Other Plant Sciences Commons^™

Weather Variability And Disease Management Strategies, Kevin Korus, Tony O. Adesemoye, Loren Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

This year’s title of “weather variability and disease management strategies” was chosen because we need to remember how weather conditions this year have impacted crop productivity and disease development. This will enable us to look forward and develop better management decisions for future growing seasons. Agricultural production is dependent on many climatic factors such as rain, humidity, temperature, and sunlight. These climate conditions have direct effects on yield as well as other indirect effects. One specific indirect effect of extreme weather events is increased pressure from pathogens and pests. Plant pathogens are commonly favored by very specific, and sometimes extreme, …

Characterization Of Novel Sorghum Brown Midrib Mutants From An Ems-Mutagenized Population, Scott E. Sattler, Ana Saballos, Zhanguo Xin, Deanna L. Funnell-Harris, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for

ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr …

Assessment Of Rice Self-Sufficiency In 2025 In Eight African Countries, P. A.J. Van Oort, K. Saito, E. Amovin-Assagba, Lenny G.J. Van Bussel, Justin Van Wart, Hugo De Groot, Martin K. Van Ittersum, Kenneth Cassman, M. C.S. Wopereis

Department of Agronomy and Horticulture: Faculty Publications

Most African countries are far from self-sufficient in meeting their rice consumption; in eight countries the production: consumption ratio, ranged from 0.16 to 1.18 in 2012. We show that for the year 2025, with population growth, diet change and yield increase on existing land (intensification), countries cannot become fully self-sufficient in rice. This implies that for the future, a mixture of area expansion and imports will be needed on top of yield gap closure. Further research is needed for identification of most suitable new land for rice area expansion and areas that should be protected.

Patch Burning: Implications On Water Erosion And Soil Properties, Altingul Ozaslan Parlak, Mehmet Parlak, Humberto Blanco-Canqui, Walter H. Schacht, John A. Guretzky, Martha Mamo

Department of Agronomy and Horticulture: Faculty Publications

Patch burning can be a potential management tool to create grassland heterogeneity and enhance forage productivity and plant biodiversity, but its impacts on soil and environment have not been widely documented. In summer 2013, we studied the effect of time after patch burning (4 mo after burning [recently burned patches], 16 mo after burning [older burned patches], and unburned patches [control]) on vegetative cover, water erosion, and soil properties on a patch-burn experiment established in 2011 on a Yutan silty clay loam near Mead, NE. The recently burned patches had 29 ± 8.0% (mean ± SD) more bare ground, 21 …

Sheep Updates 2015 - Katanning, Bruce Mullan, Kate Pritchett, Kimbal Curtis, Chris Wilcox, Mike Hyder, Leigh Sonnerman, Lynne Bradshaw, Geoff Lindon, Katherine Davies, Joe Young, Stephen Lee, Ian Robertson, Lucy Anderton, Hayley Norman, Ed Barrett-Lennard, Jackie Jarvis, Ben Patrick

Sheep Updates

This session covers fourteen papers from different authors:

1. The Sheep Industry Business Innovation project, Bruce Mullan, Sheep Industry Development Director, Department of Agriculture and Food, Western Australia

2. Western Australian sheep stocktake, Kate Pritchett and Kimbal Curtis, Research Officers, Department of Agriculture and Food, Western Australia

3. Wool demand and supply - short term volatility, long term opportunities, Chris Wilcox, Principal of Poimena Analysis

4. Lifetime management for maternal ewes, Mike Hyder, Research Officer, Department of Agriculture and Food, Western Australia

5. National Livestock Identification System (NLIS) for sheep and goats - what is the NLIS database? Leigh Sonnermann, …

Foliar Fungicide Comparisons For Gray Leaf Spot Management And Lodging In Nebraska Field Corn, 2014, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to compare foliar fungicides with other fungicide programs for gray leaf spot (GLS) efficacy. Corn was grown under normal, irrigated agronomic practices at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % organic matter, and the previous crop was corn. Reduced tillage was performed to the field prior to planting. Corn (DKC 64-83 RIB, moderately susceptible to GLS) was planted at approximately 34,000 seed/A on 20 May. Eleven treatments were arranged in a randomized complete block design with six replications. . . . …

Corn Disease Update, Tamra A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The harsh growing conditions during 2014 contributed to several disease problems in corn, in spite of the overall high yields across the state. The extended cold and wet conditions early in the season led to development of seedling diseases and crop stress. Then, in many parts of the state, repeated and unprecedented strong storms battered and wounded crops with multiple and widespread hail events, high winds, very heavy rain, and devastating tornadoes. Many fields were planted late or replanted, some more than once, further delaying the crop. Cool summer and fall conditions delayed maturity and led to early frost events …

What’S New In Plant Pathology, Tamra A. Jackson-Ziems, Loren Giesler, Robert M. Harveson, Stephen N. Wegulo, Kevin A. Korus, Tony O. Adesemoye

Department of Plant Pathology: Faculty Publications

Extension Plant Pathology Team Update

Changes to the Plant Disease Management Section of the 2015 Weed Guide

During the past year, several new products have become available for disease management. These products and additional products have been added to the Plant Disease Management Section of the 2015 Weed Guide. Products added to the Weed Guide have been summarized in Tables 1-3.

