Digital Commons Network^™

Effects Of Endophyte-Infected Tall Fescue Seed And Red Clover Isoflavones On Rumen Microbial Populations And Physiological Parameters Of Beef Cattle, Emily A. Melchior, Jason K. Smith, Liesel G. Schneider, Travis Mulliniks, Gary E. Bates, Michael D. Flythe, James L. Klotz, Huihua Ji, Jack P. Goodman, Amanda R. Lee, J. Marc Caldwell, Phillip R. Myer

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

Lolium arundinaceum [(Darbyshire) tall fescue] toxicosis is responsible for substantial beef production losses in the United States, due to its negative effects on reproduction, growth, and feed efficiency. These effects are consequences of toxic alkaloids within tall fescue. Interseeding legumes, such as Trifolium pratense (red clover), into pastures has been shown to mitigate a portion of these effects. Clovers contain isoflavones, which may play a role in tall fescue toxicosis mitigation. The present study utilized 36 Angus steers to determine the effects of daily supplementation with a red clover- isolated isoflavone feed additive on physiological symptoms of tall fescue toxicosis …

Registration Of ‘Lcs Compass’ Wheat, L. Liu, M. D. Barnett, C. A. Griffey, S. Malla, W. S. Brooks, J. E. Seago, K. Kirby, W. E. Thomason, E. G. Rucker, H. D. Behl, R. M. Pitman, D. W. Dunaway, M. E. Vaughn, J. T. Custis, B. Seabourn, R. Chen, M. Fountain, D. Marshall, R. A. Graybosch, L. A. Divis, L. E. Hansen, C. Cowger, S. Cambron, Y. Jin, B. R. Beahm, T. H. Hardiman, C. J. Lin, D. F. Mennel, D. L. Mennel

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

‘LCS Compass’ (Reg. No. CV-1149, PI 675458), a hard red winter (HRW) wheat (Triticum aestivum L.), was developed and tested as VA10HRW-13 and co-released by the Virginia Agricultural Experiment Station and Limagrain Cereal Seeds, LLC, in 2015. LCS Compass was derived from the cross ‘Vision 20’ /‘Stanof’ using a modified bulk breeding method. LCS Compass is a widely adapted, high-yielding, awned, semidwarf (Rht1) HRW wheat with early to medium maturity and resistance or moderate resistance to diseases prevalent in the mid-Atlantic and Great Plains regions of the United States. In the 2013 Uniform Bread Wheat Trial conducted over 18 locations …

Fire, Grazing And Climate Shape Plant–Grasshopper Interactions In A Tallgrass Prairie, Ellen A.R. Welti, Fan Qiu, Hannah M. Tetreault, Mark Ungerer, Anthony Joern

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

1. Species interactions are integral to ecological community function, and the structure of species interactions has repercussions for the consequences of species extinctions. Few studies have examined the role of environmental factors in controlling species interaction networks across time.

2. We examined variation in plant–grasshopper network structural properties in response to three major grassland drivers: periodic fire, ungulate grazing and climate.

3. We sequenced a plant barcoding gene from extracted grasshopper gut contents to characterize diets of 26 grasshopper species. Resulting grasshopper species’ diets were combined with long‐term plant and grasshopper surveys to assemble plant–grasshopper networks across 13–19 years for …

Design And Methodology Of A Cluster-Randomized Trial In Early Care And Education Centers To Meet Physical Activity Guidelines: Sustainability Via Active Garden Education (Sage), Rebecca E. Lee, Elizabeth Lorenzo, Jacob Szeszulski, Anel Arriola, Meg Bruening, Paul A. Estabrooks, Jennie Hill, Flavio F. Marsiglia, Teresia O'Connor, Kim Sellers Pollins, Gabriel Q. Shaibi, Erica Soltero, Michael Todd

