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Assessing Heterodera Glycines-Resistant And Susceptible Cultivar Yield Response, P. A. Donald, P. E. Pierson, S. K. St. Martin, P. R. Sellers, G. R. Noel, A. E. MacGuidwin, J. Faghihi, V. R. Ferris, C. R. Grau, D. J. Jardine, H. Melakeberhan, T. L. Niblack, W. C. Stienstra, G. L. Tylka, T. A. Wheeler, D. S. Wysong 2017 University of Missouri

Assessing Heterodera Glycines-Resistant And Susceptible Cultivar Yield Response, P. A. Donald, P. E. Pierson, S. K. St. Martin, P. R. Sellers, G. R. Noel, A. E. Macguidwin, J. Faghihi, V. R. Ferris, C. R. Grau, D. J. Jardine, H. Melakeberhan, T. L. Niblack, W. C. Stienstra, G. L. Tylka, T. A. Wheeler, D. S. Wysong

Gregory Tylka

The soybean cyst nematode Heterodera glycines (SCN) is of major economic importance and widely distributed throughout soybean production regions of the United States where different maturity groups with the same sources of SCN resistance are grown. The objective of this study was to assess SCN-resistant and -susceptible soybean yield responses in infested soils across the northcentral region. In 1994 and 1995, eight SCN-resistant and eight SCN-susceptible public soybean cultivars representing maturity groups (MG) I to IV were planted in 63 fields, either infested or noninfested, in 10 states in the north-central United States. Soil samples were taken to determine initial ...


A Standard Greenhouse Method For Assessing Soybean Cyst Nematode Resistance In Soybean: Sce08 (Standardized Cyst Evaluation 2008), T. L. Niblack, Gregory L. Tylka, Prakash Arelli, Jason Bond, Brian Diers, Pat Donald, Jamal Faghihi, V. R. Ferris, Karen Gallo, Robert D. Heinz, Horacio Lopez-Nicora, Ralph Von Qualen, Tom Welacky, John Wilcox 2017 University of Illinois at Urbana-Champaign

A Standard Greenhouse Method For Assessing Soybean Cyst Nematode Resistance In Soybean: Sce08 (Standardized Cyst Evaluation 2008), T. L. Niblack, Gregory L. Tylka, Prakash Arelli, Jason Bond, Brian Diers, Pat Donald, Jamal Faghihi, V. R. Ferris, Karen Gallo, Robert D. Heinz, Horacio Lopez-Nicora, Ralph Von Qualen, Tom Welacky, John Wilcox

Gregory Tylka

The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is distributed throughout the soybean [Glycine max (L.) Merr.] production areas of the United States and Canada (Fig. 1) (26). SCN remains the most economically important pathogen of soybean in North America; the most recent estimate of soybean yield reduction in North America due to SCN totaled 34,659,000 metric tons during 2006 (34).


Potential Of An Alkaline-Stabilized Biosolid To Manage Nematodes: Case Studies On Soybean Cyst And Root-Knot Nematodes, Inga A. Zasada, Felicitas Avendano, Yuncong C. Li, Terry Logan, Haddish Melakeberhan, Stephen R. Koenning, Gregory L. Tylka 2017 United States Department of Agriculture

Potential Of An Alkaline-Stabilized Biosolid To Manage Nematodes: Case Studies On Soybean Cyst And Root-Knot Nematodes, Inga A. Zasada, Felicitas Avendano, Yuncong C. Li, Terry Logan, Haddish Melakeberhan, Stephen R. Koenning, Gregory L. Tylka

Gregory Tylka

The use of treated biosolids for pest management and soil nutrient augmentation is not a new practice, but it has increased in the last two decades, primarily in the United States (22). In the late 1970s, the first land application regulations were formulated by the U.S. Environmental Protection Agency (USEPA) in response to the Clean Water Act (44). Land application of sewage sludge for soil amendment and land reclamation has increased over time as a result of the ban on ocean dumping of wastewater residuals (Ocean Disposal Ban Act of 1988). The Act also minimizes other disposal options, such ...


Species Diversity And Functional Composition Of Pastures That Vary In Landscape Position And Grazing Management, John A. Guretzky, Kenneth J. Moore, E. Charles Brummer, C. Lee Burras 2017 United States Army Corps of Engineers

Species Diversity And Functional Composition Of Pastures That Vary In Landscape Position And Grazing Management, John A. Guretzky, Kenneth J. Moore, E. Charles Brummer, C. Lee Burras

C. Lee Burras

The productivity of grasslands depends in part on their diversity of species and functional composition. Our objective was to examine the effects of three landscape positions (summit, backslope, and toeslope) and three stocking systems (continuous, rotational, and nongrazed) on species diversity and percentage of cover of grass, legume, and weed species functional types in southeastern Iowa pastures. Data were collected in 0.2-m2 plots randomly distributed throughout each of four replicate pastures in spring and summer 2000 and 2001. Backslope landscape positions within pastures managed with either continuous or rotational stocking contained the greatest overall diversity of species. Across years ...


