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Potential For Sorghum Genotypes In A Double-Cropping System, Ben Michael Goff, Kenneth J. Moore, Steven L. Fales, Emily A. Heaton 2017 Iowa State University

Potential For Sorghum Genotypes In A Double-Cropping System, Ben Michael Goff, Kenneth J. Moore, Steven L. Fales, Emily A. Heaton

Emily Heaton

The majority of the ethanol currently produced in the United States is derived from the hydrolysis and fermentation of starch provided from corn (Zea mays) grain. Although this is a suitable temporary solution, there are some long-term issues associated with continued use of corn grain as an ethanol feedstock. It has been estimated that if the entire U.S. corn crop was used for ethanol production, it would only meet approximately 15 to 25% of the U.S. transportation fuel need. Thus ethanol produced from biomass is expected to help meet the energy needs that grain ethanol may not provide.


New Isu Research May Help Farmers Make More Informed Decisions About Land Use, Elke Brandes, Emily A. Heaton, Lisa A. Schulte-Moore, Fred Love 2017 Iowa State University

New Isu Research May Help Farmers Make More Informed Decisions About Land Use, Elke Brandes, Emily A. Heaton, Lisa A. Schulte-Moore, Fred Love

Emily Heaton

A new study from a multidisciplinary team led by Iowa State University agronomists shows that significant portions of Iowa farmland consistently lose money and could influence many farmers to change how they use some of the acres they devote to corn and soybeans.


Miscanthus Establishment And Survival, Nicholas N. Boersma, Emily A. Heaton 2017 Iowa State University

Miscanthus Establishment And Survival, Nicholas N. Boersma, Emily A. Heaton

Emily Heaton

Rising costs of petroleum fuels and increased awareness of the adverse effects of greenhouse gases have spurred interest in renewable fuels and other ‘green’ products. Recent legislation has set goals of approximately 20 billion gallons of renewable fuel produced from non-corn starch sources by the year 2022. These driving forces have increased interest in dedicated bioenergy crops. Among perennial grasses, which have received an exceptional amount of attention as dedicated energy crops, one stands out: Miscanthus (Miscanthus × giganteus).


Miscanthus Establishment And Survival, Nicholas N. Boersma, Emily A. Heaton 2017 Iowa State University

Miscanthus Establishment And Survival, Nicholas N. Boersma, Emily A. Heaton

Emily Heaton

Rising costs of petroleum fuels and increased awareness of the adverse effects of greenhouse gases have spurred interest in renewable fuels and other ‘green’ products. Recent legislation has set goals of approximately 20 billion gallons of renewable fuel produced from non-corn starch sources by the year 2022. These driving forces have increased interest in dedicated bioenergy crops. Among perennial grasses, which have received an exceptional amount of attention as dedicated energy crops, one stands out: Miscanthus (Miscanthus x giganteus).


Is It Too Late To Dig Miscanthus For Spring Planting?, Emily A. Heaton, Nicholas N. Boersma 2017 Iowa State University

Is It Too Late To Dig Miscanthus For Spring Planting?, Emily A. Heaton, Nicholas N. Boersma

Emily Heaton

Giant Miscanthus (Miscanthus × giganteus) is a perennial warm-season grass used for bioenergy, and is being planted on thousands of acres in Missouri and Arkansas this spring. Given the warm spring, and the high level of interest in Miscanthus this year, we have been getting lots of questions around propagation and planting.


Seeds From Fresh Conventional Tomatoes Germinate Faster Than Dried Or Organic Seeds, Christopher G. Brown 7131483, Cameron Kilpatrick, Mary Vu, Mallory Weaver 2017 Georgia Gwinnett College

Seeds From Fresh Conventional Tomatoes Germinate Faster Than Dried Or Organic Seeds, Christopher G. Brown 7131483, Cameron Kilpatrick, Mary Vu, Mallory Weaver

Georgia Journal of Science

Conventionally-grown and organically-grown tomato seeds sourced from both fresh tomatoes and store-bought packages were germinated for seven days to evaluate the effect of seed source on germination rates. Seeds from fresh Roma tomatoes were prepared by allowing them to ferment in their own pulp for 24 hours, while commercially packaged dry seeds did not require any preparation. Once prepared, the seeds were spaced evenly on wet paper towels and stored in resealable plastic bags in groups of 10 for a total sample size of 100 seeds in each of four treatments. The number of germinated seeds and the length of ...


