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The Vegetation And Flora Of Edwards Air Force Base, Western Mojave Desert, California, David Charlton, Philip W. Rundel

Aliso: A Journal of Systematic and Floristic Botany

Edwards Air Force Base extends over 121,000 ha in the Antelope Valley of the western Mojave Desert, with much of the area part of a closed endorheic basin that held the Pleistocene Lake Thompson. Notable topographic features are Rogers, Rosamond and Buckhorn dry lakes, while rounded domes and scattered hills are present to the north and east. Elevation gradients are limited, ranging from a low of 690 m to 1044 m near the eastern margin. Diverse communities of saltbush scrub dominate the lower plains, while creosote bush scrub and Joshua tree woodlands are present away from the old lake basin. …

Attack And Defense Movements Involved In The Interaction Of Spodoptera Frugiperda And Helicoverpa Zea (Lepidoptera: Noctuidae), José P. F. Bentivenha, Edson L. L. Baldin, Débora Goulart Montezano, Thomas E. Hunt, Silvana L. Vieira De Paula Moraes

Department of Entomology: Faculty Publications

The fall armyworm, Spodoptera frugiperda (J. E. Smith) and the corn earworm, Helicoverpa zea (Boddie) are among the main pests of maize. Both species exhibit cannibalistic behavior and quite often share the same feeding guild in maize (maize ears), which can result in several interspecific and intraspecific interactions. Paired interaction scenarios of intraspecific and interspecific larvae were assessed in arenas in the presence and absence of food to characterize movements resulting from interactions of these insects. There was a difference in the frequency of behavioral movements in all the interactions, except for S. frugiperda in the presence of food. …

Grains Research And Development Science Highlights 2015-17, Department Of Agriculture And Food Western Australia

All other publications

Western Australian grain production and industry value has quadrupled over the past 30 years, despite declining winter rainfall, more frost and high temperature events, acidifying soils and increasing input costs. Strong evidence links this productivity growth to R&D that has delivered genetically superior varieties, better agronomic practices and more reliable farming systems. Western Australian grain growers are innovators that rapidly adopt new technology which is increasingly sourced from a wider pool of national and global science, research and innovation. Continuing to push the productivity frontier is not only critical to grower’s profitability, it underpins the international competitiveness of our exports …

Forage News [2017-01], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• 2016 Long-Term Summary of Kentucky Forage Variety Trials
• Purchase Improved Clovers for Frost Seeding NOW
• Roundup-Ready Alfalfa Variety Differences
• Understanding and Improving Fermentation in Alfalfa and Grass Baleage

The Role Of Tre6p And Snrk1 In Maize Early Kernel Development And Events Leading To Stress-Induced Kernel Abortion, Samuel W. Bledsoe, Clémence Henry, Cara A. Griffiths, Matthew J. Paul, Regina Feil, John E. Lunn, Mark Stitt, L. Mark Lagrimini

Department of Agronomy and Horticulture: Faculty Publications

Background: Drought stress during flowering is a major contributor to yield loss in maize. Genetic and biotechnological improvement in yield sustainability requires an understanding of the mechanisms underpinning yield loss. Sucrose starvation has been proposed as the cause for kernel abortion; however, potential targets for genetic improvement have not been identified. Field and greenhouse drought studies with maize are expensive and it can be difficult to reproduce results; therefore, an in vitro kernel culture method is presented as a proxy for drought stress occurring at the time of flowering in maize (3 days after pollination). This method is used to …

Changes In Soil Microbial Communities After 10 Years Of Winter Wheat Cultivation Versus Fallow In An Organic-Poor Soil In The Loess Plateau Of China, Hui Tian, Hui Wang, Xiaoli Hui, Zhaohui Wang, Rhae A. Drijber, Jinshan Liu

Department of Agronomy and Horticulture: Faculty Publications

Agricultural management methods, such as cultivation or fallowing, have led to significant changes in soil fertility and hence, crop yield. Such changes may have stemmed from changes in soil microbial communities and associated biogeochemical processes. This phenomenon is particularly true in organic-poor soil in the Loess Plateau of China. In this study, we examined three existing soil management regimes as part of a 10-year field experiment and evaluated their effects on fungal and bacterial community structures by performing high-throughput 454 pyrosequencing. These management regimes were (i) fertilized winter wheat (Triticum aestivum L.) (FW), (ii) continuous natural fallow with weeds …

