Agronomy and Crop Sciences Commons^™

Letter From The Dean, Michael Vayda

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Discovery: The Student Journal Of Dale Bumpers College Of Agricultural, Food And Life Sciences - Volume 12 2011, Several Authors

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

Arkansas Cotton Variety Test 2010, Fred M. Bourland, A. B. Beach, D. P. Roberts Jr.

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant.

Properties Of Gluten-Free Pasta Prepared From Rice And Different Starches, Alexandria W. Mertz, Ya-Jane Wang

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Rice is one of the few cereal products that does not contain gluten. However, the absence of gluten poses problems in the structure of and cooking quality of rice pasta. The objective of this project was to investigate the addition of starch on the physicochemical properties and cooking quality of rice-based pasta. Rice-based pasta was prepared from parboiled long-grain rice flour with the addition of 25% cooked starch from different sources. The color and pasting properties of the ground pasta flour were measured by a chroma meter and a Rapid Visco Analyser, respectively. The pasta was cooked to the optimum …

Plant Growth In Soil Amended With Drilling Mud, Satoshi Takaki, Duane C. Wolf

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Extraction of natural gas generates drilling fluid and drilling mud that contain high concentrations of salts. Land application of the fluid and mud can have negative impacts on plant growth and soil properties. The objective of this study was to determine the effects of drilling mud on plant growth, plant chemical concentrations, and soil chemical properties. Sudangrass (Sorghum sudanense [Piper] Stapf [Piper]) and bermudagrass (Cynodon dactylon L.) were grown in a Roxana loam soil amended with 0%, 5%, or 10% (w/w) drilling mud in a 6-wk greenhouse study. Plant biomass production and concentrations of elements in biomass were determined. Electrical …

Estimation Of Surface Soil Organic Matter Using A Ground-Based Active Sensor And Aerial Imagery, D. F. Roberts, V. I. Adamchuk, J. F. Shanahan, R. B. Ferguson, J. S. Schepers

Department of Agronomy and Horticulture: Faculty Publications

Active canopy sensors are currently being studied as a tool to assess crop N status and direct in-season N applications. The objective of this study was to use a variety of strategies to evaluate the capability of an active sensor and a wide-band aerial image to estimate surface soil organic matter (OM). Grid soil samples, active sensor reflectance and bare soil aerial images were obtained from six fields in central Nebraska before the 2007 and 2008 growing seasons. Six different strategies to predict OM were developed and tested by dividing samples randomly into calibration and validation datasets. Strategies included uniform, …

Soil Fertility And Crop Yields In Long-Term Organic And Conventional Cropping Systems In Eastern Nebraska, Samuel E. Wortman, Tomie D. Galusha, Stephen C. Mason, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Organic agriculture aims to build soil quality and provide long-term benefits to people and the environment; however, organic practices may reduce crop yields. This long-term study near Mead, NE was conducted to determine differences in soil fertility and crop yields among conventional and organic cropping systems between 1996 and 2007. The conventional system (CR) consisted of corn (Zea mays L.) or sorghum (Sorghum bicolor (L.) Moench)–soybean (Glycine max (L.) Merr.)–sorghum or corn–soybean, whereas the diversified conventional system (DIR) consisted of corn or sorghum– sorghum or corn–soybean–winter wheat (wheat, Triticum aestivum L.). The animal manure-based organic system (OAM) …

Stacking Resistance Alleles From Wild And Domestic Soybean Sources Improves Soybean Cyst Nematode Resistance, Myungsik Kim, D. L. Hyten, Terry L. Niblack, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

The soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is the most economically important soybean [Glycine max (L.) Merr.] pathogen in the United States. Field SCN populations are adapting to the narrowly based SCN resistance currently deployed in soybean cultivars. The objective of our research was to measure the effects of combinations of SCN resistance genes or quantitative trait loci (QTL) from the wild soybean (Glycine soja Siebold & Zucc.) PI 468916 and the domesticated soybean accessions PI 88788 and PI 437654. Two populations were developed to test the combinations of QTL and genes. Both populations segregated for the …

Moving Micronutrients From The Soil To The Seeds: Genes And Physiological Processes From A Biofortification Perspective, Brian M. Waters, Renuka P. Sankaran

Department of Agronomy and Horticulture: Faculty Publications

The micronutrients iron (Fe), zinc (Zn), and copper (Cu) are essential for plants and the humans and animals that consume plants. Increasing the micronutrient density of staple crops, or biofortification, will greatly improve human nutrition on a global scale. This review discusses the processes and genes needed to translocate micronutrients through the plant to the developing seeds, and potential strategies for developing biofortified crops.