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

Strategies are needed to help early care and education centers (ECEC) comply with policies to meet daily physical activity and fruit and vegetable guidelines for young children. This manuscript describes the design and methodology of Sustainability via Active Garden Education (SAGE), a 12-session cluster-randomized controlled crossover design trial using community-based participatory research (CBPR) to test a garden-based ECEC physical activity and fruit and vegetables promotion intervention for young children aged 3–5 years in 20 sites. The SAGE curriculum uses the plant lifecycle as a metaphor for human development. Children learn how to plant, water, weed, harvest, and do simple food …

International Commission On Trichinellosis: Recommendations For Genotyping Trichinella Muscle Stage Larvae, Edoardo Pozio, Dante Zarlenga

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

Being able to identify the species or genotype of Trichinella is of paramount importance not only for epidemiological studies but to better ascertain the source of outbreaks that still occur worldwide. This has become more critical in recent years given the increase in imported meat products and the relationship that wild animals play in the domestic and sylvatic transmission cycles. In contrast to a time when the genus Trichinella was considered monospecific, research in recent years has revealed that the genus consists of 9 species and at least 3 additional genotypes which have yet to be named. Except for a …

Weekly Survivorship Curves Of Soybean Aphid Biotypes 1 And 4 On Insecticidal Seed-Treated Soybean, Carlos J. Esquivel, Christopher M. Ranger, P. Larry Phelan, Erick J. Martinez, William H. Hendrix, Andrew P. Michel

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

Thiamethoxam, an insecticide used in soybean seed treatments, effectively suppresses soybean aphids (Aphis glycines) Matsumura (Hemiptera: Aphididae) for a short time after planting. However, exactly when and how quickly soybean aphid populations could increase is unknown. Likewise, we lack data on virulent soybean aphid biotypes (that can overcome soybean resistance) when fed on seed-treated soybean. Determining the survival of soybean aphids over time on insecticidal seed-treated soybean is critical for improving soybean aphid management and may provide insights to manage aphid virulence to aphid resistant-soybean. In greenhouse and field experiments, aphid-susceptible soybean plants (with and without an insecticidal seed treatment) …

Comparative Susceptibility Of Western Corn Rootworm (Coleoptera: Chrysomelidae) Neonates To Selected Insecticides And Bt Proteins In The Presence And Absence Of Feeding Stimulants, Adriano E. Pereira, Thomas A. Coudron, Kent Shelby, B. Wade French, Elisa J. Bernklau, Louis B. Bjostad, Bruce E. Hibbard

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

The susceptibility of western corn rootworm, Diabrotica virgifera virgifera LeConte, larvae to nine insecticides from five different classes and to Bt proteins eCry3.1Ab and mCry3A in the presence or absence of feeding stimulants, was estimated in filter paper and diet toxicity assays, respectively. The use of a synthetic feeding stimulant blend of the sugars glucose, sucrose, and fructose plus linoleic acid at a ratio of 30:4:4:0.3 mg/ml of distilled water was evaluated to determine whether they increase the efficacy of insecticides and Bt proteins. The efficacy of thiamethoxam diluted in solutions with feeding stimulants was significantly increased when compared to …

Effects Of Cold Storage On Nondiapausing Eggs Of The Western Corn Rootworm (Coleoptera: Chrysomelidae), Ryan W. Geisert, Dalton C. Ludwick, Bruce E. Hibbard

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

Western corn rootworm, Diabrotica virgifera virgifera LeConte, became much easier to research with the development of a nondiapausing rootworm strain. In the event that the eggs cannot be used immediately researchers have been known to delay egg hatch by storing the eggs at low temperatures. It is not well known how this technique could affect egg hatch or larval development, which could alter the results of an experiment. To test for this nondiapausing eggs of the western corn rootworm were stored at low temperatures to test for potential negative effects on hatch and larval development. Eggs were stored in either …

Variation Of Protein Molecular Weight Distribution Parameters And Their Correlations With Gluten And Mixing Characteristics For Winter Waxy Wheat, Jae‐Bom Ohm, Linda Dykes, Robert A. Graybosch

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

Background and objectives: Little data have been reported on protein molecular weight distribution (MWD) for waxy (amylose‐free) wheat (Triticum aestivum L.) despite their importance in quality. This research aimed to investigate variations of protein MWD parameters and their associations with gluten strength in winter waxy wheat.

