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Influence of hard water on 2,4-D formulations for the control of dandelion Weed Technol. (IF 1.259) Pub Date : 2020-12-09 Geoffrey P. Schortgen; Aaron J. Patton
The herbicide 2,4-D is used in a variety of cropping systems, especially in grasses because it is a selective postemergence broadleaf herbicide. However, the most common formulation (2,4-D dimethylamine) is antagonized when mixed in hard water. The objective of this research was to determine which formulations of 2,4-D or premixes of various formulations of synthetic auxin herbicides are subject to
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Hairy buttercup (Ranunculus sardous) and cutleaf evening primrose (Oenothera laciniata) control using halauxifen-methyl based programs in Mississippi and Oklahoma winter wheat Weed Technol. (IF 1.259) Pub Date : 2020-11-09 J. Connor Ferguson; Misha R. Manuchehri; Justin S. Calhoun; Justin T. Childers; Luke H. Merritt; Kayla L. Broster; Zachary R. Treadway; Zaim Ugljic; Michael T. Wesley
Hairy buttercup and cutleaf evening-primrose are winter annual weeds that have become more problematic for winter wheat growers in the Southern Great Plains and the Mid-Southern United States in recent years. Little research exists to base recommendations for controlling hairy buttercup in wheat, and little research has been published on cutleaf evening-primrose control in recent years. With growing
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Emergence pattern of Palmer amaranth (Amaranthus palmeri) influenced by tillage timings and residual herbicides Weed Technol. (IF 1.259) Pub Date : 2020-12-09 Parminder S. Chahal; Ethann R. Barnes; Amit J. Jhala
The evolution of multiple herbicide-resistant weeds, including Palmer amaranth, has necessitated the implementation of an integrated weed management (IWM) program. Understanding weed emergence patterns is critical for developing effective IWM strategies. The objective of this study was to evaluate the effect of tillage timings and residual herbicides on cumulative emergence and emergence pattern of
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Potted tropical ornamental tolerance to multiple PRE herbicides Weed Technol. (IF 1.259) Pub Date : 2020-11-25 Nathan S. Boyd; Shawn Steed
Weeds are difficult to control in potted tropical ornamentals, especially when plants are kept for extended time periods at a nursery. Management is complicated by the lack of tolerance data for many tropical species. Experiments were conducted in 2015, 2016, and 2017 at the Gulf Coast Research and Education Center in Balm, FL, to evaluate tolerance of stromanthe, croton, philodendron, arbicola, cordyline
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Control of glyphosate-resistant horseweed and giant ragweed in soybean with halauxifen-methyl applied preplant Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Jessica Quinn; Jamshid Ashigh; Nader Soltani; David C. Hooker; Darren E. Robinson; Peter H. Sikkema
Horseweed and giant ragweed are competitive, annual weeds that can negatively impact crop yield. Biotypes of glyphosate-resistant (GR) giant ragweed and horseweed were first reported in 2008 and 2010 in Ontario, respectively. GR horseweed has spread throughout the southern portion of the province. The presence of GR biotypes poses new challenges for soybean producers in Canada and the United States
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Efficacy of increasing application rates and combination of herbicides and mowing at different growth stages of common teasel (Dipsacus fullonum) Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Juan F. F. Daddario; Guillermo Tucat; Osvaldo A. Fernandez; Diego J. Bentivegna
Common teasel is a troublesome invasive weed in North and South America. Additional information on the efficacy of herbicide application and mowing at different growth stages will help in common teasel management. Firstly, an outdoor pot experiment was performed to assess increasing application rates and combinations of glyphosate and 2,4-D amine, when applied at four leaf, rosette and bolting stages
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Evaluating cereal rye and crimson clover for weed suppression within buffer areas in dicamba-resistant soybean Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Connor L. Hodgskiss; Bryan G. Young; Shalamar D. Armstrong; William G. Johnson
As herbicide-resistant weeds become more problematic, producers will consider the use of cover crops to suppress weeds. Weed suppression from cover crops may occur especially in the label-mandated buffer areas of dicamba-resistant soybean where dicamba use is not allowed. Three cover crops terminated at three timings with three herbicide strategies were evaluated for their effect on weed suppression
