Life Sciences Commons^™

Recoupling Fire And Grazing Reduces Wildland Fuel Loads On Rangelands, Heath D. Starns, Samuel D. Fuhlendore, R. Dwayne Elmore, Dirac L. Twidwell Jr, Eric T. Thacker, Torre J. Hovick, Barney Luttbeg

Department of Agronomy and Horticulture: Faculty Publications

Fire suppression and exclusion, the historically dominant paradigm of fire management, has resulted in major modifications of fire-dependent ecosystems worldwide. These changes are partially credited with a recent increase in wildfire number and extent, as well as more extreme fire behavior. Fire and herbivory historically interacted, and research has shown that the interaction creates a unique mosaic of vegetation heterogeneity that each disturbance alone does not create. Because fire and grazing have largely been decoupled in modern times, the degree to which the interaction affects fuels and fire regimes has not yet been quantified. We evaluated effects of fire-only and …

Assessment Of Soil Fertility Under Different Land-Use Systems In Dhading District Of Nepal, Sudarshan Kharal, Babu Ram Khanal, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

Unscientific land use and cropping techniques have led high soil erosion and degradation of soil quality in the mid-hills of Nepal. To understand the effects of land use systems for selected soil chemical properties in mid-hills, composite soil samples at 0 cm to 20 cm depth were collected from five different land-use systems: Grassland, forest land, upland, lowland, and vegetable farms from Dhading district of Nepal in 2017. Soil samples were analyzed for soil fertility parameters: Soil pH, organic matter (OM), total nitrogen (N), available phosphorus (P), available potassium (K) and its effect due to different land use systems were …

Digital Soil Mapping In The Bara District Of Nepal Using Kriging Tool In Arcgis, Dinesh Panday, Bijesh Maharjan, Devraj Chalise, Ram Kumar Shrestha, Bikesh Twanabasu

Department of Agronomy and Horticulture: Faculty Publications

Digital soil mapping has been widely used to develop statistical models of the relationships between environmental variables and soil attributes. This study aimed at determining and mapping the spatial distribution of the variability in soil chemical properties of the agricultural floodplain lands of the Bara district in Nepal. The study was carried out in 23 Village Development Committees with 12,516 ha total area, in the southern part of the Bara district. A total of 109 surface soil samples (0 to 15 cm depth) were collected and analyzed for pH, organic matter (OM), nitrogen (N), phosphorus (P, expressed as P_{2 …}

Research Report: Prevalence And Mechanism Of Atrazine Resistance In Waterhemp From Nebraska, Rodrigo Werle, Mithila Jugulam, Greg Kruger, Amaranatha Vennapusa, Felipe Faleco, Bruno Viera, Spencer Samuelson

Department of Agronomy and Horticulture: Faculty Publications

Waterhemp is a troublesome summer annual broadleaf weed species that has evolved resistance to glyphosate and other herbicide sites of action (SOA) in Nebraska, including to groups 2 (i.e., Classic, Pursuit, FirstRate), 4 (i.e., 2, 4-D), 5(i.e., atrazine) and 27 (e.g., Callisto, Laudis). The overall objectives of this study were to

1. Evaluate the eficay of PRE applied atrazine, metribuzin and sulfentrazone to control Nebraska waterhemp populations;
2. Evaluate the efficacy of POST applied atrazine to control Nebraska waterhemp populations; and
3. Determine the mechanism of atrazine resistance in Nebraska waterhemp populations.

Overexpression Of The Sorghum Bicolor Sbccoaomt Alters Cell Wall Associated Hydroxycinnamoyl Groups, Hannah M. Tetreault, Erin D. Scully, Tammy Gries, Nathan A. Palmer, Deanna L. Funnell-Harris, Bruce S. Dien, Gautam Sarath, Thomas E. Clemente, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor) is a drought tolerant crop, which is being developed as a bioenergy feedstock. The monolignol biosynthesis pathway is a major focus for altering the abundance and composition of lignin. Caffeoyl coenzyme-A O-methyltransferase (CCoAOMT) is an S-adenosyl methionine (SAM)-dependent O-methyltransferase that methylates caffeoyl-CoA to generate feruloyl-CoA, an intermediate required for the biosynthesis of both G- and S-lignin. SbCCoAOMT was overexpressed to assess the impact of increasing the amount of this enzyme on biomass composition. SbCCoAOMT overexpression increased both soluble and cell wall-bound (esterified) ferulic and sinapic acids, however lignin concentration and its composition …