Findings: Winter waxy wheat genotypes varied significantly (p < 0.001) for most protein MWD parameters including SDS‐extractable polymeric protein (EPP) and unextractable polymeric protein (UPP) fractions, which are major components of gluten proteins. Allelic variation of HMW glutenin subunits had significant influence on variations of EPP and UPP in waxy genotypes. Negative correlations for EPP and positive correlations for UPP were observed with mixograph peak time and gluten index for wheat genotypes. In particular, highly significant (p < 0.001) correlations were observed between mixograph peak time and the proportion of EPP in total protein for waxy genotypes.

Conclusions: Winter waxy wheat genotypes showed significant variations for EPP and UPP parameters, which were associated with variation of gluten strength.

Significance and novelty: This research identified variation of protein MWD parameters and their associations with gluten strength. The information should be valuable in segregating winter …

The Transcriptomes Of The Cattle Parasitic Nematode Ostertagia Ostartagi, Sahar Abubucker, Dante S. Zarlenga, John Martin, Yong Yin, Zhengyuan Wang, James P. Mccarter, Louis Gasbarree, Richard K. Wilson, Makedonka Mitreva

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

Ostertagia ostertagi is a gastrointestinal parasitic nematode that affects cattle and leads to a loss of production. In this study, we present the first large-scale genomic survey of O. ostertagi by the analysis of expressed transcripts from three stages of the parasite: third- stage larvae, fourth-stage larvae and adult worms. Using an in silico approach, 2284 genes were identified from over 7000 expressed sequence tags and abundant transcripts were analyzed and characterized by their functional profile. Of the 2284 genes, 66% had similarity to other known or predicted genes while the rest were novel and potentially represent genes specific to …

Evaluation Of Soil Test Phosphorus Extractants In Idaho Soils, Biswanath Dari, Christopher W. Rogers, April B. Leytem, Kurtis L. Schroeder

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

Soil P testing is critical to ensure the accuracy of fertilizer recommendations and to optimize crop yield while minimizing negative environmental consequences. Olsen-P is the most commonly used soil P test for alkaline calcareous soils found in Idaho and the western United States. The Bray- 1 test is commonly used in the Pacific Northwest on neutral to acidic soils but underestimates P in alkaline calcareous soils. Mehlich-3 has been evaluated throughout various regions in the United States. Few data evaluating Mehlich-3 exist for soils in the western United States. Additionally, the comparatively newly developed Haney–Haney–Hossner–Arnold (H3A) test, a component of …

Registration Of ‘Matterhorn’ Hard White Waxy Winter Wheat, Robert Graybosch, P. Stephen Baenziger, Dipak Santra, Teshome Regassa, Yue Jin, James Kolmer, Guihua Bai, Paul St. Amand, Richard Chen, Bradford Seabourn

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

‘Matterhorn’ (Reg. No. CV-1151, PI 687896) hard white winter waxy wheat (Triticum aestivum L.) was developed cooperatively by the USDA-ARS and the Nebraska Agricultural Experiment Station and released in 2018. Matterhorn, a sibling of the hard red waxy cultivar Mattern, has white grain color and waxy (amylose-free) endosperm starch. It was released primarily for its unique end-use quality attributes and for grain yield competitiveness with currently grown Nebraskaadapted cultivars. The waxy starch is conditioned by the presence of three naturally occurring mutations that eliminate production of the enzyme granule-bound starch synthase. Granule-bound starch synthase synthesizes amylose in typical wheats and …

