Other Plant Sciences Commons^™

Genome-Wide Association Mapping Of Qualitatively Inherited Traits In A Germplasm Collection, Nonoy B. Bandillo, Aaron J. Lorenz, George L. Graef, Diego Jarquin, David L. Hyten, Randall L. Nelson, James E. Specht

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide association (GWA) has been used as a tool for dissecting the genetic architecture of quantitatively inherited traits. We demonstrate here that GWA can also be highly useful for detecting many major genes governing categorically defined phenotype variants that exist for qualitatively inherited traits in a germplasm collection. Genome-wide association mapping was applied to categorical phenotypic data available for 10 descriptive traits in a collection of ~13,000 soybean [Glycine max (L.) Merr.] accessions that had been genotyped with a 50,000 single nucleotide polymorphism (SNP) chip. A GWA on a panel of accessions of this magnitude can offer substantial statistical …

Dioxygenase-Encoding Atdao1 Gene Controls Iaa Oxidation And Homeostasis In Arabidopsis, Silvana Porco, Aleš Pěnčík, Afaf Rashed, Ute Voβ, Rubén Casanova-Sáez, Anthony Bishop, Agata Golebiowska, Rahul Bhosale, Ranjan Swarup, Kamal Swarup, Pavlína Penáková, Ondrej Novák, Paul E. Staswick, Peter Hedden, Andrew L. Phillips, Kris Vissenberg, Malcolm J. Bennett, Karin Ljung

Department of Agronomy and Horticulture: Faculty Publications

Auxin represents a key signal in plants, regulating almost every aspect of their growth and development. Major breakthroughs have been made dissecting the molecular basis of auxin transport, perception, and response. In contrast, how plants control the metabolism and homeostasis of the major form of auxin in plants, indole-3- acetic acid (IAA), remains unclear. In this paper, we initially describe the function of the Arabidopsis thaliana gene DIOXYGENASE FOR AUXIN OXIDATION 1 (AtDAO1). Transcriptional and translational reporter lines revealed that AtDAO1 encodes a highly root-expressed, cytoplasmically localized IAA oxidase. Stable isotope-labeled IAA feeding studies of loss and …

A Population Of Deletion Mutants And An Integrated Mapping And Exome-Seq Pipeline For Gene Discovery In Maize, Shangang Jia, Aixia Li, Kyla Morton, Penny Avoles-Kianian, Shahryar F. Kianian, Chi Zhang, David Holding

Department of Agronomy and Horticulture: Faculty Publications

To better understand maize endosperm filling and maturation, we used gamma irradiation of the B73 maize reference line to generate mutants with opaque endosperm and reduced kernel fill phenotypes, and created a population of 1788 lines including 47 Mo17 × F2s showing stable, segregating and viable kernel phenotypes. For molecular characterization of the mutants, we developed a novel functional genomics platform that combined Bulked Segregant RNA and Exome sequencing (BSREx-seq) to map causative mutations and identify candidate genes within mapping intervals. To exemplify the utility of the mutants and provide proof-ofconcept for the bioinformatics platform, we present detailed characterization of …

Comprehensive Comparative Genomic And Transcriptomic Analyses Of The Legume Genes Controlling The Nodulation Process, Zhenzhen Qiao, Lise Pingault, Mehrnoush Nourbakhsh-Rey, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen is one of the most essential plant nutrients and one of the major factors limiting crop productivity. Having the goal to perform a more sustainable agriculture, there is a need to maximize biological nitrogen fixation, a feature of legumes. To enhance our understanding of the molecular mechanisms controlling the interaction between legumes and rhizobia, the symbiotic partner fixing and assimilating the atmospheric nitrogen for the plant, researchers took advantage of genetic and genomic resources developed across different legume models (e.g., Medicago truncatula, Lotus japonicus, Glycine max, and Phaseolus vulgaris) to identify key regulatory protein coding genes of the nodulation …

Comparison Of An Ultra-Low Volume (Ulv) Sprayer Against A Conventional Sprayer, For Foliar Fertiliser And Fungicide Applications In Turfgrass, Jason Connor Ferguson, Roch E. Gaussoin, John A. Eastin, Matthew D. Sousek, Greg R. Kruger

Department of Agronomy and Horticulture: Faculty Publications

Two field studies (I and II) at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA, were conducted to determine if a new ultra-low volume (ULV) sprayer can apply foliar nutrient, growth regulator, and fungicide treatments, in a manner similar to that of a conventional sprayer. Treatments were applied over creeping bentgrass ‘L-93’ (Agrostis stolonifera L.) managed as a fairway at 561 l · ha⁻¹ and 47 l · ha⁻¹ with the conventional and ULV sprayer, respectfully. Data were collected for chlorophyll content with a chlorophyll meter, and for the normalised difference …