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Effects of low-dose applications of 2,4-D and dicamba on cucumber and cantaloupe Weed Technol. (IF 1.259) Pub Date : 2020-11-09 Lavesta C. Hand; Jenna C. Vance; Taylor M. Randell; John Shugart; Thomas Gray; Xuelin Luo; A. Stanley Culpepper
Agronomic crops engineered with resistance to 2,4-D or dicamba have been commercialized and widely adopted throughout the United States. Because of this, increased use of these herbicides in time and space has increased damage to sensitive crops. From 2014 to 2016, cucumber and cantaloupe studies were conducted in Tifton, GA, to demonstrate how auxinic herbicides (namely, 2,4-D or dicamba), herbicide
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Impact of iron formulations on topramezone injury to bermudagrass Weed Technol. (IF 1.259) Pub Date : 2020-11-09 Adam P. Boyd; J. Scott McElroy; David Y. Han; Elizabeth A. Guertal
Goosegrass control options in bermudagrass are limited. Topramezone is one option that offers excellent control of mature goosegrass, but application to bermudagrass results in unacceptable symptoms of bleaching and necrosis typical of hydroxyphenylpyruvate dioxygenase inhibitors. Previous research has shown that adding chelated iron reduced the phytotoxicity of topramezone without reducing the efficacy
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Effects of fall bearing-year glufosinate applications, spring nonbearing-year glufosinate applications, and spring nonbearing-year foramsulfuron applications on hair fescue (Festuca filiformis) in lowbush blueberry Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Scott N. White; Linshan Zhang
Hair fescue is a common perennial grass that reduces yields in lowbush blueberry fields. This grass is suppressed with nonbearing-year foramsulfuron applications, though suppression may be improved through use of sequential glufosinate and foramsulfuron applications. The objective of this research was to determine the main and interactive effects of fall bearing-year glufosinate applications, spring
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Response of seashore paspalum and bermudagrass to topramezone and triclopyr mixtures Weed Technol. (IF 1.259) Pub Date : 2020-11-09 Clebson G. Gonçalves; Austin M. Brown; Suma Basak; J. Scott McElroy
Few options are available for controlling bermudagrass invasion of seashore paspalum. Bermudagrass and seashore paspalum tolerance to topramezone, triclopyr, or the combination of these two herbicides were evaluated in both greenhouse and field conditions. Field treatments included two sequential applications of topramezone (15.6 g ai ha−1) alone and five rates of topramezone + triclopyr (15.6 + 43
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Palmer amaranth control, fecundity, and seed viability from soybean herbicides applied at first female inflorescence Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Eric B. Scruggs; Mark J. VanGessel; David L. Holshouser; Michael L. Flessner
Palmer amaranth is an extremely troublesome weed for soybean growers because of its aggressive growth, adaptability, prolific seed production, and widespread resistance to many herbicides. Studies were initiated to determine the effects of herbicide application at first female inflorescence on Palmer amaranth control, biomass, seed production, cumulative germination, and seed viability. Enlist (2,4-D–resistant)
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Response of grain sorghum to low rates of glufosinate and nicosulfuron Weed Technol. (IF 1.259) Pub Date : 2020-11-06 Hunter D. Bowman; Tom Barber; Jason K. Norsworthy; Trenton L. Roberts; Jason Kelley; Edward E. Gbur
Previous research has shown that glufosinate and nicosulfuron at low rates can cause yield loss to grain sorghum. However, research has not been conducted to pinpoint the growth stage at which these herbicides are most injurious to grain sorghum. Therefore, field tests were conducted in 2016 and 2017 to determine the most sensitive growth stage for grain sorghum exposure to both glufosinate and nicosulfuron
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Tolerance of rhizoma perennial peanut to glyphosate and triclopyr Weed Technol. (IF 1.259) Pub Date : 2020-11-06 Logan J. Martin; Brent A. Sellers; Pratap Devkota; Jason A. Ferrell; Ramon G. Leon; João M.B. Vendramini
Rhizoma perennial peanut (RPP) is well adapted to the Gulf Coast region of the United States, but its varietal tolerance to glyphosate and triclopyr is not well defined. The research was conducted to determine the effect of various rates of glyphosate and triclopyr on established RPP, and the response of common RPP varieties to these herbicides. The RPP sward was approximately 7 yr younger at Zolfo