Economies Of Scale In Integrated Pest Management In Vegetable And Fruit Production, Franklin Quarcoo, Conrad Bonsi, David Nii O. Tackie, Walter A. Hill, Gertrude Wall, George Hunter 2017 Tuskegee University

Economies Of Scale In Integrated Pest Management In Vegetable And Fruit Production, Franklin Quarcoo, Conrad Bonsi, David Nii O. Tackie, Walter A. Hill, Gertrude Wall, George Hunter

Professional Agricultural Workers Journal

Abstract

Pest management is achieved directly using a variety of tools, including pesticides, and indirectly through a number of agronomic/cultural practices such as irrigation and fertilizer application; collectively these practices function to positively effect general plant health. Healthier plants are more resistant to or tolerant of pests. This study explores the scale differences that impact the pest management significance and suitability of certain agronomic practices. Scale differences were discussed using literature-based information, direct field observations, and anecdotal information on the relative advantages of drip and sprinkler irrigation systems; organic and conventional cultivation of crops; crop rotation versus mono-cropping systems ...


Control Of Glyphosate-Resistant Common Ragweed (Ambrosia Artemisiifolia L.) In Glufosinate-Resistant Soybean [Glycine Max (L.) Merr], Ethann R. Barnes, Stevan Z. Knezevic, Peter H. Sikkema, John L. Lindquist, Amit J. Jhala 2017 University of Nebraska-Lincoln

Control Of Glyphosate-Resistant Common Ragweed (Ambrosia Artemisiifolia L.) In Glufosinate-Resistant Soybean [Glycine Max (L.) Merr], Ethann R. Barnes, Stevan Z. Knezevic, Peter H. Sikkema, John L. Lindquist, Amit J. Jhala

Agronomy & Horticulture -- Faculty Publications

Common ragweed emerges early in the season in Nebraska, USA and is competitive with soybean; therefore, preplant herbicides are important for effective control. Glyphosate has been used as a preplant control option; however, confirmation of glyphosate-resistant (GR) common ragweed in Nebraska necessitates evaluating other herbicide options. The objectives of this study were to (1) evaluate the efficacy of preplant (PP) herbicides followed by (fb) glufosinate alone or in tank-mixture with imazethapyr, acetochlor, or S-metolachlor applied post-emergence (POST) for control of GR common ragweed in glufosinate-resistant soybean; (2) their effect on common ragweed density, biomass, and soybean yield; and (3) the ...


Effects Of Eight Herbicides On In Vitro Hatching Of Heterodera Glycines, A. T. S. Wong, G. L. Tylka, R. G. Hartzler 2017 Iowa State University

Effects Of Eight Herbicides On In Vitro Hatching Of Heterodera Glycines, A. T. S. Wong, G. L. Tylka, R. G. Hartzler

Gregory Tylka

Laboratory studies were conducted to evaluate effects of selected herbicides on hatching of free eggs of the soybean cyst nematode, Heterodera glycines. The herbicides used were Atrazine (atrazine), Basagran (bentazon), Bladex (cyanazine), Blazer (acifluorfen), Command (clomazone), Lasso (alachlor), Sonalan (ethalfluralin), and Treflan (trifluralin). Treatments comprised two concentrations of commercial herbicide formulations and deionized water and 3.14 mM zinc sulfate as negative and positive controls, respectively. Eggs were extracted from females and cysts, surface disinfested, and incubated in herbicide or control solutions at 25 ± 2 C in darkness. Hatched second-stage juveniles were counted every other day for 24 days. Hatching ...


