Education Commons^™

G08-1823 Barley Yellow Dwarf Of Wheat, Barley, And Oats, Stephen N. Wegulo, Gary L. Hein, Roy C. French

University of Nebraska-Lincoln Extension: Historical Materials

The symptom's, impacts and management of Barley Yellow Dwarf (BYD), a virus disease affecting small grains, are discussed in this 2008 NebGuide. This information is based on observations of BYD in Nebraska wheat and oat fields in 2007 and on published research conducted elsewhere.

G07-1677 Rhizopus Head Rot Of Sunflower In Nebraska, Robert M. Harveson

University of Nebraska-Lincoln Extension: Historical Materials

Sunflower crops grown in Nebraska are susceptible to diseases caused by bacteria, viruses and nematodes, but the most economically damaging is head rot, caused by the fungal pathogen Rhizopus. This 2007 NebGuide discusses the pathogen, disease history, symptoms, and management.

G07-1678 The Relationship Of Dry Bean And Sugar Beet Pathogens With Common Weeds In Nebraska Production Fields, Robert M. Harveson

University of Nebraska-Lincoln Extension: Historical Materials

Certain weeds in the Nebraska Panhandle can serve as hosts for pathogens that cause disease in dry edible beans and sugar beets. Properly managing weed populations and rotating with nonhost crops can help control the spread of disease. This 2007 NebGuide discusses the symptoms, results and control of these pathogens.

G06-1622 Soybean Inoculation: Applying The Facts To Your Fields (Part Two Of A Two-Part Series), Lori J. Abendroth, Roger Wesley Elmore, Richard B. Ferguson

University of Nebraska-Lincoln Extension: Historical Materials

Why is it that we see soybean yield responses from inoculating with Bradyrhizobia japonicum in some cases but not others?

This publication explains how to distinguish which fields will likely respond to inoculation with B. japonicum from those that will not. Fields are designated as either "new" or "old" based on how often soybean is grown. This designation is one criterion among many in deciding when to inoculate. In general, research trials across multiple locations in Nebraska have shown no yield advantage to re-inoculation.

G06-1621 Soybean Inoculation: Understanding The Soil And Plant Mechanisms Involved (Part One Of A Two-Part Series), Lori J. Abendroth, Roger Wesley Elmore, Richard B. Ferguson

University of Nebraska-Lincoln Extension: Historical Materials

Nitrogen gas (N₂) comprises nearly 80 percent of total atmospheric gases, yet most organisms are unable to use N2 as a source of nitrogen. Legumes, such as soybean, are able to capture atmospheric nitrogen and utilize it through the process of nitrogen fixation. This NebGuide is part one of a two-part series on soybean inoculation. Here, we will investigate how soybean inoculation occurs and which environmental conditions impact nitrogen fixation.

G06-806 Chinch Bug Management, Robert J. Wright, Barbara P. Ogg, Stephen D. Danielson

University of Nebraska-Lincoln Extension: Historical Materials

The life cycle and control of the chinch bug is discussed with descriptions of possible management options in the 2006 NebGuide.

Nf05-652 Soybean Rust Fungicide Use Guidelines For Nebraska, Loren J. Giesler, John A. Wilson, Jennifer M. Rees

University of Nebraska-Lincoln Extension: Historical Materials

While the impact that soybean rust will have on Nebraska's soybean crop is unknown, producers should be prepared to manage the disease. When soybean rust occurs or is expected to occur shortly in Nebraska, growers can use the decision-aid flow chart on page 2 of this NebFact to determine whether to treat and, if treating, which class of fungicide (chlorothalonil, strobilurin, or triazole) to use.

Nf05-634 Fungicides To Manage Soybean Rust: What Are The Product Differences?, Loren J. Giesler, Thomas J. Weissling

University of Nebraska-Lincoln Extension: Historical Materials

If Nebraska soybean producers find themselves needing to apply a fungicide for soybean rust this year, it will be important to choose an effective product based on the stage of disease development in the specific field. It will be important for all producers and crop managers to be aware of where soybean rust is being detected to pursue a treatment that provides the maximum return on investment for any fungicides being applied.

This NebFact discusses the fungicides available for Nebraska soybean fields and resistance management issues.