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Buckhorn plantain (Plantago lanceolata) resistant to 2,4-D in Pennsylvania and alternative control options Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Travis R. Russell; Tim T. Lulis; Brian A. Aynardi; Kaiyuan T. Tang; John E. Kaminski
Buckhorn plantain populations purportedly resistant to 2,4-D were identified in Pennsylvania following long-term, continual applications of the active ingredient to turfgrass. The research objectives of this study were to 1) confirm 2,4-D resistance with dose-response experiments, 2) confirm field resistance of buckhorn plantain to 2,4-D in Pennsylvania, and 3) evaluate alternative herbicides for 2
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Integrating fall-planted cereal cover crops and preplant herbicides for glyphosate-resistant horseweed (Conyza canadensis) management in soybean Weed Technol. (IF 1.259) Pub Date : 2020-11-04 John A. Schramski; Christy L. Sprague; Karen A. Renner
Glyphosate-resistant horseweed is difficult to manage in no-tillage crop production fields and new strategies are needed. Cover crops may provide an additional management tool but narrow establishment windows and colder growing conditions in northern climates may limit the cover crop biomass required to suppress horseweed. Field experiments were conducted in 3 site-years in Michigan to investigate
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Evaluation of sequential applications of quizalofop-P-ethyl and florpyrauxifen-benzyl in acetyl CoA carboxylase-resistant rice Weed Technol. (IF 1.259) Pub Date : 2020-10-19 Tameka L. Sanders; Jason A. Bond; Benjamin H. Lawrence; Bobby R. Golden; Thomas W. Allen; Taghi Bararpour
Information on performance of sequential treatments of quizalofop-P-ethyl with florpyrauxifen-benzyl on rice is lacking. Field studies were conducted in 2017 and 2018 in Stoneville, MS, to evaluate sequential timings of quizalofop-P-ethyl with florpyrauxifen-benzyl included in preflood treatments of rice. Quizalofop-P-ethyl treatments were no quizalofop-P-ethyl; sequential applications of quizalofop-P-ethyl
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Herbicide safener increases weed-management tools for control of annual grasses in wheat Weed Technol. (IF 1.259) Pub Date : 2020-10-19 Damilola A. Raiyemo; William J. Price; Traci A. Rauch; Joan M. Campbell; Fangming Xiao; Rong Ma; Rachel Gross; Timothy S. Prather
Annual grass weeds reduce profits of wheat farmers in the Pacific Northwest. The very-long-chain fatty acid elongase (VLCFA)-inhibiting herbicides S-metolachlor and dimethenamid-P could expand options for control of annual grasses but are not registered in wheat, because of crop injury. We evaluated a safener, fluxofenim, applied to wheat seed for protection of 19 soft white winter wheat varieties
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Distribution and validation of genotypic and phenotypic glyphosate and PPO-inhibitor resistance in Palmer amaranth (Amaranthus palmeri) from southwestern Nebraska – ERRATUM Weed Technol. (IF 1.259) Pub Date : 2020-11-26 Maxwel C Oliveira; Darci A Giacomini; Nikola Arsenijevic; Gustavo Vieira; Patrick J Tranel; Rodrigo Werle
Failure to control Palmer amaranth with glyphosate and protoporphyrinogen IX oxidase (PPO)-inhibitor herbicides was reported across southwestern Nebraska in 2017. The objectives of this study were to 1) confirm and 2) validate glyphosate and PPO-inhibitor (fomesafen and lactofen) resistance in 51 Palmer amaranth accessions from southwestern Nebraska using genotypic and whole-plant phenotypic assay
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Rice cultivar response to sublethal concentrations of glyphosate and paraquat late in the season Weed Technol. (IF 1.259) Pub Date : 2020-10-14 Justin McCoy; Bobby Golden; Jason Bond; Darrin Dodds; Taghi Bararpour; Jeff Gore
Differential tolerance may be observed among rice cultivars with desiccant exposure events during rice reproduction and ripening. Five field studies were established at the Mississippi State University Delta Research and Extension Center in Stoneville, MS, to determine the effects of exposure to sublethal concentrations of common desiccants across multiple rice cultivars. Rice cultivars in the study
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Flumioxazin soil persistence under plastic mulch and effects of pretransplant applications on strawberry Weed Technol. (IF 1.259) Pub Date : 2020-10-19 Nathan S. Boyd; Shaun M. Sharpe; Ramdas Kanissery
