Other Plant Sciences Commons^™

Soybean Disease Profiles Ii: Stem And Root Rot Diseases, Loren J. Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Kevin A. Korus, Bo Liu, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1904 (EC1904).

Photographs and disease descriptions of Brown Stem Rot (BSR), Charcoal Rot, Fusarium Wilt and Root Rot, Phytophthora Root and Stem Rot, Pod and Stem Blight, Phomopsis Seed Decay, Rhizoctonia Root and Cortical Rot, Sclerotinia Stem Rot, Seedling Blights, Soybean Cyst Nematode (SCN), Stem Canker, and Sudden Death Syndrome (SDS).

Corn Disease Profile Iii: Ear Rot Diseases And Grain Molds, Tamra A. Jackson-Ziems, Loren J. Giesler, Robert M. Harveson, Kevin A. Korus, Bo Liu, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1901 (EC1901).

Under certain conditions, corn ear rot and grain mold diseases are common and can lead to loss of grain quality. Moldy grain can be docked or rejected at the elevator. Additionally, some ear and grain pathogens may produce secondary metabolites called mycotoxins, which are toxic to animals and humans consuming the contaminated grain. Mycotoxin-contaminated grain can also be docked or rejected. Mycotoxin production may start in the field and continue after harvest, or it may start during storage if mold infection begins there. When grain storage is necessary, drying grain to less than 15 percent moisture …

Sunflower Disease Profiles Ii: Head And Stalk Rots And Wilts, Robert M. Harveson, Loren J. Giesler, Tamra A. Jackson, Bo Liu, Stephen N. Wegulo, Kevin A. Korus

Department of Plant Pathology: Faculty Publications

Extension Circular 1902 (EC1902).

Photographs and disease descriptions of Phoma/Phomopsis Stalk Rots, Bacterial Stalk Rot, Verticillium Wilt, Rhizopus Head Rot, and White Mold/Sclerotina Diseases.

Corn Disease Update, Tamra A. Jackson, Craig B. Langemeier, Greg R. Kruger

Department of Plant Pathology: Faculty Publications

Goss's Bacterial Wilt and Blight ... Symptoms ... Management ... 2011 Survey ... Literature Cited

Gray Leaf Spot

Seedling Diseases and Stalk/Crown Root Diseases

More Resources

Factors Influencing Deoxynivalenol Accumulation In Small Grain Cereals, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Deoxynivalenol (DON) is a mycotoxin produced by the plant pathogenic fungi Fusarium graminearum and F. culmorum. These and other closely related fungi cause a disease known as Fusarium head blight (FHB) in small grain cereals. Other mycotoxins produced by FHB-causing fungi include nivalenol, T-2 toxin, and zearalenone. Ingestion of mycotoxin-contaminated food and feed can lead to toxicosis in humans and animals, respectively. DON is the predominant and most economically important of these mycotoxins in the majority of small grain-producing regions of the world. This review examines the factors that influence DON accumulation in small grain cereals from an agricultural perspective. …

Reflections On Plant And Soil Nematode Ecology: Past, Present And Future, Howard Ferris, Bryan S. Griffiths, Dorota L. Porazinska, Thomas O. Powers, Koon-Hui Wang, Mario Tenuta

Department of Plant Pathology: Faculty Publications

The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of …

Transgenic Expression Of Lactoferrin Imparts Enhanced Resistance To Head Blight Of Wheat Caused By Fusarium Graminearum, Jigang Han, Dilip K. Lakshman, Leny C. Galvez, Sharmila Mitra, P. Stephen Baenziger, Amitava Mitra

Department of Plant Pathology: Faculty Publications

Background: The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Using the tools of plant genetic engineering, a broad-spectrum antimicrobial gene was tested for resistance against head blight caused by Fusarium graminearum Schwabe, a devastating disease of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) that reduces both grain yield and quality.

