Agronomy and Crop Sciences Commons^™

Drought Effects On Composition And Yield For Corn Stover, Mixed Grasses, And Miscanthus As Bioenergy Feedstocks, Rachel Emerson, Amber Hoover, Allison Ray, Jeffrey Lacey, Marnie Cortez, Courtney Payne, Douglas L. Karlen, Stuart Birrell, David Laird, Robert Kallenbach, Josh Egenolf, Matthew Sousek, Thomas Voigt

Department of Agronomy and Horticulture: Faculty Publications

Drought conditions in 2012 were some of the most severe in recent history. The purpose of this study is to examine the impact of drought on quality, quantity, and theoretical ethanol yield (TEY) of three bioenergy feedstocks, corn stover, mixed grasses from Conservation Reserve Program lands, and Miscanthus × giganteus. To assess drought effects on these feedstocks, samples from 2010 (minimal to no drought) and 2012 (severe drought) were compared from multiple locations in the US. In all feedstocks, drought significantly increased extractives and reduced structural sugars and lignin; subsequently, TEYs were reduced 10–15%. Biomass yields were significantly reduced …

Nonsyntenic Genes Drive Highly Dynamic Complementation Of Gene Expression In Maize Hybrids, Anja Paschold, Nick B. Larson, Caroline Marcon, James C. Schnable, Cheng-Ting Yeh, Christa Lanz, Dan Nettleton, Hans-Peter Piepho, Patrick S. Schnable, Frank Hochholdinger

Department of Agronomy and Horticulture: Faculty Publications

Maize (Zea mays) displays an exceptional level of structural genomic diversity, which is likely unique among higher eukaryotes. In this study, we surveyed how the genetic divergence of two maize inbred lines affects the transcriptomic landscape in four different primary root tissues of their F1-hybrid progeny. An extreme instance of complementation was frequently observed: genes that were expressed in only one parent but in both reciprocal hybrids. This single-parent expression (SPE) pattern was detected for 2341 genes with up to 1287 SPE patterns per tissue. As a consequence, the number of active genes in hybrids exceeded that of …

Dt2 Is A Gain-Of-Function Mads-Domain Factor Gene That Specifies Semideterminacy In Soybean, Jieqing Ping, Yunfeng Liu, Lianjun Sun, Meixia Zhao, Yinghui Li, Zongxiang Tang, Hanh Nguyen, Zhixi Tian, Lijuan Qiu, Randall L. Nelson, Thomas E. Clemente, James Specht, Jianxin Ma

Department of Agronomy and Horticulture: Faculty Publications

Similar to Arabidopsis thaliana, the wild soybeans (Glycine soja) and many cultivars exhibit indeterminate stem growth specified by the shoot identity gene Dt1, the functional counterpart of Arabidopsis TERMINAL FLOWER1 (TFL1). Mutations in TFL1 and Dt1 both result in the shoot apical meristem (SAM) switching from vegetative to reproductive state to initiate terminal flowering and thus produce determinate stems. A second soybean gene (Dt2) regulating stem growth was identified, which, in the presence of Dt1, produces semideterminate plants with terminal racemes similar to those observed in determinate plants. Here, we report positional …

Eqtl Networks Reveal Complex Genetic Architecture In The Immature Soybean Seed, Yung-Tsi Bolon, D. Hyten, James H. Orf, Carroll P. Vance, Gary J. Muehlbauer

Department of Agronomy and Horticulture: Faculty Publications

The complex network of regulatory factors and interactions involved in transcriptional regulation within the seed is not well understood. To evaluate gene expression regulation in the immature seed, we utilized a genetical genomics approach on a soybean [Glycine max (L.) Merr.] recombinant inbred line (RIL) population and produced a genome-wide expression quantitative trait loci (eQTL) dataset. The validity of the dataset was confirmed by mapping the eQTL hotspot for flavonoid biosynthesis-related genes to a region containing repeats of chalcone synthase (CHS) genes known to correspond to the soybean inhibitor locus that regulates seed color. We then identified eQTL for …