Weeds are managed in Florida strawberry production systems with plastic mulches, fumigants, and herbicides. There are limited post-transplant options to control weeds that emerge in the planting holes in the plastic-covered beds, but flumioxazin at 107 g ai ha−1 can be applied pretransplant under the plastic mulch to control broadleaf and grass weeds. Three research trials were conducted in Balm and
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Stakeholder and field surveys on weed issues and research needs in rice production in Texas Weed Technol. (IF 1.259) Pub Date : 2020-10-05 Rui Liu; Vijay Singh; Xin-Gen Zhou; Muthukumar Bagavathiannan
A paper-based survey was conducted from 2015 to 2017 among stakeholders of the Texas rice industry on current weed management challenges and factors influencing management decisions. A total of 108 survey questionnaires were completed by stakeholders at the rice Cooperative Extension meetings conducted in the rice-growing counties of Texas. In addition, late-season field surveys were conducted prior
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Dicamba emissions under field conditions as affected by surface condition Weed Technol. (IF 1.259) Pub Date : 2020-09-17 Thomas C. Mueller; Lawrence E. Steckel
The evolution and widespread distribution of glyphosate-resistant broadleaf weed species catalyzed the introduction of dicamba-resistant crops that allow this herbicide to be applied POST to soybean and cotton. Applications of dicamba that are most cited for off-target movement have occurred in June and July in many states when weeds are often in high densities and at least 10 cm or taller at the time
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Comparison of aminocyclopyrachlor to standard herbicides for basal stem treatment of Eucalyptus benthamii Weed Technol. (IF 1.259) Pub Date : 2020-10-14 Patrick J. Minogue; Kimberly A. Lorentz
Eucalyptus species are grown for fiber, fuel, and other uses on more than 17.8 million ha worldwide, yet some species are considered invasive and may have adverse environmental or social impacts outside their native range. Aminocyclopyrachlor (AMCP) and standard applications of imazapyr and triclopyr herbicides were compared for eucalyptus control using a basal stem application method. At 6 and 12
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Reducing topramezone injury to bermudagrass using chelated iron and other additives Weed Technol. (IF 1.259) Pub Date : 2020-10-05 Adam P. Boyd; J. Scott McElroy; James D. McCurdy; Patrick E. McCullough; David Y. Han; Elizabeth A. Guertal
POST goosegrass and other grassy weed control in bermudagrass is problematic. Fewer herbicides that can control goosegrass are available due to regulatory pressure and herbicide resistance. Alternative herbicide options that offer effective control are needed. Previous research demonstrates that topramezone controls goosegrass, crabgrass, and other weed species; however, injury to bermudagrass may
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Effects of fall-planted cereal cover-crop termination time on glyphosate-resistant horseweed (Conyza canadensis) suppression Weed Technol. (IF 1.259) Pub Date : 2020-09-14 John A. Schramski; Christy L. Sprague; Karen A. Renner
Integrated strategies for management of glyphosate-resistant (GR) horseweed are needed to reduce reliance on herbicides. Planting a cover crop after corn or soybean harvest in the Upper Midwest may reduce horseweed establishment and growth. Experiments were conducted in Michigan to determine if cereal rye and winter wheat, seeded at 67 or 135 kg ha−1, and terminated with glyphosate at 1.27 kg ae ha−1
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PRE herbicides influence critical time of weed removal in glyphosate-resistant corn Weed Technol. (IF 1.259) Pub Date : 2020-09-17 Ayse Nur Ulusoy; O. Adewale Osipitan; Jon Scott; Amit J. Jhala; Nevin C. Lawrence; Stevan Z. Knezevic
Residual herbicides applied PRE provide early season weed control, potentially avoid the need for multiple POST herbicides, and can provide additional control of herbicide-resistant weeds. Thus, field studies were conducted in 2017 and 2018 at Concord, NE, to evaluate the influence of PRE herbicides on critical time for postemergence weed removal (CTWR) in corn. The studies were arranged in a split-plot
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Evaluation of terbacil-based herbicide treatments for hair fescue (Festuca filiformis) management in lowbush blueberry Weed Technol. (IF 1.259) Pub Date : 2020-11-04 Scott N. White; Linshan Zhang
Hair fescue is a common tuft-forming perennial grass weed that reduces yields and hinders mechanical harvest in lowbush blueberry fields. PRE terbacil applications traditionally controlled hair fescue but currently only provide suppression in most fields. Terbacil use has not, however, been evaluated in conjunction with other currently registered herbicides in lowbush blueberry. The objective of this