Results: A construct containing a bovine lactoferrin cDNA was used to transform wheat using an Agrobacterium …

Assessing Genetic Diversity In The Web Blight Pathogen Thanatephorus Cucumeris (Anamorph = Rhizoctonia Solani) Subgroups Ag-1-Ie And Ag-1-If With Molecular Markers, N. González, James R. Steadman, Robert Higgins, Kent M. Eskridge

Department of Plant Pathology: Faculty Publications

Web blight, an important foliar disease of dry beans in the Americas, is a challenge to manage. We studied genetic variation of 92 isolates of Rhizoctonia solani subgroups AG-1-IE and AG-1-IF using DNA fingerprinting methods and mycelial compatibility grouping. The isolates were collected over 13 years from bean fields in the Dominican Republic, Honduras and Puerto Rico. Cluster and AMOVA analysis of combined data from two universal rice primers and two internal sequence repeats revealed significant genetic variation among and within populations of both subgroups. Variation was influenced by geographic origin and sampling year for AG-1-IE isolates and geographic origin …

Relevance Of Lysine Snorkeling In The Outer Transmembrane Domain Of Small Viral Potassium Ion Channels, Manuela Gebhardt, Leonhard M. Henkes, Sascha Tayefeh, Brigitte Hertel, Timo Greiner, James L. Van Etten, Dirk Baumeister, Christian Cosentino, Anna Moroni, Stefan M. Kast, Gerhard Thiel

Department of Plant Pathology: Faculty Publications

Transmembrane domains (TMDs) are often flanked by Lys or Arg because they keep their aliphatic parts in the bilayer and their charged groups in the polar interface. Here we examine the relevance of this so-called “snorkeling” of a cationic amino acid, which is conserved in the outer TMD of small viral K+ channels. Experimentally, snorkeling activity is not mandatory for KcvPBCV-1 because K29 can be replaced by most of the natural amino acids without any corruption of function. Two similar channels, KcvATCV-1 and KcvMT325, lack a cytosolic N-terminus, and neutralization of their equivalent cationic amino acids inhibits their function. To …

Rna-Seq Analysis Of The Sclerotinia Homoeocarpa – Creeping Bentgrass Pathosystem, Angela M. Orshinsky, Jinnan Hu, Stephen O. Opiyo, Venu Reddyvari-Channarayappa, Thomas K. Mitchell, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Sclerotinia homoeocarpa causes dollar spot disease, the predominate disease on highly-maintained turfgrass. Currently, there are major gaps in our understanding of the molecular interactions between S. homoeocarpa and creeping bentgrass. In this study, 454 sequencing technology was used in the de novo assembly of S. homoeocarpa and creeping bentgrass transcriptomes. Transcript sequence data obtained using Illumina’s first generation sequencing-by-synthesis (SBS) were mapped to the transcriptome assemblies to estimate transcript representation in different SBS libraries. SBS libraries included a S. homoeocarpa culture control, a creeping bentgrass uninoculated control, and a library for creeping bentgrass inoculated with S. homoeocarpa and incubated for …

Gene Expression Profiling Of The Plant Pathogenic Basidiomycetous Fungus Rhizoctonia Solani Ag 4 Reveals Putative Virulence Factors, Dilip K. Lakshman, Nadim Alkharoud, Daniel P. Roberts, Savithiry S. Natarajan, Amitava Mitra

Department of Plant Pathology: Faculty Publications

Rhizoctonia solani is a ubiquitous basidiomycetous soilborne fungal pathogen causing damping- off of seedlings, aerial blights and postharvest diseases. To gain insight into the molecular mechanisms of pathogenesis a global approach based on analysis of expressed sequence tags (ESTs) was undertaken. To get broad gene-expression coverage, two normalized EST libraries were developed from mycelia grown under high nitrogen-induced virulent and low nitrogen/methylglucose-induced hypovirulent conditions. A pilot-scale assessment of gene diversity was made from the sequence analyses of the two libraries. A total of 2280 cDNA clones was sequenced that corresponded to 220 unique sequence sets or clusters (contigs) and 805 …

Effects Of Early Application Timing Of Foliar Fungicides In Field Corn In Central Nebraska, 2011, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

A foliar fungicide early application timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 3 May in 30 in. rows with a target population of 32,000 plants/A. The trial area was disked with a crop history of seven years of continuous corn. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 …

Nebline, January 2012

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: UNL Food Processing Center Provides Valuable Assistance to Food Manufacturers