Nebraska’S Groundwater Legacy: Nitrate Contamination Beneath Irrigated Cropland, Mary E. Exner Spaulding, Aaron J. Hirsh, Roy F. Spalding

Department of Agronomy and Horticulture: Faculty Publications

A 31 year record of ~44,000 nitrate analyses in ~11,500 irrigation wells was utilized to depict the decadal expansion of groundwater nitrate contamination (N>10 mg/L) in the irrigated corn-growing areas of eastern and central Nebraska and analyze long-term nitrate concentration trends in 17 management areas (MAs) subject to N fertilizer and budgeting requirements. The 1.3 M contaminated hectares were characterized by irrigation method, soil drainage, and vadose zone thickness and lithology. The areal extent and growth of contaminated groundwater in two predominately sprinkler-irrigated areas was only ~20% smaller beneath well-drained silt loams with thick clayey-silt unsaturated layers and unsaturated …

Multilocation Corn Stover Harvest Effects On Crop Yields And Nutrient Removal, Douglas L. Karlen, Stuart J. Birrell, Jane M.F. Johnson, Shannon L. Osborne, Thomas E. Schumacher, Gary E. Varvel, Richard B. Ferguson, Jeff M. Novak, James R. Frederick, John M. Baker, John A. Lamb, Paul R. Alder, Greg W. Roth, Emerson D. Nafziger

Department of Agronomy and Horticulture: Faculty Publications

Corn (Zea mays L.) stover was identified as an important feedstock for cellulosic bioenergy production because of the extensive area upon which the crop is already grown. This report summarizes 239 site-years of field research examining effects of zero, moderate, and high stover removal rates at 36 sites in seven different states. Grain and stover yields from all sites as well as N, P, and K removal from 28 sites are summarized for nine longitude and six latitude bands, two tillage practices (conventional vs no tillage), two stoverharvest methods (machine vs calculated), and two crop rotations {continuous corn (maize) …

Do Cover Crops Increase Or Decrease Nitrous Oxide Emissions? A Meta-Analysis, Andrea D. Basche, F. E. Miguez, T. C. Kaspar, M. J. Castellano

Department of Agronomy and Horticulture: Faculty Publications

There are many environmental benefits to incorporating cover crops into crop rotations, such as their potential to decrease soil erosion, reduce nitrate (NO₃) leaching, and increase soil organic matter. Some of these benefits impact other agroecosystem processes, such as greenhouse gas emissions. In particular, there is not a consensus in the literature regarding the effect of cover crops on nitrous oxide (N₂O) emissions. Compared to site-specific studies, meta-analysis can provide a more general investigation into these effects. Twenty-six peer-reviewed articles including 106 observations of cover crop effects on N₂O emissions from the soil surface …

Challenges And Opportunities In Transdisciplinary Science: The Experience Of Next Generation Scientists In An Agriculture And Climate Research Collaboration, Andrea D. Basche, Gabrielle E. Roesch-Mcnally, Lindsay A. Pease, Christopher D. Eidson, Guy Bou Lahdou, Mike W. Dunbar, Trevor J. Frank, Laura Frescoln, Lei Gu, Ryan Nagelkirk, Jose Pantoja, Adam K. Wilke

Department of Agronomy and Horticulture: Faculty Publications

Agriculture in the twenty-first century faces unprecedented challenges from increasing climate variability to growing demands on natural resources to globalizing economic markets. These emerging agricultural issues, spanning both human and natural dimensions, are uniquely formulated, exceedingly complex, and difficult to address within existing disciplinary domains (Eigenbrode et al. 2007; Reganold et al. 2011; Foley et al. 2005; Hansen et al. 2013). Therefore, the next generation of scientists working on these issues must not only be highly trained within a disciplinary context but must also have the capacity to collaborate with others to solve systems-level problems.

