Agronomy and Crop Sciences Commons^™

A Non-Destructive Approach For Measuring Rice Panicle-Level Photosynthetic Responses Using 3d-Image Reconstruction, Jaspinder Singh Dharni, Balpreet Kaur Dhatt, Puneet Paul, Tian Gao, Tala Awada, Paul Staswick, Jason Hupp, Hongfeng Yu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Our understanding of the physiological response of rice inflorescence (panicle) to environmental stresses is limited by the challenge of accurately determining panicle photosynthetic parameters and their impact on grain yield. This is primarily due to lack of a suitable gas exchange methodology for panicles, as well as non-destructive methods to accurately determine panicle surface area. To address these challenges, we have developed a custom panicle gas exchange cylinder compatible with the LiCor 6800 Infra-red Gas Analyzer. Accurate surface area measurements were determined with a 3D panicle imaging platform to normalize the panicle-level photosynthetic measurements. We observed differential responses in both …

Identification Of Beneficial And Detrimental Bacteria Impacting Sorghum Responses To Drought Using Multi-Scale And Multisystem Microbiome Comparisons, Mingsheng Qi, Jeffrey C. Berry, Kira W. Veley, Lily O'Connor, Omri M. Finkel, Isai Salas-González, Molly Kuhs, Julietta Jupe, Emily Holcomb, Tijana Glavina Del Rio, Cody Creech, Peng Liu, Susannah G. Tringe, Jeffery L. Dangl, Daniel P. Schachtman, Rebecca S. Bart

Department of Agronomy and Horticulture: Faculty Publications

Drought is a major abiotic stress limiting agricultural productivity. Previous field-level experiments have demonstrated that drought decreases microbiome diversity in the root and rhizosphere. How these changes ultimately affect plant health remains elusive. Toward this end, we combined reductionist, transitional and ecological approaches, applied to the staple cereal crop sorghum to identify key root-associated microbes that robustly affect drought-stressed plant phenotypes. Fifty-three Arabidopsis-associated bacteria were applied to sorghum seeds and their effect on root growth was monitored. Two Arthrobacter strains caused root growth inhibition (RGI) in Arabidopsis and sorghum. In the context of synthetic communities, Variovorax strains were able to …

Evaluation Of Uav-Derived Multimodal Remote Sensing Data For Biomass Prediction And Drought Tolerance Assessment In Bioenergy Sorghum, Jiating Li, Daniel P. Schachtman, Cody F. Creech, Lin Wang, Yufeng Ge, Yeyin Shi

Department of Agronomy and Horticulture: Faculty Publications

Screening for drought tolerance is critical to ensure high biomass production of bioenergy sorghum in arid or semi-arid environments. The bottleneck in drought tolerance selection is the challenge of accurately predicting biomass for a large number of genotypes. Although biomass prediction by low-altitude remote sensing has been widely investigated on various crops, the performance of the predictions are not consistent, especially when applied in a breeding context with hundreds of genotypes. In some cases, biomass prediction of a large group of genotypes benefited from multimodal remote sensing data; while in other cases, the benefits were not obvious. In this study, …

Temporal Changes In The Nutrient Content Of Cattle Dung In The Nebraska Sandhills Ecosystem, Amanda Shine, Martha Mamo, Gandura O. Abagandura, Walter Schacht, Jerry Volesky

Department of Agronomy and Horticulture: Faculty Publications

Dung excreted by cattle composes a significant portion of the nutrient inputs in a grazed ecosystem and can have wide-ranging effects on soil properties and vegetation. However, little research has been conducted on the nutrient dynamics of excreted dung in situ that has not been disturbed prior to field sampling. In this study, we analyzed 294 dung pats (1–24 days old) collected from a Nebraska Sandhills meadow to determine water-extractable organic carbon (WEOC), water-extractable nitrogen (WEN), water-extractable phosphorus (WEP), and percent dry matter (DM) changes over time. In addition, we investigated if sample handling - frozen storage – and the …

Predicting Munsell Color For Turfgrass Leaves, William L. Berndt, Roch E. Gaussoin

Department of Agronomy and Horticulture: Faculty Publications

Linking turfgrass color to hue, value, chroma (H V/C) in the Munsell Plant Tissue Color Book is a visual comparison process for specifying and communicating plant color. If subjectivity of visual comparison can be mitigated, then accuracy of color matching may be improved. Research was conducted to develop an algorithm predicting H V/C from CIE-xyY color (xyY) in digital images of leaves of four turfgrasses. First, value-chroma (V/C) arrays for Munsell hue groups 5Y, 2.5GY, 5GY, 7.5GY, 10GY, and 2.5G were converted to xyY. Next, chromaticity (xy) plots from each array were fitted with …