Effectiveness Of Foliar Fungicides By Timing On Northern Leaf Blight On Hybrid Corn In Northern Iowa, Alison Robertson, Matt Schnabel 2017 Iowa State University

Effectiveness Of Foliar Fungicides By Timing On Northern Leaf Blight On Hybrid Corn In Northern Iowa, Alison Robertson, Matt Schnabel

Alison Robertson

Fungicide use on hybrid corn continues to be of interest to many farmers in Iowa. The number of fungicides registered for use on corn continues to increase, especially with the introduction of various generics. The objectives of this project were to assess the effect of timing of application of fungicides on disease, evaluate the yield response of hybrid corn to foliar fungicide application, and discern differences, if any, between fungicide products.


Effectiveness Of Foliar Fungicides By Timing On Northern Leaf Blight On Hybrid Corn In Northeast Iowa, Alison Robertson, Ken Pecinovsky 2017 Iowa State University

Effectiveness Of Foliar Fungicides By Timing On Northern Leaf Blight On Hybrid Corn In Northeast Iowa, Alison Robertson, Ken Pecinovsky

Alison Robertson

Fungicide use on hybrid corn continues to be of interest to many farmers in Iowa. The number of fungicides registered for use on corn continues to increase, especially with the introduction of various generics. The objectives of this project were to assess the effect of timing of application of fungicides on disease, evaluate the yield response of hybrid corn to foliar fungicide application, and discern differences, if any, between fungicide products.


2015 Evaluation Of Commercial Seed Treatments On Soybean At Three Locations In Iowa, Alison E. Robertson, Mauricio Serrano, Stith N. Wiggs 2017 Iowa State University

2015 Evaluation Of Commercial Seed Treatments On Soybean At Three Locations In Iowa, Alison E. Robertson, Mauricio Serrano, Stith N. Wiggs

Alison Robertson

In 2015, 13 currently available commercial seed treatments were evaluated at three locations in Iowa. Seed treatments that reduce the risk of seedling diseases, soybean cyst nematode (SCN) and sudden death syndrome (SDS) were included in the trial. The goal of the trials is to provide information of the effect of commercial seed treatments on stand count, disease incidence and severity, and yield of soybean. Funding is provided by Iowa Soybean Association.


Effectiveness Of Foliar Fungicides By Timing On Northern Leaf Blight And Common Rust On Hybrid Corn, Alison Robertson, Chad Huffman, Josh Sievers 2017 Iowa State University

Effectiveness Of Foliar Fungicides By Timing On Northern Leaf Blight And Common Rust On Hybrid Corn, Alison Robertson, Chad Huffman, Josh Sievers

Alison Robertson

Fungicide use on hybrid corn continues to be of interest to many farmers in Iowa. The number of fungicides registered for use on corn continues to increase, especially with the introduction of various generics. The objectives of this project were to assess the effect of timing of application of fungicides on disease, evaluate the yield response of hybrid corn to foliar fungicide application, and discern differences, if any, between fungicide products.


Comparison Of Commercial Seed Treatments On Soybean In Iowa, Mauricio Serrano, Alison Robertson, Myron Rees 2017 Iowa State University

Comparison Of Commercial Seed Treatments On Soybean In Iowa, Mauricio Serrano, Alison Robertson, Myron Rees

Alison Robertson

The use of seed treatments on soybean is becoming more prevalent in Iowa. Due to increasing seed costs, many farmers are reducing their seeding rates, consequently stand establishment is very important. Seed treatment products may include fungicides, nematicides, insecticides, and biologicals. Seed treatments protect stand by reducing risk of seedling disease and early-season insect damage. The objectives of this study were to evaluate commercial seed treatments for stand establishment, disease and insect control, and effect on yield.


Phenotypic And Genotypic Diversity Of Eastern Leatherwood In Five Populations That Span Its Geographic Distribution, Bryan J. Peterson, William R. Graves, Jyotsna Sharma 2017 Iowa State University

Phenotypic And Genotypic Diversity Of Eastern Leatherwood In Five Populations That Span Its Geographic Distribution, Bryan J. Peterson, William R. Graves, Jyotsna Sharma

William R Graves

Knowledge of variation among populations is important for making decisions about conservation of rare, threatened or endangered taxa. We investigated variation within and among five populations ofDirca palustris L. an understory shrub with a sporadic distribution and life-history traits that led us to predict strong phenotypic and genetic differentiation characteristic of historically limited gene flow. Populations sampled in Florida, Alabama, Illinois, Wisconsin and North Dakota spanned the geographic distribution of the species. Phenotypic traits differed among populations, and many traits correlated with latitude and environmental characteristics of the five sites. Principal components (PC) analysis showed that the first three PCs ...