Estimated Costs Of Producing Hops In Nebraska, David P. Lambe, Stacy A. Adams

Department of Agronomy and Horticulture: Faculty Publications

Hop production opportunities exist in Nebraska given heightened interest by craft brewers for unique and locally produced hop. Farmers are additionally exploring opportunities to diversify for improved on-farm income. Strategic planning, market considerations, and having a clear plan of implementation are critical, as well as, predicting infrastructural and production costs one would expect towards planning for profitability in this specialty crop. This publication provides information on how to determine productivity, infrastructural investment, and operational costs associated with the initial development of the hop production operation.

Mechanisms, Applications, And Perspectives Of Antiviral Rna Silencing In Plants / Mecanismos, Aplicaciones Y Perspectivas Del Silenciamiento Génico De Virus En Plantas, Hernan Garcia-Ruiz, Mayra Teresa Garcia Ruiz, Sergio Manuel Gabriel Peralta, Cristina Betzabeth Miravel Gabriel, Kaoutar El-Mounadi

Department of Plant Pathology: Faculty Publications

Viral diseases of plants cause important economic losses due to reduction in crop quality and quantity to the point of threatening food security in some countries. Given the reduced availability of natural sources, genetic resistance to viruses has been successfully engineered for some plant-virus combinations. A sound understanding of the basic mechanisms governing plant-virus interactions, including antiviral RNA silencing, is the foundation to design better management strategies and biotechnological approaches to engineer and implement antiviral resistance in plants. In this review, we present current molecular models to explain antiviral RNA silencing and its application in basic plant research, biotechnology and …

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …

Incidence Of Wheat Streak Mosaic Virus, Triticum Mosaic Virus, And Wheat Mosaic Virus In Wheat Curl Mites Recovered From Maturing Winter Wheat Spikes, E. Byamukama, S. Tatineni, G. Hein, J. Mcmechan, S. N. Wegulo

Department of Plant Pathology: Faculty Publications

Wheat curl mites (WCM; Aceria tosichella) transmit Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and Wheat mosaic virus (WMoV) to wheat (Triticum aestivum L.) in the Great Plains region of the United States. These viruses can be detected in single, double, or triple combinations in leaf samples. Information on incidence of viruses inWCM at the end of the growing season is scant. The availability of this information can enhance our knowledge of the epidemiology ofWCM-transmitted viruses. This research was conducted to determine the frequency of occurrence of WSMV, TriMV, and WMoV in WCM populations on fieldcollected maturing …

Developing The Framework For A Risk Map For Mite Vectored Viruses In Wheat Resulting From Pre-Harvest Hail Damage, Anthony L. Nguy-Robertson, Arthur Zygielbaum, Anthony J. Mcmechan, Gary L. Hein, Stephen N. Wegulo, Abby R. Stilwell, Travis M. Smith

Department of Plant Pathology: Faculty Publications

There is a strong economic incentive to reduce mite-vectored virus outbreaks. Most outbreaks in the central High Plains of the United States occur in the presence of volunteer wheat that emerges before harvest as a result of hail storms. This study provides a conceptual framework for developing a risk map for wheat diseases caused by mite-vectored viruses based on pre-harvest hail events. Traditional methods that use NDVI were found to be unsuitable due to low chlorophyll content in wheat at harvest. Site-level hyperspectral reflectance from mechanically hailed wheat showed increased canopy albedo. Therefore, any increase in NIR combined with large …

Cryptic Species: A Leitmotif Of Contemporary Mycology Has Challenges And Benefits For Plant Pathologists, Frank M. Dugan, Sydney Everhart

Department of Plant Pathology: Faculty Publications

Multiple traditional species names for plant pathogenic fungi have been supplemented with new names that delimit formerly cryptic species. In separate instances, isolates within a species are clearly differentiated by both phylogeny and distinctive pathogenic traits and are assigned sub-specific designations. These new species names and the sub-specific designations are both cases of cryptic species that are, in some instances, relevant and/or critical for plant disease management. Here we provide examples of such instances in which newly described taxa differ from the original (“parent”) in phenotypic traits of importance to plant disease management: host range, fungicide sensitivity, environmental niche, metabolite …