4-Hydroxyphenylpyruvate Dioxygenase (Hppd)-Inhibiting Herbicides: Past, Present, And Future, Amit J. Jhala, Vipan Kumar, Ramawatar Yadav, Prashant Jha, Mithila Jugulam5, Martin M. Williams Ii, Nicholas E. Hausman, Franck E. Dayan, Paul M. Burton, Richard P. Dale, Jason K. Norsworthy

Department of Agronomy and Horticulture: Faculty Publications

The 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides are primarily used for weed control in corn, barley, oat, rice, sorghum, sugarcane, and wheat production fields in the United States. The objectives of this review were to summarize (1) the history of HPPD-inhibitor and their use in the United States, (2) HPPD-inhibitor resistant weeds, their mechanism of resistance, and management, (3) interaction of HPPD-inhibitor with other herbicides, and (4) the future of HPPD-inhibitor-resistant crops. As of 2022, three broadleaf weeds (Palmer amaranth, waterhemp, and wild radish) have evolved resistance to the HPPD-inhibitor. The predominance of metabolic resistance to HPPD-inhibitor was found in aforementioned three …

Limited Irrigation For Managing Declining Water Resources In The Us High Plains, Bijesh Maharjan, Gary Hergert, Saurav Das

Department of Agronomy and Horticulture: Faculty Publications

The US High Plains region has a semiarid climate receiving between 330 and 455 mm of rainfall annually. In the Nebraska Panhandle of the High Plains, 30-year average rainfall is 394 mm, and one-fourth of agriculture is under irrigation. In addition to concerns about water quality, there is a growing concern over water quantity for ground- and surface-water resources that producers use for irrigation. Wisely managing limited water resources for irrigation can help maintain crop productivity and profitability. Deficit irrigation research for 13 years (2005–2017) was conducted in the Nebraska Panhandle to study effects of limited irrigation on maize ( …

Charles A. Francis, Abstracts And Publications [1969--2022], December 2022, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Contents

I. Journal articles (218), p.1

II. Book reviews (60), p. 18

III. Published abstracts (213), p. 23

IV. Books (23), p. 40

V. Chapters in books (81), p. 42

VI. Symposium or workshop proceedings (127), p. 50

VII. Symposia or extension publications edited (31), p. 62

VIII. Miscellaneous (522), p. 65

Getting To The Root Cause: The Genetic Underpinnings Of Root System Architecture And Rhizodeposition In Sorghum, Farren Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Plants are some of the most diverse organisms on earth, consisting of more than 350,000 different species. To understand the underlying processes that contributed to plant diversification, it is fundamental to identify the genetic and genomic components that facilitated various adaptations over evolutionary history. Most studies to date have focused on the underlying controls of above-ground traits such as grain and vegetation; however, little is known about the “hidden half” of plants. Root systems comprise half of the total plant structure and provide vital functions such as anchorage, resource acquisition, and storage of energy reserves. The execution of these key …

Domestication Reshaped The Genetic Basis Of Inbreeding Depression In A Maize Landrace Compared To Its Wild Relative, Teosinte, Luis Fernando Samayoa, Bode A. Olukolu, Chin Jian Yang, Qiuyue Chen, Markus G. Stetter, Alessandra M. York, Jose De Jesus Sanchez-Gonzalez, Jeffrey C. Glaubitz, Peter J. Bradbury, Maria Cinta Romay, Qi Sun, Jinliang Yang, Jeffrey Ross-Ibarra, Edward S. Buckler, John F. Doebley, James B. Holland

Department of Agronomy and Horticulture: Faculty Publications

Inbreeding depression is the reduction in fitness and vigor resulting from mating of close relatives observed in many plant and animal species. The extent to which the genetic load of mutations contributing to inbreeding depression is due to large-effect mutations versus variants with very small individual effects is unknown and may be affected by population history. We compared the effects of outcrossing and self-fertilization on 18 traits in a landrace population of maize, which underwent a population bottleneck during domestication, and a neighboring population of its wild relative teosinte. Inbreeding depression was greater in maize than teosinte for 15 of …

Identification Of Candidate Genes And Genomic Regions Associated With Adult Plant Resistance To Stripe Rust In Spring Wheat, Amira M. I. Mourad, Mohamed A. Abou-Zeid, Shamseldeen Eltaher, P. Stephen Baenziger, Andreas Börner

