scholarly journals Exserohilum turcicum Race Population Distribution in the North Central United States

Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 292-299 ◽  
Author(s):  
Japheth D. Weems ◽  
Carl A. Bradley
Keyword(s):  
United States ◽  
Resistance Genes ◽  
Population Distribution ◽  
The United States ◽  
Population Diversity ◽  
Exserohilum Turcicum ◽  
North Central ◽  
Physiological Races ◽  
The North ◽  
Central United States

Northern leaf blight (NLB) of corn, caused by Exserohilum turcicum, is a foliar disease common across corn production regions of the world, including those in the north central United States. Previous race population distribution studies identified five physiological races present in the United States, prior to 1995. For this study, 156 E. turcicum isolates were screened on corn differential lines containing Ht1, Ht2, Ht3, Htm1, and Htn1 resistance genes. Isolates were collected from fields in Iowa, Illinois, Indiana, Minnesota, North Carolina, Ohio, and Wisconsin, which included 143 isolates collected between 2007 and 2014 and 13 isolates collected between 1979 and 1985. Twenty different physiological races were observed based on the symptom response of the differential corn lines. E. turcicum race 0, 1, and 1mn were the most prevalent races, comprising 21, 27, and 13% of the 156 isolates, respectively. Race populations were diverse within states and years. Virulence to multiple Ht resistance genes within individual isolates was observed in 47% of those tested, with 3% of the isolates conferring virulence to all Ht resistance genes. Virulence to the Ht1, Ht2, Ht3, Htm1, and Htn1 resistance genes was present in 64, 20, 18, 32, and 27% of the E. turcicum isolates, respectively. Virulence to Ht resistance genes was fairly evenly distributed across states, in isolates collected after 2008. Virulence to Ht2, Ht3, Htm1, and Htn1 decreased after 2010. Variations in race population diversity are difficult to explain without knowing the level of selection pressure present in fields, and information regarding Ht resistance gene deployment in commercial varieties is not publicly available. Although virulence was observed against all Ht resistance genes, qualitative Ht resistance genes could be used in conjunction with quantitative resistance to increase NLB control.

scholarly journals Performance of Landscape Roses Grown with Minimal Input in the North-central, Central, and South-central United States

2017 ◽  
Vol 27 (5) ◽  
pp. 718-730 ◽  
Author(s):  
David C. Zlesak ◽  
Randy Nelson ◽  
Derald Harp ◽  
Barbara Villarreal ◽  
Nick Howell ◽  
...  
Keyword(s):  
United States ◽  
National Level ◽  
The United States ◽  
The South ◽  
Flower Number ◽  
North Central ◽  
The North ◽  
South Central ◽  
Central United States ◽  
Plant Hardiness

Landscape roses (Rosa sp.) are popular flowering shrubs. Consumers are less willing or able to maintain landscape beds than in years past and require plants that are not only attractive, but well-adapted to regional climatic conditions, soil types, and disease and pest pressures. Marketing and distribution of rose cultivars occurs on a national level; therefore, it is difficult for U.S. consumers in the U.S. Department of Agriculture (USDA) Plant Hardiness Zones 3 to 5 to identify well-adapted, cold-hardy cultivars. Identifying suitable cultivars that have strong genetic resistance to pests and disease and that will tolerate temperature extremes without winter protection in the USDA Plant Hardiness Zones 3 to 5 is of tremendous value to consumers and retailers in northern states. Twenty landscape rose cultivars, primarily developed in north-central North America, were evaluated at five locations in the United States (three in the north-central United States, one in the central United States, and one in the south-central United States) using the low-input, multiyear Earth-Kind® methodology. Six roses had ≥75% plant survival at the end of the study and were in the top 50% of performers for overall mean horticultural rating at each of the three north-central U.S. sites: ‘Lena’, ‘Frontenac’, ‘Ole’, ‘Polar Joy’, ‘Sunrise Sunset’, and ‘Sven’. Five of these six roses met the same criteria at the central United States (exception ‘Lena’) and the south-central United States (exception ‘Polar Joy’) sites. Cultivar, rating time, and their interaction were highly significant, and block effects were not significant for horticultural rating for all single-site analyses of variance. Significant positive correlations were found between sites for flower number, flower diameter, and overall horticultural rating. Significant negative correlations were found between flower number and diameter within each site and also between black spot (Diplocarpon rosae) lesion size from a previous study and overall horticultural rating for three of the five sites. Cane survival ratings were not significantly correlated with overall horticultural rating, suggesting some cultivars can experience severe winter cane dieback, yet recover and perform well. Data from this study benefit multiple stakeholders, including nurseries, landscapers, and consumers, with evidence-based regional cultivar recommendations and breeders desiring to identify regionally adapted parents.

