Digital Commons Network^™

Computation-Driven Analysis Of Model Polyextremo- Tolerant Fungus Exophiala Dermatitidis: Defensive Pigment Metabolic Costs And Human Applications, Wheaton L. Schroeder, Steven D. Harris, Rajib Saha

Department of Chemical and Biomolecular Engineering: Faculty Publications

Extremophiles are organisms that can live in extreme conditions of temperature, acidity, alkalinity, or salinity. Studying these organisms not only expands our knowledge on the diversity of life but can also provide significant insights into how organisms adapt to stress, particularly metabolic and regulatory responses. Exophiala dermatitidis (hereafter, Exophiala or E. dermatitidis, also known as Wangiella derma- titidis), a highly melanized black fungus and perhaps best known for its H. sapiens (hereafter, human) path- ogenic properties (Paolo et al., 2006; Poyntner et al., 2016; Sudhadham et al., 2008), is a potential model extremophile system owing to its small genome of …

Engineered Clostridium Botulinum Toxin Adapted To Deliver Molecules Into Selected Cells, Benjamin J. Pavlik, Paul Blum, Kevin Van Cott

Department of Chemical and Biomolecular Engineering: Faculty Publications

An engineered payload-delivery system includes a target cell binding unit, covlently bound to a pore forming unit, and a payload portion adapted with a region capable of non-covalently binding to the pore forming unit. The pore forming unit is derived from a particular sub-serotype of Clostridium toxin, while the payload region is derived from a different sub-serotype of Clostridium toxin. The disclosed chimeri protein-based composition is capable of specifically delivering payload to neural cells.

Leveraging Plasma-Derived Exosomes For Biomarker Discovery In Sickle Cell Disease: Preparation For A Large Prospective Study, Y. Lamarre, A. Aich, Mohammad Mazharul Islam, J.M. Scianni, A.C.S. Pinto, A.M.C Tavassie, J. Elion, W.E. Nemer, Rajib Saha, S. Kashimab, D.T. Covas

Department of Chemical and Biomolecular Engineering: Faculty Publications

Diverse clinical variability among sickle cell disease (SCD) patients opposes crises prediction, health monitor- ing and streamlined management. Thus, an unmet need for objective biomarkers prevails. Exosomes are extra-cellular nano-vesicles (50-150nm), enriched in bioactive lipids, proteins, mRNAs and miRNAs, released by cells. They transport molecular cargo to nearby/distant cells to affect-regulate biological processes. Recent studies by Khalyfa et al. assessed the plasma exosome content, their sources and transcriptomics signature as predictive marker in SCD children with acute chest syndrome. However, the small sample sizes (32 and 33 individuals, respectively) may not capture the clinical variability.

Novel Fibrin-Fibronectin Matrix Accelerates Mice Skin Wound Healing, Carlos Poblete Jara, Ou Wang, Thais Paulino Do Prado, Ayman Ismailc, Frank Marco Fabianc, Han Li, Licio A. Velloso, Mark A. Carlson, William Burgess, Yuguo Lei, William H. Velander, Eliana P, Araújo

Department of Chemical and Biomolecular Engineering: Faculty Publications

Plasma fibrinogen (F1) and fibronectin (pFN) polymerize to form a fibrin clot that is both a hemostatic and provisional matrix for wound healing. About 90% of plasma F1 has a homodimeric pair of γ chains (γγF1), and 10% has a heterodimeric pair of γ and more acidic γ′ chains (γγ′F1). We have synthesized a novel fibrin matrix exclusively from a 1:1 (molar ratio) complex of γγ′F1 and pFN in the presence of highly active thrombin and recombinant Factor XIII (rFXIIIa). In this matrix, the fibrin nanofibers were decorated with pFN nanoclusters (termed γγ′F1:pFN fibrin). In contrast, fibrin made from 1:1 …

Investigation Of Microbial Community Interactions Between Lake Washington Methanotrophs Using Genome-Scale Metabolic Modeling, Mohammad Mazharul Islam, Tony Le

Department of Chemical and Biomolecular Engineering: Faculty Publications

Background. The role of methane in global warming has become paramount to the environment and the human society, especially in the past few decades. Methane cycling microbial communities play an important role in the global methane cycle, which is why the characterization of these communities is critical to understand and manipulate their behavior. Methanotrophs are a major player in these communities and are able to oxidize methane as their primary carbon source.