Warm-Season Grass Monocultures And Mixtures For Sustainable Bioenergy Feedstock Production In The Midwest, Usa, Moon-Sub Lee, Robert B. Mitchell, Emily Heaton, Colleen Zumpf, Dokyoung Lee

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

Biomass yield and adaptability to a broad range of environments are important characteristics of dedicated energy crops for sustainable bioenergy feedstock production. In addition to yield potential, the role of species diversity on ecosystem services is also growing in importance as we seek to develop sustainable feedstock production systems. The objective of this study was to compare the biomass yield potential of the commercially available germplasm of native warm-season grasses in monocultures and in blends (mixture of different cultivars of the same species) or mixtures of different species across an environmental gradient (temperature and precipitation) in the Midwest, USA. Warm-season …

Herbicide Metabolism: Crop Selectivity, Bioactivation, Weed Resistance, And Regulation, Vijay K. Nandula, Dean E. Riechers, Yurdagul Ferhatoglu, Michael Barrett, Stephen O. Duke, Franck E. Dayan, Alina Goldberg-Cavalleri, Catherine Tétard-Jones, David J. Wortley, Nawaporn Onkokesung, Melissa Brazier-Hicks, Robert Edwards, Todd Gaines, Satoshi Iwakami, Mithila Jugulam, Rong Ma

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

Several grass and broadleaf weed species around the world have evolved multiple-herbicide resistance at alarmingly increasing rates. Research on the biochemical and molecular resistance mechanisms of multiple-resistant weed populations indicate a prevalence of herbicide metabolism catalyzed by enzyme systems such as cytochrome P450 monooxygenases and glutathione S-transferases and, to a lesser extent, by glucosyl transferases. A symposium was conducted to gain an understanding of the current state of research on metabolic resistance mechanisms in weed species that pose major management problems around the world. These topics, as well as future directions of investigations that were identified in the symposium, are …

Estimating And Exploring The Proportions Of Inter- And Intrastate Cattle Shipments In The United States, Lindsay M. Beck-Johnson, Clayton Hallman, Ryan S. Miller, Katie Portacci, Erin E. Gorsich, Daniel A. Grear, Katherine Hartmann, Colleen T. Webb

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

Mathematical models are key tools for the development of surveillance, preparedness and response plans for the potential events of emerging and introduced foreign animal diseases. Creating these types of plans requires data; when data are incomplete, mathematical models can help fill in missing information, provided they are informed by the data that are available. In the United States, the most complete national-scale data available on cattle shipments are based on Interstate Certificates of Veterinary Inspection, which track the shipment of cattle between states; data on intrastate cattle shipments are lacking. Here we develop four new datasets on intrastate cattle shipments …

Mortality And Flowering Of Great Basin Perennial Forbs After Experimental Burning: Implications For Wild Bees, Byron G. Love, James H. Cane

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

The fates of native bee communities in the Great Basin sagebrush steppe are linked with the susceptibilities of their floral hosts to increasingly frequent wildfires. Postfire survival and subsequent flowering of six prevalent perennial wildflowers representing five families were quantified across a range of realistic fire severities created using a calibrated propane burn barrel. Five burn prescriptions of varying intensity and duration were applied to cultivated rows of basalt milkvetch (Astragalus filipes Torr. ex A. Gray), Blue Mountain prairie clover (Dalea ornata Eaton & J. Wright), sulphur-flower buckwheat (Eriogonum umbellatum Torr.), fernleaf biscuitroot (Lomatium dissectum Nutt.), blue penstemon (Penstemon cyaneus …

Co2 Enrichment And Soil Type Additively Regulate Grassland Productivity, H. Wayne Polley, Michael J. Aspinwall, Harold P. Collins, Anne E. Gibson, Richard A. Gill, Robert B. Jackson, Virginia L. Jin, Albina R. Khasanova, Lara G. Reichmann, Philip A. Fay

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

The development of a predictive understanding of how atmospheric CO2 enrichment is affecting the primary productivity of the terrestrial biosphere is among the most pressing of ecological challenges. The terrestrial biosphere absorbs c. 25% of anthropogenic carbon (C) emissions (Le Quere et al., 2018). Uncertainty in CO2 effects on ecosystem C uptake is a major constraint in the prediction of C cycling and the provisioning of productivity- related ecosystem services.

