Plant Biology Commons^™

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 …

Solar Dimming Decreased Maize Yield Potential On The North China Plain, Qingfeng Meng, Baohua Liu, Haishun Yang, Xinping Chen

Department of Agronomy and Horticulture: Faculty Publications

Solar dimming has been increasing in rapidly developing regions (China and India) and threatening food security. Although previous studies have summarized the ef- fects of climate change-associated increases in temperature on agriculture, few have examined the effects due to solar dimming. Here, we analyzed the effects of solar dimming on maize on the North China Plain (NCP). It is reported that solar dimming intensified and maize yield potential decreased since the 1960s. The total decrease in solar radiation for the whole maize growing season of this period was 17%, and solar dimming explained 87% of the decrease in yield potential. …

Management Strategies For Early- And Late-Planted Soybean In The North-Central United States, Emma G. Matcham, Spyridon Mourtzinis, Shawn P. Colney, Juan I. Rattalino Edreira, Patricio Grassini, Adam C. Roth, Shaun N. Casteel, Igancio A. Ciampitti, Hans J. Kandel, Peter M. Kyveryga, Mark A. Licht, Daren S. Mueller, Emerson Nafziger, Seth Naeve, Jordan D. Stanley, Michael J. Staton, Laura E. Lindsey

Department of Agronomy and Horticulture: Faculty Publications

It is widely recognized that planting soybean [Glycine max (L.) Merr.] early is critical to maximizing yield, but the influence of changing management factors when soybean planting is delayed is not well understood. The objectives of this research were to (a) identify management decisions that increase seed yield in either early- or late-planted soybean scenarios, and (b) estimate the maximum break-even price of each management factor identified to influence soybean seed yield in early- or late-planted soybean. Producer data on seed yield and management decisions were collected from 5682 fields planted with soybean during 2014−2016 and grouped into 10 technology …

Calibrating Soybean Parameters In Jules 5.0 From The Us-Ne2/3 Fluxnet Sites And The Soyface-O3 Experiment, Felix Leung, Karina Williams, Stephen Sitch, Amos P.K. Tai, Andy Wiltshire, Jemma Gornall, Elizabeth A. Ainsworth, Timothy J. Arkebauer, David Scoby

Department of Agronomy and Horticulture: Faculty Publications

Abstract. Tropospheric ozone (O3) is the third most important anthropogenic greenhouse gas. O3 is detrimental to plant productivity, and it has a significant impact on crop yield. Currently, the Joint UK Land Environment Simula- tor (JULES) land surface model includes a representation of global crops (JULES-crop) but does not have crop-specific O3 damage parameters and applies default C3 grass O3 pa- rameters for soybean that underestimate O3 damage. Physiological parameters for O3 damage in soybean in JULES- crop were calibrated against leaf gas-exchange measure- ments from the Soybean Free Air Concentration Enrichment (SoyFACE) with O3 experiment in Illinois, USA. Other …

Insufficient Nitrogen Supply From Symbiotic Fixation Reduces Seasonal Crop Growth And Nitrogen Mobilization To Seed In Highly Productive Soybean Crops, Nicolas Cafaro La Menza, Juan Pablo Monzon, John L. Lindquist, Timothy J. Arkebauer, Johannes M.H. Knops, Murray Unkovich, James E. Specht, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) supply can limit the yields of soybean [Glycine max (L.) Merr.] in highly productive environments. To explore the physiological mechanisms underlying this limitation, seasonal changes in N dynamics, aboveground dry matter (ADM) accumula- tion, leaf area index (LAI) and fraction of absorbed radiation (fAPAR) were compared in crops relying only on biological N2 fixation and available soil N (zero-N treatment) versus crops receiving N fertilizer (full-N treatment). Experiments were conducted in seven high-yield environments without water limitation, where crops received optimal management. In the zero-N treatment, biological N2 fixation was not sufficient to meet the N demand of …

Seeding Rates And Productivity Of Broadcast Interseeded Cover Crops, Katja Koehler-Cole, Roger W. Elmore