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Herbicidal control of deathcamas (Zigadenus paniculatus) Weed Technol. (IF 1.259) Pub Date : 2020-09-14 Clinton A. Stonecipher; Corey Ransom; Eric Thacker; Kevin Welch; Dale R. Gardner; Matt Palmer
Foothill deathcamas is a bulbous, perennial, native forb found throughout the western United States. Deathcamas begins growth early in the spring. The lack of alternative forages at this time can result in livestock becoming poisoned from the consumption of deathcamas. Research on herbicides for deathcamas control is limited to work from the 1950s and 1960s that identified 2,4-D as a control agent
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Pollen-mediated gene flow and transfer of resistance alleles from herbicide-resistant broadleaf weeds Weed Technol. (IF 1.259) Pub Date : 2020-09-08 Amit J. Jhala; Jason K. Norsworthy; Zahoor A. Ganie; Lynn M. Sosnoskie; Hugh J. Beckie; Carol A. Mallory-Smith; Jun Liu; Wei Wei; Junming Wang; David E. Stoltenberg
Pollen-mediated gene flow (PMGF) refers to the transfer of genetic information (alleles) from one plant to another compatible plant. With the evolution of herbicide-resistant (HR) weeds, PMGF plays an important role in the transfer of resistance alleles from HR to susceptible weeds; however, little attention is given to this topic. The objective of this work was to review reproductive biology, PMGF
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Vegetable response to sulfentrazone soil residues at four planting intervals Weed Technol. (IF 1.259) Pub Date : 2020-09-08 John S. Rachuy; Steven A. Fennimore
Sulfentrazone was recently granted food-use tolerance approval for use on Brassica head and stem, as well as Brassica leafy vegetables. To date, one sulfentrazone registrant has listed those crops on its use label. In coastal California multiple crops per year including Brassica vegetables are grown in rapid succession; therefore, to avoid injury to rotational crops, herbicides used in those fields
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Developing a multispecies weed competition model for high-yielding cotton Weed Technol. (IF 1.259) Pub Date : 2020-08-28 Graham W. Charles; Brian M. Sindel; Annette L. Cowie; Oliver G. G. Knox
Glyphosate-tolerant and glyphosate-resistant weeds are becoming increasingly problematic in cotton fields in Australia, necessitating a return from a glyphosate dominated system to a more integrated approach to weed management. The development of an integrated weed management system can be facilitated by identifying the critical period for weed control (CPWC), a model that enables cotton growers to
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Vertical mobility and cotton tolerance to trifludimoxazin, a new protoporphyrinogen oxidase-inhibiting herbicide, in three West Texas soils Weed Technol. (IF 1.259) Pub Date : 2020-08-25 B. Scott Asher; Peter A. Dotray; Rex A. Liebl; J. Wayne Keeling; Glen D. Ritchie; Theophilus K. Udeigwe; Jacob D. Reed; Kyle E. Keller; Steve J. Bowe; Ryan B. Aldridge; Anja Simon
Trifludimoxazin, a new protoporphyrinogen oxidase–inhibiting herbicide, is being evaluated for possible use as a soil-residual active herbicide treatment in cotton for control of small-seeded annual broadleaf weeds. Laboratory and greenhouse studies were conducted to compare vertical mobility and cotton tolerance of trifludimoxazin to flumioxazin and saflufenacil, which are two currently registered
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Functionality and efficacy of Franklin Robotics’ Tertill™ robotic weeder Weed Technol. (IF 1.259) Pub Date : 2020-08-24 Johnny Sanchez; Eric R. Gallandt
Agricultural weeds remain an important production constraint, with labor shortages and a lack of new herbicide options in recent decades making the problem even more acute. Robotic weeding machines are a possible solution to these increasingly intractable weed problems. Franklin Robotics’ Tertill™ is an autonomous weeding robot designed for home gardeners that relies on a minimalistic design to be
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Influence of sulfentrazone and metribuzin applied preemergence on soybean development and yield Weed Technol. (IF 1.259) Pub Date : 2020-09-01 Nikola Arsenijevic; Matheus de Avellar; Liberty Butts; Nicholas John Arneson; Rodrigo Werle