Elucidating Sorghum Biomass, Nitrogen And Chlorophyll Contents With Spectral And Morphological Traits Derived From Unmanned Aircraft System, Jiating Li, Yeyin Shi, Arun-Narenthiran Veeranampalayam-Sivakumar, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Unmanned aircraft systems (UAS) provide an efficient way to phenotype cropmorphology with spectral traits such as plant height, canopy cover and various vegetation indices (VIs) providing information to elucidate genotypic responses to the environment. In this study, we investigated the potential use of UAS-derived traits to elucidate biomass, nitrogen and chlorophyll content in sorghum under nitrogen stress treatments. A nitrogen stress trial located in Nebraska, USA, contained 24 different sorghum lines, 2 nitrogen treatments and 8 replications, for a total of 384 plots. Morphological and spectral traits including plant height, canopy cover and various VIs were derived from UAS flights …

The Effect Of Ingredient-Specific Calorie Information On Calories Ordered, Christopher R. Gustafson, Eliana Zeballos

Department of Agronomy and Horticulture: Faculty Publications

Providing calorie labeling is a widely used strategy to combat obesity. However, there is little evidence that the availability of calorie information at food-away-from-home establishments has an effect on food choices. Listing calorie information for each ingredient, though, may allow customers to avoid high-calorie items that add little to their enjoyment. Data from a natural experiment were used to compare total calories ordered before and after the provision of per-ingredient versus for build-your-own sandwiches, and per-sandwich for pre-defined sandwiches, at a supermarket sandwich counter. Sandwich order slips from a Lincoln, Neb. supermarket were collected from December 15, 2016 to February …

Phylogenomic Evidence For Ancient Recombination Between Plastid Genomes Of The Cupressus-Juniperus-Xanthocyparis Complex (Cupressaceae), Andan Zhu, Weishu Fan, Robert P. Adams, Jeffrey P. Mower

Department of Agronomy and Horticulture: Faculty Publications

Background: Phylogenetic relationships among Eastern Hemisphere cypresses, Western Hemisphere cypresses, junipers, and their closest relatives are controversial, and generic delimitations have been in flux for the past decade. To address relationships and attempt to produce a more robust classification, we sequenced 11 new plastid genomes (plastomes) from the five variously described genera in this complex (Callitropsis, Cupressus, Hesperocyparis, Juniperus, and Xanthocyparis) and compared them with additional plastomes from diverse members of Cupressaceae.

Results: Phylogenetic analysis of protein-coding genes recovered a topology in which Juniperus is sister to Cupressus, whereas a tree based on …

Mobile Elements Shape Plastome Evolution In Ferns, Tanner A. Robison, Amanda L. Grusz, Paul G. Wolf, Jeffrey P. Mower, Blake D. Fauskee, Karla Sosa, Eric Schuettpelz

Department of Agronomy and Horticulture: Faculty Publications

Plastid genomes display remarkable organizational stability over evolutionary time. From green algae to angiosperms, most plastid genomes are largely collinear, with only a few cases of inversion, gene loss, or, in extremely rare cases, gene addition. These plastome insertions are mostly clade-specific and are typically of nuclear or mitochondrial origin. Here, we expand on these findings and present the first family-level survey of plastome evolution in ferns, revealing a novel suite of dynamic mobile elements. Comparative plastome analyses of the Preridaceae expose several mobile open reading frames that vary in sequence length, insertion site, and configuration among sampled taxa. Even …

Utilizing Random Regression Models For Genomic Prediction Of A Longitudinal Trait Derived From High‐Throughput Phenotyping, Malachy T. Campbell, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

