Agronomy and Crop Sciences Commons^™

Maize Leaf Angle Genetic Gain Is Slowing Down In The Last Decades, Elvis F. Elli, Jode Edwards, Jianming Yu, Slobodan Trifunovic, Douglas M. Eudy, Kevin R. Kosola, Patrick S. Schnable, Kendall R. Lamkey, Sotirios V. Archontoulis

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Quantifying historical changes in maize leaf angle and factors affecting it can enhance our understanding of canopy architecture and light capture, and hence crop productivity. Our objectives were to (1) quantify leaf angle genetic gain per canopy position in Bayer's legacy maize (Zea mays L.) hybrids; (2) dissect the contribution of breeding from plant density on historical changes in leaf angle; and (3) synthesize our findings with literature to determine leaf angle changes over a century of breeding. We measured leaf angle in 78 maize hybrids released between 1980 and 2020 across eight environments in the US Corn Belt. …

Long-Term Impacts Of Conservation Pasture Management In Manuresheds On System-Level Microbiome And Antibiotic Resistance Genes, Mitiku Mihiret Seyoum, Amanda Ashworth, Kristina M. Feye, Steven C. Ricke, Phillip R. Owens, Philip A. Moore Jr., Mary Savin

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Animal manure improves soil fertility and organic carbon, but long-term deposition may contribute to antibiotic resistance genes (ARGs) entering the soil-water environment. Additionally, long-term impacts of applying animal manure to soil on the soil-water microbiome, a crucial factor in soil health and fertility, are not well understood. The aim of this study is to assess: (1) impacts of long-term conservation practices on the distribution of ARGs and microbial dynamics in soil, and runoff; and (2) associations between bacterial taxa, heavy metals, soil health indicators, and ARGs in manures, soils, and surface runoff in a study following 15 years of continuous …

Assessment Of Dicamba And 2,4-D Residues In Palmer Amaranth And Soybean, Maria Leticia Zaccaro-Gruener, Jason K. Norsworthy, Leonard B. Piveta, L. Tom Barber, Andronikos Mauromostakos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Off-target movement of 2,4-D and dicamba is sometimes to blame as the cause of symptoms observed in weeds growing in production fields. Pesticide regulatory authorities routinely sample tissues of weeds or crops from fields under investigation for potential illegal use of auxin herbicides. This research aimed to determine if analytical tests of herbicide residue on soybean or Palmer amaranth vegetation treated with dicamba or 2,4-D could be used to differentiate between rates applied and how the residue levels decay over a 1-mo interval. Four rates of each herbicide (1X, 0.1X, 0.01X, and 0.001X) were applied, with a 1X rate of …

Herbicide Physiology And Environmental Fate, Luis Avila, Nilda Roma-Burgos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Editorial

Herbicide Physiology and Environmental Fate

Effect Of Rice Leaf Stage On Tolerance To Benzobicyclon In A Drill-Seeded Production System, Jake A. Patterson, Jason K. Norsworthy, Thomas R. Butts, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Benzobicyclon is a new postflood-applied herbicide that was registered for use in U.S. rice (Oryza sativa L.) in 2021 by Gowan Company. Therefore, research was conducted to evaluate tolerance of commonly grown rice cultivars to benzobicyclon. In 2018 and 2019, field experiments were conducted near Stuttgart, AR to evaluate the influence of growth stage on rice tolerance to benzobicyclon, and to evaluate pure line and hybrid rice tolerance to benzobicyclon following repeated use of acetolactate synthase-inhibiting herbicides. In one of two years, rice growth stage (leaf number) at application impacted tolerance to benzobicyclon. In 2018, the two-leaf application of …

Influence Of Cover Crops On Soybean Yield And Partial Returns As An Alternative To Double-Crop Soybean In Arkansas, Drew Kirkpatrick, Trenton L. Roberts, Kris Brye, Jeremy Ross

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The number of hectares dedicated to winter wheat (Triticum aestivum L.) in the southern United States has been trending downward for almost a decade, presenting an opportunity for producers to utilize alternatives in their soybean [Glycine max (L.) Merr.] rotations, such as winter cover crops. A study was established to compare the cover crops to traditional cropping systems by determining the effect each had on a successive soybean crop and to examine partial economic returns. Cropping systems implemented were winter fallow, winter wheat, and seven cover crop treatments, including cereal rye (Secale cereale L.), black-seeded oat ( …