Farm Views

Urban Agriculture

Food & Fitness

Home & Family Living

Horticulture

Environmental Focus

4-H & Youth

Community Focus

Extension Calendar

Nutrition Education Program

Family and Community Education (FCE) Clubs

and other extension news and events

2011 Annual Report Special Pullout Section

Greenhouse Production Of Strawberries During The Winter, Ellen T. Paparozzi, George E. Meyer, Stacy A. Adams, M. Elizabeth Conley, Benjamin A. Loseke, Paul E. Read

Department of Agronomy and Horticulture: Faculty Publications

Strawberries are one of America’s favorite fruits and are available in grocery stores year round. Given increased shipping and other associated costs as well as the opportunity to provide a fresh, nutritious, local product, our research team is exploring the feasibility of growing strawberries during the winter in Nebraska.

Productivity Of Field Pea (Pisumsativum L.) And Spring Oat (Avena Sativa L.) Grown As Sole And Intercrops Under Different Nitrogen Levels, Chengchou Han, Christopher Borman, Dori Osantowski, Jeremy Wagnitz, Katja Koehler-Cole, Kevin Korus, Evan Sonderegger, Rodrigo Werle, Tara Wood, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Intercropping cereal grains and legumes has potential as an alternative cool-season forage crop in low-input farming systems. The objectives of this study were to quantify the effects of density, species proportion, and nitrogen (N) supply on the biomass accumulation of field pea and spring oat grown as sole or intercrops. Greenhouse experiments were conducted using an additive series experimental design. Treatments included three fertilizer N rates and 20 density/proportion combinations in a randomized complete block with four replications. Sole plant densities included 2, 3, 4, 5 plants of each species pot-1 (16 cm in diameter, 16 cm in height). The …

Spatial Patterns Of Brown Rot Epidemics And Development Of Microsatellite Markers For Analyzing Fine-Scale Genetic Structure Of Monilinia Fructicola Populations Within Peach Tree Canopies, Sydney E. Everhart, A. Askew, L. Seymour, T. C. Glenn, H. Scherm

Department of Plant Pathology: Faculty Publications

To better understand the fine-scale spatial dynamics of brown rot disease and corresponding fungal genotypes, we analyzed three-dimensional spatial patterns of pre-harvest fruit rot caused by Monilinia fructicola in individual peach tree canopies and developed microsatellite markers for canopy-level population genetics analyses. Using a magnetic digitizer, high-resolution maps of fruit rot development in five representative trees were generated, and M. fructicola was isolated from each affected fruit. To characterize disease aggregation, nearest-neighbor distances among symptomatic fruit were calculated and compared with appropriate random simulations. Within-canopy disease aggregation correlated negatively with the number of diseased fruit per tree (r = −0.827, …

Prothioconazole Tolerant Cryptococcus Flavescens Strains For Biological Control Of Fusarium Head Blight, David A. Schisler, Michael J. Boehm

Department of Plant Pathology: Faculty Publications

Strains of Cryptococcus flavescens which are superior antagonists of F. graminearum for suppression and control of FHB in cereals, particularly in wheat and barley, are described. The strains are prothioconazole tolerant variants of previously described C. flavescens OH 182.9 (NRRL Y-30216). Moreover, these prothioconazole tolerant variants exhibit significantly increased efficacy against F. graminearum in comparison to the parent strain OH 182.9.

Product Comparison Of Foliar Fungicide Efficacy On Diseases Of Field Corn In Nebraska, 2011, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

foliar fungicide efficacy trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Dekalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 3 May in 30-in. rows with a target population of 32,000 plants/A. The trial area was disked with soybean as the previous year’s crop. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 lb/A) was applied to the trial site. …

Efficacy Evaluation Of Foliar Fungicide Application Timing On Diseases Of Field Corn In Nebraska, 2011, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

foliar fungicide efficacy timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Dekalb corn hybrid DKC 62-54, rating of “good” (6 out of 9) for gray leaf spot (GLS) and “excellent” (2 out of 9) for common rust (CR), was planted on 3 May in 30-in. rows with a target population of 32,000 plants/A. The trial area was disked with soybean as the previous year’s crop. On 9 May before plant emergence, a herbicide program of Roundup (1 pt/A), Verdict (16 fl oz/A) and Atrazine (1 lb/A) was applied to the trial …