Results. Lake Washington is a freshwater lake characterized by a methane-oxygen countergradient that contains a methane cycling microbial community. Methanotrophs are a major part of this community involved …

Functional Genetic Encoding Of Sulfotyrosine In Mammalian Cells, Xinyuan He, Yan Chen, Daisy Guiza Beltran, Maia Kelly, Bin Ma, Justin Lawrie, Feng Wang, Eric Dodds, Limei Zhang, Jiantao Guo, Wei Niu

Department of Chemical and Biomolecular Engineering: Faculty Publications

Protein tyrosine O-sulfation (PTS) plays a crucial role in extracellular biomolecular interac- tions that dictate various cellular processes. It also involves in the development of many human diseases. Regardless of recent progress, our current understanding of PTS is still in its infancy. To promote and facilitate relevant studies, a generally applicable method is needed to enable efficient expression of sulfoproteins with defined sulfation sites in live mammalian cells. Here we report the engineering, in vitro biochemical characterization, structural study, and in vivo functional verification of a tyrosyl-tRNA synthetase mutant for the genetic encoding of sulfotyrosine in mammalian cells. We further …

Narratives Of Queer Men Of Color In Culturally-Based Fraternities Making Meaning Of Masculinities, Antonio Duran, Crystal Garcia

Department of Educational Administration: Faculty Publications

This constructivist grounded theory study examined how Queer Men of Color in culturally-based fraternities made meaning of their masculinities. Through two intensive interviews and a reflection journal activity, nine participants shared their constructions of masculinities before joining a culturally-based organization and how their thinking changed after affiliating with a fraternity. Specifically, Queer Men of Color first spoke to pre-collegiate experiences that largely shaped their views of masculinities. Next, participants discussed how culturally-based fraternities both reinforced hegemonic masculinity, as well as opened up the possibilities to construct a more productive view of masculinities. Implications are then offered for chapter advisors, fraternity …

Reframing Community (Dis)Engagement: The Discursive Connection Between Undemocratic Policy Enactment, Minoritized Communities And Resistance, James S. Wright, Taeyeon Kim

Department of Educational Administration: Faculty Publications

While studies have examined leadership efforts to improve community engagement, less is known about how deeply rooted structured discourses, systems, and practices influence leadership actions and responses from communities. Deficit approaches to educational policy reform are pervasive in the most historically marginalized communities and school districts in the United States (US). Drawing on critical policy analysis, this study examines a disengaged school district’s leadership of a Federal School Turnaround Policy from the perspectives of minoritized communities in an urban US school district. We analyzed deficit policy discourses, its enactment, and leadership practices using interview data and archived documents. This study …

The Lateral Root Density Gene Regulates Root Growth During Water Stress In Wheat, Dante F. Placido, Jaspreet Sandhu, Shirley Sato, Natalya Nersesian, Truyen Quach, Thomas E. Clemente, Paul E. Staswick, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Drought stress is the major limiting factor in agriculture. Wheat, which is the most widely grown crop in the world, is predominantly cultivated in drought-prone rainfed environments. Since roots play a critical role in water uptake, root response to water limitations is an important component for enhancing wheat adaptation. In an effort to discover novel genetic sources for improving wheat adaptation, we characterized a wheat translocation line with a chromosomal segment from Agropyron elongatum, a wild relative of wheat, which unlike common wheat maintains root growth under limited-water conditions. By exploring the root transcriptome data, we found that reduced …

Rhizosphere Microbiome Of Arid Land Medicinal Plants And Extra Cellular Enzymes Contribute To Their Abundance, Abdul Latif Khan, Sajjad Asaf, Raeid M. M. Abed, Yen Ning Chai, Ahmed N. Al-Rawahi, Tupan Kumar Mohanta, Ahmed Al-Rawahi, Daniel P. Schachtman, Ahmed Al-Harrasi

Department of Agronomy and Horticulture: Faculty Publications

Revealing the unexplored rhizosphere microbiome of plants in arid environments can help in understanding their interactions between microbial communities and plants during harsh growth conditions. Here, we report the first investigation of rhizospheric fungal and bacterial communities of Adenium obesum, Aloe dhufarensis and Cleome austroarabica using next-generation sequencing approaches. A. obesum and A. dhufarensis grows in dry tropical and C. austroarabica in arid conditions of Arabian Peninsula. The results indicated the presence of 121 fungal and 3662 bacterial operational taxonomic units (OTUs) whilst microbial diversity was significantly high in the rhizosphere of A. obesum and A. dhufarensis and low …

