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Resin Monoterpene Defenses Decline Within Three Widespread Species Of Pine (Pinus) Along A 1530-M Elevational Gradient, Scott Ferrenberg, Joseph M. Langenhan, Jeffry B. Mitton 2017 New Mexico State University - Main Campus

Resin Monoterpene Defenses Decline Within Three Widespread Species Of Pine (Pinus) Along A 1530-M Elevational Gradient, Scott Ferrenberg, Joseph M. Langenhan, Jeffry B. Mitton

University Libraries Open Access Fund Supported Publications

The elevational gradient in plant defense (EGPD) hypothesis posits that natural enemy pressures increase alongside temperature across elevational climatic gradients, thereby selecting for enhanced defenses at lower elevations while leaving plants less defended at higher elevations. Phylogenetically constrained tests of this hypothesis are uncommon, with tests focused on defenses of mature trees in natural settings being exceedingly rare. In the absence of this information, predicting the spatiotemporal dynamics of forest pests that preferentially attack mature trees is rendered more difficult. Tree properties such as age, growth rate, and size have all been correlated with levels of tree defenses against insect ...


A Cellular Automaton Modeling Approach To Chestnut Blight Canker Development, Samuel Iselin 2017 Illinois State University

A Cellular Automaton Modeling Approach To Chestnut Blight Canker Development, Samuel Iselin

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Tracking 19th Century Late Blight From Archival Documents Using Text Analytics And Geoparsing, Laura Tateosian, Rachael Guenter, Yi-Peng Yang, Jean Ristaino 2017 NC State University Center For Geospatial Analytics

Tracking 19th Century Late Blight From Archival Documents Using Text Analytics And Geoparsing, Laura Tateosian, Rachael Guenter, Yi-Peng Yang, Jean Ristaino

Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings

In 1845, Ireland's potato crop was struck by a devastating potato disease that killed Ireland’s crop caused devastation for seven years and led to mass starvation and emigration from the country. The cause of the potato destruction was a fungus-like plant pathogen. There are several theories about the origin of the disease and the source of the 19th century outbreaks. We use historical documents contemporary to that time to investigate spatial information that might inform these mysteries. We present methodologies for automatically extracting information from these voluminous data sources. We identify and map geographic locations that are proximate ...


Surface-Soil Properties Of Alder Balds With Respect To Grassy And Rhododendron Balds On Roan Mountain, North Carolina—Tennessee, James T. Donaldson, Zachary C. Dinkins, Foster Levy, Arpita Nandi 2017 East Tennessee State University

Surface-Soil Properties Of Alder Balds With Respect To Grassy And Rhododendron Balds On Roan Mountain, North Carolina—Tennessee, James T. Donaldson, Zachary C. Dinkins, Foster Levy, Arpita Nandi

Foster Levy

We analyzed soils in Alder Bald, Grassy Bald, and Rhododendron Bald communities on Roan Mountain to infer the influence of vegetation on soil and to help guide management strategies. In all vegetation types, soils were acid (pH = 4–5) sandy loams. We found vegetation-associated differences for organic content, cation exchange capacity, acidity, two plant macronutrients (K, Mg), and three cations (Fe, Na, Zn). We predicted that nitrogen compounds would be highest in the Alder Bald because Alnus viridis ssp. crispa (Green Alder) can harbor nitrogen-fixing bacteria. Organic content was highest at the alder-bald sites, ammonium was similar among vegetation types ...


Pattern And Rate Of Decline Of A Population Of Carolina Hemlock (Tsuga Caroliniana Engelm.) In North Carolina, Foster Levy, Elaine S. Walker 2017 East Tennessee State University

Pattern And Rate Of Decline Of A Population Of Carolina Hemlock (Tsuga Caroliniana Engelm.) In North Carolina, Foster Levy, Elaine S. Walker

Foster Levy

We monitored a population of Carolina Hemlocks in northwestern North Carolina for four years to examine the rate and pattern of decline in response to infestation by Adelges tsugae (Hemlock Woolly Adelgid). Our yearly census of hemlock condition and severity of the adelgid infestation included trees of all sizes. We estimated declines in condition as the portions of the leaf canopy that were lost. Initially, infestation occurred throughout the population but was severe in only a small cluster of individuals. Within 1 year, the area of severe infestation increased in size to encompass 48% of the population. In another region ...