Mapping And Characterization Of The Fefe Gene That Controls Iron Uptake In Melon (Cucumis Melo L.), Raghuprakash Kastoori Ramamurthy, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) deficiency in plants limits crop growth and productivity. Molecular mechanisms that plants use to sense and respond to Fe deficiency by coordinated expression of Feuptake genes are not fully understood. The C940-fe chlorotic melon (Cucumis melo) mutant known as fefe is unable to upregulate Fe-uptake genes, however, the FeFe gene had not been identified. In this study, we used two F₂ mapping populations to map and identify the FeFe gene as bHLH38, a homolog of subgroup Ib bHLH genes from Arabidopsis thaliana that are involved in transcriptional regulation of Feuptake genes in partnership with the …

Population Structure And Genetic Diversity Of Bromus Tectorum Within The Small Grain Production Region Of The Pacific Northwest, Nevin C. Lawrence, Amber L. Hauvermale, Amit Dhingra, Ian C. Burke

Department of Agronomy and Horticulture: Faculty Publications

Bromus tectorum L. is an invasive winter annual grass naturalized across the United States. Numerous studies have investigated B. tectorum population structure and genetics in the context of B. tectorum as an ecological invader of natural areas and rangeland. Despite the wealth of information regarding B. tectorum, previous studies have not focused on, or made comparisons to, B. tectorum as it persists in individual agroecosystems. The objectives of this study were to assess the genetic diversity and structure, the occurrence of generalist and specialist genotypes, and the influence of climate on distribution of B. tectorum sourced exclusively from within …

A Transcriptome‑Snp‑Derived Linkage Map Of Apios Americana (Potato Bean) Provides Insights About Genome Re‑Organization And Synteny Conservation In The Phaseoloid Legumes, Jugpreet Singh, Scott R. Kalberer, Vikas Belamkar, Teshale Assefa, Matthew N. Nelson, Andrew D. Farmer, William J. Blackmon, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

Apios (Apios americana; “apios”), a tuberous perennial legume in the Phaseoleae tribe, was widely used as a food by Native Americans. Work in the last 40 years has led to several improved breeding lines. Aspects of the pollination biology (complex floral structure and tripping mechanism) have made controlled crosses difficult, and the previous reports indicated that the plant is likely primarily an outcrosser. We used a pseudo-testcross strategy to construct a genetic map specific to the maternal parent. The map was built using single-nucleotide polymorphism markers identified by comparing the expressed sequences of individuals in the mapping population …

The Trouble With Cover Crops: Farmers’ Experiences With Overcoming Barriers To Adoption, Gabrielle E. Roesch-Mcnally, Andrea D. Basche, J. G. Arbuckle, John C. Tyndall, Fernando E. Miguez, Troy Bowman, Rebecca Clay

Department of Agronomy and Horticulture: Faculty Publications

Cover crops are known to promote many aspects of soil and water quality, yet estimates find that in 2012 only 2.3% of the total agricultural lands in the Midwestern USA were using cover crops. Focus groups were conducted across the Corn Belt state of Iowa to better understand how farmers confront barriers to cover crop adoption in highly intensive agricultural production systems. Although much prior research has focused on analyzing factors that help predict cover crop use on farms, there is limited research on how farmers navigate and overcome field-level (e.g. proper planting of a cover crop) and structural barriers …

Genetic Diversity Of Danthonia Spicata (L.) Beauv. Based On Genomic Simple Sequence Repeat Markers, Chandra S. Thammina, Keenan Amundsen, Shaun B. Bushman, Matthew H. Kramer, Scott E. Warnke

Department of Agronomy and Horticulture: Faculty Publications

Danthonia spicata (L.) Beauv., commonly known as poverty oatgrass, is a perennial bunch-type grass native to North America. D. spicata is often found in low input turfgrass areas on the East Coast of the United States and has potential for development as a new native low input turfgrass species. Roche 454 sequenced randomly sheared genomic DNA reads of D. spicata were mined for SSR markers using the MIcroSAtellite identification tool. A total of 66,553 singlet sequences (approximately 37.5 Mbp) were examined, and 3454 SSR markers were identified. Trinucleotide motifs with greater than six repeats and possessing unique PCR priming sites …

Molecular And Phenotypic Characterization Of Transgenic Wheat And Sorghum Events Expressing The Barley Alanine Aminotransferase, Pamela A. Peña, Truyen Quach, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Ismail M. Dweikat, Madhavan Soundararajan, Tom Clemente

Department of Agronomy and Horticulture: Faculty Publications

Main conclusion — The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat.