Nf05-633 Soybean Rust: How Great Is The Threat For Nebraska?, Loren J. Giesler

University of Nebraska-Lincoln Extension: Historical Materials

Soybean rust is a serious foliar disease that has caused significant crop losses in other parts of the world. It was first detected in the United States in November 2004 and has since been identified in several southeastern states. The fact that wind-borne spores principally spread soybean rust suggests it will be a seasonal problem in Nebraska.

This NebFact discusses the symptoms, life cycle, host range, potential impact on soybean production, and management of soybean rust in the state of Nebraska.

Nf04-614 Management Program For Powdery Mildew Of Wheat (Revised August 2005), John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact, Wheat Disease Fact Sheet No. 7, discusses the management program for powdery mildew of wheat. It covers the cause and occurrence, key symptoms, cultural management practices, fungicide treatment programs with a table listing the fungicdes registered for foliar diseases of wheat, and application.

Nf04-599 Soybean Aphid Management In Nebraska, Thomas E. Hunt

University of Nebraska-Lincoln Extension: Historical Materials

The soybean aphid (Aphis glycines) is Nebraska's newest soybean insect pests, arriving in the United States in 2000 and in Nebraska in 2002. Yield losses of over 20 percent have been documented in some northeast Nebraska fields.

This NebFact covers the description, initial observations, life cycle and injury, and management of the soybean aphid in Nebraska.

Nf04-594 Resistanct Management For Yieldgard Rootworm™ Bt Corn, Robert J. Wright, Thomas E. Hunt

University of Nebraska-Lincoln Extension: Historical Materials

In 2003, the U.S. Environmental Protection Agency and Monsanto announced the registration of YieldGard Rootworm™ corn containing event MON863. These hybrids express a protein in the roots from the soil bacterium, Bacillus thuringiensis (Bt) that is toxic to larval corn rootworms.

This NebFact discusses management requirements, refuge considerations, within-field configurations when using YieldGard Rootworm™.

G03-1513 Understanding Fungal (Mold) Toxins (Mycotoxins), Michael P. Carlson, Steveb M. Ensley

University of Nebraska-Lincoln Extension: Historical Materials

Mycotoxins are chemicals produced by fungi (molds) under certain conditions. They are not essential for fungal growth or reproduction, and are toxic to animals or humans.

This NebGuide briefly discusses mycotoxins commonly encountered in grains and feeds used in Nebraska and the mycotoxicoses they cause. Mycotoxin sources and clinical signs, lesions, diagnostic aids and treatment for each mycotoxicosis are listed.

G03-1504 Lime Use For Soil Acidity Management, Martha Mamo, Charles S. Wortmann, Charles A. Shapiro

University of Nebraska-Lincoln Extension: Historical Materials

Soil acidity can reduce crop production by directly affecting roots and changing the availability of essential nutrients and toxic elements. Liming can neutralize soil acidity, but several factors can affect the economic benefits of liming. With continuous cropping, soil pH can decrease (i.e., increase in acidity) because of various factors, including crop removal and leaching of basic cations, application of ammoniabased nitrogen fertilizers, and organic matter decomposition. Adding lime or other materials can raise soil pH to the ideal range for crop production, create an environment for a healthy function of microbes, and increase the levels of calcium or magnesium …

G03-1521 Using Corn Hybrid Yield Data To Improve Selection Of Rapidly Changing Hybrids, Robert N. Klein, Lenis Alton Nelson, Roger Wesley Elmore

University of Nebraska-Lincoln Extension: Historical Materials

How often should you change hybrids? One might conclude that to maximize corn yield, hybrids must be constantly replaced. Choosing the proper hybrid can greatly enhance crop production profitability. This NebGuide illustrates how to use corn hybrid test data and adjust it to your farm when selecting seed.

G03-1528 Recommended Seeding Rates And Hybrid Selection For Rainfed (Dryland) Corn In Nebraska, Robert N. Klein, Drew J. Lyon

University of Nebraska-Lincoln Extension: Historical Materials

Differences in climate between Lincoln and Scottsbluff are as great as from Lincoln to the east coast of the United States. These climatic differences across the state greatly affect recommended seeding rates for rainfed corn in Nebraska. This NebGuide provides information useful in assessing accumulated growing degree days, soil type and field conditions, average precipitation, and the field's microclimate when determining seeding rate for dryland corn.