Sequence Variation In Two Genes Determines The Efficacy Of Transmission Of Citrus Tristeza Virus By The Brown Citrus Aphid, S. J. Harper, N. Killiny, Satyanarayana Tatineni, S. Gowda, S. J. Cowell, T. Shilts, W. O. Dawson

Department of Plant Pathology: Faculty Publications

Vector transmission is an important part of the viral infection cycle, yet for many viruses little is known about this process, or how viral sequence variation affects transmission efficacy. Here we examined the effect of substituting genes from the highly transmissible FS577 isolate of citrus tristeza virus (CTV) in to the poorly transmissible T36-based infectious clone. We found that introducing p65 or p61 sequences from FS577 significantly increased transmission efficacy. Interestingly, replacement of both genes produced a greater increase than either gene alone, suggesting that CTV transmission requires the concerted action of co-evolved p65 and p61 proteins.

Field Damage Of Sorghum (Sorghum Bicolor) With Reduced Lignin Levels By Naturally Occurring Insect Pests And Pathogens, Patrick F. Dowd, Deanna L. Funnell-Harris, Scott E. Sattler

Department of Plant Pathology: Faculty Publications

Sorghum (Sorghum bicolor (L.) Moench) brown midrib (bmr) mutant lines have reduced levels of lignin, which is a potentially useful trait for bioenergy production, but the effects of this trait on insect and plant pathogen interactions are unknown under field conditions. Field-grown bmr6, bmr12, and wild-type (WT) plants were examined for insect and disease damage. In most cases, observed frequency, population, or leaf area damage caused by insects or pathogens on bmr6 or bmr12 plants were not greater than those observed on WT plants in the field or laboratory assays. European corn borers [Ostrinia nubilalis (Hübner)(Lepidoptera: …

What's New In Plant Pathology, Anthony O. Adesemoye, Loren Giesler, Robert M. Harveson, Tamra A. Jackson-Ziems, Kevin Korus, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Changes to the Disease Management Section of the 2016 Guide for Weed, Disease, and Insect Management in Nebraska

Biological control Products

Trivapro Fungicide

Priaxor D. Fungicide

Table 1. Foliar products for disease control that were updated in the 2016 Guide for Weed, Disease and Insect Management in Nebraska.

Table 2. Seed treatment products for disease control that were updated in the 2016 Guide for Weed, Disease and Insect Management in Nebraska.

Table 3. Seed treatment nematicide product that was updated in the 2016 Guide for Weed, Disease and Insect Management in Nebraska.

Fungicide Application Timing And Disease Control, Tamra A. Jackson-Ziems, Loren J. Giesler, Robert M. Harveson, Stephen N. Wegulo, Kevin Korus, Anthony O. Adesemoye

Department of Plant Pathology: Faculty Publications

Wet weather that persisted during much of the 2015 growing season proved to be very favorable for disease development in several crops across Nebraska. In particular, diseases caused by fungi were favored by repeated rainfall events and high relative humidity, fog, etc., that supported the production of more spores and continuous plant infection. On some susceptible varieties and hybrids, diseases developed early and quickly eventually reaching moderate to severe levels. Foliar fungicides were applied one or more times to some crops in an effort to mitigate losses due to disease. However, low crop prices and narrow profit margins made foliar …

Corn Disease Update, Tamra A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The 2015 corn crop was impacted by several corn diseases from the beginning to the end of the season and in all areas of Nebraska. The increased severity and incidence of some diseases was largely due to the extended periods of favorable weather conditions in varying parts of the state that supported the increase in some diseases. In particular, frequent rainfall and high relative humidity were especially favorable for several fungal diseases. Unfortunately, almost all diseases of corn (except rusts) are caused by pathogens that can successfully overwinter in Nebraska. For this reason, making detailed notes on disease development and …

Trivapro A + Trivapro B Application Timing And Disease Efficacy In Field Corn In Nebraska, 2015, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to evaluate foliar fungicides and application timings for crop response and foliar disease efficacy. Irrigated corn was grown based on Nebraska Extension irrigation recommendations at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % OM and the previous crop was soybean. Reduced tillage was performed to the field prior to planting. Corn (DKC 65-79 RIB, tolerant to grey leaf spot (GLS)) was planted at approximately 34,000 seed/A on 26 May. Seven treatments were arranged in a randomized complete block design with six replications. …