scholarly journals Analyses of Yield and Economic Response from Foliar Fungicide and Insecticide Applications to Soybean in the North Central United States

2016 ◽  
Vol 17 (4) ◽  
pp. 232-238 ◽  
Author(s):  
Yuba R. Kandel ◽  
Daren S. Mueller ◽  
Chad E. Hart ◽  
Nathan R. C. Bestor ◽  
Carl A. Bradley ◽  
...  
Keyword(s):  
United States ◽  
Field Experiments ◽  
Foliar Application ◽  
The United States ◽  
Insect Management ◽  
North Central ◽  
The North ◽  
Central United States ◽  
Foliar Fungicide ◽  
The Impact

Foliar disease and insect management on soybean (Glycine max L. Merrill) in the North Central region of the United States has been increasingly accomplished through foliar fungicide and insecticide application. Data from research trials conducted in Illinois, Indiana, Iowa, and Nebraska were compiled from 2008 to 2014 to determine the impact of fungicide, insecticide, and fungicide + insecticide applications on soybean yield and profitability. In each state, field experiments occurred each year in two to seven locations. All treatments were applied at the R3 growth stage. Disease and insect pressure were very low in all states and years. A foliar application of fungicide, insecticide, or the combination, increased yield in seven out of 14 total site-years (P < 0.10). Economic analysis using an average soybean price of $0.42 per kilogram and average application cost of $62 per hectare indicated that fungicide applications were only profitable in 14% of the trial site-years. Insecticide alone and fungicide + insecticide was profitable in 39% and 45% of site-years, respectively. Effect of fungicide class on yield was inconsistent. Our results indicate that although yield increases can occur with foliar fungicide and/or insecticide treatments, current market prices and application costs may limit profitability when disease and/or insect pressure is low. Accepted for publication 22 September 2016.

scholarly journals Evaluation of Griffith Buck Roses for Resistance to Black Spot

2008 ◽  
Vol 18 (4) ◽  
pp. 588-591
Author(s):  
Daren S. Mueller ◽  
Mark L. Gleason ◽  
Nicholas P. Howell ◽  
Edward M. Moran
Keyword(s):  
United States ◽  
Disease Resistance ◽  
Field Trial ◽  
Black Spot ◽  
The United States ◽  
The Other ◽  
North Central ◽  
The North ◽  
Disease Resistant ◽  
Central United States

Recently, roses (Rosa spp.) that require relatively little maintenance have gained in popularity in the United States. One group of these roses is the Griffith Buck roses, which were selected to survive the extremely cold winters of the north-central United States. Many of these roses were rated qualitatively as having disease resistance when they were released, but their resistance levels to black spot (Marssonina rosae) have not been quantified, compared with each other, or rated against other resistant or susceptible roses. In a field trial in Iowa in 2005 and 2006, 24 Griffith Buck roses that were originally described as disease resistant were compared with susceptible and resistant control cultivars for susceptibility to black spot. No fungicides were applied in either year. Plants were rated five times each year for black spot incidence, and also to assess overall plant appearance. Griffith Buck roses ‘Carefree Beauty’, ‘Aunt Honey’, ‘Honeysweet’, ‘Earthsong’, and ‘Pearlie Mae’ had significantly less black spot than many of the other cultivars. In addition, these cultivars also remained attractive and could be used in low-maintenance landscapes in the north-central United States, even under moderate black spot pressure.