Nf03-587 Management Program To Prevent Smut Diseases Of Wheat (Revised September 2005), John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact, Wheat Disease Fact Sheet No. 6, discusses the management program to prevent smut diseases of wheat. It covers the cause and occurrence, key symptoms, cultural management practices, fungicide seed treatment program, economic significance, and applications for controlling the smut diseases.

G03-1515 Sampling And Analyzing Feed For Fungal (Mold) Toxins (Mycotoxins), Michael P. Carlson, Steven M. Ensley

University of Nebraska-Lincoln Extension: Historical Materials

Mycotoxins are chemicals produced by fungi (molds) under certain conditions. They are not essential for fungal growth or reproduction, and are toxic to animals or humans. They are naturally present in feed and cannot always be avoided.

The purposes of this NebGuide are to provide information about sampling feeds to detect the presence of mycotoxins in them and about how feeds may be analyzed for mycotoxins.

G03-1514 Use Of Feed Contaminated With Fungal (Mold) Toxins (Mycotoxins), Michael P. Carlson, Steve M. Ensley

University of Nebraska-Lincoln Extension: Historical Materials

Mycotoxins are chemicals produced by fungi (molds) under certain conditions. They are not essential for fungal growth or reproduction, and they are toxic to animals or humans. They are naturally occurring chemicals found in grains, food and feed consumed by humans and animals and cannot be completely avoided. Accordingly, we try to control the amount of such chemicals ingested by humans and animals.

The purpose of this NebGuide is to provide guidelines on use of mycotoxin-contaminated feeds.

Nf03-571 Aspergillus Flavus And Aflatoxins In Corn, Jim Stack, Michael Carlson

University of Nebraska-Lincoln Extension: Historical Materials

The severe weather conditions of the 2002 growing season resulted in an increase in the incidence and severity of aflatoxin contamination of both food grade and feed grade corn in Nebraska.

The mycotoxin called aflatoxin is produced by the grain mold Aspergillus flavus. Not all isolates of A. flavus produced aflatoxin and isolates that are capable of producing aflatoxin do not always synthesize the toxin. Many factors including environmental conditions and host suscepbitility, determine the incidence and severity of grain mold and subsequent mycotoxin contamination.

This NebFact discusses the cause and occurrence of aflatoxin in corn; the effects it has …

Nf03-570 Fumonisins In Corn, Jim Stack, Michael Carlson

University of Nebraska-Lincoln Extension: Historical Materials

During the past two years, millers have rejected some Nebraska food grade corn because it was contaminated with the mycotoxin fumonisin. Most of the contaminated samples and the highest levels of contamination were detected in corn from counties in the eastern half of Nebraska.

Fumonisins are mycotoxins produced by the grain molds Fusarium verticillioides and Fusarium proliferatum. These fungi are commonly found in corn throughout the United States.

This NebFact discusses the cause and occurrence of fumonisin in corn; the effects it has on plants, animals and humans; and management options to minimize fumonisin contamination.

Nf02-518 Management Of Phytophthora Diseases Of Soybeans, Loren J. Giesler, Jane A. Christensen, Christopher M. Zwiener

University of Nebraska-Lincoln Extension: Historical Materials

Phythophthora diseases of soybean, caused by Phytophthora sojae, are present wherever soybeans are grown in Nebraska. The pathogen survives primarily as "resting" spores in the soil or in association with infested crop debris. Symptoms associated with Phytophthora sojae, infections include seed rots, pre- and post-emergence dampin goff of seedlings and stem rot of plants at various growth stages.

Knowledge of the races present in the state and how varieties with different resistance genes have performed in a grower's field is critical to variety selection for maximum profitability.

Nf02-506 Plant Disease Central Web Site, Jim Stack

University of Nebraska-Lincoln Extension: Historical Materials

Disease is a natural part of every crop production system. This is true for all crop species and for each type of production system; irrigated or rain-fed, conventional or conservation tillage, and continuous or rotational cropping. In any given year, the question is which diseases will occur in Nebraska's field crops and at what incidence and severity.

To help producers, consultants, and other agricultural professionals diagnose and manage field crop diseases in Nebraska, the Plant Disease Central (PDC) web site was developed. The home page includes instructions on navigating the site under the "About This Site" link.