Dicamba Air Concentrations In Eastern Arkansas And Impact On Soybean, Maria Leticia Zaccaro-Gruener, Jason K. Norsworthy, Chad B. Brabham, L. Tom Barber, Trenton Roberts, Andronikos Mauromostakos, Thomas C. Mueller

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Damage to non–dicamba resistant (non-DR) soybean [Glycine max (L.) Merr.] has been frequent in geographies where dicamba-resistant (DR) soybean and cotton (Gossypium hirsutum L.) have been grown and sprayed with the herbicide in recent years. Off-target movement field trials were conducted in northwest Arkansas to determine the relationship between dicamba concentration in the air and the extent of symptomology on non-DR soybean. Additionally, the frequency and concentration of dicamba in air samples at two locations in eastern Arkansas and environmental conditions that impacted the detection of the herbicide in air samples were evaluated. Treatment applications included dicamba at …

Does Residue Incorporation Influence Available Nitrogen Release From Cereal Rye And Tillage Radish Cover Crops Under Controlled Conditions?, Kelsey Greub, Trenton L. Roberts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Nitrogen (N) captured by cover crops can be recycled for use by the following crop via decomposition and net mineralization. This study assessed the magnitude of inorganic-N released from radish (Raphanus sativus L.) and cereal rye (Secale cereale L.) residue. The experiment was designed using a five by two factorial treatment structure with five cover crop residue treatments (radish shoots, radish roots, whole radish, cereal rye shoots, and no cover crop) and two levels of residue incorporation (incorporated and surface applied). Cover crop residues were applied to a silt loam soil on an equivalent N basis, incubated for …

Molecular Mapping And Characterization Of Qtls For Grain Quality Traits In A Ril Population Of Us Rice Under High Nighttime Temperature Stress, Anuj Kumar, Julie Thomas, Navdeep Gill, Yheni Dwiningsih, Charles Ruiz, Adam Famoso, Andy Pereira

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Elevated nighttime temperatures resulting from climate change significantly impact the rice crop worldwide. The rice (Oryza sativa L.) plant is highly sensitive to high nighttime temperature (HNT) during grain-filling (reproductive stage). HNT stress negatively affects grain quality traits and has a major impact on the value of the harvested rice crop. In addition, along with grain dimensions determining rice grain market classes, the grain appearance and quality traits determine the rice grain market value. During the last few years, there has been a major concern for rice growers and the rice industry over the prevalence of rice grains opacity …

Identification Of Genomic Regions Associated With The Plasticity Of Carbon 13 Ratio In Soybean, Siva K. Chamarthi, Avjinder Kaler, Hussein Abdel-Haleem, Felix B. Fritschi, Jason D. Gillman, Jeffery D. Ray, James R. Smith, Sarah Purcell

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Improving water use efficiency (WUE) for soybean [Glycine max (L.) Merr.] through selection for high carbon isotope (C13) ratio may increase drought tolerance, but increased WUE may limit growth in productive environments. An ideal genotype would be plastic for C13 ratio; that is, be able to alter C13 ratio in response to the environment. Our objective was to identify genomic regions associated with C13 ratio plasticity, C13 ratio stability, and overall C13 ratio in two panels of diverse Maturity Group IV soybean accessions. A second objective was to identify accessions that differed in their C13 ratio plasticity. Panel 1 …

Fenclorim Rice Safening And Weed Control With Fall-Applied Acetochlor And Pyroxasulfone, Tristen H. Avent, Jason K. Norsworthy, Thomas R. Butts, Trenton Roberts, Nicholas R. Bateman

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Applications of very long-chained fatty acid elongase (VLCFA)-inhibiting herbicides are currently not labeled within U.S. rice (Oryza sativa L.) production but have been used in Asian rice production to suppress weedy rice and control other annual grasses and small-seeded broadleaves. Therefore, separate experiments were initiated in the fall of 2019 and 2020 to evaluate rice tolerance and weedy rice (O. sativa L.) control with acetochlor and pyroxasulfone in the following spring. A three-factor experiment within a randomized complete block design was implemented with the factors being (1) herbicide choice (acetochlor or pyroxasulfone), (2) a low or high herbicide …