Foliar Fungicide Comparison For Southern Rust Management, Stay Green, Push Lodging, And Yield In Nebraska, 2015, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to compare foliar fungicides for southern rust (SR) efficacy. Irrigated corn was grown based on Nebraska Extension irrigation recommendations at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % OM and the previous crop was soybean. Reduced tillage was performed to the field prior to planting. Corn (DKC 65-79 RIB, tolerant to gray leaf spot (GLS)) was planted at approximately 34,000 seed/A on 26 May. Eight treatments were arranged in a randomized complete block design with six replications. . . . Stalk lodging …

Fungicide And Herbicide Effects On Grey Leaf Spot In Nebraska Field Corn, 2015, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to compare foliar fungicides applied to three growth stages of corn for grey leaf spot (GLS) efficacy. Irrigated corn was grown based on Nebraska Extension irrigation recommendations at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % OM and the previous crop was soybean. Reduced tillage was performed to the field prior to planting. Corn (DKC 65-79 RIB, tolerant to gray leaf spot (GLS)) was planted at approximately 34,000 seed/A on 26 May. Five treatments were arranged in a randomized complete block design …

A Foliar Fungicide Plus Herbicide Tank Mixture Evaluation In Field Corn In Nebraska, 2015, J. D. Harbour, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

The objective of the trial was to evaluate the tank mixture of Laudis herbicide plus Stratego YLD fungicide for corn response. Irrigated corn was grown based on Nebraska Extension irrigation recommendations at the South Central Ag Lab near Clay Center, NE. Soils were a silt loam with 6.7 pH and 1.8 % OM and the previous crop was soybean. Reduced tillage was performed to the field prior to planting. Corn (DKC 65-79 RIB, tolerant to gray leaf spot (GLS)) was planted at approximately 34,000 seed/A on 26 May. Four treatments were arranged in a randomized complete block design with six …

Corn Disease Profiles: Diseases Favored By Dry Conditions, Tamra A. Jackson-Ziems, Anthony O. Adesemoye, Loren J. Giesler, Robert M. Harveson, Kevin A. Korus, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1910 (EC1910)

Extreme weather events are predicted to become increasingly common and could bring periods of drought as well as intense rainfall events. Wet conditions are favorable for many plant pathogens and the development of diseases, but some diseases may also develop during or following dry weather. The timing during the season when dry conditions occur, as well as other factors, such as temperature, impact which diseases develop and when. The list summarizes some of the most common corn diseases that can develop during dry conditions: Seedling Root Rot Diseases, Nematodes, Common Smut, Rust Diseases Charcoal Rot, Stalk …

Corn Disease Profiles: Diseases Favored By Wet Conditions, Tamra A. Jackson-Ziems, Anthony O. Adesemoye, Loren J. Giesler, Robert M. Harveson, Kevin A. Korus, Stephen N. Wegulo

Department of Plant Pathology: Faculty Publications

Extension Circular 1909 (EC1909)

Extreme weather events are predicted to become increasingly common and could bring periods of more intense rainfall. Wet conditions are favorable for many plant pathogens and the development of diseases. Seasonal timing when these conditions occur, as well as other factors such as temperature, impact which diseases develop and when. Listed, described, and illustrated are some common corn diseases favored by wet conditions: Pythium Root Rot, Eyespot, Northern Corn Leaf Blight, Gray Leaf Spot, Physoderma Brown Spot, Rust Diseases (Puccinia spp.), Stalk and Crown Rot Diseases (such as those caused by Fusarium and Diplodia spp.), …

Association Of Neonectria Macrodidyma With Dry Root Rot Of Citrus In California, A. O. Adesemoye, J. S. Mayorquin, B. B. Peacock, K. Moreno, S. Hajeri, R. Yokomi, A. Eskalen

Department of Plant Pathology: Faculty Publications

During yearly surveys that started in 2010 to identify pathogens associated with dry root rot disease of citrus in California, samples with root rot symptoms were collected in Tulare County. Small pieces of tissue from root samples were plated onto potato dextrose agar amended with 0.01% tetracycline and incubated at 25°C. Pure cultures of fungal isolates were identified by morphology and sequence analysis of the Internal Transcribed Spacer and Beta Tubulin regions. Neonectria macrodidyma (Cylindrocarpon macrodidymum) was first recovered in 2011 and has subsequently been recovered multiple times from citrus samples. The pathogen appeared to be widely distributed …

Shrubland Resilience Varies Across Soil Types: Implications For Operationalizing Resilience In Ecological Restoration, Carissa L. Wonkka, Dirac L. Twidwell, Jacob B. West, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