Table 1. Foliar Products

Table 2. Seed Treatment Products

Table 3. Seed Treatment Nematicides

Differentiating Chemical And Disease Symptoms In The Field, Kevin A. Korus, Loren J. Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Lowell Sandell, Stephen Wegulo

Department of Plant Pathology: Faculty Publications

In years with conditions favorable for seedling disease and other disease there are typically concerns and inquiries about the cause(s) of symptoms in agronomic plants. Many of the questions focus on differentiating between plant injuries potentially caused by recent herbicide applications versus symptoms caused by plant pathogens. Chemical injury in row crops is caused by chemicals such as herbicides, fertilizers, fungicides, insecticides, growth regulators, and crop oils when they are applied individually, as a mixture, or together with adjuvants. If chemicals are applied incorrectly, plants may be damaged at any point during the growing season. Chemical injury can result from …

Effect Of Waxy (Low Amylose) On Fungal Infection Of Sorghum Grain, Deanna L. Funnell-Harris, Scott E. Sattler, Patrick M. O'Neill, Kent M. Eskridge, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

Loss of function mutations in waxy, encoding granule bound starch synthase (GBSS) that synthesizes amylose, results in starch granules containing mostly amylopectin. Low amylose grain with altered starch properties has increased usability for feed, food, and grain-based ethanol. In sorghum, two classes of waxy (wx) alleles had been characterized for absence or presence of GBSS: wx^a (GBSS^-) and wx^b (GBSS+, with reduced activity). Field-grown grain of wild-type; waxy, GBSS^-; and waxy, GBSS⁺ plant introduction accessions were screened for fungal infection. Overall, results showed that waxy grains were not more susceptible than …

Multi-Year Pathogen Survey Of Biofuel Switchgrass Breeding Plots Reveals High Prevalence Of Infections By Panicum Mosaic Virus And Its Satellite Virus, Catherine L. Stewart, Jesse D. Pyle, Charlene C. Jochum, Kenneth P. Vogel, Gary Y. Yuen, Karen-Beth G. Scholthof

Department of Plant Pathology: Faculty Publications

Switchgrass (Panicum virgatum) cultivars are currently under development as lignocellulosic feedstock. Here we present a survey of three established switchgrass experimental nurseries in Nebraska in which we identified Panicum mosaic virus (PMV) as the most prevalent virus. In 2012, 72% of 139 symptomatic plants tested positive for PMV. Of the PMV-positive samples, 19% were coinfected with its satellite virus (SPMV). Less than 14% of all sampled plants in 2012 were positive for four additional viruses known to infect switchgrass. In 2013, randomized sampling of switchgrass individuals from the same 2012 breeding plots revealed that infection by PMV or PMV+SPMV …

In Vitro Transcripts Of Wild-Type And Fluorescent Protein-Tagged Triticum Mosaic Virus (Family Potyviridae) Are Biologically Active In Wheat, Satyanarayana Tatineni, Anthony J. Mcmechan, Melissa Bartels, Gary L. Hein, Robert A. Graybosch

Department of Plant Pathology: Faculty Publications

Triticum mosaic virus (TriMV) (genus Poacevirus, family Potyviridae) is a recently described eriophyid mite-transmitted wheat virus. In vitro RNA transcripts generated from full-length cDNA clones of TriMV proved infectious on wheat. Wheat seedlings inoculated with in vitro transcripts elicited mosaic and mottling symptoms similar to the wildtype virus, and the progeny virus was efficiently transmitted by wheat curl mites, indicating that the cloned virus retained pathogenicity, movement, and wheat curl mite transmission characteristics. A series of TriMV-based expression vectors was constructed by engineering a green fluorescent protein (GFP) or red fluorescent protein (RFP) open reading frame with homologous …

Fine-Scale Genetic Structure Of Monilinia Fructicola During Brown Rot Epidemics Within Individual Peach Tree Canopies, Sydney E. Everhart, H. Scherm

Department of Plant Pathology: Faculty Publications

The purpose of this study was to determine the fine-scale genetic structure of populations of the brown rot pathogen Monilinia fructicola within individual peach tree canopies to better understand within-tree plant pathogen diversity and to complement previous work on spatiotemporal development of brown rot disease at the canopy level. Across 3 years in a total of six trees, we monitored disease development, collected isolates from every M. fructicola symptom during the course of the season, and created high-resolution three-dimensional maps of all symptom and isolate locations within individual canopies using an electromagnetic digitizer. Each canopy population (65 to 173 isolates …