Assessment Of Efficacy And Mechanism Of Resistance To Soil-Applied Ppo Inhibitors In Amaranthus Palmeri, Gulab Rangani, Aimone Perri, Reiofeli A. Salas-Perez, Jens Lerchl, Srikanth Kumar Karaikal, Juan Camilo Velásquez, Nilda Roma-Burgos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Resistance to protoporphyrinogen oxidase (PPO) inhibitors in Palmer amaranth is a major concern, given the high selection pressure and increasing number of populations with reduced sensitivity to PPO herbicides in the US. We evaluated the effect of five soil-applied herbicides on Palmer amaranth (Amaranthus palmeri S. Wats.) populations collected in 2014 and 2015 in Arkansas, USA. Soil-applied saflufenacil, sulfentrazone, and flumioxazin reduced the seedling emergence 91–100%; however, fomesafen and oxyfluorfen showed reduced (63–90%) efficacy on some populations. Target-site mutation (TSM) is the major mechanism of resistance to PPO herbicides; therefore, six populations showing resistance to soil-applied fomesafen were selected for …

Rice Tolerance To Acetochlor With A Fenclorim Seed Treatment, Tristen H. Avent, Jason K. Norsworthy, Thomas R. Butts, Trenton Roberts, Nicholas R. Bateman

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Rice producers in the United States need effective herbicides to control problematic weeds. Previous research has demonstrated that acetochlor can provide in-season weed control in rice; however, undesirable injury is common. Thus, trials were initiated in 2020 and 2021 to evaluate 1) rice cultivar tolerance to microencapsulated (ME) acetochlor with the use of a fenclorim seed treatment at 2.5 g ai kg⁻¹ of seed; 2) a dose-response of a fenclorim seed treatment with ME acetochlor; and 3) rice tolerance to fenclorim and ME acetochlor under cool, wet conditions. For all trials, acetochlor was applied delayed-preemergence (4 to 7 d …

Quizalofop-Resistant Rice Response To Quizalofop When Exposed To Low Rates Of Glyphosate And Imazethapyr, Navdeep Godara, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Injury to quizalofop-resistant rice was reported in some fields following postemergence applications of quizalofop. Glyphosate-resistant (GR) corn, cotton, and soybean, and imidazolinone-resistant rice are grown near quizalofop-resistant rice. Herbicide drift from glyphosate and imazethapyr and the resulting crop injury and potential yield loss is a cause of concern for producers. Field experiments conducted near Colt, and Keiser, AR, in 2021 evaluated whether low rates of glyphosate or imazethapyr interact with sequential quizalofop applications to exacerbate injury to quizalofop-resistant rice compared to quizalofop applications alone. Herbicide treatments consisted of a low rate of glyphosate (90 g ae ha(-1)) or imazethapyr (10.7 …

Evaluation Of Rice Tolerance And Weed Control With Acetochlor And Fenclorim, Tristen H. Avent, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts, Nicholas R. Bateman

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Many problematic weeds have evolved resistance to herbicides in mid-southern U.S. rice fields. With the lack of new effective herbicides, rice producers seek alternatives that are currently not labeled for rice production. Inhibitors of very-long chain fatty acid elongase (VLCFA) are currently not labeled for use with U.S. rice crops but are labeled for use in other U.S. row cropping systems and rice production in Asia. Previous research has demonstrated the utility of VLCFA inhibitors for weed control in rice; however, these herbicides induce variable amounts of injury to the crop when applied early in the growing season. Experiments were …

Profit-Maximizing Potassium Fertilizer Recommendations For Corn And Cotton, Kimberly B. Oliver, Michael P. Popp, Nathan A. Slaton, Gerson L. Drescher, Trenton L. Roberts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Whereas K fertilization is necessary to maximize corn (Zea mays L.) and cotton (Gossypium hirsutum L.) yields in soils with sub-optimum K availability, maximizing yield is rarely profit-maximizing. Estimating the tradeoff between yield and fertilizer cost using current soil-building and/or yield-maximizing rate recommendations vs. profit-maximizing fertilizer-K rates (KR^*) provides insights for producers. Thirty-nine and 24 fertilizer-K rate trials were used to estimate respective corn and cotton yield response based on soil-K availability (SK). Using a field's SK, yield potential, yield response to fertilizer-K, crop price, and fertilizer-K cost, KR^* were calculated over the past 10 …

Herbicide Spray Drift From Ground And Aerial Applications: Implications For Potential Pollinator Foraging Sources, Thomas R. Butts, Bradley K. Fritz, K. Badou-Jeremie Kouame, Jason K. Norsworthy, L. Tom Barber, W. Jeremy Ross, Gus M. Lorenz, Benjamin C. Thrash, Nicholas R. Bateman, John J. Adamczyk