Wheat Growth Monitoring And Yield Estimation Based On Multi-Rotor Unmanned Aerial Vehicle, Zhaopeng Fu, Jie Jang, Yang Gao, Brian Krienke, Meng Wang, Kaitai Zhong, Qiang Cao, Yongchao Tian, Yan Zhu, Weixing Cao, Xiaojun Liu

Department of Agronomy and Horticulture: Faculty Publications

Leaf area index (LAI) and leaf dry matter (LDM) are important indices of crop growth. Real-time, nondestructive monitoring of crop growth is instructive for the diagnosis of crop growth and prediction of grain yield. Unmanned aerial vehicle (UAV)-based remote sensing is widely used in precision agriculture due to its unique advantages in flexibility and resolution. This study was carried out on wheat trials treated with different nitrogen levels and seeding densities in three regions of Jiangsu Province in 2018–2019. Canopy spectral images were collected by the UAV equipped with a multi-spectral camera during key wheat growth stages. To verify the …

The State Of Sustainable Agriculture And Agroecology Research And Impacts: A Survey Of U.S. Scientists, Marcia Delonge, Tali Robbins, Andrea D. Basche, Lindsey Haynes-Maslow

Department of Agronomy and Horticulture: Faculty Publications

A growing body of research suggests that although sustainable agriculture, particularly agroecology, can address challenges such as those related to climate change, ecosystem services, food insecurity, and farmer livelihoods, the transition to such systems remains limited. To gain insight into the state of U.S. sustainable agriculture and agroecology, we developed a 28-question mixed-method survey that was administered to scientists in these fields. Respondents (N=168) represented diverse locations, institutions, and career stages. They offered varied definitions of sustainable agriculture, with 40% considering economic and social well-being to be core components. Respondents identified the amount and duration of public research …

Multi-Trait Random Regression Models Increase Genomic Prediction Accuracy For A Temporal Physiological Trait Derived From High-Throughput Phenotyping, Toshimi Baba, Mehdi Momen, Malachy T. Campbell, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

Random regression models (RRM) are used extensively for genomic inference and predic- tion of time-valued traits in animal breeding, but only recently have been used in plant sys- tems. High-throughput phenotyping (HTP) platforms provide a powerful means to collect high-dimensional phenotypes throughout the growing season for large populations. How- ever, to date, selection of an appropriate statistical genomic framework to integrate multiple temporal traits for genomic prediction in plants remains unexplored. Here, we demonstrate the utility of a multi-trait RRM (MT-RRM) for genomic prediction of daily water usage (WU) in rice (Oryza sativa) through joint modeling with shoot …

Gwas: Fast-Forwarding Gene Identification And Characterization In Temperate Cereals: Lessons From Barley – A Review, Ahmad M. Alqudah, Ahmed Sallam, P. Stephen Baenziger, Andreas Börner

Department of Agronomy and Horticulture: Faculty Publications

Understanding the genetic complexity of traits is an important objective of small grain temperate cereals yield and adaptation improvements. Bi-parental quantitative trait loci (QTL) linkage mapping is a pow- erful method to identify genetic regions that co-segregate in the trait of interest within the research pop- ulation. However, recently, association or linkage disequilibrium (LD) mapping using a genome-wide association study (GWAS) became an approach for unraveling the molecular genetic basis underlying the natural phenotypic variation. Many causative allele(s)/loci have been identified using the power of this approach which had not been detected in QTL mapping populations. In barley (Hordeum …

Soil Carbon Increased By Twice The Amount Of Biochar Carbon Applied After 6 Years: Field Evidence Of Negative Priming, Humberto Blanco-Canqui, David A. Laird, Emily A. Heaton, Samuel Rathke, Bharat Sharma Acharya

Department of Agronomy and Horticulture: Faculty Publications

Applying biochar to agricultural soils has been proposed as a means of sequester-ing carbon (C) while simultaneously enhancing soil health and agricultural sustain-ability. However, our understanding of the long-term effects of biochar and annual versus perennial cropping systems and their interactions on soil properties under field conditions is limited. We quantified changes in soil C concentration and stocks, and other soil properties 6 years after biochar applications to corn (Zea mays L.) and dedicated bioenergy crops on a Midwestern US soil. Treatments were as fol-lows: no-till continuous corn, Liberty switchgrass (Panicum virgatum L.), and low-diversity prairie grasses, 45% big bluestem …

