NF05-633 Soybean Rust: How Great is the Threat for Nebraska?

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

NF05-633 Soybean Rust: How Great is the Threat for Nebraska?

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

Can herbicides affect disease development? An overview of differentiating herbicide injury from crop disease and what is known about herbicide effects on disease development

With the current changes in weed management and the onset of glyphosate resistant weed species, soybean farmers are using both additional herbicide modes and action and more preplant herbicide options to supplement glyphosate in their weed management programs. 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

Quantitative Relationship of Soil Texture with the Observed Population Density Reduction of Heterodera glycines after Annual Corn Rotation in Nebraska

Soil texture has been commonly associated with the population density of Heterodera glycines (soybean cyst nematode: SCN), but such an association has been mainly described in terms of textural classes. In this study, multivariate analysis and a generalized linear modeling approach were used to elucidate the quantitative relationship of soil texture with the observed SCN population density reduction after annual corn rotation in Nebraska. Forty-five commercial production fields were sampled in 2009, 2010, and 2011 and SCN population density (eggs/100 cm3 of soil) for each field was determined before (Pi) and after (Pf) annual corn rotation from ten 3 3 3-m sampling grids. Principal components analysis revealed that, compared with silt and clay, sand had a stronger association with SCN Pi and Pf. Cluster analysis using the average linkage method and confirmed through 1,000 bootstrap simulations identified two groups: one corresponding to predominant silt-and-clay fields and other to sand-predominant fields. This grouping suggested that SCN relative percent population decline was higher in the sandy than in the silt-and-clay predominant group. However, when groups were compared for their SCN population density reduction using Pf as the response, Pi as a covariate, and incorporating the year and field variability, a negative binomial generalized linear model indicated that the SCN population density reduction was not statistically different between the sand-predominant field group and the silt-and-clay predominant group

NF518 Management of Phytophthora Diseases of Soybeans

Phytophthora diseases of soybean, present wherever soybeans are grown, is outlined in this NebFact

NF01-450 Daylily Rust: A New Disease in the United States

This particular rust is very aggressive and destroys daylily foliage. So far all infections have been on the foliage; it is not known whether tuber infections occur

What’s New in Plant Pathology

Extension Plant Pathology Team Update Plant and Pest Diagnostic Clinic Update Disease Management Products Table 1. Foliar Fungicide Label Updates Table 2. New Product

Pine wilt : a fatal disease of exotic pines in the Midwest (2000)

"February 2000.""Sustainable urban landscapes.

Phytophthora root and stem rot of soybean

Phytophthora sojae is a soil borne pathogen that in the past has caused very large economic losses. During the late 1970s, 300,000 soybean acres (approximately 10% of total soybean production in Ohio) were lost due to P. sojae. This disease has since been effectively managed predominately through the incorporation of single-gene mediated resistance but quantitative or partial resistance has been used as well. In fact, today, we can repeat 100% loss by planting soybean cultivars that were popular during earlier epidemics. Without high levels of resistance to this pathogen, many soybean acres would be lost each year to this disease. Phytophthora doesn’t forget and it doesn’t go away

Proceedings of the 42nd Annual Meeting, Southern Soybean Disease Workers (March 11-12, 2015, Pensacola Beach, Florida)