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

A field spray drift experiment using florpyrauxifen-benzyl was conducted to measure drift from commercial ground and aerial applications, evaluate soybean [Glycine max (L.) Merr.] impacts, and compare to United States Environmental Protection Agency (US EPA) drift models. Collected field data were consistent with US EPA model predictions. Generally, with both systems applying a Coarse spray in a 13-kph average wind speed, the aerial application had a 5.0- to 8.6-fold increase in drift compared to the ground application, and subsequently, a 1.7- to 3.6-fold increase in downwind soybean injury. Soybean reproductive structures were severely reduced following herbicide exposure, potentially negatively …

Evaluation Of Potassium Borate As A Volatility-Reducing Agent For Dicamba, Mason Castner, Jason K. Norsworthy, Trenton Roberts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Dicamba was labeled in dicamba-resistant cotton (Gossypium hirsutum L.) and soybean [Glycine max (L.) Merr.] in 2017, resulting in a record number of off-target complaints. To address off-target movement via volatilization, experiments were conducted to evaluate the effectiveness of potassium tetraborate tetrahydrate (KBo) as a volatility-reducing agent (VRA) with dicamba. Low-tunnel experiments examined: (1) whether KBo functions as a dicamba VRA, (2) the relationship between KBo concentration and dicamba volatilization, (3) the effectiveness of KBo compared with potassium acetate as a VRA, and (4) the impact of KBo on dicamba volatilization with and without glufosinate. In a large-scale trial (0.4-ha …

Involvement Of Glutamine Synthetase 2 (Gs2) Amplification And Overexpression In Amaranthus Palmeri Resistance To Glufosinate, Matheus M. Noguera, Aimone Porri, Isabel S. Werle, James Heiser, Frank Brandle, Jens Lerchl, Brent Murphy, Michael Betz, Fanny Gatzmann, Martin Penkert, Clara Tuerk, Lucie Meyer, Nilda Roma-Burgos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Amaranthus palmeri has recently evolved resistance to glufosinate herbicide. Several A. palmeri populations from Missouri and Mississippi, U.S.A. had survivors when sprayed with glufosinate-ammonium (GFA, 657 g ha⁻¹). One population, MO#2 (fourfold resistant) and its progeny (sixfold resistant), were used to study the resistance mechanism, focusing on the herbicide target glutamine synthetase (GS). We identified four GS genes in A. palmeri; three were transcribed: one coding for the plastidic protein (GS2) and two coding for cytoplasmic isoforms (GS1.1 and GS1.2). These isoforms did not contain mutations associated with resistance. The 17 glufosinate survivors …

Effect Of Cultivar And Planting Date On Soybean Response To Dicamba, Wesley France, Jason K. Norsworthy, Trenton Roberts, Jeremy Ross, L. Tom Barber, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Off-target movement of dicamba has been blamed for damaging millions of hectares of soybean in the United States since registration of the herbicide for use in dicamba-resistant cotton and soybean. Understanding the effect of a low dose of dicamba on non-dicamba-resistant soybean across multiple cultivars, growth stages, and planting dates could help producers better understand the implication of current management practices on yield loss from dicamba in fields where non-dicamba-resistant soybean are grown. A field experiment was conducted in 2019 in Fayetteville and Stuttgart, Arkansas, to evaluate the impact of planting date on response of soybean to a low dose …

Optimizing Weed Control Using Dicamba And Glufosinate In Eligible Crop Systems, Grant Lawson Priess, Michael P. Popp, Jason K. Norsworthy, Andronikos Mauromostakos, Trenton L. Roberts, Thomas R. Butts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

A field experiment was conducted in 2019 and 2020 that included six site-years and four locations in Arkansas to determine the optimal sequence and timing of dicamba and glufosinate applications when applied alone, sequentially, or in combination to control Palmer amaranth by size: labeled (<10 cm height) and non-labeled (13 to 25 cm height). Single applications of dicamba, glufosinate, and dicamba plus glufosinate (not labeled) resulted in less than 80% Palmer amaranth control, regardless of weed size. The mixture of dicamba plus glufosinate was antagonistic for Palmer amaranth control and percent mortality. Sequential applications, averaged over all time intervals and herbicides, improved the percentage of Palmer amaranth control 11 to 17 percentage points over a single application, regardless of weed size at application 28 d after final application (DAFA). Palmer amaranth control with glufosinate followed by (fb) glufosinate and dicamba fb dicamba, pending weed size, were optimized at intervals of 7 d, and 14 to 21 d, respectively. Because single site of action (SOA) postemergence herbicide systems increase the likelihood of the development of resistant biotypes and are not a best management practice (BMP) in that regard; sequential applications involving both dicamba and glufosinate were more effective. Furthermore, the sequence of application mattered with a preference for applying dicamba first. Dicamba fb glufosinate at a 14-d interval was profit-maximizing and the only herbicide treatment that resulted in 100% weed control when size was <10 cm. For larger weed sizes, economic analysis revealed that dicamba fb dicamba performed better than dicamba fb glufosinate when no penalty was assigned for using a single SOA. This resulted in greater yield loss risk and soil weed seed bank in comparison to timelier weed control with the smaller weed size. Hence, timely weed control and two SOAs to control Palmer amaranth are recommended as BMPs that reduce producer risk.