Transforming Unmanned Aerial Vehicle (Uav) And Multispectral Sensor Into A Practical Decision Support System For Precision Nitrogen Management In Corn, Laura J. Thompson, Laila A. Puntel

Department of Agronomy and Horticulture: Faculty Publications

Determining the optimal nitrogen (N) rate in corn remains a critical issue, mainly due to unaccounted spatial (e.g., soil properties) and temporal (e.g., weather) variability. Unmanned aerial vehicles (UAVs) equipped with multispectral sensors may provide opportunities to improve N management by the timely informing of spatially variable, in-season N applications. Here, we developed a practical decision support system (DSS) to translate spatial field characteristics and normalized difference red edge (NDRE) values into an in-season N application recommendation. On-farm strip-trials were established at three sites over two years to compare farmer’s traditional N management to a split-application N management guided by …

Benchmarking Impact Of Nitrogen Inputs On Grain Yield And Environmental Performance Of Producer Fields In The Western Us Corn Belt, Fatima A.M. Tenorio, Eileen L. Mclellan, Alison J. Eagle, Kenneth G. Cassman, Daryl Andersen, Marie Krausnick, Russell Oaklund, John Thorburn, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Benchmarking crop yields against nitrogen (N) input levels can help provide opportunities to improve N ferti-lizer efficiency and reduce N losses on maize in the US Corn Belt by identifying fields most likely to benefit from improved N management practices. Here, we evaluated a large producer database that includes field-level data on yield and applied N inputs from 9280 irrigated and rainfed fields over a 7-year period (2009–2015) in Nebraska (USA). A spatial framework, based on technology extrapolation domains, was used to cluster each field into spatial units with similar climate and soil type that represent 1.3 million ha of …

Prediction Strategies For Leveraging Information Of Associated Traits Under Single- And Multi-Trait Approaches In Soybeans, Reyna Persa, Arthur Bernardeli, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

The availability of molecular markers has revolutionized conventional ways to improve genotypes in plant and animal breeding through genome-based predictions. Several models and methods have been developed to leverage the genomic information in the prediction context to allow more efficient ways to screen and select superior genotypes. In plant breeding, usually, grain yield (yield) is the main trait to drive the selection of superior genotypes; however, in many cases, the information of associated traits is also routinely collected and it can potentially be used to enhance the selection. In this research, we considered different prediction strategies to leverage the information …

Overexpression Of Ferulate 5‑Hydroxylase Increases Syringyl Units In Sorghum Bicolor, Hannah M. Tetreault, Tammy Gries, Nathan Palmer, Deanna L. Funnell-Harris, Shirley Sato, Zhengxiang Ge, Gautam Sarath, Scott Sattler

Department of Agronomy and Horticulture: Faculty Publications

Ferulate 5-hydroxylase (F5H) of the monolignol pathway catalyzes the hydroxylation of coniferyl alcohol, coniferaldehyde and ferulic acid to produce 5-hydroxyconiferyl moieties, which lead to the formation of sinapic acid and syringyl (S) lignin monomers. In contrast, guaiacyl (G) lignin, the other major type of lignin monomer, is derived from polymerization of coniferyl alcohol. In this study, the effects of manipulating S-lignin biosynthesis in sorghum (Sorghum bicolor) were evaluated. Overexpression of sorghum F5H (SbF5H), under the control of the CaMV 35S promoter, increased both S-lignin levels and the ratio of S/G lignin, while plant growth and development …

Biological And Cellular Functions Of The Microdomain-Associated Fwl/Cnr Protein Family In Plants, Sandra Thibivilliers, Andrew Farmer, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Membrane microdomains/nanodomains are sub-compartments of the plasma membrane enriched in sphingolipids and characterized by their unique protein composition. They play important roles in regulating plant development and plant-microbe interactions including mutualistic symbiotic interactions. Several protein families are associated with the microdomain fraction of biological membranes such as flotillins, prohibitins, and remorins. More recently, GmFWL1, a FWL/CNR protein exclusively expressed in the soybean nodule, was functionally characterized as a new microdomain-associated protein. Interestingly, GmFWL1 is homologous to the tomato FW2-2 protein, a major regulator of tomato fruit development. In this review, we summarize the knowledge gained about the biological, cellular, and …