The accessibility of high‐throughput phenotyping platforms in both the greenhouse and field, as well as the relatively low cost of unmanned aerial vehicles, has provided researchers with an effective means to characterize large populations throughout the growing season. These longitudinal phenotypes can provide important insight into plant development and responses to the environment. Despite the growing use of these new phenotyping approaches in plant breeding, the use of genomic prediction models for longitudinal phenotypes is limited in major crop species. The objective of this study was to demonstrate the utility of random regression (RR) models using Legendre polynomials for genomic …

Identification Of Genomic Regions Contributing To Protein Accumulation In Wheat Under Well-Watered And Water Deficit Growth Conditions, Ibrahim S. Elbasyoni, Sabah M. Morsy, Raghuprakash Kastoori Ramamurthy, Atef M. Nassar

Department of Agronomy and Horticulture: Faculty Publications

Sustaining wheat production under low-input conditions through development and identifying genotypes with enhanced nutritional quality are two current concerns of wheat breeders. Wheat grain total protein content, to no small extent, determines the economic and nutritive value of wheat. Therefore, the objectives of this study are to identify accessions with high and low grain protein content (GPC) under well-watered and water-deficit growth conditions and to locate genomic regions that contribute to GPC accumulation. Spring wheat grains obtained from 2111 accessions that were grown under well-watered and water-deficit conditions were assessed for GPC using near-infrared spectroscopy (NIR). Results indicated significant influences …

Vegetation And Soil Responses To Concrete Grinding Residue Application On Highway Roadsides Of Eastern Nebraska, Ana Wingeyer, Martha Mamo, Walter H. Schacht, Dennis L. Mccallister, Pamela Sutton

Department of Agronomy and Horticulture: Faculty Publications

As a precautionary principle, the National Pollutant Discharge Elimination System (NPDES) permit establishes that the primary pollutant in concrete grinding residue (CGR) is its alkalinity and restricts CGR roadside discharge to 11 Mg ha⁻¹ or the agronomic liming rate, whichever is lower. We evaluated the effect of CGR application on roadside soil chemical properties, existing vegetation, and rainfall runoff. Five CGR rates (0, 11, 22, 45, and 90 dry Mg ha⁻¹) were tested on roadsides slopes at two different locations in eastern Nebraska. Vegetation, soil, and runoff characteristics were evaluated before CGR application and 30 d and …

A Systems Modeling Approach To Forecast Corn Economic Optimum Nitrogen Rate, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Peter J. Thorburn, Michael J. Castellano, Kenneth J. Moore, Andy Vanloocke, Emily A. Heaton, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the …

Review Of Genome-Wide Association Studies: From Polymorphism To Personalized Medicine, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide association studies (GWAS) has become a powerful tool in the area of quantitative genetics to map the relationship between trait and genomic variations. This volume provides a great resource for beginners to learn about the recent advances in GWAS and for domain experts to identify the gaps in the area. The first part of the volume lays out the statistical background of GWAS. I really liked the article by Yang et al., Introduction to Statistical Methods in Genome-Wide Association Studies. In this chapter, the authors talked about the missing heritability issue and introduced ways to calculate heritability using the …

An Epigenetic Breeding System In Soybean For Increased Yield And Stability, Sunil K. Kenchanmane Raju, Mon-Ray Shao, Robersy Sanchez, Ying-Zhi Xu, Ajay Sandhu, George L. Graef, Sally A. Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Epigenetic variation has been associated with a wide range of adaptive phenotypes in plants, but there exist few direct means for exploiting this variation. RNAi suppression of the plant-specific gene, MutS HOMOLOG1 (MSH1), in multiple plant species produces a range of developmental changes accompanied by modulation of defence, phytohormone and abiotic stress response pathways along with methylome repatterning. This msh1-conditioned developmental reprogramming is retained independent of transgene segregation, giving rise to transgene-null ‘memory’ effects. An isogenic memory line crossed to wild type produces progeny families displaying increased variation in adaptive traits that respond to selection. This study …

Inheritance Of Mesotrione Resistance In An Amaranthus Tuberculatus (Var. Rudis) Population From Nebraska, Usa, Maxwel C. Oliveira, Todd A. Gaines, Amit J. Jhala, Stevan Z. Knezevic