The use of photosystem II (PSII)-inhibitor and/or protoporphyrinogen oxidase (PPO)-inhibitor PRE herbicides in soybean may, under adverse environmental conditions, result in early season crop injury. A field study was conducted near Brule and North Platte, Nebraska, during the 2016 and 2017 growing seasons with the objective to evaluate the impact of PRE herbicides metribuzin (PSII-inhibitor) and sulfentrazone
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Relating initial paraquat injury to final efficacy in selected weed species influenced by environmental conditions Weed Technol. (IF 1.259) Pub Date : 2020-10-05 Nick T. Harre; Garth W. Duncan; Julie M. Young; Bryan G. Young
Weed control of paraquat can be erratic and may be attributable to differing species sensitivity and/or environmental factors for which minor guidance is available on commercial labels. Therefore, the objectives of this research were to quantify selectivity of paraquat across select weed species and the influence of environmental factors. Experiments were performed under controlled conditions in the
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Effective two-pass herbicide programs to control glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in glyphosate/dicamba-resistant soybean Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Vipan Kumar; Rui Liu; Dallas E. Peterson; Phillip W. Stahlman
Field experiments were conducted in 2018 and 2019 at Kansas State University Ashland Bottoms (KSU-AB) research farm near Manhattan, KS, and Kansas State University Agricultural Research Center (KSU-ARC) near Hays, KS, to determine the effectiveness of various PRE-applied herbicide premixes and tank mixtures alone or followed by (fb) an early POST (EPOST) treatment of glyphosate + dicamba for controlling
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The influence of soybean population and POST herbicide application timing on in-season and subsequent-season Palmer amaranth (Amaranthus palmeri) control and economic returns Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Denis J. Mahoney; David L. Jordan; Andrew T. Hare; Nilda Roma-Burgos; Katherine M. Jennings; Ramon G. Leon; Matthew C. Vann; Wesley J. Everman; Charles W. Cahoon
Overreliance on herbicides for weed control has led to the evolution of herbicide-resistant Palmer amaranth populations. Farm managers should consider the long-term consequences of their short-term management decisions, especially when considering the soil weed seedbank. The objectives of this research were to (1) determine how soybean population and POST herbicide application timing affects in-season
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Management of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in 2,4-D–, glufosinate-, and glyphosate-resistant soybean Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Chandrima Shyam; Parminder S. Chahal; Amit J. Jhala; Mithila Jugulam
Glyphosate-resistant (GR) Palmer amaranth is a problematic, annual broadleaf weed in soybean production fields in Nebraska and many other states in the United States. Soybean resistant to 2,4-D, glyphosate, and glufosinate (Enlist E3TM) has been developed and was first grown commercially in 2019. The objectives of this research were to evaluate the effect of herbicide programs applied PRE, PRE followed
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Spray solution pH and soybean injury as influenced by synthetic auxin formulation and spray additives Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Sarah Striegel; Maxwel C. Oliveira; Nicholas Arneson; Shawn P. Conley; David E. Stoltenberg; Rodrigo Werle
Use of synthetic auxin herbicides has increased across the midwestern United States after adoption of synthetic auxin-resistant soybean traits, in addition to extensive use of these herbicides in corn. Off-target movement of synthetic auxin herbicides such as dicamba can lead to severe injury to sensitive plants nearby. Previous research has documented effects of glyphosate on spray-solution pH and
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Survey of ground and aerial herbicide application practices in Arkansas agronomic crops Weed Technol. (IF 1.259) Pub Date : 2020-07-21 Thomas R. Butts; L. Tom Barber; Jason K. Norsworthy; Jason Davis
A thorough understanding of commonly used herbicide application practices and technologies is needed to provide recommendations and determine necessary application education efforts. An online survey to assess ground and aerial herbicide application practices in Arkansas was made available online in spring 2019. The survey was direct-emailed to 272 agricultural aviators and 831 certified commercial
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Atrazine residues in flooded and nonflooded soil and effects on soybean Weed Technol. (IF 1.259) Pub Date : 2020-09-22 Thomas C. Mueller; David R. Kincer; Lawrence E. Steckel