Nozzle Type And Arrangement Alternatives For Improved Application Of Suckercides In Burley Tobacco (Nicotiana Tabacum L.), Beau Robert Neal

University of Kentucky Master's Theses

Maleic hydrazide (MH) applications have been standard practice for sucker control in burley tobacco (Nicotiana tabacum L.) production for the last half-century because it is relatively inexpensive, effective and easy to apply. Non-MH suckercides such as fatty alcohols and local systemics can be utilized to reduce or replace MH and lower undesirable residues in the cured leaf. The objective of this study was to evaluate various nozzle types and arrangements for efficiency to determine if sucker control with fatty alcohol could be consistently improved over the currently used TG3-5-3 arrangement, as well as examine sprayer positioning (center vs. off-center) …

Subsurface Compaction A Guide For Wa Farmers And Consultants, Stephen Davies, Alison Lacey

Bulletins 4000 -

For plants to grow in agricultural soils, roots and emerging shoots must be able to force their way through the soil. In soils of high strength, this growth is physically restricted. High strength soils may be due to natural soil characteristics and conditions or develop as a result of agricultural practices and may be in layers or throughout the soil profile.

In agriculture, high strength soils commonly occur as a result of compaction. Compaction of agricultural soils can be in the surface (often caused by stock trampling or rain drop splatter) or in the subsurface (usually in a layer at …

Restoration Of Tall Fescue Pastures To Native Warm Season Grasslands: Does A Fungal Endophyte Symbiosis Play A Role In Restoration Success?, Sarah Lynn Hall

University of Kentucky Doctoral Dissertations

Tall fescue, a cool-season grass native to Europe, central Asia, and northern Africa, has been widely distributed throughout the U.S. for use as turf and forage. Following its widespread planting, its ability to associate with a toxic fungal endophyte, Neotyphodium coenophialum, was discovered. Research has linked this fescue-endophyte association with increased biotic and abiotic stress resistance in endophyte-infected (E+) versus endophyte-free (E-) plants, and these differences may affect the ability of land managers to eradicate tall fescue and restore native grasslands. I conducted three studies to examine whether E+ tall fescue plants respond differently to management than E- plants, …

T-Phylloplanin And Cis-Abienol, Two Natural Products From Tobacco Have Broad Spectrum, Anti-Fungal Activities, Brian Christopher King

University of Kentucky Doctoral Dissertations

Tobacco phylloplanins (T-phylloplanin) are a group of closely-related glycoproteins that are formed and disposed at the interface between the plant aerial surface (the phylloplane) and the atmosphere. They are synthesized in short procumbent trichomes and are secreted to aerial surfaces where they are thought to serve the plant as a first line of defense against fungal pathogens. Here it is shown using in vitro and in planta assays that tobacco and sunflower phylloplanins have broad-spectrum antifungal activities against spores - and also hyphae for two species - of several true fungi. Field tests show that T-phylloplanin reduces diseases caused by …

Small Mammal Populations In Switchgrass Stands Managed For Biomass Production Compared To Hay And Corn Fields In Kentucky, Laura Mary Jane Schwer

University of Kentucky Master's Theses

Switchgrass (Panicum virgatum), a native warm-season grass, has been investigated as a renewable energy crop that may provide viable wildlife habitat. This study investigated small mammal populations in switchgrass, hay, and corn to assess the relative habitat quality. Four, three-night trapping sessions were conducted at four locations in Kentucky using Sherman livetraps. Trapping occurred in spring (before first hay harvest), summer, fall (before switchgrass and corn harvest), and winter (post-harvest). Relative abundance of small mammals, calculated using a capture per unit effort index (per 100 trapnights), and mean taxonomic richness were used to compare habitats. Switchgrass had a …

Using Manual Defoliation To Simulate Soybean Rust: Effect On Growth And Yield Formation, Abdullah Mohammad Aqeel