Grasslands cover c. 25% of the terrestrial area and are an important contributor to the global C balance (Sala et al., 1996). CO2 enrichment stimulates the aboveground net primary productivity …

Pm223899, A New Recessive Powdery Mildew Resistance Gene Identified In Afghanistan Landrace Pi 223899, Genqiao Li, Brett F. Carver, Christina Cowger, Guihua Bai, Xiangyang Xu

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

Key message A new recessive powdery mildew resistance gene, Pm223899, was identified in Afghanistan wheat landrace PI 223899 and mapped to an interval of about 831 Kb in the terminal region of the short arm of chromosome 1A. Abstract Wheat powdery mildew, a globally important disease caused by the biotrophic fungus Blumeria graminis f.sp. tritici (Bgt), has occurred with increased frequency and severity in recent years, and some widely deployed resistance genes have lost effectiveness. PI 223899 is an Afghanistan landrace exhibiting high resistance to Bgt isolates collected from the Great Plains. An F2 population and F2: 3 lines derived …

Investigation On Various Aboveground Traits To Identify Drought Tolerance In Cowpea Seedlings, Waltram Ravelombola, Ainong Shi, Jun Qin, Yuejin Weng, Gehendra Bhattarai, Bazgha Zia, Beiquan Mou

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

Impacts of drought stress on crop production can significantly impair farmer’s revenue, hence adversely impacting the gross national product growth. For cowpea [Vigna unguiculata (L.) Walp.], which is a legume of economic importance, effects of drought at early vegetative growth could lead to substantial yield losses. However, little has been done with respect to breeding for cowpea cultivars withstanding drought at early vegetative growth. In addition, previous investigations have focused on how plantmorphology and root architecture can confer drought tolerance in cowpea, which is not sufficient in efforts to unravel unknown drought tolerance–related genetic mechanisms, potentially of great importance in …

Lethal And Repellent Effects Of The Botanical P-Anisaldehyde On Musca Domestica (Diptera: Muscidae), Allan T. Showler, Jessica L.. Harlien

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

The house fly, Musca domestica L., is a globally distributed nuisance and disease-carrying urban and livestock pest. Control mostly relies on synthetic insecticides but resistance to them has become problematic. p-Anisaldehyde, a compound found in many edible plants, was assessed for its effects on different life stages of M. domestica. Whereas p-anisaldehyde, applied as an adult contact spray, caused >80% mortality by 30 min at a 30% concentration, egg mortality on treated substrate was complete at 0.1%, and the LC90 was 0.024%. Only 0.5 and 1 ml of 1.5% p-anisaldehyde mixed into 100 g of cow manure curtailed pupation. When …

Grain Yield, Evapotranspiration, And Water-Use Efficiency Of Maize Hybrids Differing In Drought Tolerance, Baozhen Hao, Qingwu Xue, Thomas H. Marek, Kirk E. Jessup, Jacob D. Becker, Xiaobo Hou, Wenwei Xu, Edsel D. Bynum, Brent W. Bean, Paul D. Colaizzi, Terry A. Howell

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

Adoption of drought-tolerant (DT) hybrids is a viable strategy for maize production in drought-prone environments. We conducted four-year field studies (2011–2014) to investigate yield, crop evapotranspiration (ETc), and water-use efficiency (WUE) in one conventional (N58L) and one DT hybrid (N59B-DT) under three water regimes ( I100, I75, and I50, where the subscripts were the percentage of irrigation applied relative to meeting full ETc) and three plant densities. At I100 and I75, N59B-DT did not show advantage in yield and WUE relative to N58L, however, at I50 it showed an advantage of 8.5% and 10.5%, respectively. At I100 and I75, high …