The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic …

Multisite Evaluation Of Apex For Water Quality: Ii. Regional Parameterization, Nathan O. Nelson, Claire Baffaut, John A. Lory, G.M.M.M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney, Matt J. Helmers, Mike W. Van Liew, Antonio P. Mallarino, Charles S. Wortmann

Department of Agronomy and Horticulture: Faculty Publications

Phosphorus (P) Index assessment requires independent estimates of long-term average annual P loss from fields, representing multiple climatic scenarios, management practices, and landscape positions. Because currently available measured data are insufficient to evaluate P Index performance, calibrated and validated process-based models have been proposed as tools to generate the required data. The objectives of this research were to develop a regional parameterization for the Agricultural Policy Environmental eXtender (APEX) model to estimate edgeof- field runoff, sediment, and P losses in restricted-layer soils of Missouri and Kansas and to assess the performance of this parameterization using monitoring data from multiple sites …

Nebraska Grazing Conference Proceedings, 2017, Center For Grassland Studies, University Of Nebraska-Lincoln

Nebraska Grazing Conference Proceedings

Fences and Water Points: Where They Should Go by Jim Gerrish

Beef Systems Initiative by Archie Clutter

Grass-based Health and the Ruminant Revolution by Peter Ballerstedt

The Good, Bad, and Ugly of Weedy Plants by Chris Helzer

2016 Leopold Conservation Award Winner by Nancy Peterson

Managing Grassland Vegetation to Benefit Livestock and Wildlife by Patricia Johnson

What is Plant Cover, and How Can We Manage it for Wildlife Needs? by Dwayne Elmore

Producer Panel: Annual Forages vs Row Crops Under Irrigation moderated by John Maddux

Producer Panel: Economics of Grazing Strategies moderated by Jim Jankins

It Costs How Much!? by …

Field-Observed Angles Of Repose For Stored Grain In The United States, Rumela Bhadra, Mark E. Casada, Sidney A. Thompson, Josephine M. Boac, Ronaldo G. Maghirang, Michael D. Montross, Aaron P. Turner, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Bulk grain angle of repose (AoR) is a key parameter for inventorying grain, predicting flow characteristics, and designing bins and grain handling systems. The AoR is defined for two cases, piling (dynamic) or emptying (static), and usually varies with grain type. The objective of this study was to measure piling angles of repose for corn, sorghum, barley, soybeans, oats, and hard red winter (HRW) wheat in steel and concrete bins in the United States. Angles were measured in 182 bins and 7 outdoor piles. The piling AoR for corn ranged from 15.7° to 30.2° (median of 20.4° and standard deviation …

A Vascular Flora Of The Kiavah Wilderness, Scodie Mountains, Kern County, California, Erika M. Gardner

Aliso: A Journal of Systematic and Floristic Botany

Congress designated the Kiavah Wilderness in 1994 under the California Desert Protection Act. It is located in the Scodie Mountains in Kern County, ca. 24 km (15 mi) east of Lake Isabella and 24 km (15 mi) west of Ridgecrest, and encompasses a total of 137 mi² (354 km²) with elevations ranging from 1000 to 2200 m (3500–7294 ft). The Wilderness is ecologically important because it occurs in a transition zone between two floristic provinces, the Sierra Nevada of the California Floristic Province and the Mojave Desert of the Desert Province. It is of cultural significance because …

Plant Phenology And Water Relations In A Saline Pan-Dune Mosaic In The Western Mojave Desert, M. Rasoul Sharifi, William N. Brostoff, Philip W. Rundel

Aliso: A Journal of Systematic and Floristic Botany

An extensive mosaic of small clay pans and low stable dunes exists within Edwards Air Force Base in the western Mojave Desert of California. This pan-dune ecosystem, positioned between the large Rosamond and Rogers dry lakes on the old Pleistocene lakebed of Lake Thompson, provides an opportunity to study the seasonal patterns in growth and flowering phenology and water relations in a saltbush scrub community dominated by a mix of C₃ and C₄ species. C₃ shrubs initiated vegetative growth in February, with current shoot and leaf production largely ceasing in most species by mid-April. The deeply rooted …

Nitrogen Pulses And Competition Between Native And Invasive Plant Species, Nicolas Matallana, Mandy L. Slate, Ragan M. Callaway

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Variation in the timing and size of resource fluctuations can influence how plants grow, allocate biomass, and reproduce. Resources are sometimes made available in relatively continuous, reliable pulses while other times they are temporally separated and unpredictable. Native and invasive plant species are thought to respond differently to resource fluctuations, or pulses, which can influence competitive outcomes. The “Fluctuating Resource Hypothesis” predicts that resource fluctuations benefit invasive species more than native species, potentially because many invaders are highly effective at rapidly capturing resources. In a field setting, we examined the effects of varying nitrogen pulses on competition between exotic invasive …