Flow Cytometric Analysis And Sorting Of Heterodera Glycines Eggs, G. L. Tylka, T. L. Niblack, T. C. Walk, K. R. Harkins, L. Barnett, N. K. Baker 2017 Iowa State University

Flow Cytometric Analysis And Sorting Of Heterodera Glycines Eggs, G. L. Tylka, T. L. Niblack, T. C. Walk, K. R. Harkins, L. Barnett, N. K. Baker

Gregory Tylka

A nondestructive technique was developed to characterize and separate eggs of soybean cyst nematode, Heterodera glycines, by developmental stage using flow cytometry. Eggs from cysts cultured on susceptible soybean roots were suspended in 0.1% xanthan gum or 59% sucrose and loaded into either a Coulter EPICS 752 or EPICS 753 flow cytometer. Eggs were analyzed and sorted according to forward angle and 90º light scatter, flow cytometric parameters that are relative measures of object size and granularity, respectively. Mature eggs containing vermiform juveniles were less granular and slightly larger than eggs in earlier stages of embryogeny, allowing for separation ...


A Screen For Arabidopsis Thalianamutants With Altered Susceptibility To Heterodera Schachtii, T. J. Baum, M. J. E. Wubben II, K. A. Hardy, H. Su, S. R. Rodermel 2017 Iowa State University

A Screen For Arabidopsis Thalianamutants With Altered Susceptibility To Heterodera Schachtii, T. J. Baum, M. J. E. Wubben Ii, K. A. Hardy, H. Su, S. R. Rodermel

Thomas Baum

Genetic approaches are a powerful means to elucidate plant-pathogen interactions. An in vitro screening protocol was developed to identify Arabidopsis thaliana mutants with altered susceptibility to Heterodera schachtii, the sugar beet cyst nematode. In an initial screen of approximately 5,200 ethyl methanesulfonate-generated mutant plants, two stable mutations were identified. Both mutant lines were backcrossed and were found to harbor single recessive mutant alleles. Mutant line 2-4-6 shows an approximately two-fold increase in sedentary and developing nematodes, while mutant line 10-5-2 exhibits a significant decrease in susceptibility that manifests itself only after nematodes become sedentary. Analyses of progeny from crosses ...


Isolation Of Beta-1,4-Endoglucanase Genes From Globodera Tabacumand Their Expression During Parasitism, M. Goellner, G. Smant, J. M. De Boer, T. J. Baum, E. L. Davis 2017 North Carolina State University

Isolation Of Beta-1,4-Endoglucanase Genes From Globodera Tabacumand Their Expression During Parasitism, M. Goellner, G. Smant, J. M. De Boer, T. J. Baum, E. L. Davis

Thomas Baum

Two beta-1,4-endoglucanase (EGase) cDNAs were isolated from Globodera tabacum, the tobacco cyst nematode, and have been designated as GT-eng-1 and GT-eng-2. GT-eng-1 and GT-eng-2 encode precursor proteins with a predicted secretion signal sequence, cellulolytic catalytic domain, and a linker domain. The protein product GT-ENG-1 contains an additional 95 amino acid carboxy terminal sequence with strong similarity to type II cellulose binding domains. Riboprobes and polyclonal antibodies raised to recombinant cyst nematode EGases were used to follow expression patterns of EGase transcripts and proteins throughout the nematode life cycle. EGase transcripts and proteins were specifically detected within the subventral esophageal ...


Cloning Of A Putative Pectate Lyase Gene Expressed In The Subventral Esophageal Glands Of Heterodera Glycines, J. M. de Boer, J. P. McDermott, E. L. Davis, R. S. Hussey, H. Popeijus, G. Smant, T. J. Baum 2017 Iowa State University

Cloning Of A Putative Pectate Lyase Gene Expressed In The Subventral Esophageal Glands Of Heterodera Glycines, J. M. De Boer, J. P. Mcdermott, E. L. Davis, R. S. Hussey, H. Popeijus, G. Smant, T. J. Baum

Thomas Baum

We report the cloning of a Heterodera glycines cDNA that has 72% identity at the amino acid level to a pectate lyase from Globodera rostochiensis. In situ hybridizations showed that the corresponding gene (Hg-pel-1) is expressed in the subventral esophageal gland cells of second-stage juveniles. The deduced amino acid sequence of the H. glycines cDNA shows homology to class III pectate lyases of bacterial and fungal origin.