Department of Agronomy and Horticulture: Faculty Publications

A population of Amaranthus tuberculatus (var. rudis) evolved resistance to 4- hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor herbicides (mesotrione, tembotrione, and topramezone) in Nebraska. The level of resistance was the highest to mesotrione, and the mechanism of resistance in this population is metabolism-based likely via cytochrome P450 enzymes. The increasing number of weeds resistant to herbicides warrants studies on the ecology and evolutionary factors contributing for resistance evolution, including inheritance of resistance traits. In this study, we investigated the genetic control of mesotrione resistance in an A. tuberculatus population from Nebraska, USA. Results showed that reciprocal crosses in the F1 families exhibited …

Genome-Wide Analysis Of Grain Yield Stability And Environmental Interactions In A Multiparental Soybean Population, Alencar Xavier, Diego Jarquin, Reka Howard, Vishnu Ramasubramanian, James E. Specht, George L. Graef, William D. Beavis, Brian W. Diers, Qijian Song, Perry B. Cregan, Randall L. Nelson, Rouf Mian, J. Grover Shannon, Leah K. Mchale, Dechun Wang, William Schapaugh, Aaron J. Lorenz, Shizhong Xu, William M. Muir, Katy M. Rainey

Department of Agronomy and Horticulture: Faculty Publications

Genetic improvement toward optimized and stable agronomic performance of soybean genotypes is desirable for food security. Understanding how genotypes perform in different environmental conditions helps breeders develop sustainable cultivars adapted to target regions. Complex traits of importance are known to be controlled by a large number of genomic regions with small effects whose magnitude and direction are modulated by environmental factors. Knowledge of the constraints and undesirable effects resulting from genotype by environmental interactions is a key objective in improving selection procedures in soybean breeding programs. In this study, the genetic basis of soybean grain yield responsiveness to environmental factors …

Overlapping Residual Herbicides For Control Of Photosystem (Ps) Ii- And 4-Hydroxyphenylpyruvate Dioxygenase (Hppd)-Inhibitor-Resistant Palmer Amaranth (Amaranthus Palmeri S. Watson) In Glyphosate-Resistant Maize, Parminder S. Chahal, Zahoor Ahmad Ganie, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

A Palmer amaranth (Amaranthus palmeri S. Watson) biotype has evolved resistance to photosystem (PS) II- (atrazine) and 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides (mesotrione, tembotrione, and topramezone) in maize seed production field in Nebraska, USA. The objectives of this study were to determine the effect of soil residual pre-emergence (PRE) herbicides followed by (fb) tank-mixture of residual and foliar active post-emergence (POST) herbicides on PS-II- and HPPD-inhibitor-resistant Palmer amaranth control, maize yield, and net economic returns. Field experiments were conducted in a grower’s field infested with PS II- and HPPD-inhibitor-resistant Palmer amaranth near Shickley in Fillmore County, Nebraska, USA in 2015 …

Genotype-Corrector: Improved Genotype Calls For Genetic Mapping In F2 And Ril Populations, Chenyong Miao, Jingping Fang, Delin Li, Pingping Liang, Xingtan Zhang, Jinliang Yang, James C. Schnable, Haibao Tang

Department of Agronomy and Horticulture: Faculty Publications

F₂ and recombinant inbred lines (RILs) populations are very commonly used in plant genetic mapping studies. Although genome-wide genetic markers like single nucleotide polymorphisms (SNPs) can be readily identified by a wide array of methods, accurate genotype calling remains challenging, especially for heterozygous loci and missing data due to low sequencing coverage per individual. Therefore, we developed Genotype-Corrector, a program that corrects genotype calls and imputes missing data to improve the accuracy of genetic mapping. Genotype-Corrector can be applied in a wide variety of genetic mapping studies that are based on low coverage whole genome sequencing (WGS) or Genotyping-by-Sequencing …