Effect Of Irrigation Regime And Fertilization On Recovery Of Dicamba Injured Soybean, Wesley France, Jason K. Norsworthy, Trenton Roberts, Jeremy Ross, L. Tom Barber, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

With the release of the dicamba-resistant crop technology and subsequent increase in dicamba off-target movement to non-dicamba-resistant crops, discovering means of mitigating yield loss through studying dicamba injury to soybean and interactions with factors such as irrigation regime and fertilization would prove beneficial. Field experiments were conducted in 2019 in Fayetteville and Colt, Arkansas, to evaluate the effect of irrigation regime to non-dicamba-resistant soybean that was injured by dicamba at a low dose at multiple timings. Another experiment was conducted in Fayetteville in 2019 and 2020 evaluating the impact of nitrogen (N) and potassium (K) fertilization on soybean recovery following …

Palmer Amaranth Control In Furrow-Irrigated Rice With Florpyrauxifen-Benzyl, James Winston Beesinger, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Palmer amaranth is a common weed on levees in rice fields but has become increasingly problematic with the adoption of furrow-irrigated rice and lack of an established flood. Florpyrauxifen-benzyl previously has been found effective for controlling Palmer amaranth in rice, but the efficacy of low rates of florpyrauxifen-benzyl and the effect of Palmer amaranth size on controlling it is unknown. The objective of this research was to determine the level of Palmer amaranth control expected with single and sequential applications of florpyrauxifen-benzyl at varying weed heights. The first study was conducted near Marianna, AR, in 2019 and 2020, to determine …

Benzobicyclon For Weedy Rice Control In Quizalofop- And Imidazolinone-Resistant Rice Systems, Jake A. Patterson, Jason K. Norsworthy, Thomas R. Butts, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Gowan Company recently registered benzobicyclon, a WSSA Group 27 herbicide, as a postflood option in rice. It is the first 4-hydroxyphenylpyruvate dioxygenase-inhibiting herbicide commercially available in mid-southern U.S. rice production. In 2018 and 2019, field experiments were conducted across multiple sites in Arkansas to determine if the addition of benzobicyclon to quizalofop- or imidazolinone-resistant rice herbicide programs would improve weedy rice control. Across site-years, one application of quizalofop, either at the 1- or 3-leaf rice stage, followed by benzobicyclon applied postflood, provided comparable weedy rice control to two sequential applications of quizalofop, which is a standard herbicide program in quizalofop-resistant …

Assessment Of Struvite As An Alternative Sources Of Fertilizer-Phosphorus For Flood-Irrigated Rice, Kristofor R. Brye, Niyi Sunday Omidire, Leah Ashley English, Ranjan Parajuli, Laszlo Kekedy-Nagy, Ruhi Sultana, Jennie Popp, Greg Thoma, Trenton L. Roberts, Lauren F. Greenlee

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Phosphorus (P) recovery from wastewaters as struvite (MgNH4PO4 center dot 6H(2)O) may be a viable alternative fertilizer-P source for agriculture. The objective of this study was to evaluate the economic and environmental implications of struvite as a fertilizer-P source for flood-irrigated rice (Oryza sativa) relative to other commonly used commercially available fertilizer-P sources. A field study was conducted in 2019 and 2020 to evaluate the effects of wastewater-recovered struvite (chemically precipitated struvite (CPST) and electrochemically precipitated struvite (ECST)) on rice yield response in a P-deficient, silt-loam soil in eastern Arkansas relative to triple superphosphate, monoammonium and diammonium phosphate, and rock …