Investigation Of Heat-Induced Changes In The Grain Yield And Grains Metabolites, With Molecular Insights On The Candidate Genes In Barley, Mona F.A. Dawood, Yasser S. Moursi, Ahmed Amro, P. Stephen Baenziger, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Heat stress is one of the abiotic stresses that cause a significant reduction in barley yield. Climate change will increase the number of heatwaves, which will result in more deterioration in the agricultural sector. Therefore, understanding the physiological changes that occur in the plant to tolerate heat stress is very important. A collection of 60 Egyptian spring barley genotypes has been tested for heat stress under field conditions. To quantify the changes in yield-related traits and the grain-reserve parameters as indicators for heat tolerance, several traits were scored. The causative genes that regulate the variation of all traits of interest …

Soil Sample Timing, Nitrogen Fertilization, And Incubation Length Influence Anaerobic Potentially Mineralizable Nitrogen, Jason Clark, Kristen S. Veum, Fabián G. Fernández, Newell R. Kitchen, James J. Camberato, Paul Carter, Richard Ferguson, David W. Franzen, Daniel E. Kaiser, Carrie A. M. Laboski, Emerson Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Understanding the variables that affect the anaerobic potentially mineralizable N (PMNan) test should lead to a standard procedure of sample collection and incubation length, improving PMNan as a tool in corn (Zea mays L.) N management. We evaluated the effect of soil sample timing (preplant and V5 corn development stage [V5]), N fertilization (0 and 180 kg ha−1) and incubation length (7, 14, and 28 d) on PMNan (0–30 cm) across a range of soil properties and weather conditions. Soil sample timing, N fertilization, and incubation length affected PMNan differently based on soil and weather conditions. Preplant vs. V5 PMNan …

Weather And Soil In The Us Midwest Influence The Effectiveness Of Single- And Split-Nitrogen Applications In Corn Production, Jason D. Clark, Fabián G. Fernández, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Newell R. Kitchen, Carrie A. M. Laboski, Emerson Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Splitting the N application into two or more timings may improve corn (Zea mays L.) grain yield and N recovery relative to a single-N application. A 49 site-year study across eight U.S. Midwestern states compared the effect of an at-planting (single-N application) and two split-N applications [45 (45+SD) or 90 kg N ha−1 (90+SD) at planting with the remainder of the total rate (180 or 270 kg N ha−1) applied at V9]. For split-N applications, soil and plant responses were similar between 45+SD and 90+SD 93–98% of the time, indicating the at-planting N rate of 45 kg N ha−1 may …

Organic Fertilizer Abrasive Grits Increase Soil Available Nitrogen, Plant Height, And Biomass, Michael Carlson, Frank Forcella, Samuel E. Wortman, David Clay, Sharon A. Clay

Department of Agronomy and Horticulture: Faculty Publications

In organic cropping systems, air-propelled abrasive grits can be used to control in-row weeds. If the applied abrasive grit is an approved organic fertilizer, these applications may serve a dual purpose of weed control and crop fertility. Laboratory soil incubations examined the N mineralization rates of several grit types with differing C/N ratios (Agra Grit [crushed walnut shells, 170:1], corncob grit [91:1], Sustane [composted turkey litter, 5.0:1], Phytaboost Plant Food [crushed and pelletized soybean meal, 5.0:1]). A greenhouse study determined plant wheat (Triticum aestivum L.), kale (Brassica napus pabluaria DC), and velvetleaf (Abu- tilon theophrasti Medik.) growth response in soils …

Does Cover Crop Grazing Damage Soils And Reduce Crop Yields?, Humberto Blanco-Canqui, Mary E. Drewnoski, Jim C. Macdonald, Daren Redfearn, Jay Parsons, Gary W. Lesoing, Tyler Williams