Biomass Production Of Herbaceous Energy Crops In The United States: Field Trial Results And Yield Potential Maps From The Multiyear Regional Feedstock Partnership, Dokyoung Lee, Ezra Aberle, Eric K. Anderson, William Anderson, Brian S. Baldwin, David D. Baltensperger, Michael Barrett, Jurg Blumenthal, Stacy Bonos, Joe Bouton, David I. Bransby, Charlie Brummer, Pane S. Burks, Chengci Chen, Christopher Daly, Jose Egenolf, Rodney L. Farris, John H. Fike, Roch E. Gaussoin, John R. Gill, Kenneth Gravois, Michael D. Halbleib, Anna Hale, Wayne Hanna, Keith Harmoney, Emily A. Heaton, Ron W. Heiniger, Lindsey Hoffman, Chang O. Hong, Gopal Kakani, Robert Kallenbach, Bisoondat Macoon, James C. Medley, Ali Missaoui, Robert B. Mitchell, Ken J. Moore, Jesse I. Morrison, Gary N. Odvody, Jonathan D. Richwine, Richard Ogoshi, Jimmy Ray Parrish, Lauren Quinn, Ed Richard, William L. Rooney, J. Brett Rushing, Ronnie Schnell, Matt Sousek, Scott A. Staggenborg, Thomas Tew, Goro Uehara, Donald R. Viands, Thomas Voigt, David Williams, Linda Williams, Lloyd Ted Wilson, Andrew Wycislo, Yubin Yang, Vance Owens

Department of Agronomy and Horticulture: Faculty Publications

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock …

Prospects For Increasing Sugarcane And Bioethanol Production On Existing Crop Area In Brazil, Fábio R. Marin, Geraldo B. Martha Jr., Kenneth Cassman, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

This article assesses sugarcane yield gaps (YG) in Brazil to determine the degree to which production can be increased without land expansion. In our scenario assessments, we evaluated how much of the projected sugarcane demand to 2024 (for both sugar and bioethanol) can be satisfied through YG closure. The current national average yield is 62% of yield potential estimated for rainfed conditions (i.e., a YG of 38%). Continuing the historical rate of yield gain is not sufficient to meet the projected demand without an area expansion by 5% and 45% for lowand high-demand scenarios, respectively. Closing the exploitable YG to …

Gene Expression Profiling Of Iron Deficiency Chlorosis Sensitive And Tolerant Soybean Indicates Key Roles For Phenylpropanoids Under Alkalinity Stress, Brian M. Waters, Keenan Amundsen, George L. Graef

Department of Agronomy and Horticulture: Faculty Publications

Alkaline soils comprise 30% of the earth and have low plant-available iron (Fe) concentration, and can cause iron deficiency chlorosis (IDC). IDC causes soybean yield losses of $260 million annually. However, it is not known whether molecular responses to IDC are equivalent to responses to low iron supply. IDC tolerant and sensitive soybean lines provide a contrast to identify specific factors associated with IDC.We used RNA-seq to compare gene expression under combinations of normal pH (5.7) or alkaline pH (7.7, imposed by 2.5mM bicarbonate, or pH 8.2 imposed by 5mM bicarbonate) and normal (25μM) or low (1μM) iron conditions from …

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 …

Enhancing Resolution Of Natural Methylome Reprogramming Behavior In Plants, Robersy Sanchez, Xiaodong Yang, Hardik Kundariya, Jose R. Barreras, Yashitola Wamboldt, Sally A. Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

We have developed a novel methylome analysis procedure, Methyl-IT, based on information thermodynamics and signal detection. Methylation analysis involves a signal detection problem, and the method was designed to discriminate methylation regulatory signal from background noise induced by thermal fluctuations. Comparison with three commonly used programs and various available datasets to furnish a comparative measure of resolution by each method is included. To confirm results, methylation analysis was integrated with RNAseq and network enrichment analyses. Methyl-IT enhances resolution of genome methylation behavior to reveal network-associated responses, offering resolution of gene pathway influences not attainable with previous methods.