This NebFact offers …

Nf02-561 Management Program For Common Root Rot And Fusarium Foot Rot (Crown Rot) (Revised September 2005), John E. Watkins

University of Nebraska-Lincoln Extension: Historical Materials

This NebFact, the Wheat Disease Fact Sheet No. 3 of a series, discusses the cause and occurrence, key symptoms, cultural management practices, fungicide programs, and applications for controlling common root rot and fusarium foot rot (crown rot) of wheat.

Nf02-551 Management Of Blister Beetles In Alfalfa, John B. Campbell, Steve Ensley

University of Nebraska-Lincoln Extension: Historical Materials

Adult blister beetles (Epicauta spp.) tend to be gregarious, and several may be observed feeding on the same flowering plant such as alfalfa or sometimes soybeans, goldenrod or occasionally musk thistle, They feed primarily on leaves and flowers but do little damage to crops.

This NebFact discusses the life cycle, damage, treatment, and prevention avoidance of the blister beetle here in Nebraska.

Nf02-504 Atrazine And Non-Atrazine Herbicide Comparisons In No-Till Corn, Fred Roeth, Alex Martin

University of Nebraska-Lincoln Extension: Historical Materials

Atrazine herbicide has been in an EPA special review since 1994 because of soil surface runoff concerns. Beginning in 1997, we evaluated atrazine and non-atrazine herbicide treatments in conventional tillage corn and no-till corn on university research farms at Clay Center (irrigated) and Lincoln, Nebraska (non-irrigated). The objective was to compare some common atrazine and non-atrazine herbicides in soil-applied and post emergence treatment combinations. Fourteen herbicide treatments were selected to represent commonly used herbicide classes and application timings. This NebFact reports the no-till results.

Nf02-503 Atrazine And Non-Atrazine Herbicide Comparisons In Conventional Till Corn, Fred Roeth, Alex Martin

University of Nebraska-Lincoln Extension: Historical Materials

Atrazine herbicide has been in an EPA special review since 1994 because of surface and groundwater contamination concerns. Beginning in 1997, we evaluated atrazine and non-atrazine herbicides in conventional tillage corn and no-till corn on university research farms at Clay Center and Lincoln, Nebraska. The objective was to compare some common atrazine and non-atrazine herbicides for weed control and crop response. Thirteen herbicides were selected to represent commonly used herbicide classes and treatment timings. This NebFact reports the conventional till results.

Nf02-543 Ascochyta Blight Of Chickpeas, Robert M. Harveson

University of Nebraska-Lincoln Extension: Historical Materials

The chickpea (Cicer arietinum) ranks among the world's three most important pulse (legume) crops. It is an important source of protein in many parts of central Asia, Africa and the Mediterranean and among the food legumes, is the most effective in reducing blood ocholesterol levels. The crop is antive to western Asia and the Middle East, and is usually grown as a rainfed cool-weather crop or as a dry climate crop in semi-arid regions.

Although chickpeas are reported to be susceptible to over 50 pathogens, few diseases are currently recognized as significant economic constraints to production. Ascochyta blight …

Ec02-153 Selecting Alfalfa Varieties For Nebraska 2002, Bruce Anderson, Michael Trammell, Charles A. Shapiro, Patrick E. Reece

University of Nebraska-Lincoln Extension: Historical Materials

Yield potential, pest resistance and seed price should be considered when selecting alfalfa varieties in Nebraska. The most important variety decision on many farms and ranches is the selection of alfalfa. The choice of alfalfa variety affects production for three to 10 or more years, whereas varieties of annual crops can be changed every year. Many alfalfa varieties are available from private and public plant breeders. Over the years, yield trials conducted at widely distributed Nebraska locations have tested most varieties sold in the state.

Ec01-1880 Diseases Of Nebraska's Field Crops, Loren J. Giesler, Robert M. Harveson, Jim Stack, John E. Watkins, Jennifer L. Chaky

University of Nebraska-Lincoln Extension: Historical Materials

Each year, plant diseases are an important factor in reducing yields of Nebraska's field crops. The purpose of this publication is to provide concise information in an easy to use table for many of Nebraska's field crop diseases. The disease information is organized by crop.

Diseases covered in this publication include the four main groups of plant pathogens: fungi, bacteria, viruses, and nematodes.