The Carbon-Nitrogen Balance Of The Nodule And Its Regulation Under Elevated Carbon Dioxide Concentration, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN₂). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the …

Constructing A Block And Fence Growing Bench For Use With A Capillary Mat Irrigation System For Greenhouse Plant Production, Stacy A. Adams, Ellen T. Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

Plant health and productivity of greenhouse grown plants are improved when grown on raised benches where they can have optimal environmental conditions. Often seasonal plant growers set plants directly on the greenhouse floor which is less than optimum due to temperature stratification, cold drafts, poor air movement, and wet conditions. This publication describes how to construct simple and economical growing benches and a irrigation system useful for the specialty crop grower.

Corn (Zea Mays) Emergence And Early Growth As Influenced By Tansymustard (Descurainia Pinnata) Residue, Rodrigo Werle, Leonardo L. Perez, Lowell D. Sandell, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Farmers have observed reduced early growth of corn in the presence of tansymustard [Descurainia pinnata (Walt.) Britt.], a winter annual weed of the Brassicaceae family. A greenhouse study was conducted to evaluate the effect of tansymustard on corn (Zea mays L.) emergence and early growth. Treatments included corn growing in pots with only tansymustard root residue, with only tansymustard shoot residue, and with whole tansymustard plant residue (roots plus shoots); tansymustard plants treated with glyphosate 2 days after planting (DAP) corn seeds; and a control (no tansymustard residue). Corn emergence was recorded and biomass measured after 4 weeks of …

Estimating The Frequency Of Cry1f Resistance In Field Populations Of The European Corn Borer (Lepidoptera: Crambidae), Blair D. Siegfried, Murugesan Rangasamy, Haichuan Wang, Terence A. Spencer, Chirakkal V. Haridas, Brigitte Tenhumberg, Douglas V. Sumerford, Nicholas P. Storer

School of Biological Sciences: Faculty Publications

Background: Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) have suppressed European corn borer populations and reduced the pest status of this insect throughout much of the US corn belt. A major assumption of the high-dose/refuge strategy proposed for insect resistance management and Bt corn is that the frequency of resistance alleles is low so that resistant pests surviving exposure to Bt corn will be rare. Results: The frequency of resistance to the Cry1F Bt toxin was estimated using two different screening tools and compared with annual susceptibility monitoring based on diagnostic bioassays and LC_{50 …}

Evaluation Of Soilless Media Sensors For Managing Winter-Time Greenhouse Strawberry Production Using A Capmat System, George E. Meyer, Ellen T. Paparozzi, Stacy A. Adams, Diego Scacalossi Voltan

Department of Agronomy and Horticulture: Faculty Publications

It is important for a greenhouse strawberry grower to know that their capillary mat (CapMat™) fertigation system is working correctly and that plants are receiving the correct amounts of water and fertilizer. Pots with soilless mix are not expected to hold more than 70% water on a volumetric basis. Pots with less than 40% water content continuously are not supplied enough water and nutrients to the plants. Typically, pots located near the manifold distribution system get a little more water than those at the other locations, but water use will really vary according to the factors listed above as well …

Tall Fescue Ergovaline Concentration Based On Sample Handling And Storage Method, Krista La Moen Lea

Theses and Dissertations--Plant and Soil Sciences

Ergovaline is produced by the endophyte Neotyphodium coenophialum (Morgan-Jones and Gams) in tall fescue (Schedonorus arundinacea (Schreb.) Dumort. = Festuca arundinacea Schreb.) and is blamed for a multitude of costly livestock disorders. Testing of pastures is common in both research and on farm situations. Since ergovaline is known to be unstable and affected by many variables, the objective of this study was to determine the effect of sample handling and storage on the stability of this compound. Homogeneous milled tall fescue sub-samples were analyzed for ergovaline concentration using HPLC after a range of sample handling procedures or storage. Ergovaline …

Evaluating The Effect Maturity On The Intake And Digestibility Of Switchgrass Hay Consumed By Beef Steers, David H. Davis

