Moisture remains a concern, but the week's rainfall coincided with pollination, which is a very good thing.


Manure Management Clinic To Focus On Open Feedlot Manure Issues, Jean Mcguire Jul 2006

Manure Management Clinic To Focus On Open Feedlot Manure Issues, Jean Mcguire

Integrated Crop Management News

The Iowa Manure Management Action Group (IMMAG), in cooperation with Iowa State University (ISU) Extension and the College of Agriculture, is sponsoring a two-day Manure Management Clinic on August 22 and 23, at the Field Extension Education Laboratory (FEEL) near Ames. The purpose of this short course is to train service providers, commodity partners, agency personnel, and Iowa State University Extension field staff in issues related to manure management for open feedlots in Iowa. Producers are welcome to attend.


Consider Nematode Feeding As Cause For Poor Corn Growth, Gregory L. Tylka Jul 2006

Consider Nematode Feeding As Cause For Poor Corn Growth, Gregory L. Tylka

Integrated Crop Management News

Plant-parasitic nematodes can cause serious damage to corn. There are numerous species that occur in Iowa, including those with common names like the dagger, lance, lesion, needle, spiral, stubby-root, and stunt nematodes. Symptoms of nematode damage on corn include stunting and/or yellowing of foliage, uneven tasseling, and stunting, swelling, and/or browning of roots.


Protect Pollinating Bees From Pesticides, Chuck Eckermann, Joyce Hornstein Jul 2006

Protect Pollinating Bees From Pesticides, Chuck Eckermann, Joyce Hornstein

Integrated Crop Management News

A pesticide applicator is required to notify all owners of registered beeyards (apiaries) within a 2-mile radius of the site of application if the pesticide is labeled as "toxic to bees." Notification is required at least 24 hours and no more than 72 hours before the application. This enables beekeepers to move or otherwise protect their bees from harm. This notification is required by the Iowa Administrative Code rule IAC 21-45.31(206).


In Vitro Bile Acid Binding Activity Within Flour Fractions From Oat Lines With Typical And High Β-Glucan Amounts, Sedat Sayar, Jean-Luc Jannink, Pamela J. White Jul 2006

In Vitro Bile Acid Binding Activity Within Flour Fractions From Oat Lines With Typical And High Β-Glucan Amounts, Sedat Sayar, Jean-Luc Jannink, Pamela J. White

Food Science and Human Nutrition Publications

Whole flours from four oat lines with different amounts of β-glucan (4.8−8.1%) were examined for their antioxidant activity and total phenolic and lignin concentrations. These data, along with the β-glucan percentages, were compared with bile acid (BA) binding. Only the lignin concentrations of the flours significantly (P < 0.01) correlated with the BA binding values. The oat flours also were fractionated into bran, protein concentrate, starch, layer above starch, and soluble β-glucan (SBG)-free flour, and their BA binding capacities were evaluated. The bran fractions were the only fractions that bound greater BA than did the whole oat flours on dry matter basis. Extraction of the soluble β-glucan to create the SBG-free flour significantly (P < 0.01) decreased the BA binding of the remaining flour. These data suggest that BA binding of the oat flours involves the synergistic interactions of the oat components, with β-glucan and lignin (insoluble fiber) having a great impact.


Midsummer Soybean Disease Scouting, X. B. Yang Jul 2006

Midsummer Soybean Disease Scouting, X. B. Yang

Integrated Crop Management News

Cool weather this year has resulted in different soybean diseases than we have experienced in other years. Cool and wet conditions are favorable to the development of fungal disease. This year has been cool but not wet; therefore, the disease picture will be unique. This article discusses diseases that you are likely to find during summer disease scouting.


Mite Watch 2006, Carol Pilcher, Richard O. Pope Jul 2006

Mite Watch 2006, Carol Pilcher, Richard O. Pope

Integrated Crop Management News

Whenever hot, dry weather persists, spider mite populations may develop on both corn and soybean. Twospotted spider mites, Tetranychus urticae, are serious pests of many crops throughout the United States. Producers in areas of Iowa where the weather remains dry should be on the lookout for spider mite infestations.


Dry Weather: Worried About High Nitrates In Forages?, Stephen K. Barnhart Jul 2006

Dry Weather: Worried About High Nitrates In Forages?, Stephen K. Barnhart

Integrated Crop Management News

During periods of dry growing conditions, forage producers begin to ask about the increased risk of nitrate accumulation in forages and how best to manage them. Plants take up nitrogen from available soil sources during normal plant growth. Soil-source nitrates are used by the plant to form protein. Since photosynthesis-formed sugars are also components of protein, anything that influences normal plant growth (such as drought) will reduce protein synthesis, and nitrate (NO3) can accumulate in the plant in higher than normal amounts.


Greensnap In Iowa, Roger W. Elmore, Lori Abendroth, George Cummins Jul 2006

Greensnap In Iowa, Roger W. Elmore, Lori Abendroth, George Cummins

Integrated Crop Management News

Straight-line winds as high as 60 mph caused considerable greensnap in corn across north-central and northeast Iowa last Saturday evening, July 1. Damage was more frequent and most severe in a narrow, long band running from eastern Cerro Gordo County generally along county road B60 and across several counties to the east and northeast and included the Iowa State University Northeast Research and Demonstration Farm at Nashua.


July Picks Up Where June Left Off, Richard O. Pope Jul 2006

July Picks Up Where June Left Off, Richard O. Pope

Integrated Crop Management News

The first week of July was slightly cooler than normal statewide, and again, unfortunately, drier than normal. Corn is starting to tassel across Iowa, and moisture stress is a growing concern. Fortunately, crop breeding has provided us with varieties with improved drought tolerance; however, that only works to a point. Monitoring for pests is important, and grasshoppers and spider mites are two key insects to watch for.


Western Bean Cutworm In 2006, Richard O. Pope, Marlin E. Rice Jul 2006

Western Bean Cutworm In 2006, Richard O. Pope, Marlin E. Rice

Integrated Crop Management News

A network of pheromone traps has been placed throughout the state to assist in scouting efforts for western bean cutworm. Iowa State University Extension is cooperating with Pioneer Hi-Bred agronomists to survey for western bean cutworm emergence. Most traps are now in place and results are being posted on a western bean cutworm website. Traps cannot be used to predict which fields should be sprayed; rather, they can indicate those areas that have significant moth flights and where fields should be scouted.