Biomass Yield Of Warm-Season Grasses Affected By Nitrogen And Harvest Management, Chamara S. Weerasekara, Newell R. Kitchen, Shibu Jose, Peter P. Motavalli, Sougata Bardhan, Robert B. Mitchell

Department of Agronomy and Horticulture: Faculty Publications

Native perennial warm-season grasses (NPWSG) have drawn interest as bioenergy feedstocks due to their high productivity with minimal amounts of inputs under a wide range of environments. Nitrogen fertility and harvest timing are critical management practices when optimizing biomass yield of NPWSG. Our objective was to quantify the impact of N fertilizer rate and timing in combination with harvest timing and frequency on NPWSG yield. Research was conducted in 2014 and 2015 on four field-plot locations in Missouri. The experiment was a split-plot design with three replications where N rate and harvest timing were the main and sub-plot treatments, respectively. …

Genome-Wide Association Study For Identification And Validation Of Novel Snp Markers For Sr6 Stem Rust Resistance Gene In Bread Wheat, Amira M. I. Mourad, Ahmed Sallam, Vikas Belamkar, Stephen N. Wegulo, Robert Bowden, Yue Jin, Ezzat Mahdy, Bahy Bakheit, Atif A. El-Wafaa, Jesse Poland, Peter S. Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat (Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ~35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in …

Crop Residue Harvest Impacts Wind Erodibility And Simulated Soil Loss In The Central Great Plains, Yuxin He, Deann R. Presley, John Tatarko, Humberto Blanco-Canqui

Department of Agronomy and Horticulture: Faculty Publications

Crop residue removal can affect the susceptibility to soil wind erosion in climates such as those of the Central Great Plains, United States. Six on-farm trials were conducted in Kansas from 2011 to 2013 to determine the effects of winter wheat (Triticum aestivum L.), corn (Zea mays L.), and grain sorghum (Sorghum bicolor (L.) Moench), residue removal at 0, 25, 50, 75, and 100% of initial height on soil wind erosion parameters. Those parameters include soil surface random roughness (RR), and wind erodible fraction (EF; aggregates -¹ for three hours. Threshold wind velocity required to initiate …

Lowland Rice Nutrient Responses For The Guinea And Sudan Savannas Of Nigeria, Christogonus K. Daudu, Enemona M. Ugbaje, Eunice Y. Oyinlola, Bitrus D. Tarfa, Adamu A. Yakubu, Ishaku Y. Amapu, Charles S. Wortmann

Department of Agronomy and Horticulture: Faculty Publications

Copyright © 2018 by the American Society of Agronomy

This is an open access article

doi:10.2134/agronj2017.08.0469

Lowland Rice Nutrient Responses For The Guinea And Sudan Savannas Of Nigeria, Christogonus K. Daudu, Enemona M. Ugbaje, Eunice Y. Oyinlola, Bitrus D. Tarfa, Adamu A. Yakubu, Ishaku Y. Amapu, Charles S. Wortmann

Department of Agronomy and Horticulture: Faculty Publications

Yield response of irrigated lowland rice (Oryza sativa L.) to nutrient application was determined to improve the information base for fertilizer use in the Sudan and Southern Guinea Savannas of Nigeria. Economically optimal rates (EOR) and agronomic efficiency (AE) were determined. Five N levels and four levels each P, K, and Zn were evaluated with two varieties at two locations. Nitrogen effects varied by variety and location but mean paddy yield with 0 kg ha^–1 N was 3.4 Mg ha^–1 and was increased by 1.3 Mg ha^–1 with 40 kg ha^–1 N. The mean EOR …

Impaired Phloem Loading In Zmsweet13a,B,C Sucrose Transporter Triple Knock-Out Mutants In Zea Mays, Margaret Bezrutczyk, Thomas Hartwig, Marc Horschman, Si Nian Char, Jinliang Yang, Bing Yang, Wolf B. Frommer, Davide Sosso

Department of Agronomy and Horticulture: Faculty Publications

Crop yield is critical for human nutrition, yet the underlying machinery that ultimately determines yield potential is still not understood. Crop productivity under ideal conditions is determined by the efficiency with which plants intercept light, convert it into chemical energy, translocate photosynthates and convert these to storage products in harvestable organs (Zhu et al., 2010). In many crops, sucrose is the primary form for translocation inside the conduit (i.e. the phloem). A combination of SWEETmediated efflux from phloem parenchyma and subsequent secondary active sucrose import by SUT sucrose/H+ symporters is thought to create the driving force for pressure gradient-driven …