An Observational Examination of Long-Lived Supercells. Part I: Characteristics, Evolution, and Demise

2006 ◽  
Vol 21 (5) ◽  
pp. 673-688 ◽  
Author(s):  
Matthew J. Bunkers ◽  
Mark R. Hjelmfelt ◽  
Paul L. Smith
Keyword(s):  
United States ◽  
The United States ◽  
Eastern United States ◽  
North Central ◽  
The North ◽  
Central United States ◽  
Bow Echo ◽  
Primary Focus ◽  
Convective Mode

Abstract Observations of supercells and their longevity across the central and eastern United States are examined, with the primary focus on understanding the properties of long-lived supercells (defined as supercells lasting ≥4 h). A total of 224 long-lived supercells, occurring in 184 separate events, are investigated. These properties are compared with those of short-lived supercells (lifetimes ≤2 h) to determine the salient differences between the two classifications. A key finding is that long-lived supercells are considerably more isolated and discrete than short-lived supercells; as a result, the demise of a long-lived supercell (i.e., the end of the supercell phase) is often signaled by a weakening of the storm’s circulation and/or a rapid dissipation of the thunderstorm. In contrast, short-lived supercells commonly experience a demise linked to storm mergers and convective transitions (e.g., evolution to a bow echo). Also noteworthy, 36% of the long-lived supercell events were associated with strong or violent tornadoes (F2–F5), compared with only 8% for the short-lived supercell events. Evolutionary characteristics of long-lived supercells vary geographically across the United States, with the largest contrasts between the north-central United States and the Southeast. For example, 86% of the long-lived supercells across the north-central United States were isolated for most of their lifetime, whereas only 35% of those in the Southeast displayed this characteristic. Not surprisingly, the convective mode was discrete for 70% of the long-lived supercell events across the north-central United States, compared with 39% for the Southeast.

scholarly journals Genetic Variation of Sclerotinia sclerotiorum from Multiple Crops in the North Central United States

PLoS ONE ◽  
2015 ◽  
Vol 10 (9) ◽  
pp. e0139188 ◽  
Author(s):  
Laura Aldrich-Wolfe ◽  
Steven Travers ◽  
Berlin D. Nelson
Keyword(s):  
United States ◽  
Genetic Variation ◽  
Sclerotinia Sclerotiorum ◽  
North Central ◽  
The North ◽  
Central United States

Relation of algal biovolume to chlorophyll a in selected lakes and wetlands in the north-central United States

1995 ◽  
Vol 52 (2) ◽  
pp. 416-424 ◽  
Author(s):  
James W. LaBaugh
Keyword(s):  
United States ◽  
North Dakota ◽  
Chlorophyll A ◽  
Linear Relation ◽  
Algal Biomass ◽  
Open Water ◽  
Light Penetration ◽  
North Central ◽  
The North ◽  
Central United States

Algal chlorophyll a is commonly used as a surrogate for algal biomass. Data from three lakes in western Nebraska, five wetlands in north-central North Dakota, and two lakes in north-central Minnesota represented a range in algal biovolume of over four orders of magnitude and a range in chlorophyll a from less than 1 to 380 mg∙m−3. Analysis of these data revealed that there was a linear relation, log10 algal biovolume = 5.99 + 0.09 chlorophyll a (r2 = 0.72), for cases in which median values of chlorophyll a for open-water periods were less than 20 mg∙m−3. There was no linear relation in cases in which median chlorophyll a concentrations were larger than 20 mg∙m−3 for open-water periods, an occurrence found only in shallow prairies lakes and wetlands for years in which light penetration was the least.

Processing Snap Bean Variety Responses to Applied Nitrogen and Irrigation in the North Central United States

2015 ◽  
Vol 107 (4) ◽  
pp. 1401-1410 ◽  
Author(s):  
Yi Wang ◽  
Matthew D. Ruark ◽  
Amanda J. Gevens ◽  
Don T. Caine ◽  
Amanda L. Raster ◽  
...  
Keyword(s):  
United States ◽  
Snap Bean ◽  
North Central ◽  
The North ◽  
Bean Variety ◽  
Central United States ◽  
Applied Nitrogen
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