Survivorship And Growth Among Three Developmental Stages Of Black Mangrove (Avicennia Germinans) Seedlings In Southernmost Texas, Frank W. Judd, Kenneth R. Sunny, Robert I. Lonard, Ruben A. Mazariegos

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Black mangrove is useful for shoreline stabilization in Texas and Mexico but there is insufficient information regarding propagule survivorship and seedling growth. We compared survivorship and growth of three develop-mental groups of black mangrove seedlings planted on three dredge spoil islands in the Lower Laguna Madre of Texas, to better understand optimum planting strategy. Each spoil island had 100 seedlings without emergent radicles, 100 seedlings with emergent radicles, and 75 head-started seedlings. Survivorship of seedlings with and with-out emergent radicles was low, (0-16%). Survivorship of head-started seedlings was higher, (60 – 62.7%). Varia-tion in survivorship among developmental categories was significant …

Political Ecology Of Medicinal Plant Use In Rural Nepal: Globalization, Environmental Degradation, And Cultural Transformation, Emily Dovydaitis

Honors Undergraduate Theses

Prior to the advent of biomedicine, rural communities in Nepal relied on phytochemically active compounds in medicinal plants as their primary source of medicine; however, ethnobotanical practices have shifted over time due to economic, environmental, and sociocultural stimuli. Findings from 2016 fieldwork conducted in Dumrikharka, Nepal and Tutung, Nepal are compared to existing literature to describe the political ecology of medicinal plants in rural Nepal.

Anthropogenic climate change threatens individual plant species and ecosystem biodiversity. Globalized markets unabated by weak conservation programs place increasing demands on medicinal plants. As indigenous plants become overharvested and more difficult to access, Nepalis incorporate …

Investigation Of Candidate Loci Associated With Maize Perennialism, Anjun Ma

Electronic Theses and Dissertations

Developing perennial grain crops is an effective and crucial way to prevent soil erosion caused by conventional agriculture of using annual crops while meeting the increasing need of global food demand. We hypothesized that the regrowth in Zea might be controlled by two dominant complementary genes. F1 hybrids were created by crossing Zea diploperennis Iltis, Doebley & R. Guzman with annual Zea mays L. ssp. mays inbred line B73. A Total of 134 F2 plants derived from nine F1 were planted and phenotyped. A subpopulation of 94 F2 plants were genotyped with Genotype-by- Sequencing (GBS) and called 10,431 SNPs after …

A Survey Of Non-Crop Plants As Alternative Hosts To Raspberries For Drosophila Suzukii (Spotted Wing Drosophila), Bennur Agbaba

Electronic Theses and Dissertations

The spotted wing fruit fly (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is a pest of small fruit crops. Unlike most other Drosophila species, this insect can oviposit into ripe fruits, rendering them unmarketable. Drosophila suzukii is spreading quickly throughout the continental United States including South Dakota, and causing serious damage to horticultural crops, particularly those within the fruit industry. This study determines the D. suzukii host plant both commercial crops and native plants, and defines non-crop host plants by season in South Dakota. Further, it confirms the occurrence of the fly in southeastern South Dakota and identifies high-risk infestation areas …

Assessment Of Hard Red Spring Wheat Germplasm For Cold Temperature Germination Tolerance, Ulas Cinar

Electronic Theses and Dissertations

When planted early in the season, hard red spring wheat (HRSW; Triticum aestivum L.) can help for both vegetative growth and yield providing maximum agronomic productivity. The north-central Great Plains growing region is considered best for developing varieties that germinate in sub-optimal temperatures. Within limited regions, spring wheat planting typically occurs between mid-April and late May, when soil temperatures are 8 °C to 14 °C. Early season planting may result in freezing stress, while late season planting can result in heat and drought stress. Our study tested the germination rate of hard red spring wheat (HRSW) over a range of …

Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid

Electronic Theses and Dissertations

Diverse cropping systems and no-till (NT) are beneficial in improving soil organic carbon (SOC) and other soils properties. The present study was conducted to evaluate the interactions and impacts of long-term tillage and diverse crop rotation systems on soil quality indicators that include a range of soil chemical, physical, hydrological, and microbial properties. The study was established in 1991 at Beresford, South Dakota and included three crop rotation systems [2-yr; maize (Zea mays L.)-soybean (Glycine max L.), 3-yr; maize-soybean-oat (Avena sativa L.), and 4-yr; maize-soybean-oat-wheat (Triticum aestivum L.)] managed under two tillage systems (NT and CT; conventional- tillage). Soil sampling …