Recommendations Of Generic Names In Diaporthales Competing For Protection Or Use, Amy Y. Rossman, Gerard C. Adams, Paul F. Cannon, Lisa A. Castlebury, Pedro W. Crous, Marieka Gryzenhout, Walter M. Jaklitsch, Luis C. Mejia, Dmitar Stoykov, Dhanushka Udayanga, Hermann Voglmayr, Donald M. Walker

Department of Plant Pathology: Faculty Publications

In advancing to one name for fungi, this paper treats generic names competing for use in the order Diaporthales (Ascomycota, Sordariomycetes) and makes a recommendation for the use or protection of one generic name among synonymous names that may be either sexually or asexually typified. A table is presented that summarizes these recommendations. Among the genera most commonly encountered in this order, Cytospora is recommended over Valsa and Diaporthe over Phomopsis. New combinations are introduced for the oldest epithet of important species in the recommended genus. These include Amphiporthe tiliae, Coryneum lanciforme, Cytospora brevispora, C. ceratosperma, C. …

Species Associated With Cytospora Canker On Populus Tremuloides, Jeff B. Kepley, F. Brent Reeves, William R. Jacobi, Gerard C. Adams

Department of Plant Pathology: Faculty Publications

A new species that is often associated with Cytospora chrysosperma was found commonly on stems of Populus tremuloides in Colorado. This fungus is illustrated and described as Cytospora notastroma sp. nov., and morphological and molecular data demonstrate that the new species is distinct from C. chrysosperma, C. nivea, C. translucens, and other species found on Populus. Diagnostic features are superficially visible, darkly pigmented conceptacles circumscribing the ascostromata and conidiomata and surrounding the white to grayish-white discs; some isolates produce a Phialocephala-like synanamorph in vitro in addition to the Cytospora anamorph.

Plant Functional Traits Of Dominant Native And Invasive Species In Mediterranean-Climate Ecosystems, Jennifer L. Funk, Rachel J. Standish, William D. Stock, Fernando Valladares

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global datasets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five Mediterranean-climate regions, which are drought-prone and increasingly threatened by human activities including the introduction of exotic species. Traits differed strongly across the five regions. In …

Transgenic Wheat Expressing A Barley Udp-Glucosyltransferase Detoxifies Deoxynivalenol And Provides High Levels Of Resistance To Fusarium Graminearum, Xi Li, Sanghyun Shin, Shane Heinen, Ruth Dill-Macky, Franz Berthiller, Natalya Nersesian, Thomas Clemente, Susan Mccormick, Gary J. Muehbauer

Department of Agronomy and Horticulture: Faculty Publications

Fusarium head blight (FHB), mainly caused by Fusarium graminearum, is a devastating disease of wheat that results in economic losses worldwide. During infection, F. graminearum produces trichothecene mycotoxins, including deoxynivalenol (DON), that increase fungal virulence and reduce grain quality. Transgenic wheat expressing a barley UDP-glucosyltransferase (HvUGT13248) were developed and evaluated for FHB resistance, DON accumulation, and the ability to metabolize DON to the less toxic DON-3-O-glucoside (D3G). Pointinoculation tests in the greenhouse showed that transgenic wheat carrying HvUGT13248 exhibited significantly higher resistance to disease spread in the spike (type II resistance) compared with nontransformed controls. Two transgenic …

Nebline, January 2015

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: Extension 2014 Highlights

Food & Health

Family Living

Farm & Acreage

Horticulture

Pests & Wildlife

4-H & Youth

Extension Calendar

and other extension news and events

Striking The Balance: Challenges And Perspectives For The Protected Areas Network In Northeastern European Russia, Svetlana V. Degteva, Vasily I. Ponomarev, Sasha W. Eisenman, Vyacheslav Dushenkov

Publications and Research

Increasing anthropogenic pressure on the largest remaining tracts of old-growth boreal forest in Europe necessitates additional conservation of ecosystems and biodiversity in northeastern European Russia. In a regional network comprising 8 % of the Nenets Autonomous District and 13.5 % of the Komi Republic, 248 areas have varying protected statuses as state nature reserves (zapovedniks), national parks, reserves/sanctuaries (zakazniks), or natural monuments. Due to increased natural resource extraction in this relatively pristine area, designation of additional protected areas is critical for the protection of key ecological sites. The history of ecological preservation in these regions is herein described, and recent …

Toxicity Of Leaf Extract Of Acer Spp. On Equine Erythrocytes, Bailey Katherine Dye

Undergraduate Honors Thesis Projects

Red maple toxicosis is a phenomenon that occurs in equines after the consumption of dried or wilted red maple (Acer rubrum L.) leaves. Within the erythrocytes, it causes hemolysis, methemoglobinemia, and Heinz body development. The toxic agent of red maple leaves has not yet been identified; however, the development of hemolytic anemia and methemoglobinemia in equines after ingestion of the leaves, suggests that the toxin is acting as a strong oxidant. Some studies have noted that not only are wilted red maples leaves toxic to equines, but that wilted leaves of other maple species may also be toxic. Therefore, …