Department of Agronomy and Horticulture: Faculty Publications

Broadcast interseeding cover crops into corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) instead of drill-planting after harvest extends the cover crop season and improves productivity, but establishment can be insufficient. Our objectives were to find broadcast seeding rates that result in maximum spring biomass and N uptake. We tested cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) in south-central and eastern Nebraska in 2016–2017 and 2017–2018. Seeding rates for rye were 341, 512, and 682 seeds·m−2, and 119, 178, and 238 seeds·m−2 for vetch. We broadcast in late September and terminated by early May. …

Winter Wheat Residue Impact On Soil Water Storage And Subsequent Corn Yield, Luana Machado Simão, Amanda Easterly, Greg Kruger, Cody Creech

Department of Agronomy and Horticulture: Faculty Publications

Standing winter wheat (Triticum aestivum L.) residue can capture snow, reduce soil erosion and water evaporation, and increase crop yields in semi-arid environments. Solid-stemmed winter wheat (SSWW) varieties may remain standing longer in the field; however, SSWW consistently yields less than conventional hollow-stemmed winter wheat (HSWW). This research investigates if the negative economic impact of yield loss of SSWW may be overcome by increasing the subsequent corn (Zea mays L.) yield due to increased snow capture and soil moisture. The experiment covered two cycles of a wheat–corn–fallow rotation in two separate fields between 2016 and 2019 near Sidney, NE. …

Improvement Of Smallholder Farming Systems In Africa, Charles S. Wortmann, Tilahun Amede, Mateete Bekunda, Keziah Ndung’U-Magiroi, Patricia Masikati, Sieglinde S. Snapp, Zachary P. Stewart, Mark Westgate, Zacarie Zida, Charles E. Kome

Department of Agronomy and Horticulture: Faculty Publications

This forum paper provides a synthesis and discussion of 14 categories of lessons learned from experiences for achieving farm-level impact with smallholder farm- ers in Africa. These lessons were reported in a symposium hosted by the Agron- omy in Africa community of the American Society of Agronomy. The lessons, listed in order of frequency of reporting, were the need to: have adequate infras- tructure and services; enable spontaneous adoption; have multi-disciplinary and institutional collaboration; build on previous adoption of good agronomic practices (GAP); have farmer participation in research; encourage and learn from smallholder adaptations; make GAP promotion demand-driven; allow GAP …

Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens And Induce Growth Promotion In Tomato, Serkan Tokgöz, Dilip K. Lakshman, Mahmoud H. Ghozlan, Hasan Pinar, Daniel P. Roberts, Amitava Mitra

Department of Agronomy and Horticulture: Faculty Publications

The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered diverse groups of bacteria within the legume nodules. In this report soybean nodule-associated bacteria were studied in an effort to identify beneficial bacteria for plant disease control and growth promotion. Analysis of surface-sterilized single nodules showed bacterial diversity of the nodule microbiome. Five hundred non-rhizobial colonies from 10 nodules, 50 colonies per nodule, were tested individually against the tomato …

Foliar Micronutrient Application For High-Yield Maize, Zachary P. Stewart, Ellen T. Paparozzi, Charles S. Wortmann, Prakash Kumar Jha, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

Nebraska soils are generally micronutrient sufficient. However, critical levels for current yields have not been validated. From 2013 to 2015, 26 on-farm paired comparison strip-trials were conducted across Nebraska to test the effect of foliar-applied micronutrients on maize (Zea mays L.) yield and foliar nutrient concentrations. Treatments were applied from V6 to V14 at sites with 10.9 to 16.4 Mg ha−1 yield. Soils ranged from silty clays to fine sands. Soil micronutrient availability and tissue concentrations were all above critical levels for deficiency. Significant grain yield increases were few. Micronutrient concentrations for leaf growth that occurred after foliar applications were …

Estimating Economic Minimums Of Mowing, Fertilizing, And Irrigating Turfgrass, Douglas J. Soldat, James T. Brosnan, Ambika Chandra, Roch E. Gaussoin, Alec Kowalewski, Bernd Leinauer, Frank S. Rossi, John C. Stier, J. Bryan Unruh

Department of Agronomy and Horticulture: Faculty Publications

The public health crisis and economic recession caused by the COVID-19 pandemic have forced turfgrass industry professionals to re-evaluate standard practices. Minimum costs required to fertilize, irrigate, and mow turfgrasses can be roughly estimated using climate data, turfgrass physiology information, and resource costs. Although the actual minimum costs vary situationally and regionally, mowing golf putting greens optimally requires about US$34 per acre per month, whereas other turfgrass areas cost less than US$11 per acre per growing month. Fertilizer applications to turfgrass cost US$22 or less per acre per growing month. Irrigation costs (water and electricity for pumping) vary widely, with …