Evaluation Of Foliar Fungicide Efficacy On Sorghum In Nebraska, 2011, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb sorghum hybrid DKS 36-06 was planted on 23 May in 30-in. rows with a target population of approximately 120,000 plants/A. The trial area was disked with soybean as the previous year’s crop. Four treatments and a nontreated control were replicated six times in a randomized complete block design. Each plot was four rows (10 ft) wide by 40 ft in length. . . . There were significant differences in GLS AUDPC among treatments. The nontreated control exhibited the largest …

Application Timing On Foliar Fungicide Efficacy On Sorghum In Nebraska, 2009, C. M. Schleicher, T. A. Jackson

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy trial was established at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. Grain sorghum hybrid NC+ 7R83 was planted on 18 May in 30-in. rows with a target population of 90,000 plants/A. The trial area was disked with a crop history of five years of continuous corn. Eight treatments and a non-treated control were replicated six times in a randomized complete block design. Each plot was four rows (10 ft) wide by 40 ft in length. . . . There were no significant differences in stay green. Stay green percentages ranged from …

Effects Of Crop Injury On Disease Development, Tamra A. Jackson, Loren J. Giesler, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

The effect of damage caused by blowing soil and leaf contact with high speed winds and hail will all create a similar level of wounding that is often sufficient for pathogens that require wounds to enter (infect) plants. As we look at the level of disease and crop damage we can identify several examples in the corn and soybean disease systems when this can be a factor that could lead to significant disease development and possibly trigger a disease management action.

Hail and wind damage can result in an open canopy which can affect the microclimate and impact disease development. …

What's New In Plant Pathology: Resistance: Mystery And Misunderstandings, Amy D. Timmerman, Loren J. Giesler, Robert M. Harveson, Tamra Jackson-Ziems, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

One of the most common management recommendations for plant diseases is the use of resistant or tolerant varieties/hybrids in your production system. However, there is common confusion on the definition and differentiation of susceptible, tolerant, and resistant varieties/hybrids from a plant pathology viewpoint. A susceptible variety/hybrid allows the pathogen to reproduce and causes significant disease development and in turn compromises the productivity of the plant (i.e., yield). A tolerant variety/hybrid allows the pathogen to reproduce and cause disease at the same or at a slightly reduced rate as a susceptible variety/cultivar; however, there is no noticeable reduction in the plant’s …

Inheritance Of Grain Polyphenol Oxidase (Ppo) Activity In Multiple Wheat (Triticum Aestivum L.) Genetic Backgrounds, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Grain polyphenol oxidase (PPO) activity can cause discoloration of wheat (Triticum aestivum L.) food products. Five crosses (PI 117635/Antelope; Fielder/ NW03681; Fielder/Antelope; NW07OR1070/Antelope; NW07OR1066/OR2050272H) were selected to study the genetic inheritance of PPO activity. STS markers, PPO18, PPO29 and STS01, were used to identify lines with putative alleles at the Ppo-A1 and Ppo-D1 loci conditioning low or high PPO activity. ANOVA showed significant genotypic effects on PPO activity (P\0.0001) in all populations. The generations and generation 9 genotype effects were not significant in any population. A putative third (null) genotype at Ppo-A1 (no PCR fragments for PPO18) was discovered …

Identification And Characterization Of Four Missense Mutations In Brown Midrib 12 (Bmr12), The Caffeic O-Methyltranferase (Comt) Of Sorghum, Scott E. Sattler, Nathan A. Palmer, Ana Saballos, Ann M. Greene, Zhanguo Xin, Gautam Sarath, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Modifying lignin content and composition are targets to improve bioenergy crops for cellulosic conversion to biofuels. In sorghum and other C4 grasses, the brown midrib mutants have been shown to reduce lignin content and alter its composition. Bmr12 encodes the sorghum caffeic O-methyltransferase, which catalyzes the penultimate step in monolignol biosynthesis. From an EMS-mutagenized TILLING population, four bmr12 mutants were isolated. DNA sequencing identified the four missense mutations in the Bmr12 coding region, which changed evolutionarily conserved amino acids Ala71Val, Pro150Leu, Gly225Asp, and Gly325Ser. The previously characterized bmr12 mutants all contain premature stop codons. These newly identified mutants, along …

Cultivating A Movement: Excerpts From An Oral History Of Organic Farming And Sustainable Agriculture On California’S Central Coast [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Edited by I. Reti and S. Rabkin, 2011. University of California, Santa Cruz, Library, Santa Cruz, California, United States. 299 p., US$19.95, ISBN 9-780972-33431, paper.