In ecosystems with alternative stable states, restoration success can be thought of as overcoming the resilience of an undesirable state to promote an alternative state that yields greater ecosystem services. Since greater resilience of undesirable states translates into reduced restoration potential, quantifying differences in resilience can enhance restoration planning. In the context of shrub- encroached rangeland restoration, shrubland resilience is the capacity of a woody vegetated state to absorb management interventions designed to produce a more desirable grass- dominated state, and remain within its current regime. Therefore, differences in the resilience of a state can be quantifi ed in a …

Growing Sensitivity Of Maize To Water Scarcity Under Climate Change, Qingfeng Meng, Xinping Chen, David B. Lobell, Zhenling Cui, Yi Zhang, Haishun Yang, Fusuo Zhang

Department of Agronomy and Horticulture: Faculty Publications

Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change …

Information Thermodynamics Of Cytosine Dna Methylation, Robersy Sanchez Rodriguez, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Cytosine DNA methylation (CDM) is a stable epigenetic modification to the genome and a widespread regulatory process in living organisms that involves multicomponent molecular machines. Genome-wide cytosine methylation patterning participates in the epigenetic reprogramming of a cell, suggesting that the biological information contained within methylation positions may be amenable to decoding. Adaptation to a new cellular or organismal environment also implies the potential for genome-wide redistribution of CDM changes that will ensure the stability of DNA molecules. This raises the question of whether or not we would be able to sort out the regulatory methylation signals from the CDM background …

Horizontal Gene Acquisitions, Mobile Element Proliferation, And Genome Decay In The Host-Restricted Plant Pathogen Erwinia Tracheiphila, Lori R. Shapiro, Erin D. Scully, Timonthy J. Straub, Jihye Park, Andrew G. Stephenson, Gwyn A. Beattie, Mark L. Gleason, Roberto Kolter, Miguel C. Coelho, Consuelo M. De Moraes, Mark C. Mescher, Olga Zhaxybayeva

Department of Agronomy and Horticulture: Faculty Publications

Modern industrial agriculture depends on high-density cultivation of genetically similar crop plants, creating favorable conditions for the emergence of novel pathogens with increased fitness in managed compared with ecologically intact settings. Here, we present the genome sequence of six strains of the cucurbit bacterial wilt pathogen Erwinia tracheiphila (Enterobacteriaceae) isolated from infected squash plants in New York, Pennsylvania, Kentucky, and Michigan. These genomes exhibit a high proportion of recent horizontal gene acquisitions, invasion and remarkable amplification of mobile genetic elements, and pseudogenization of approximately 20% of the coding sequences. These genome attributes indicate that E. tracheiphila recently emerged as a …

Herbicide Options For Effective Weed Management In Dry Directseeded Rice Under Scented Rice-Wheat Rotation Of Western Indo- Gangetic Plains, Vijay Singh, Mangi L. Jat, Zahoor A. Ganie, Bhagirath S. Chauhan, Raj K. Gupta

Department of Agronomy and Horticulture: Faculty Publications

Farmers' participatory field trials were conducted at Madhuban, and Taraori, the two participatory experimental sites/locations of the Cereal Systems Initiative for South Asia (CSISA), a collaborative project of IRRI and CIMMYT in Karnal district of Haryana, India, during Kharif (wet season) 2010 and 2011. This research aimed to evaluate preemergence (PRE) and postemergence (POST) herbicides for providing feasible and economically viable weed management options to farmers for predominant scented rice varieties. Treatments with pendimethalin PRE fb bispyribac-sodium þ azimsulfuron POST had lower weed biomass at 45 days after sowing (DAS). At Madhuban, highest grain yield of scented basmati rice (3.43 …

Prospects For Increasing Sugarcane And Bioethanol Production On Existing Crop Area In Brazil, Fabio R. Martin, Geraldo B. Martha,Jr, Kenneth G. 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 …

Glyphosate-Resistant Weed Control And Soybean Injury In Response To Different Ppo-Inhibiting Herbicides, Jatinder S. Aulakh, P. S. Chahal, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

In Nebraska, 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) as well as acetolactate synthase (ALS)-inhibitor-resistant weeds occur in many soybean fields where herbicides from these modes-of-action have been frequently used in the past. Currently, the protoporphyrinogen oxidase (PPO)-inhibitors are the only effective herbicides for POST control of both glyphosate- and ALS-inhibitor-resistant weeds in soybean. Greenhouse experiments were conducted in 2014 to evaluate the efficacy of PPO-inhibitors applied POST for the control of three glyphosate-resistant (GR) weeds and potential for soybean injury, when applied at two growth stages. All herbicide treatments controlled 10- and 20-cm tall GR common waterhemp ≥ 95% at 21 DAT. …