Atrazine applied at planting is commonly used for weed control in corn. With global climate change causing an increase in river flooding in the United States over the past decade, producers need information to determine the best course of action in flooded fields treated with atrazine into which they wish to immediately plant soybean. Studies were designed to understand the effect of flooding on atrazine
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PRE- and POST-applied herbicide options for alfalfa interseeded with corn silage Weed Technol. (IF 1.259) Pub Date : 2020-09-17 William R. Osterholz; José Luiz C. S. Dias; John H. Grabber; Mark J. Renz
Establishment of alfalfa by interseeding it with corn planted for silage can enhance crop productivity but weed management is a challenge to adoption of the practice. Although a simple and effective approach to weed management would be to apply a glyphosate-based herbicide, concerns about herbicide resistance and limitations in available alfalfa varieties exist. Field experiments were conducted to
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Molecular confirmation of resistance to PPO inhibitors in Amaranthus tuberculatus and Amaranthus palmeri, and isolation of the G399A PPO2 substitution in A. palmeri Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Jacob S. Montgomery; Darci A. Giacomini; Patrick J. Tranel
During the 2017 to 2019 growing seasons, samples of waterhemp and Palmer amaranth that had reportedly survived field-rate applications of protoporphyrinogen oxidase (PPO)–inhibiting herbicides were collected from the American Midwest and tested for target-site mutations known at the time to confer resistance. Target-site resistance was identified in nearly all (135 of 145) tested common waterhemp populations
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Efficacy of residual herbicides influenced by cover-crop residue for control of Amaranthus palmeri and A. tuberculatus in soybean Weed Technol. (IF 1.259) Pub Date : 2020-07-20 Clay M. Perkins; Karla L. Gage; Jason K. Norsworthy; Bryan G. Young; Kevin W. Bradley; Mandy D. Bish; Aaron Hager; Lawrence E. Steckel
Field studies were conducted in 2018 and 2019 in Arkansas, Indiana, Illinois, Missouri, and Tennessee to determine if cover-crop residue interfered with herbicides that provide residual control of Palmer amaranth and waterhemp in no-till soybean. The experiments were established in the fall with planting of cover crops (cereal rye + hairy vetch). Herbicide treatments consisted of a nontreated or no
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Assessment of crop and weed management strategies prior to introduction of auxin-resistant crops in Brazil Weed Technol. (IF 1.259) Pub Date : 2020-08-28 Maxwel C. Oliveira; Anelise Lencina; André R. Ulguim; Rodrigo Werle
A stakeholder survey was conducted from April through June of 2018 to understand stakeholders’ perceptions and challenges about cropping systems and weed management in Brazil. The dominant crops managed by survey respondents were soybean (73%) and corn (66%). Approximately 75% of survey respondents have grown or managed annual cropping systems with two to three crops per year cultivated in succession
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Evaluation of dicamba retention in spray tanks and its impact on flue-cured tobacco Weed Technol. (IF 1.259) Pub Date : 2020-07-09 Matthew D. Inman; Matthew C. Vann; Loren R. Fisher; Travis W. Gannon; David L. Jordan; Katie M. Jennings
In recent years, there has been increased use of dicamba due to the introduction of dicamba-resistant cotton and soybean in the United States. Therefore, there is a potential increase in off-target movement of dicamba and injury to sensitive crops. Flue-cured tobacco is extremely sensitive to auxin herbicides, particularly dicamba. In addition to yield loss, residue from drift or equipment contamination
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Distribution and validation of genotypic and phenotypic glyphosate and PPO-nhibitor resistance in Palmer amaranth (Amaranthus palmeri) from southwestern Nebraska Weed Technol. (IF 1.259) Pub Date : 2020-07-09 Maxwel C Oliveira; Darci A Giacomini; Nikola Arsenijevic; Gustavo Vieira; Patrick J Tranel; Rodrigo Werle
Failure to control Palmer amaranth with glyphosate and protoporphyrinogen IX oxidase (PPO)-inhibitor herbicides was reported across southwestern Nebraska in 2017. The objectives of this study were to 1) confirm and 2) validate glyphosate and PPO-inhibitor (fomesafen and lactofen) resistance in 51 Palmer amaranth accessions from southwestern Nebraska using genotypic and whole-plant phenotypic assay