Department of Agronomy and Horticulture: Faculty Publications

Wheat stripe rust (caused by Puccinia striiformis f. sp. tritici) is a major disease that damages wheat plants and affects wheat yield all over the world. In recent years, stripe rust became a major problem that affects wheat yield in Egypt. New races appeared and caused breakdowns in the resistant genotypes. To improve resistance in the Egyptian genotypes, new sources of resistance are urgently needed. In the recent research, a set of 95 wheat genotypes collected from 19 countries, including Egypt, were evaluated for their resistance against the Egyptian race(s) of stripe rust under field conditions in the two …

Relationships Among College-Level Science Course Enrollment, Environmental Perception, And Pro-Environmental Attitude: Evidence From The Us General Social Survey, Mazbahul G. Ahamad, Fahian Tanin

Department of Agronomy and Horticulture: Faculty Publications

Understanding pro-environmental attitudes is critical to encouraging pollution-minimizing behaviors. Therefore, identifying associated factors is essential for understanding different types of pro-environmental attitudes. We aimed to investigate the associations among individuals’ college-level science course enrollment and their perceptions of the level of spending to improve and protect the environment, as well as their pro-environmental attitudes. We used nationwide population-based cross-sectional survey data from 2,348 individuals obtained from the General Social Survey in the United States. An ordered logistic model was used to examine the associations among college-level science course enrollment, environmental perception, and pro-environmental attitude. We found that science course enrollment …

Cold Conditioned: Discovery Of Novel Alleles For Low-Temperature Tolerance In The Vavilov Barley Collection, Ahmad H. Sallam, Kevin P. Smith, Gongshe Hu, Jamie Sherman, Peter Stephen Baeziger, Jochum Wiersma, Carl Duley, Eric J. Stockinger, Mark E. Sorrells, Tamas Szinyei, Igor G. Loskutov, Olga N. Kovaleva, Jed Eberly, Brian J. Steffenson

Department of Agronomy and Horticulture: Faculty Publications

Climate changes leading to higher summer temperatures can adversely affect cool season crops like spring barley. In the Upper Midwest region of the United States, one option for escaping this stress factor is to plant winter or facultative type cultivars in the autumn and then harvest in early summer before the onset of high-temperature stress. However, the major challenge in breeding such cultivars is incorporating sufficient winter hardiness to survive the extremely low temperatures that commonly occur in this production region. To broaden the genetic base for winter hardiness in the University of Minnesota breeding program, 2,214 accessions from the …

Sustainable Intensification For A Larger Global Rice Bowl, Shen Yuan, Bruce A. Linquist, Lloyd T. Wilson, Kenneth G. Cassman, Alexander M. Stuart, Valerien Pede, Berta Miro, Kazuki Saito, Nurwulan Agustiani, Vina Eka Aristya, Leonardus Y. Krisnadi, Alencar Junior Zanon, Alexandre Bryan Heinemann, Gonzalo Carracelas, Nataraja Subash, Pathula S. Brahmanand, Tao Li, Shaobing Peng, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Future rice systems must produce more grain while minimizing the negative environmental impacts. A key question is how to orient agricultural research & development (R&D) programs at national to global scales to maximize the return on investment. Here we assess yield gap and resource-use efficiency (including water, pesticides, nitrogen, labor, energy, and associated global warming potential) across 32 rice cropping systems covering half of global rice harvested area. We show that achieving high yields and high resource-use efficiencies are not conflicting goals. Most cropping systems have room for increasing yield, resource-use efficiency, or both. In aggregate, current total rice production …

Climate And Agronomy, Not Genetics, Underpin Recent Maize Yield Gains In Favorable Environments, Gonzalo Rizzo, Juan Pablo Monzon, Fatima Amor Tenorio, Réka Howard, Kenneth G. Cassman, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Quantitative understanding of factors driving yield increases of major food crops is essential for effective prioritization of research and development. Yet previous estimates had limitations in distinguishing among contributing factors such as changing climate and new agronomic and genetic technologies. Here, we distinguished the separate contribution of these factors to yield advance using an extensive database collected from the largest irrigated maize-production domain in the world located in Nebraska (United States) during the 2005-to-2018 period. We found that 48% of the yield gain was associated with a decadal climate trend, 39% with agronomic improvements, and, by difference, only 13% with …

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison K. Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

Livestock Grazing Impacts On Crop And Soil Responses For Two Cropping Systems, Alyssa Kuhn

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Diversified crop, forage, and livestock systems are assumed to be more sustainable and economically competitive than traditional cropping systems. Objectives of this study were to determine effects of integrating grazing livestock into corn (Zea mays)-soybean (Glycine max (L.) Merr.) (C-S) and corn-soybean-wheat (Triticum aestivum L.) (C-S-W) cropping systems on plant population, grain yield, soil nutrients and soil carbon dioxide (CO₂) flux following winter grazing corn residue (both systems) and an oat (Avena sativa) cover crop (C-S-W only) planted after wheat. For the 2019 and 2020 production seasons, neither corn nor soybean plant …