Resistance Of Palmer Amaranth (Amaranthus Palmeri) To S-Metolachlor In The Midsouthern United States, Koffi Badou Jeremie Kouame, Matthew B. Bertucci, Mary C. Savin, Taghi Bararpour, Lawrence E. Steckel, Thomas R. Butts, Cammy D. Willett, Fellipe G. Machado, Nilda R. Burgos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Palmer amaranth (Amaranthus palmeri S. Watson) is one of the most problematic weeds in many cropping systems in the midsouthern United States because of its multiple weedy traits and its propensity to evolve resistance to many herbicides with different mechanisms of action. In Arkansas, A. palmeri has evolved metabolic resistance to S-metolachlor, compromising the effectiveness of an important weed management tool. Greenhouse studies were conducted to evaluate the differential response of A. palmeri accessions from three states (Arkansas, Mississippi, and Tennessee) to (1) assess the occurrence of resistance to S-metolachlor among A. palmeri populations, (2) evaluate the resistance level …

Unraveling The Mechanism Of Resistance In A Glufosinate-Resistant Palmer Amaranth (Amaranthus Palmeri) Accession, Pamela Carvalho-Moore, Jason K. Norsworthy, Fidel Gonzalez-Torralva, Jeong-In Hwang, Jinesh D. Patel, L. Tom Barber, Thomas R. Butts, J. Scott Mcelroy

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Glufosinate resistance in Palmer amaranth (Amaranthus palmeri S. Watson) was recently detected in three accessions from Arkansas, USA. Amaranthus palmeri is the first and only broadleaf weed species resistant to this herbicide, and the resistance mechanism is still unclear. A previous study characterized the glufosinate resistance level in the accessions from Arkansas. A highly glufosinate-resistant accession was further used to investigate the mechanism conferring glufosinate resistance in A. palmeri. Experiments were designed to sequence the herbicide target enzyme cytosolic and chloroplastic glutamine synthetase isoforms (GS1 and GS2, respectively) and quantify copy number and expression. Absorption, translocation, and metabolism of glufosinate …

Calibration Set Optimization And Library Transfer For Soil Carbon Estimation Using Soil Spectroscopy - A Review, Minerva J. Dorantes, Bryan A. Fuentes, David M. Miller

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Resource-efficient techniques for accurate soil property estimation are necessary to satisfy the increasing demand for soil data to support environmental monitoring, precision agriculture, and spatial modeling. Over the last 30 yr, infrared soil spectroscopy has developed into a rapid, robust, and cost-effective technique for soil carbon analysis. Ongoing global efforts to make soil spectroscopy operational require the development of soil spectral libraries, which are the main source of data for the construction of calibration models. Understanding calibration optimization is important to ensure the efficient use of soil spectral libraries for the accurate estimation of soil carbon. Moreover, spectral library transfer …

Targeting Tor And Snrk1 Genes In Rice With Crispr/Cas9, Bhuvan Pathak, Chandan Maurya, Maria C. Faria, Zahra Alizada, Soumen Nandy, Shan Zhao, Muhammed Jamsheer K, Vibha Srivastava

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Genome targeting with CRISPR/Cas9 is a popular method for introducing mutations and creating knock-out effects. However, limited information is currently available on the mutagenesis of essential genes. This study investigated the efficiency of CRISPR/Cas9 in targeting rice essential genes: the singleton TARGET OF RAPAMYCIN (OsTOR) and the three paralogs of the Sucrose non-fermenting-1 (SNF1)-related kinase 1 (OsSnRK1α), OsSnRK1αA, OsSnRK1αB and OsSnRK1αC. Strong activity of constitutively expressed CRISPR/Cas9 was effective in creating mutations in OsTOR and OsSnRK1α genes, but inducible CRISPR/Cas9 failed to generate detectable mutations. The rate of OsTOR mutagenesis was relatively lower and only the …

Wastewater-Recycled Struvite As A Phosphorus Source In A Wheat-Soybean Double-Crop Production System In Eastern Arkansas, Niyi Sunday Omidire, Kristofor R. Brye

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Fertilizer-phosphorus (P) sources are mainly derived from rock phosphate (RP), which is a finite, actively mined resource. With growing human populations globally, alternative P sources are vitally important to ensure future food security. Precipitation of the mineral struvite (MgNH₄PO₄·6H₂O) from wastewater could be a potential alternative fertilizer-P option from crop production. The objective of this study was to evaluate the effects of chemically precipitated struvite (CPST), compared with triple superphosphate (TSP) and an unamended control (UC) treatment, and irrigation (irrigated and non-irrigated/dryland) on above- (dry matter, yield, and tissue-N, -P, and -Mg concentrations and …