Pinching And Spacing Effects On Cut Sunflower (Helianthus Annuus) Production In East Texas, Rebecca B. Burnett 2017 Stephen F Austin State University

Pinching And Spacing Effects On Cut Sunflower (Helianthus Annuus) Production In East Texas, Rebecca B. Burnett

Electronic Theses and Dissertations

Three experiments evaluated pinching and spacing on Helianthus annuus in East Texas to determine their effects on growth and development. Experiment 1 was designed to determine the effects of pinching nodes 1, 2, 3, or 4 on ‘Pro Cut Gold’ sunflowers. Results from experiment 1 showed non-pinched plants produced marketable stem lengths and flower sizes, while pinched plants’ stem length, stem diameter, flower diameter, and disk diameter decreased compared to the non-pinched plants. The objective for experiment 2 was to evaluate pinching and spacing treatments on ‘Pro Cut Gold’ sunflowers. All spacings for non-pinched plants in experiment 2 produced marketable ...


Evaluating Mine Soil Prepared By Scraper Pans For Herbaceous Plants And Pine Seedlings At An East Texas Lignite Surface Mine, Hannah Z. Angel 2017 Stephen F. Austin State University

Evaluating Mine Soil Prepared By Scraper Pans For Herbaceous Plants And Pine Seedlings At An East Texas Lignite Surface Mine, Hannah Z. Angel

Electronic Theses and Dissertations

Since 1974, Luminant Mining Company, LLC (Luminant) has planted over 38.7 million trees on its reclaimed lignite surface mine operations in Texas. For decades, the use of improved reclamation techniques on Luminant’s mined lands have resulted in over 31,160 ha reclaimed to forests, wildlife habitat, and pastures with productivity levels similar to those found on unmined lands. The development of new reclamation methodologies offers opportunities to further improve productivity of planted trees at Luminant’s Martin Lake Oak Hill Mine in east Texas. The conventional haulback or ‘truck shovel’ reclamation method uses haul trucks for the selective ...


Differences In Hatching Of Heterodera Glycines Egg-Mass And Encysted Eggs In Vitro, J. M. Thompson, G. L. Tylka 2017 Iowa State University

Differences In Hatching Of Heterodera Glycines Egg-Mass And Encysted Eggs In Vitro, J. M. Thompson, G. L. Tylka

Gregory Tylka

Hatching studies with Heterodera glycines typically have been conducted with a mixture of egg-mass and encysted eggs. Laboratory research was conducted to compare hatching of H. glycines eggs from external egg masses with that of eggs extracted from within females and cysts (encysted eggs). Egg-mass eggs were collected by soaking infected soybean roots in 0.5% sodium hypochlorite, and encysted eggs were collected from females and cysts dislodged from the same roots with a stream of water. Eggs were incubated at 25ºC in deionized water, 3.0 mM ZnSO[sub4]solution, or one of three synthetic H. glycines hatch inhibitors ...


Responses Of Heterodera Glycines Populations To A Postemergence Herbicide Mixture And Simulated Insect Defoliation, J. A. Browde, G. L. Tylka, L. P. Pedigo, M. D. K. Owen 2017 Iowa State University

Responses Of Heterodera Glycines Populations To A Postemergence Herbicide Mixture And Simulated Insect Defoliation, J. A. Browde, G. L. Tylka, L. P. Pedigo, M. D. K. Owen

Gregory Tylka

Effects of a mixture of the postemergence herbicides acifluorfen and bentazon, and simulated defoliation expected from green cloverworm on population densities of Heterodera glycines were determined in field plots in Iowa. The herbicide mixture and defoliation each suppressed soybean growth. Population densities of H. glycines were generally lower in herbicide-treated than untreated plots. Population densities of the nematode were unaffected by defoliation in 1988 and 1990-91, but were increased by the treatment in 1989. Key words: acifluorfen, bentazon, defoliation, Glycine max, green cloverworm, herbicide, Heterodera glycines, nematode, Plathypena scabra, postemergence herbicides, soybean, soybean cyst nematode.