Confirmation That Dirca Spp. (Thymelaeaeae) Reproduce From Rhizomes, William R. Graves 2017 Iowa State University

Confirmation That Dirca Spp. (Thymelaeaeae) Reproduce From Rhizomes, William R. Graves

William R Graves

There are three North American species of deciduous shrubs in the genus Dirca L. Dirca palustris L. occurs in the eastern United States and in southeastern Canada (Vogelmann 1953). Although its distribution is broad, D. palustris typically is obscure locally and is restricted to moist soils as an understory species along wooded slopes (Kurz 1997). Dirca occidentalis Gray also occurs on slopes (McMinn and Forderhase 1935), but its distribution is narrowly restricted to six counties of California near the San Francisco Bay. Within this area, D. occidentalis inhabits cool niches with frequent fog and relatively uniform soil moisture (Johnson 1994 ...


Function And Biodegradation In Soil Of Bioplastic Horticultural Containers Made Of Pla-Biorestm Composites, James Schrader, Kenneth McCabe, William Graves, David Grewell 2017 Iowa State University

Function And Biodegradation In Soil Of Bioplastic Horticultural Containers Made Of Pla-Biorestm Composites, James Schrader, Kenneth Mccabe, William Graves, David Grewell

William R Graves

Container-crops horticultural industries rely almost exclusively on petroleum-based plastic containers for modern production systems. Containers made of these materials fulfill all of the functions required during crop production, and perform better than containers made of clay, peat, and other natural materials, but the source of the plastic materials (fossil carbon), their lack of biodegradability, and their end-of-life disposal (97% end up in landfills) are major obstacles to sustainability. Although function and efficiency are among the most important aspects in determining the best materials for horticultural containers, there is no need for containers to persist in the environment for decades when ...


Systematics Of Dirca (Thymelaeaceae) Based On Its Sequences And Issr Polymorphisms, James A. Schrader, William R. Graves 2017 Iowa State University

Systematics Of Dirca (Thymelaeaceae) Based On Its Sequences And Issr Polymorphisms, James A. Schrader, William R. Graves

William R Graves

The genus Dirca consists of three disjunct species of shrubs. Dirca palustris is found in the eastern United States and adjacent Canada; D, occidcntahs is Umited to six counties near the San Francisco Bay in California; and the recently discovered D, mcxicana is known from one isolated population in northeastern Mexico. The three species have been described and classified according to morphological characters, but the morphological evidence does not provide a clear assessment of the relationships among the species. Morphologically D. mexicana most closely resembles D. occidenlalis., but known biogeographical trends raise doubt regarding how the three species are interrelated ...


Alnus Maritima: A Rare Woody Species From The New World, James A. Schrader, William R. Graves 2017 Iowa State University

Alnus Maritima: A Rare Woody Species From The New World, James A. Schrader, William R. Graves

William R Graves

Although first introduced into cultivation in the 1870's and praised for its ornamental character, Alnus maritima (Marsh.) Muhl. ex Nutt. (seaside alder) remains a rare woody species with unrealised potential. The ornamental promise of A. maritima was first recognised by Thomas Meehan, an Englishman who emigrated to the United States (Philadelphia, Pa). In 1848 after serving for two years at the Royal Botanic Gardens, Kew, Mr. Meehan was best known as the publisher of Meehan's Monthly (1891- 1902) and as the author of The American Handbook of Ornamental Trees (1853) and The Native Flowers and Ferns of the ...


Conclusive Evidence Of Replication Of A Plant Virus In Honeybees Is Lacking, W. Allen Miller, Jimena Carrillo-Tripp, Bryony C. Bonning, Adam G. Dolezal, Amy L. Toth 2017 Iowa State University

Conclusive Evidence Of Replication Of A Plant Virus In Honeybees Is Lacking, W. Allen Miller, Jimena Carrillo-Tripp, Bryony C. Bonning, Adam G. Dolezal, Amy L. Toth

W. Allen Miller

The recent article by Li et al. (1) lacks adequate evidence to support the authors’ assertion that a plant virus propagates or replicates in honeybees. Instead, it is possible that tobacco ringspot virus (TRSV) virions associate with the honeybee and parasitic Varroa mites in the absence of TRSV replication.