Continuous Cropping Alters Multiple Biotic And Abiotic Indicators Of Soil Health, Pervaiz Ahmad, Javed Iqbal, Qingming Zhang, Dima Chen, Hui Wei, Muhammad Saleem

Department of Agronomy and Horticulture: Faculty Publications

The continuous cropping (CC) of major agricultural, horticultural, and industrial crops is an established practice worldwide, though it has significant soil health-related concerns. However, a combined review of the effects of CC on soil health indicators, in particular omics ones, remains missing. The CC may negatively impact multiple biotic and abiotic indicators of soil health, fertility, and crop yield. It could potentially alter the soil biotic indicators, which include but are not limited to the composition, abundance, diversity, and functioning of soil micro- and macro-organisms, microbial networks, enzyme activities, and soil food web interactions. Moreover, it could also alter various …

Use Of Family Structure Information In Interaction With Environments For Leveraging Genomic Prediction Models, Reyna Persa, Hiroyoshi Iwata, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

The characterization of genomes with great detail offered by the modern genotyping platforms have opened a venue for accurately predicting the genotype-by-environment interaction (GE) effects of untested genotypes in different environmental conditions. Already developed statistical models have shown the advantages of including the GE interaction component in the prediction context using molecular markers, pedigree, or both. In order to leverage the family information of highly structured populations when pedigree data is not available, we developed a model that uses the family membership instead. The proposed model extends the reaction norm model by including the interaction between families and environments (FE). …

Coal Char Affects Soil Ph To Reduce Ammonia Volatilization From Sandy Loam Soil, Dinesh Panday, Maysoon M. Mikha, Bijesh Maharjan

Department of Agronomy and Horticulture: Faculty Publications

Ammonia (NH3) volatilization loss adversely affects N availability in soil-plant systems, reduces crop yield, and negatively impacts environment. Char (coal combus- tion residue), which contains up to 293 g kg−1 total C by weight, has been shown to reduce NH3 volatilization due to its considerably high surface area and cation exchange capacity. The NH3 loss can be greatly affected by a shift in soil pH or urea hydrolysis. A 21-d laboratory study was conducted to evaluate the effects of char on soil pH, N transformations, and subsequent NH3 volatilization in sandy loam soil. Two char rates (0 and 13.4 Mg …

Isoseq Transcriptome Assembly Of C3 Panicoid Grasses Provides Tools To Study Evolutionary Change In The Panicoideae, Daniel S. Carvalho, Aime Nishimwe, James Schnable

Department of Agronomy and Horticulture: Faculty Publications

The number of plant species with genomic and transcriptomic data has been increasing rapidly. The grasses—Poaceae—have been well represented among species with published reference genomes. However, as a result the genomes of wild grasses are less frequently targeted by sequencing efforts. Sequence data from wild relatives of crop species in the grasses can aid the study of domestication, gene discovery for breeding and crop improvement, and improve our understanding of the evolution of C₄ photosynthesis. Here, we used long-read sequencing technology to characterize the transcriptomes of three C₃ panicoid grass species: Dichanthelium oligosanthes, Chasmanthium laxum, and …

Adjusting Corn Nitrogen Management By Including A Mineralizable-Nitrogen Test With The Preplant And Presidedress Nitrate Tests, Jason Clark, Fabián G. Fernández, Kristen S. Veum, James J. Camberato, Paul R. Carter, Richard Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, C. A.M. Laboski, Emerson Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

The anaerobic potentially mineralizable N (PMN) test combined with the preplant (PPNT) and presidedress (PSNT) nitrate tests may improve corn (Zea mays L.) N fertilization predictions. Forty-nine corn N response experiments (mostly corn following soybean [Glycine max (L.) Merr.]) were conducted in the U.S. Midwest from 2014–2016 to evaluate the ability of the PPNT and PSNT to predict corn relative yield (RY) and N fertilizer over- and under-application rates when adjusted by PMN. Before planting and N fertilization, PPNT (0–30, 30–60, and 60–90 cm) and PMN (0–30 cm) samples were obtained. In-season soil samples were obtained at the …