A Method For Visualizing Water Flow Through Modified Root Zones, Dallas M. Williams

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

As the number of impervious surfaces in urban environments increases, the ability of modified root zones to infiltrate water is becoming more important. Current methods of tracing water flow through soil profiles include excavating large pits in situ or analyzing soil cores in the laboratory with computed tomography or magnetic resonance imaging. While useful, these methods may not be suitable for urban settings or practical in every laboratory. We propose a new method that is less invasive, does not require extensive technical equipment and can reliably trace water movement through the soil profile in order to calculate flow rate based …

Arkansas Corn And Grain Sorghum Performance Tests 2021, J. F. Carlin, R. B. Morgan, R. D. Bond

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2021 corn performance tests contained 70 hybrids and were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Bell Farming Company (BFC) near Des Arc, the Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. The …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Seeding Rate Effects On Forage Mass And Vegetation Dynamics Of Cool-Season Grass Sod Interseeded With Sorghum-Sudangrass, John A. Guretzky, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor x S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 …

Impact Of Urbanization Trends On Production Of Key Staple Crops, José F. Andrade, Kenneth G. Cassman, Juan I. Rattalino Edreira, Fahmuddin Agus, Abdullahi Bala, Nanyan Deng, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Urbanization has appropriated millions of hectares of cropland, and this trend will persist as cities continue to expand. We estimate the impact of this conversion as the amount of land needed elsewhere to give the same yield potential as determined by differences in climate and soil properties. Robust spatial upscaling techniques, well-validated crop simulation models, and soil, climate, and cropping system databases are employed with a focus on populous countries with high rates of land conversion. We find that converted cropland is 30–40% more productive than new cropland, which means that projection of food production potential must account for expected …

Influence Of Surfactant-Humectant Adjuvants On Physical Properties, Droplet Size, And Efficacy Of Glufosinate Formulations, Estefania G. Polli, Guilherme S. Alves, Jesaelen Gizotti De Moraes, Greg Robert Kruger

Department of Agronomy and Horticulture: Faculty Publications

Glufosinate efficacy is inconsistent among weed species and under environmental conditions that favor rapid droplet drying. Surfactant-humectant adjuvants could maximize glufosinate efficacy by increasing wetting and penetration into the leaf surface while decreasing evaporation rate (ER). However, there is a lack of information in the literature about the interaction of surfactant-humectants adjuvants with glufosinate. The objective of this study was to investigate the influence of surfactanthumectant adjuvants on the physical properties, droplet size, and efficacy of two glufosinate formulations. Laboratory, greenhouse, and field studies were conducted at the Pesticide Application Technology Laboratory of the University of Nebraska- Lincoln. Treatment design …

Prosopis Glandulosa Persistence Is Facilitated By Differential Protection Of Buds During Low- And High-Energy Fires, Heath D. Starns, Carissa L. Wonkka, Matthew B. Dickinson, Alexandra G. Lodge, Morgan L. Treadwell, Kathleen L. Kavanagh, Douglas R. Tolleson, Dirac L. Twidwell Jr, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

Rangelands worldwide have experienced significant shifts from grass-dominated to woody-plant dominated states over the past century. In North America, these shifts are largely driven by overgrazing and landscape-scale fire suppression. Such shifts reduce productivity for livestock, can have broad-scale impacts to biodiversity, and are often difficult to reverse. Restoring grass dominance often involves restoring fire as an ecological process. However, many resprouting woody plants persist following disturbance, including fire, by resprouting from protected buds, rendering fire ineffective for reducing resprouting woody plant density. Recent research has shown that extreme fire (high-energy fires during periods of water stress) may reduce resprouting …

Genome-Wide Dna Polymorphism Analysis And Molecular Marker Development For The Setaria Italica Variety “Ssr41” And Positional Cloning Of The Setaria White Leaf Sheath Gene Siwls1, Hui Zhang, Sha Tang, James C. Schnable, Qiang He, Yuanzhu Gao, Mingzhao Luo, Guanqing Jia, Baili Feng, Hui Zhi, Xianmin Diao