Riparian Buffer Systems -- The Basics, Thomas M. Isenhart, Michael J. Tidman 2017 Iowa State University

Riparian Buffer Systems -- The Basics, Thomas M. Isenhart, Michael J. Tidman

Thomas M. Isenhart

If you have a stream running through your farm, you may be interested in learning about a conservation technique that has gained the respect of many Iowa landowners and conservation professionals. It is called a riparian buffer system and involves planting trees, shrubs, and native grasses along streams to prevent sediment and chemicals from entering creeks and rivers.


Effects Of Stocking Rate, Botanical Composition, And Stream Bank Erosion On The Physical Characteristics Of The Streamside Zones Of Pastures (Three-Year Progress Report), Douglas Allen Bear, James R. Russell, Daniel G. Morrical, Mustafa Tufekcioglu, Thomas M. Isenhart, John L. Kovar 2017 Iowa State University

Effects Of Stocking Rate, Botanical Composition, And Stream Bank Erosion On The Physical Characteristics Of The Streamside Zones Of Pastures (Three-Year Progress Report), Douglas Allen Bear, James R. Russell, Daniel G. Morrical, Mustafa Tufekcioglu, Thomas M. Isenhart, John L. Kovar

Thomas M. Isenhart

Grazing management practices that allow cattle to congregate near pasture streams may result in the loss of vegetative cover and promote accumulation of manure near the streams, increasing the risk of nonpoint source pollution of the stream


Get Acquainted With The Iowa Crep, Thomas M. Isenhart, Michael J. Tidman 2017 Iowa State University

Get Acquainted With The Iowa Crep, Thomas M. Isenhart, Michael J. Tidman

Thomas M. Isenhart

The Conservation Reserve Enhancement Program (CREP), an offshoot of the original Conservation Reserve Program (CRP), is a voluntary program for agricultural landowners. Unique state and federal partnerships allow producers to receive incentive payments for installing specific conservation practices. Through CREP, farmers with eligible land receive annual rental payments and cost-share assistance to establish long-term, resource-conserving cover.


Parsing A Multifunctional Biosynthetic Gene Cluster From Rice: Biochemical Characterization Of Cyp71z6 & 7, Yinsheng Wu, Matthew L. Hillwig, Qiang Wang, Reuben J. Peters 2017 Iowa State University

Parsing A Multifunctional Biosynthetic Gene Cluster From Rice: Biochemical Characterization Of Cyp71z6 & 7, Yinsheng Wu, Matthew L. Hillwig, Qiang Wang, Reuben J. Peters

Reuben J. Peters

Rice (Oryza sativa) contains a biosynthetic gene cluster associated with production of at least two groups of diterpenoid phytoalexins, the antifungal phytocassanes and antibacterial oryzalides. While cytochromes P450 (CYP) from this cluster are known to be involved in phytocassane production, such mono-oxygenase activity relevant to oryzalide biosynthesis was unknown. Here we report biochemical characterization demonstrating that CYP71Z6 from this cluster acts as an ent-isokaurene C2-hydroxylase that is presumably involved in the biosynthesis of oryzalides. Our results further suggest that the closely related and co-clustered CYP71Z7 likely acts as a C2- hydroxylase involved in a latter step of phytocassane biosynthesis. Thus ...


Maximum Soil Organic Carbon Storage In Midwest U.S. Cropping Systems When Crops Are Optimally Nitrogen-Fertilized, Hanna J. Poffenbarger, Daniel W. Barker, Matthew J. Helmers, Fernando E. Miguez, Daniel C. Olk, John E. Sawyer, Johan Six, Michael J. Castellano 2017 Iowa State University

Maximum Soil Organic Carbon Storage In Midwest U.S. Cropping Systems When Crops Are Optimally Nitrogen-Fertilized, Hanna J. Poffenbarger, Daniel W. Barker, Matthew J. Helmers, Fernando E. Miguez, Daniel C. Olk, John E. Sawyer, Johan Six, Michael J. Castellano

Matthew J. Helmers

Nitrogen fertilization is critical to optimize short-term crop yield, but its long-term effect on soil organic C (SOC) is uncertain. Here, we clarify the impact of N fertilization on SOC in typical maize-based (Zea mays L.) Midwest U.S. cropping systems by accounting for site-to-site variability in maize yield response to N fertilization. Within continuous maize and maize-soybean [Glycine max (L.) Merr.] systems at four Iowa locations, we evaluated changes in surface SOC over 14 to 16 years across a range of N fertilizer rates empirically determined to be insufficient, optimum, or excessive for maximum maize yield. Soil organic C ...


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