Department of Agronomy and Horticulture: Faculty Publications

Cover crop (CC) grazing can be a potential strategy to support livestock and crop production while enhancing soil ecosystem services, but research on this potential multi-functionality of CCs is limited. We assessed 3-yr cereal rye (Secale cereale L.) CC grazing impacts on soil compaction, structure, water infiltration, fertility, and crop yields on an on-farm irrigated strip-till continuous corn (Zea mays L.) silage experiment on a sandy loam with <1% slope in west-central Nebraska. Treatments were: (a) non-grazed CC, (b) grazed CC, and (c) no CC. Across the 3 yr, cattle grazed CCs at 5.9 AUM ha−1 with grazing occurring over a 4-mo period during winter and/or spring, depending on the year. We measured soil properties within 5 d after grazing ended in spring before tilling and plant- ing corn. Cattle grazing resulted in a 92% decrease of CC biomass, compared with non-grazed CCs. Grazing did not affect soil penetration resistance (com- paction parameter), bulk density, aggregate stability, pH, and concentration of organic matter and nutrients except in the 2nd yr where it reduced cumulative infiltration by 80% and increased penetration resistance from 1.23 to 1.72 MPa but such increase was below root growth thresholds (<2 MPa). Cover crop grazing had no negative effect on corn silage yields although data were variable. Overall, CC grazing for 3 yr had small and variable effects on soils and crop yields, indi- cating that it can be a management option to support livestock production but more long-term data from different tillage and cropping systems, and climates are needed to further understand CC grazing implications.

A Systematic Review Of Durum Wheat: Enhancing Production Systems By Exploring Genotype, Environment, And Management (G × E × M) Synergies, Brian L. Beres, Elham Rahmani, John M. Clarke, Patricio Grassini, Curtis J. Pozniak, Cameron Guy Robinson Geddes, Kenton D. Porker, William E. May, Joel Ransom

Department of Agronomy and Horticulture: Faculty Publications

According to the UN-FAO, agricultural production must increase by 50% by 2050 to meet global demand for food. This goal can be accomplished, in part, by the development of improved cultivars coupled with modern best management practices. Overall, wheat production on farms will have to increase significantly to meet future demand, and in the face of a changing climate that poses risk to even current rates of production. Durum wheat [Triticum turgidum L. ssp. durum (Desf.)] is used largely for pasta, couscous and bulgur production. Durum producers face a range of factors spanning abiotic (frost damage, drought, and sprouting) and …

Genome Biology Of The Paleotetraploid Perennial Biomass Crop Miscanthus, Therese Mitros, Adam M. Session, Brandon T. James, Guohong Albert Wu, Katarzyna Glowacka, Kankshita Swaminathan, Daniel S. Rokhsar, 35 Additional Co-Authors

Department of Biochemistry: Faculty Publications

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. …

Transformative Education In Agroecology: Student, Teacher, And Client Involvement In Co-Learning, Charles A. Francis, Anna Marie Nicolaysen, Geir Lieblein, Tor Arvid Breland

Department of Agronomy and Horticulture: Faculty Publications

Educational methods have evolved rapidly in agroecology, which is a complex and holistic field without a long history or the formal tradition of any single academic discipline. Definitions of agroecology have evolved from its initial conception as a marriage of agriculture with ecology, to an aggregation of different paths including science, practices, and movements, and recently as a broad appreciation of the ecology of food systems. In contrast with traditional courses that begin with a history of the discipline and review the contributions of early leaders, we have embraced phenomenology to firmly establish roots in students’ learning through their experiences …

Training For Specialists Vs. Education For Agroecologists, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

I admit to being a slow learner. Graduate school training in agronomy at the University of California, Davis and in plant breeding at Cornell University provided me with top-quality opportunities to acquire the tools for crop improvement, plus the contacts to join professionals at the International Center for Tropical Agriculture in Colombia. As a young scientist dedicated to building on successes of the Green Revolution, I was convinced that genetic changes would solve global hunger. This had been amply demonstrated with the yield increases of wheat in Mexico and India, and with rice in Southeast Asia. Should this success not …

Validation Of Predictive Empirical Weed Emergence Models Of Abutilon Theophrasti Medik Based On Intercontinental Data, Valle Egea-Cobrero, Kevin Bradley, Isabel M. Calha, Adam S. Davis, Jose Dorado, Frank Forcella, John L. Lindquist, Christy L. Sprague, Jose L. Gonzalez-Andujar

Department of Agronomy and Horticulture: Faculty Publications

Good weed management relies on the proper timing of weed control practices in relation to weed emergence dynamics. Therefore, the development of models that predict the timing of emergence may help provide growers with tools to make better weed management decisions. The aim of this study was to validate and compare two previously published predictive empirical thermal time models of the emergence of Abutilon theophrasti growing in maize with data sets from the USA and Europe, and test the hypothesis that a robust and general weed emergence model can be developed for this species. Previously developed Weibull and Logistic models …