Relating Four-Day Soil Respiration To Corn Nitrogen Fertilizer Needs Across 49 U.S. Midwest Fields, G. M. Bean, Newell R. Kitchen, Kristen S. Veum, James J. Camberato, Richard Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A.M. Laboski, Emerson Nafziger, John E. Sawyer, Matt Yost

Department of Agronomy and Horticulture: Faculty Publications

Soil microbes drive biological functions thatmediate chemical and physical processes necessary for plants to sustain growth. Laboratory soil respiration has been proposed as one universal soil health indicator representing these functions, potentially informing crop and soil management decisions. Research is needed to test the premise that soil respiration is helpful for profitable in-season nitrogen (N) rate management decisions in corn (Zea mays L.). The objective of this research was two-fold: (i) determine if the amount of N applied at the time of planting effected soil respiration, and (ii) evaluate the relationship of soil respiration to corn yield response to …

Adding A Late Fall Application Of Proxy (Ethephon) Before Two Traditional Spring Applications Improves Seedhead Control Of Annual Bluegrass, Zachary Reicher, Matthew Sousek, Aaron J. Patton, Adam Van Dyke, William C. Kreuser, John C. Inguagiato, Kevin M. Miele, John Brewer, Shawn D. Askew, Aaron Hathaway, Thomas A. Nikolai, Alec Kowalewski, Brian Mcdonald

Department of Agronomy and Horticulture: Faculty Publications

Annual bluegrass (ABG) (Poa annua L.) is a prolific seed producer in the spring on golf courses that in turn decreases aesthetic quality and trueness of ball roll on coolseason putting greens. Proxy (ethephon) applied twice in the spring after green-up is the current industry standard after the loss of Embark (mefluidide) from the turf and ornamental market. However, plant growth regulators including Proxy have been used for years to help suppressABGseedheads with inconsistent success. The primary objective of this study was to determine if ABG seedhead suppression is improved by adding a late fall application of Proxy to …

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 …

Do Coffee Agroforestry Systems Always Improve Soil Carbon Stocks Deeper In The Soil?—A Case Study From Turrialba, Costa Rica, Nilovna Chatterjee, P. K. Ramachandran Nair, Vimala D. Nair, Abhishek Bhattacharjee, Elias De Melo Virginio Filho, Rheinhold G. Muschler, Martin R.A. Noponen

Department of Agronomy and Horticulture: Faculty Publications

Shaded perennial agroforestry systems (AFS) are regarded as desirable land‐use practices that improve soil carbon sequestration. However, most studies assume a positive correlation between above ground and below ground carbon without considering the effect of past and current land management, textural variations (silt and clay percentage), and such other site‐specific factors that have a major influence on the extent of soil C sequestration. We assessed SOC stock at various depths (0–10, 10–30, 30–60, and 60–100 cm) in shaded perennial coffee (Coffea arabica L.) AFS in a 17‐ year‐old experimental field at the Centro Agronómico Tropical de Investigación y Enseñanza, (9°53′44′′ …

Pi‑Plat: A High‑Resolution Image‑Based 3d Reconstruction Method To Estimate Growth Dynamics Of Rice Inflorescence Traits, Jaspreet Sandhu, Feiyu Zhu, Puneet Paul, Tian Gao, Balpreet K. Dhatt, Yufeng Ge, Paul E. Staswick, Hongfeng Yu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Background: Recent advances in image-based plant phenotyping have improved our capability to study vegetative stage growth dynamics. However, more complex agronomic traits such as inflorescence architecture (IA), which predominantly contributes to grain crop yield are more challenging to quantify and hence are relatively less explored. Previous efforts to estimate inflorescence-related traits using image-based phenotyping have been limited to destructive end-point measurements. Development of non-destructive inflorescence phenotyping platforms could accelerate the discovery of the phenotypic variation with respect to inflorescence dynamics and mapping of the underlying genes regulating critical yield components.