Contents Schedule Southern United States Soybean Disease Loss Estimates for 2014. TW Allen, JP Damicone, NS Dufault, TR Faske, DE Hershman, CA Hollier, T Isakeit, RC Kemerait, NM Kleczewski, SR Koenning, HL Mehl, JD Mueller, C Overstreet, P Price, EJ Sikora, and H Young Graduate student competition (Trey Price, moderator) Effect of Secondary Nutrient Applications on Suppression of Charcoal Rot in Soybean. T Wilkerson, M Tomasu-Peterson, BR Golden, S Lu, AB Johnson, and TW Allen Molecular Characterization of the G143A Mutation Leading to QoI Fungicide Resistance among Fungal Pathogens Causing Cercospora Leaf Blight and Purple Seed Stain of Soybean. S Albu, P Price, V Doyle, and RW Schneider The Effects of Starter Fertilizer on Soybean Infected with Fusarium virguliforme or Rhizoctonia solani. J Miller, C Vick, A Vick, and J Bond Root-knot Nematodes (Meloidogyne spp.) Associated with Soybean in Arkansas. C Khanal, RT Robbins, C Overstreet, and EC McGawley Tillage, Fungicide, and Cultivar Effects on Frogeye Leaf Spot Severity and Yield in Soybean. J Jordan, A Mengistu, HM Kelly, N Bellaloui, PR Arelli, KN Reddy, and AJ Wrather Frogeye Leaf Spot Response to Solo and Combination Fungicides. AM Cochran, HM Kelly, K Lamour, and C Bradley A New Perspective on Cercospora Leaf Blight Symptoms on Soybean. EC Silva, TG Garcia, AV Lygin, AK Chanda, CL Robertson, BM Ward, and RW Schneider Using a Hill Plot Technique for Evaluating Soybean Varieties for Resistance to Sudden Death Syndrome. J Padgett, A Vick, C Vick, C Schmidt, and J Bond Evaluating the Resistance of Some Soybean Varieties/Cultivars on Reniform Isolates from Louisiana. MT Kularathna, C Overstreet, EC McGawley, and DM Xavier Investigating Fungicide Sensitivities Beyond the QoIs in Cercospora sojina from Mississippi. JR Standish, M Tomaso-Peterson, TW Allen, S Sabanadzovic, and N Aboughanem-Sabanadzovic Using Fluopyram as a Seed Treatment to Reduce Sudden Death Syndrome in Resistant and Susceptible Soybean Varieties. D Esker, C Vick, A Vick, and J Bond Glyphosate Affects Cercospora Leaf Blight and Brown Spot of Soybean. TG Garcia, EC Silva, BM Ward, CL Robertson, R Levy, and RW Schneider Efficacy of Seed Treatments for Management of Fusarium virguliforme and Heterodera glycines. N Frederking, A Fakhoury, J Bond Minor Element Application as a Management Strategy for Soybean Rust and Cercospora Leaf Blight. BM Ward, CL Robertson, EC Silva, TG Garcia, and RW Schneider Management of Frogeye Leaf Spot and Determining the Impact of Fungicide Phytotoxicity in Mississippi Soybean. WJ Mansour, JT Irby, BR Golden, TH Wilkerson, and TW Allen Contributed papers (Heather Kelly, moderator) Soybean Disease Management Issues in Louisiana During 2014. P Price, MA Purvis, and HN Pruitt Soybean Vein Necrosis Virus in Mississippi N. Aboughanem-Sabanadzovic, S. Sabanadzovic. TW Allen, WF Moore, and RC Stephenson Monitoring for Soybean Vein Necrosis Virus in Alabama (2014). E Sikora, K Conner, and L Zhang Challenges and Opportunities in the Use of Molecular Tools to Detect Strobilurin/QoI Fungicide Resistance: The Case of Frogeye Leaf Spot. H Kelly and B Vega An Update of Research on Phomopsis Seed Decay in Soybean. S Li, J Rupe, P Chen, G Shannon, and G Sciumbato Assessment of Several Commercially Available Triazole and Premix Fungicides for Management of Frogeye Leaf Spot in Arkansas. TR Faske and M Emerson ILeVO® Seed Treatment for Control of SDS and Nematodes in Soybeans. C Graham Use of Random Point Assignments to Determine the Impact of Sudden Death Syndrome and Other Soilborne Diseases. T Spurlock and W Kirkpatrick Effect of Planting Date, Planting Density, Seed Treatment, and Seed Quality on Soybean Stand and Yield in Arkansas. JC Rupe, AJ Steger, RT Holland, CS Rothrock, EE Gbur, Jr, WJ Ross, and MP Popp Proceedings of the Southern Soybean Disease Workers are published annually by the Southern Soybean Disease Workers. Text, references, figures, and tables are reproduced as they were submitted by authors. The opinions expressed by the participants at this conference are their own and do not necessarily represent those of the Southern Soybean Workers. Mention of a trademark or proprietary products in this publication does not constitute a guaran-tee, warranty, or endorsement of that product by the Southern Soybean Disease Workers