Often the most compelling evidence for success of organic farming comes from the personal stories of farmers. Coupled with reports on the application of science in organics, the practical knowledge of people in the field provides a rich foundation for the ongoing growth of this intriguing sector of the food system. This collection of interviews by the staff of the Regional History Project is one unique activity of the University of California, Santa Cruz library, …

Estimating Construction Costs For A Low-Cost Quonset-Style Greenhouse, David P. Lambe, Stacy A. Adams, Ellen T. Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

Double polyethylene Quonset-style greenhouses offergrowers and farmers a more cost-effective structure than glass- or acrylic-covered structures for growing plants off-season. These greenhouses are especially applicablefor producing off-season high value crops such as fruits and vegetables for local markets. To support this production alternative, this publication contains a list of greenhouse components, the start-up costs associated with these items and an estimate of the number of person hours required to assemble and outfit a 24-foot-by-72-foot double polyethylene, air-inflated greenhouse structure. As there are many options available for building double polyethylene greenhouses, the main purpose of this publication is to identify the …

The ‘Pi 438489b’ By ‘Hamilton’ Snp-Based Genetic Linkage Map Of Soybean [Glycine Max (L.) Merr.] Identified Quantitative Trait Loci That Underlie Seedling Sds Resistance, Kassem My Abdelmajid, Laura Ramos, Leonor Leandro, Gladys Mbofung, D. L. Hyten, Stella K. Kantartzi, Robert L. Grier Iv, Victor N. Njiti, Khalid Meksem

Department of Agronomy and Horticulture: Faculty Publications

Soybeans [Glycine max (L.) Merr.] are susceptible to many diseases including fungal diseases such as soybean sudden death syndrome (SDS). Several studies reported SDS resistance quantitative trait loci (QTL) on the soybean genome using different recombinant inbred line (RIL) populations and low density genetic linkage maps. High density exclusively single nucleotide polymorphisms-based (SNP-based) maps were not yet reported in soybean. The objectives of this study were (1) to construct a high density SNP-based genetic linkage map of soybean using the ‘PI438489B’ by ‘Hamilton’ (PIxH, n=50) recombinant inbred line population, and (2) to map QTL for SDS resistance using this …

Structural Variants In The Soybean Genome Localize To Clusters Of Biotic Stress-Response Genes, Leah K. Mchale, William J. Haun, Wayne W. Xu, Pudota B. Bhaskar, Justin E. Anderson, D. L. Hyten, Daniel J. Gerhardt, Jeffrey A. Jeddeloh, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide structural and gene content variations are hypothesized to drive important phenotypic variation within a species. Structural and gene content variations were assessed among four soybean (Glycine max) genotypes using array hybridization and targeted resequencing. Many chromosomes exhibited relatively low rates of structural variation (SV) among genotypes. However, several regions exhibited both copy number and presence-absence variation, the most prominent found on chromosomes 3, 6, 7, 16, and 18. Interestingly, the regions most enriched for SV were specifically localized to gene-rich regions that harbor clustered multigene families. The most abundant classes of gene families associated with these regions …

Identification Of Positive Yield Qtl Alleles From Exotic Soybean Germplasm In Two Backcross Populations, K.-S. Kim, B. W. Diers, D. L. Hyten, M. A. Rouf Mian, J. G. Shannon, R. L. Nelson

Department of Agronomy and Horticulture: Faculty Publications

Increasing seed yield is an important breeding goal of soybean [Glycine max (L.) Merr.] improvement efforts. Due to the small number of ancestors and subsequent breeding and selection, the genetic base of current soybean cultivars in North America is narrow. The objective of this study was to map quantitative trait loci (QTL) in two backcross populations developed using soybean plant introductions as donor parents. The first population included 116 BC₂F₃-derived lines developed using ‘‘Elgin’’ as the recurrent parent and PI 436684 as the donor parent (E population). The second population included 93 BC₃F …