Effects Of Zinc Fertilization Of Corn On Hatching Of Heterodera Glycines In Soil, J. E. Behm, G. L. Tylka, T. L. Niblack, W. J. Wiebold, P. A. Donald 2017 Iowa State University

Effects Of Zinc Fertilization Of Corn On Hatching Of Heterodera Glycines In Soil, J. E. Behm, G. L. Tylka, T. L. Niblack, W. J. Wiebold, P. A. Donald

Gregory Tylka

Experiments were conducted to determine the effects of zinc fertilizers on hatching and soil population densities of Heterodera glycines. In vitro egg hatching in solutions of reagent-grade zinc sulfate and zinc chloride and fertilizer-grade zinc sulfate was significantly greater than hatching in deionized water, whereas zinc chelate fertilizer significantly inhibited egg hatching relative to deionized water. In greenhouse experiments, no differences in cumulative percentage egg hatch were detected in soil naturally infested with H. glycines amended with fertilizer-grade zinc sulfate and zinc chelate at rates equivalent to 0, 1.12, 11.2, and 112 kg Zn/ha and subsequently planted ...


Heterodera Glycines Cyst Components And Surface Disinfestants Affect H. Glycines Hatching, D. V. Charlson, G. L. Tylka 2017 Iowa State University

Heterodera Glycines Cyst Components And Surface Disinfestants Affect H. Glycines Hatching, D. V. Charlson, G. L. Tylka

Gregory Tylka

We investigated the effects of Heterodera glycines cyst components and surface disinfestants on hatching of H. glycines eggs in vitro. Eggs were incubated in either H. glycines cyst wall fragments, cyst wall and egg rinsate, egg homogenate, or control solutions of soybean root diffusate, sterile distilled water, or zinc sulfate. Hatch in cyst wall and egg rinsate, and egg homogenate, was greater ([alpha] = 0.05) than hatch in sterile distilled water; however, it was not different from hatch in zinc sulfate according to Dunnett's test. Hatch in cyst wall fragments was similar to hatch in sterile distilled water. To ...


The Soybean Rhg1 Locus For Resistance To The Soybean Cyst Nematode Heterodera Glycines Regulates The Expression Of A Large Number Of Stress- And Defense-Related Genes In Degenerating Feeding Cells, Pramod Kaitheri Kandoth, Nagabhushana Ithal, Justin Recknor, Tom Maier, Dan Nettleton, Thomas J. Baum, Melissa G. Mitchum 2017 University of Missouri

The Soybean Rhg1 Locus For Resistance To The Soybean Cyst Nematode Heterodera Glycines Regulates The Expression Of A Large Number Of Stress- And Defense-Related Genes In Degenerating Feeding Cells, Pramod Kaitheri Kandoth, Nagabhushana Ithal, Justin Recknor, Tom Maier, Dan Nettleton, Thomas J. Baum, Melissa G. Mitchum

Thomas Baum

To gain new insights into the mechanism of soybean (Glycine max) resistance to the soybean cyst nematode (Heterodera glycines), we compared gene expression profiles of developing syncytia in soybean near-isogenic lines differing at Rhg1 (for resistance to Heterodera glycines), a major quantitative trait locus for resistance, by coupling laser capture microdissection with microarray analysis. Gene expression profiling revealed that 1,447 genes were differentially expressed between the two lines. Of these, 241 (16.8%) were stress- and defense-related genes. Several stress-related genes were up-regulated in the resistant line, including those encoding homologs of enzymes that lead to increased levels of ...


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