Results: The major objective of this study is to evaluate …

Divergent Phenotypic Response Of Rice Accessions To Transient Heat Stress During Early Seed Development, Puneet Paul, Balpreet K. Dhatt, Jaspreet Sandhu, Waseem Hussain, Larissa Irvin, Gota Morota, Paul E. Staswick, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Increasing global surface temperatures is posing a major food security challenge. Part of the solution to address this problem is to improve crop heat resilience, especially during grain development, along with agronomic decisions such as shift in planting time and increasing crop diversification. Rice is a major food crop consumed by more than 3 billion people. For rice, thermal sensitivity of reproductive development and grain filling is well-documented, while knowledge concerning the impact of heat stress (HS) on early seed development is limited. Here, we aim to study the phenotypic variation in a set of diverse rice accessions for elucidating …

Deep Kernel And Deep Learning For Genome-Based Prediction Of Single Traits In Multienvironment Breeding Trials, José Crossa, Johannes W.R. Martini, Daniel Gianola, Paulino Pérez-Rodríguez, Diego Jarquin, Philomin Juliana, Osval Antonio Montesinos López, Jaime Cuevas

Department of Agronomy and Horticulture: Faculty Publications

Deep learning (DL) is a promising method for genomic-enabled prediction. However, the implementation of DL is difficult because many hyperparameters (number of hidden layers, number of neurons, learning rate, number of epochs, batch size, etc.) need to be tuned. For this reason, deep kernel methods, which only require defining the number of layers, may be an attractive alternative. Deep kernel methods emulate DL models with a large number of neurons, but are defined by relatively easily computed covariance matrices. In this research, we compared the genome-based prediction of DL to a deep kernel (arc-cosine kernel, AK), to the commonly used …

Plant Hormones Differentially Control The Sub-Cellular Localization Of Plasma Membrane Microdomains During The Early Stage Of Soybean Nodulation, Zhenzhen Qiao, Prince Zogli, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Phytohormones regulate the mutualistic symbiotic interaction between legumes and rhizobia, nitrogen-fixing soil bacteria, notably by controlling the formation of the infection thread in the root hair (RH). At the cellular level, the formation of the infection thread is promoted by the translocation of plasma membrane microdomains at the tip of the RH. We hypothesize that phytohormones regulate the translocation of plasma membrane microdomains to regulate infection thread formation. Accordingly, we treated with hormone and hormone inhibitors transgenic soybean roots expressing fusions between the Green Fluorescent Protein (GFP) and GmFWL1 or GmFLOT2/4, two microdomain-associated proteins translocated at the tip of the …

Integration Of Cover Crops Into Midwest Corn-Soybean Cropping Systems And Potential For Weed Suppression, Joshua S. Wehrbein

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

Cover crops have potential to provide benefits to agricultural systems, such as improved soil productivity, nutrient scavenging, weed suppression, and livestock forage. There are several challenges associated with cover crop integration into traditional Midwest corn-soybean cropping systems. One of these challenges is timely establishment in the fall, which is limited by the relatively late harvest of corn and soybean. Cover crop effectiveness is related to the amount of biomass produced, thus maximizing the growth period in the fall is desired. To address this challenge, we evaluated the potential to utilize early-season soybean maturity groups (MGs) to allow for earlier soybean …

Critical Time For Weed Removal In Corn (Zea Mays L.) As Influenced By Pre Herbicides, Ayse Nur Ulusoy

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

A weed control program that utilizes PRE herbicides and ensures a timely post-emergence weed removal could protect growth and yield of corn. The use of pre-emergence (PRE) herbicides for weed control could reduce the need for multiple POST applications of glyphosate in glyphosate-tolerant (GT) corn and provide an additional mode of action for combating glyphosate-resistant weeds. Thus, field studies were conducted in 2017 and 2018 at Concord, NE with the following objectives develop weed management recommendations that considers soil applied herbicides and determine proper timing of glyphosate based on the crop growth stage.

Therefore the material in this thesis is …

Effects Of Different Water And Nitrogen Regimens On Yield Of Winter Wheat Produced In Nebraska, Joseph Emory Davis

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

Wheat is the 3rd most prominent crop in the United States and approximately 50% is exported annually. Nebraska wheat production is 11^th in the country, and it plays a major role in the state's agricultural economy, especially in western Nebraska. Generally, wheat is grown under dryland conditions and the region grows much more wheat on unirrigated land than it does on irrigated. However, deficit irrigation has shown great value in producing high yielding wheat with much less water than needed for other crops. Finding new ways to leverage irrigation in wheat production may help address the need to produce …