Diaporthe, Soybean Cyst Nematode, And Soybean Aphid: An Evaluation Of Potential Interactions Occurring Among Pests On Soybean In South Dakota, John Philip Posch

Electronic Theses and Dissertations

Soybean Glycine max (L.) Merr., is an important crop grown in South Dakota, with an estimated production of $2.33 billion in 2015. However, soybean production in South Dakota is compromised by four pests, the fungal pathogens Diaporthe longicolla (Hobbs) Santos, Vrandecic, and Phillips and Diaporthe caulivora (Athow and Caldwell) Santos, Vrandecic, and Phillips, the soybean cyst nematode Heterodera glycines Ichinohe (SCN), and the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae). Additionally, these pest can co-occur in fields within South Dakota and the implications associated with interactions among these pests are unknown. We hypothesized that both Diaporthe species would interact with …

Araucaria In The Urban Landscape: A Novel Leaning Pattern And Evidence Of Cultivated Hybridization, Jason W. Johns

Master's Theses

Our understanding of the natural world is constantly evolving and strengthening as more observations are made and experiments are performed. For example, we understand that tree stems grow toward the light (positive phototropism; Darwin 1880, Loehle 1986, Christie et al. 2013) and against gravity (negative gravitropism; Knight 1806, Hashiguchi et al. 2013). We also know that plants respond to mechanical stimulus and perturbation (thigmotropism; Braam 2005). Genes and their resulting proteins have been described to uncover some of the mechanisms for these environmental responses, but relatively speaking, we have just scratched the surface (Wyatt et al. 2013). While the discovery …

On The Complexity Of Simples, Pharmacognosy, And Actaea Racemosa, W. John Hayden

Biology Faculty Publications

Pharmacognosy, a discipline at the intersection of botany and medicine, deals with knowledge about medicines derived from plants (Youngken 1950). A central goal of pharmacognosy is the accurate and consistent taxonomic identification of medicinal plants and medicinal plant products. Unlike drugstore pill bottles, medicinal plants in nature do not come with labels. One aspect of pharmacognosy, then, is the identification of whole plants found in nature. Much as in field botany and plant systematics, this aspect of pharmacognosy involves learning to recognize species by overall appearance (gestalt), or by dichotomous keys, or both.

Sepals And Petals And Stamens—Oh, My! Or, A Brief Discourse On Putative Homologies Of Perianth Elements Of Common Black Cohosh, W. John Hayden

Biology Faculty Publications

I encountered some contradictory information while preparing to write the 2017 Wildflower of the Year brochure: some sources describe flowers of Actaea racemosa, Common Black Cohosh, as having petals, while others say petals are absent. How can that be? How could there be such uncertainty about this common plant, one known to science since before the time of Linnaeus? After a little research, I decided to describe Black Cohosh flowers as having a series of organs interpretable either as staminodes (nonfunctional stamens) or as petals located between its sepals and stamens (Figure 1). Frankly, I waffled on the petal issue, …

Actaea Racemosa: The Slender Wands Of Flowering Common Black Cohosh Beckon Us To Explore Woodlands, W. John Hayden

Biology Faculty Publications

Common Black Cohosh is a perennial rhizomatous forest herb. Its horizontal rhizomes bear numerous adventitious roots on the underside and aerial stems of annual duration on the upper side, along with knobby scars left from aerial stems of previous years. Leaves are alternate, twice or thrice compound in ternate or pinnate patterns, and large—up to 1 m long. Individual leaflet size and shape vary with position in the large compound leaves, with position of a leaf on the stem, and from population to population. Most often leaflets are coarsely serrate, lobed to deeply incised, with a truncate to cuneate base …

Wheat Streak Mosaic Virus Coat Protein Deletion Mutants Elicit More Severe Symptoms Than Wild-Type Virus In Multiple Cereal Hosts, Satyanarayana Tatineni, Christian G. Elowsky, Robert A. Graybosch

Department of Plant Pathology: Faculty Publications

Previously, we reported that coat protein (CP) of Wheat streak mosaic virus (WSMV) (genus Tritimovirus, family Potyviridae) tolerates deletion of amino acids 36 to 84 for efficient systemic infection of wheat. In this study, we demonstrated that WSMV mutants with deletion of CP amino acids 58 to 84 but not of 36 to 57 induced severe chlorotic streaks and spots, followed by acute chlorosis in wheat, maize, barley, and rye compared with mild to moderate chlorotic streaks and mosaic symptoms by wild-type virus. Deletion of CP amino acids 58 to 84 from the WSMV genome accelerated cell-to-cell movement, …