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide DNA polymorphism analysis and molecular marker development are important for forward genetics research and DNA marker-assisted breeding. As an ideal model system for Panicoideae grasses and an important minor crop in East Asia, foxtail millet (Setaria italica) has a high-quality reference genome as well as large mutant libraries based on the “Yugu1” variety. However, there is still a lack of genetic and mutation mapping tools available for forward genetics research on S. italica. Here, we screened another S. italica genotype, “SSR41”, which is morphologically similar to, and readily cross-pollinates with, “Yugu1”. High-throughput resequencing of “SSR41” …

A Chickpea Genetic Variation Map Based On The Sequencing Of 3,366 Genomes, Rajeev K. Varshney, Manish Roorkiwal, Shuai Sun, Prasad Bajaj, Annapurna Chitikineni, Mahendar Thudi, Narendra P. Singh, Xiao Du, Hari D. Upadhyaya, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

Zero hunger and good health could be realized by 2030 through effective conservation, characterization and utilization of germplasm resources1 . So far, few chickpea (Cicerarietinum) germplasm accessions have been characterized at the genome sequence level2 . Here we present a detailed map of variation in 3,171 cultivated and 195 wild accessions to provide publicly available resources for chickpea genomics research and breeding. We constructed a chickpea pan-genome to describe genomic diversity across cultivated chickpea and its wild progenitor accessions. A divergence tree using genes present in around 80% of individuals in one species allowed us to estimate the divergence of …

University Research On Winter Growing Of Container-Grown Strawberries Translates To Grower's Farm Trial, Stacy A. Adams, Ellen T. Paparozzi, Ryan Pekarek, Dave P. Lambe, George Meyer, M. Elizabeth Conley, Paul Read

Department of Agronomy and Horticulture: Faculty Publications

Strawberries are only seasonally available in Nebraska (NE). If an affordable heated structure can be designed, then opportunity exists to increase on-farm income by producing strawberries off-season during high-value market periods. A series of university greenhouse trials were conducted from 2010 to 2012. The varieties Evie-2 and Seascape were identified as being most productive under a low technology growing scheme. A new research project, which ran from fall to late spring (2013–2014), was designed to determine if this production scheme would translate to a commercial grower. Varieties Seascape and Evie-2 (each at two grades indicated by +) and San Andreas …

Control Of Acetolactate Synthase Inhibitor/Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Isoxaflutole/Glufosinate/Glyphosate-Resistant Soybean, Jasmine Mausbach, Suat Irmak, Debalin Sarangi, John L. Lindquist, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Palmer amaranth is the most problematic and troublesome weed in agronomic cropping systems in the United States. Acetolactate synthase (ALS) inhibitor and glyphosate-resistant (GR) Palmer amaranth has been confirmed in Nebraska and it is widespread in several counties. Soybean resistant to isoxaflutole/glufosinate/glyphosate has been developed that provides additional herbicide site of action for control of herbicide-resistant weeds. The objectives of this study were to evaluate herbicide programs for control of ALS inhibitor/GR Palmer amaranth and their effect on Palmer amaranth density and biomass, as well as soybean injury and yield in isoxaflutole/glufosinate/glyphosate-resistant soybean. Field experiments were conducted in a grower's …

Identification And Validation Of High Ld Hotspot Genomic Regions Harboring Stem Rust Resistant Genes On 1b, 2a (Sr38), And 7b Chromosomes In Wheat, Shamseldeen Eltaher, Amira M.I. Mourad, P Stephen Baenziger, Stephen Wegulo, Vikas Belamkar, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Stem rust caused by Puccinia graminis f. sp. tritici Eriks. is an important disease of common wheat globally. The production and cultivation of genetically resistant cultivars are one of the most successful and environmentally friendly ways to protect wheat against fungal pathogens. Seedling screening and genome-wide association study (GWAS) were used to determine the genetic diversity of wheat genotypes obtained on stem rust resistance loci. At the seedling stage, the reaction of the common stem rust race QFCSC in Nebraska was measured in a set of 212 genotypes from F3:6 lines. The results indicated that 184 genotypes (86.8%) had different …

Spatial Frameworks For Robust Estimation Of Yield Gaps, Juan I. Rattalino Edreira, José F. Andrade, Kenneth G. Cassman, Martin K. Ittersum, Marloes P. Van Loon, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Food security interventions and policies need reliable estimates of crop production and the scope to enhance production on existing cropland. Here we assess the performance of two widely used ‘top-down’ gridded frameworks (Global Agro-ecological Zones and Agricultural Model Intercomparison and Improvement Project) versus an alternative ‘bottom-up’ approach (Global Yield Gap Atlas). The Global Yield Gap Atlas estimates extra production potential locally for a number of sites representing major breadbaskets and then upscales the results to larger spatial scales. We find that estimates from top-down frameworks are alarmingly unlikely, with estimated potential production being lower than current farm production at some …