Theses and Dissertations--Plant and Soil Sciences

There has been increased interest in utilizing switchgrass (Panicum virgatum) as biomass. There are several challenges to developing this industry, and these have led to the potential use of switchgrass as hay for feeding beef cattle in Kentucky. The effect of increasing maturity on crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and nutritive values of switchgrass hay has been well documented, but few in vivo intake and digestibility trials have been conducted to assess this effect on animal performance when feeding beef cattle. Two in vivo intake and digestibility trials were conducted in 2011 …

Evaluation Of Correlation Between Within-Barn Curing Environment And Tsna Accumulation In Dark Air-Cured Tobacco, Mitchell Dale Richmond

Theses and Dissertations--Plant and Soil Sciences

Significant variability in cured leaf tobacco-specific nitrosamine (TSNA) content is commonly observed when sampling within dark air-curing barns. This variability may be due to inconsistency in the curing environment within different areas of the barn. A study was initiated in 2012 through support from a CORESTA Study Grant to evaluate if leaf TSNA content is related to microenvironmental conditions in the barn. Seed screened for low conversion of nicotine to nornicotine (sc) and high converter (HC) selections of TR Madole dark tobacco were cured in barns near Princeton and Lexington, Kentucky in 2012 and 2013. Temperature and relative humidity were …

Corn (Zea Mays L.) Yield Response To Defoliation At Different Row Widths, Martin Leonardo Battaglia

Theses and Dissertations--Plant and Soil Sciences

Corn (Zea mays L.) defoliation experiments have been conducted for more than 120 years. However, there is limited data on the effect of row width on defoliation in modern hybrids. A two-year experiment was conducted in Lexington, Kentucky with two hybrids (113 relative maturity (RM) and 120 RM), two row widths (38 and 76 cm) and a combination of defoliation timings and severities: 0% defoliation (control), V7-100%, V14-50%, V14-100%, R2-50% and R2-100%. No yield difference among hybrids was observed in 2012. Yields were 26% greater in 38-cm rows than 76-cm rows in 2012. For 2013, corn yield for 38-cm …

Two-Source Energy Balance Model To Calculate E, T, And Et: Comparison Of Priestley-Taylor And Penman-Monteith Formulations And Two Time Scaling Methods, Paul D. Colaizzi, Nurit Agam, Judy A. Tolk, Steven R. Evett, Terry A. Howell, Prasanna H. Gowda, Susan A. O'Shaughnessy, William P. Kustas, Martha C. Anderson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The two-source energy balance (TSEB) model calculates the energy balance of the soil-canopy-atmosphere continuum, where transpiration is initially determined by the Priestley-Taylor equation. The TSEB was revised recently using the Penman-Monteith equation to replace the Priestley-Taylor formulation, thus better accounting for the impact of large and varying vapor pressure deficits (VPD) typical of advective, semiarid climates. This study is a comparison of the Priestley- Taylor and Penman-Monteith versions of the TSEB (termed TSEB-PT and TSEB-PM, respectively). Evaporation (E), transpiration (T), and evapotranspiration (ET) calculated by the TSEB-PT and TSEB-PM versions were compared to measurements obtained with microlysimeters, sap flow gauges, …

Glyphosate Resistant Weeds - Beat Them Before They Beat You, Sally Peltzer

Grain and other field crops published reports

Herbicide resistance develops if the weeds exist in the population and set fertile seed. Being vigilant, keeping weed populations low and stopping seed set is the best way to prevent glyphosate resistance development:

• know the herbicide use history of each paddock. If glyphosate has been the dominant knockdown and spray-topping product used, it's time to change
• conduct herbicide resistance testing to determine what herbicides are effective on key weeds
• aim for maximum control
• establish a more diverse rotation to increase the number of control tactics available
• use non-herbicide control tactics at every opportunity
• always monitor the success of each control …

Grains Highlights 2013 / 2014, Department Of Agriculture And Food, Western Australia

Grain and other field crops published reports

DAFWA strives to support growers and agribusiness with relevant and timely information, tools and services to make better business decisions.