Supplemental Data, Russell J. Ingram, Foster Levy, Cindy L. Barrett, James T. Donaldson 2017 University of Georgia

Supplemental Data, Russell J. Ingram, Foster Levy, Cindy L. Barrett, James T. Donaldson

Foster Levy

No abstract provided.


Deidamia Inscriptum (Lettered Sphinx Moth) Caterpillars Feeding On Oxydendrum Arboreum (Sourwood) And Their Predation By Black Bears In Northeast Tennessee, Foster Levy, David L. Wagner, Elaine S. Walker 2017 East Tennessee State University

Deidamia Inscriptum (Lettered Sphinx Moth) Caterpillars Feeding On Oxydendrum Arboreum (Sourwood) And Their Predation By Black Bears In Northeast Tennessee, Foster Levy, David L. Wagner, Elaine S. Walker

Foster Levy

An outbreak of Deidamia inscriptum (Lettered Sphinx Moth) caterpillars was noted in northeast Tennessee where Oxydendrum arboreum (Sourwood) trees were defoliated. Nearly all published literature and online resources list only plants in the grape family (Vitaceae) as larval food plants. Food-plant preference trials using fresh leaves of 3 woody plant species showed that Deidamiacaterpillars from this region had a preference for Sourwood over Parthenocissus quinquefolia(Virginia Creeper), and rejected Acer rubrum (Red Maple), a non-host species. Ursus americanus(Black Bear) were feeding on the caterpillars as evidenced by bent and broken Sourwood saplings bearing claw marks and by abundant ...


Flax As An Iowa Crop, Chas. S. Reddy, L. C. Burnett 2017 Iowa State College

Flax As An Iowa Crop, Chas. S. Reddy, L. C. Burnett

Bulletin

Among the grain crops in the United States, seed flax is exceeded in value by corn, wheat, oats and barley. It has approximately the same value as rye, rice and sorghums.

As a crop for new land, the flax seed acreage reached a peak (3,700,000 acres) in 1902, but gradually declined to little more than a million acres by 1922. As a crop for old land, taking its place in rotations, flax acreage reached a second peak equal to the first in 1930. Consumption of flax in the United States surpassed production in 1909 and for the past ...


Control Of Cherry Yellow-Leaf On Nursery Stock, George L. McNew, Donald E. Bliss 2017 Iowa State College

Control Of Cherry Yellow-Leaf On Nursery Stock, George L. Mcnew, Donald E. Bliss

Bulletin

Yellow-leaf, caused by the fungus Coccomyces hiemalis Higgins, is the most prevalent and destructive cherry disease in Iowa, since it often causes premature defoliation of both nursery and orchard trees. Early defoliation in nursery stock results in decreased growth during the current and subsequent years, and precludes all possibility of forcing the trees into marketable size in one growing season. In the orchard, defoliation may decrease fruit bud formation and vegetative growth and increase the amount of winterkilling.

All defoliated nursery stock must be held in the nursery row a second season, and even then many of the trees must ...


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.


Cabbage Yellows, Caused By Fusarium Conglutinans, In Iowa, I. E. Melhus, A. T. Erwin, Frank Van Haltern 2017 Iowa State College

Cabbage Yellows, Caused By Fusarium Conglutinans, In Iowa, I. E. Melhus, A. T. Erwin, Frank Van Haltern

Bulletin

Cabbage yellows caused by Fusarium conglutinans is widely distributed in Iowa. It probably was introduced into the state just previous to 1910 on cabbage transplants shipped from the southern states. The organism causing cabbage yellows is the chief limiting factor in cabbage production in the Muscatine Island section and contiguous territory on the Iowa side of the Mississippi River. The yellows organism may live in the soil for long periods of time, at least 11 years, and still be destructive to a cabbage crop. Cabbage, cauliflower, Chinese cabbage, kohlrabi and brussels sprouts are known to be hosts of this organism ...


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 ...


Four New Fungous Diseases In Iowa, L. H. Pammel, Charlotte M. King 2017 Iowa State College

Four New Fungous Diseases In Iowa, L. H. Pammel, Charlotte M. King

Bulletin

During the past two seasons several important destructive fungous diseases of cultivated plants have made their appearance in Iowa, namely: Timothy rust, alfalfa rust, apple canker, and onion smut.

About the middle of July, 1910, there was an abundance of timothy rust in a meadow in the vicinity of Ames; subsequently it was reported from other localities in the state. It was again noticed after the September rains in 1911, especially in the timothy breeding plots.


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