A Tale Of Three Kingdoms: Members Of The Phylum Nematoda Independently Acquired The Detoxifying Enzyme Cyanase Through Horizontal Gene Transfer From Plants And Bacteria, Dante Zarlenga, M. Mitreva, P. Thompson, R. Tyagi, W. Tuo, E.P. Hoberg

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

Horizontal gene transfer (HGT) has played an important role in the evolution of nematodes. Among candidate genes, cyanase, which is typically found only in plants, bacteria and fungi, is present in more than 35 members of the Phylum Nematoda, but absent from free-living and clade V organisms. Phylogenetic analyses showed that the cyanases of clade I organisms Trichinella spp., Trichuris spp. and Soboliphyme baturini (Subclass: Dorylaimia) represent a well-supported monophyletic clade with plant cyanases. In contrast, all cyanases found within the Subclass Chromadoria which encompasses filarioids, ascaridoids and strongyloids are homologous to those of bacteria. Western blots exhibited typical multimeric …

Repellent Effects Of Methyl Anthranilate On Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae) In Soil Bioassays, E. J. Bernklau, B. E. Hibbard, L. B. Bjostad

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

Methyl anthranilate (MA), a compound in maize roots that is repellent to western corn rootworm larvae (Diabrotica virgifera virgifera LeConte) was tested in behavioral bioassays in a soil environment. MA prevented larvae from locating roots of a maize seedling, and the repellency strengthened with increasing rates of MA. In a simple push– pull strategy between an MA-treated seedling and an untreated seedling, granules containing 0.1 mg/g MA pushed larvae to the untreated seedling. This push effect increased with dose, with 90% repellency observed for the highest dose tested (100 mg/g). Chemical analysis showed that MA concentrations remained high for 4 …

Effect Of Stocking Rate On Growing Juvenile Sunshine Bass, Morone Chrysops × M. Saxatilis, In An Outdoor Biofloc Production System, Bartholomew W. Green, Steven D. Rawles, Carl D. Webster, Matthew E. Mcentire

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

The biofloc technology production system is a production intensifying management strategy used primarily for culturing tilapia and penaeid shrimp, both of which can consume the biofloc. Other fish can be grown in biofloc systems because the biofloc serves to maintain water quality, metabolizing the ammonia excreted by intensively fed fish. A dose-response study was conducted in an outdoor biofloc system to begin quantifying the stocking rate-production function for sunshine bass, Morone chrysops x M. saxatilis, advanced fingerlings. Sunshine bass (2.9 ± 0.2 g/fish) were stocked into tanks at 50 to 250 fish/m² in 50 fish/m² increments. After …

Forage Potential Of Summer Annual Grain Legumes In The Southern Great Plains, Gurjinder S. Baath, Brian K. Northup, Alexandre C. Rocateli, Prasanna H. Gowda, James P. S. Neel

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

Winter wheat (Triticum aestivum L.) and perennial warm-season grasses are the primary forage resources for grazing yearling stocker cattle (Bos taurus) in the US Southern Great Plains (SGP). However, low nutritive value of perennial grasses during mid to late summer limits high rates of growth by stocker cattle. In response, there has been a continued search for plant materials with the potential to provide forage high in crude protein (CP) and digestibility during August through September. A broad range of under-utilized legume species that are grown as grain crops in Africa, India, and South and Central America may have some …

Assessment Of Alternative Agricultural Land Use Options For Extending The Availability Of The Ogallala Aquifer In The Northern High Plains Of Texas, Yong Chen, Gary W. Marek, Thomas H. Marek, Jerry E. Moorhead, Kevin R. Heflin, David K. Brauer, Prasanna H. Gowda, Raghavan Srinivasan