University of Kentucky Doctoral Dissertations

Field experiments were conducted in Kentucky and Louisiana in 2008 and 2009 (split-plot in a randomized complete block design with four replications) to investigate it is possible to simulate with manual defoliation the effect of soybean rust (SBR) (Phakopsora pachyrhizi Syd. and P. Syd) injury on a healthy soybean [Glycine max, (L.) Merr.] canopy, understand how defoliation affects the growth dynamics and canopy light interception, and if defoliation affectsleaf senescence and nitrogen remobilization during the seed-filling period. Two manual defoliation treatments based on changes in effective leaf area index (ELAI) (calculated as the reduction in leaf area …

Switchgrass Contains Two Cinnamyl Alcohol Dehydrogenases Involved In Lignin Formation, Aaron J. Saathoff, Christian M. Tobias, Scott E. Sattler, Eric J. Haas, Paul Twigg, Gautam Sarath

Department of Agronomy and Horticulture: Faculty Publications

Lignin content of switchgrass (Panicum virgatum L.), a bioenergy species, is a critical determinant of biomass quality since it can negatively impact conversion of biomass into liquid fuels via biochemical platforms. Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in lignin biosynthesis. Here, we have shown that cv. Kanlow switchgrass contains at least two closely related CAD genes (PviCAD1 and PviCAD2) that code for proteins containing highly conserved domains and residues that identify them as bona fide CADs. Both recombinant proteins displayed substrate kinetics consistent with their presumed role in cell wall lignification. Proteomic and immunoblotting detected …

The Composition And Origins Of Genomic Variation Among Individuals Of The Soybean Reference Cultivar Williams 82, William J. Haun, D. L. Hyten, Wayne W. Xu, Daniel J. Gerhardt, Thomas J. Albert, Todd Richmond, Jeffrey A. Jeddeloh, Gaofeng Jia, Nathan M. Springer, Carroll P. Vance, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max) is a self-pollinating species that has relatively low nucleotide polymorphism rates compared with other crop species. Despite the low rate of nucleotide polymorphisms, a wide range of heritable phenotypic variation exists. There is even evidence for heritable phenotypic variation among individuals within some cultivars. Williams 82, the soybean cultivar used to produce the reference genome sequence, was derived from backcrossing a Phytophthora root rot resistance locus from the donor parent Kingwa into the recurrent parent Williams. To explore the genetic basis of intracultivar variation, we investigated the nucleotide, structural, and gene content variation of different …

Genome-Wide Association Analysis Identifies Candidate Genes Associated With Iron Deficiency Chlorosis In Soybean, Sujan Mamidi, Shireen Chikara, R. Jay Goos, D. L. Hyten, Deepti Annam, Samira Mafi Moghaddam, Rian K. Lee, P. B. Cregan, Phillip E. Mcclean

Department of Agronomy and Horticulture: Faculty Publications

Iron deficiency chlorosis (IDC) is a significant yield-limiting problem in several major soybean [Glycine max (L.) Merr.] production regions in the United States. Soybean plants display a variety of symptoms that range from a slight yellowing of the leaf to interveinal chlorosis, to stunted growth that reduces yield. The objective of this analysis was to employ single nucleotide polymorphism (SNP)-based genome-wide association mapping to uncover genomic regions associated with IDC tolerance. Two populations [2005 (n = 143) and 2006 (n = 141)] were evaluated in replicated, multilocation IDC trials. After controlling for population structure and individual relatedness, and selecting …

The Role Of Transition Metal Homeostasis In Plant Seed Development, Elsbeth L. Walker, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Copyright © 2011 Elsevier Ltd. Used by permission.

Moving Magnesium In Plant Cells, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Magnesium (Mg) is among the most abundant mineral elements in plants, yet the knowledge of which genes control its accumulation in specific tissues and organelles lags behind that of many other mineral elements. Only in recent years has identification of important molecular players begun to take shape. In this issue of New Phytologist, Conn et al. (pp. 583–594) shed additional light on two Mg transporters that play important roles in accumulation of Mg in leaf cell vacuoles. Using subcellular-level ion measurements on leaves, gene expression measurements after single-cell sampling, a genetic approach, and clever use of calcium (Ca) and …