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

The Ogallala Aquifer has experienced a continuous decline in water levels due to decades of irrigation pumping with minimal recharge. Corn is one of the major irrigated crops in the semi-arid Northern High Plains (NHP) of Texas. Selection of less water-intensive crops may provide opportunities for groundwater conservation. Modeling the long-term hydrologic impacts of alternative crops can be a time-saving and cost-effective alternative to field-based experiments. A newly developed management allowed depletion (MAD) irrigation scheduling algorithm for Soil and Water Assessment Tool (SWAT) was used in this study. The impacts of irrigated farming, dryland farming, and continuous fallow on water …

Cover Crops And Returning Residue Impact On Soil Organic Carbon, Bulk Density, Penetration Resistance, Water Retention, Infiltration, And Soybean Yield, Kopila Subedi Chalise, Shikha Singh, Brianna R. Wegner, Sandeep Kumar, Juan D. Pérez-Gutiérrez, Shannon L. Osborne, Thandiwe Nleya, Jose Guzman, Jai S. Rohila

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

Residue management with cover crops (CC) can conserve soil moisture and thus has a potential to increase crop yield, but its effectiveness varies significantly by region and cropping system management. A study was conducted at Brookings, SD, on finesilty, mixed, superactive, frigid, Calcic/Pachic Hapludolls soils to understand the impact of CC and crop residue on soil properties and soil-water dynamics for soybean (Glycine max L.) crop grown after corn (Zea mays L.). The site had two crop residue treatments (residue returned [RR] and residue not returned [RNR]) under a no-till corn–soybean rotation. Each residue returned treatment was later subdivided to …

Comparative Demography Elucidates The Longevity Of Parasitic And Symbiotic Relationships, Luke B.B. Hecht, Peter C. Thompson, Benjamin M. Rosenthal

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

Parasitic and symbiotic relationships govern vast nutrient and energy flows, yet controversy surrounds their longevity. Enduring relationships may engender parallel phylogenies among hosts and parasites, but so may ephemeral relationships when parasites colonize related hosts. An understanding of whether symbiont and host populations have grown and contracted in concert would be useful when considering the temporal durability of these relationships. Here, we devised methods to compare demographic histories derived from genomic data. We compared the historical growth of the agent of severe human malaria, Plasmodium falciparum, and its mosquito vector, Anopheles gambiae, to human and primate histories, thereby discerning long-term …

Soil Water Extraction For Several Dryland Crops, David C. Nielsen, Merle Virgil

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

Dryland cropping decisions would benefit from information about soil water extraction by various candidate crops. The objectives of this experiment were to: (i) quantify average soil water extraction by depth in the soil profile for winter wheat (Triticum aestivum L.), corn (Zea mays L.), proso millet (Panicum milliaceum L.) , and dry pea (Pisum sativum L.), and (ii) verify previously published values of drained upper limit (DUL) and lower limit (LL) of water extraction for each crop grown on a silt loam soil in northeastern Colorado. Soil water contents at planting and physiological maturity were measured over a 21-yr period. …

Comparison Of Six Artificial Diets For Western Corn Rootworm Bioassays And Rearing, Lisa N. Meihls, Man P. Huynh, Dalton C. Ludwick, Thomas A. Coudron, B. Wade French, Kent S. Shelby, Andrea J. Hitchon, Jocelyn L. Smith, Art W. Schaafsma, Adriano E. Pereira, B. E. Hibbard

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

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is considered the most important maize (Zea mays L.) pest in the U.S. Corn Belt. Bioassays testing susceptibility to Bacillus thuringiensis Berliner (Bt) and other toxins of corn rootworm larvae often rely on artificial diet formulations. Successful bioassays on artificial diet for corn rootworm have sometimes been challenging because of microbial contamination. Toward the long-term goal of developing a universal artificial diet for western corn rootworm larvae, we compared larval survival, dry weight, and percentage of molt in 10-d bioassays from six current diets of which we were aware. In …