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Comparison of 2,4-D, dicamba and halauxifen-methyl alone or in combination with glyphosate for preplant weed control Weed Technol. (IF 1.259) Pub Date : 2020-08-18 M. Carter Askew; Charles W. Cahoon; Alan C. York; Michael L. Flessner; David B. Langston; J. Harrison Ferebee
A field study was conducted in 2017 and 2018 to determine foliar efficacy of halauxifen-methyl, 2,4-D, or dicamba applied alone and in combination with glyphosate at preplant burndown timing. Experiments were conducted near Painter, VA; Rocky Mount, NC; Jackson, NC; and Gates, NC. Control of horseweed, henbit, purple deadnettle, cutleaf evening primrose, curly dock, purple cudweed, and common chickweed
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Influence of glyphosate on corn hybrid tolerance to tolpyralate + atrazine Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Nicole M. Langdon; Nader Soltani; Alan J. Raeder; David C. Hooker; Darren E. Robinson; Peter H. Sikkema
This study consisting of six field experiments was conducted in 2018 and 2019 to evaluate the tolerance of four corn hybrids (P9998AM, P9840AM, DKC42-60RIB, and DKC43-47RIB) to the tank mix of tolpyralate + atrazine with a commercial glyphosate formulation. At 1 wk after application (WAA), two corn hybrids (P9998AM and P9840AM) exhibited more injury from tolpyralate + atrazine (2× rate) applied alone
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Time-of-day effect on weed control efficacy with tolpyralate plus atrazine Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Nicole M. Langdon; Nader Soltani; Alan J. Raedar; David C. Hooker; Darren E. Robinson; Peter H. Sikkema
Tolpyralate is a new 4-hydroxyphenyl-pyruvate dioxygenase (HPPD)–inhibiting herbicide for weed control in corn. Previous research has reported efficacy of tolpyralate + atrazine on several annual grass and broadleaf weed species; however, no studies have evaluated weed control of tolpyralate + atrazine depending on time-of-day (TOD) of application. Six field experiments were conducted over a 2-yr period
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Tolerance of pintoi peanut to PRE and POST herbicides Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Logan J. Martin; José Luiz C.S. Dias; Brent A. Sellers; Jason A. Ferrell; Ramon G. Leon; João M.B. Vendramini
Pintoi peanut is a warm-season perennial legume that shows promise as a forage crop for the southeastern United States, however, little is known about the proper methods of weed management during establishment for this species. The objective of this study was to determine the ability of pintoi peanut to tolerate applications of PRE and POST herbicides during the year of and year after planting. The
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Phenology affects differentiation of crop and weed species using hyperspectral remote sensing Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Nicholas T. Basinger; Katherine M. Jennings; Erin L. Hestir; David W. Monks; David L. Jordan; Wesley J. Everman
The effect of plant phenology and canopy structure of four crops and four weed species on reflectance spectra were evaluated in 2016 and 2017 using in situ spectroscopy. Leaf-level and canopy-level reflectance were collected at multiple phenologic time points in each growing season. Reflectance values at 2 wk after planting (WAP) in both years indicated strong spectral differences between species across
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Impacts of repeated glyphosate use on growth of orchard crops Weed Technol. (IF 1.259) Pub Date : 2020-08-18 O. Adewale Osipitan; Bahar Yildiz-Kutman; Seth Watkins; Patrick H. Brown; Bradley D. Hanson
Glyphosate is an important component of herbicide programs in orchard crops in California. It can be applied alone or in tank-mix combinations under the crop rows or to the entire field and often is used multiple times each year. There has been speculation about the potential impacts of repeated use of glyphosate in perennial crop systems, because of uptake from shallow root systems or indirectly because
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A holistic carrot production system for season-long weed management Weed Technol. (IF 1.259) Pub Date : 2020-08-18 Jed B. Colquhoun; Richard A. Rittmeyer; Daniel J. Heider
Weed management in carrot is challenging, given slow and inconsistent crop emergence and early-season growth and the lack of practical season-long management tools such as herbicides. We investigated holistic carrot production systems with a focus on minimizing inputs while optimizing resource use. In an overall sense, results of this work were consistent between years, and stark. The choice of carrot
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Dicamba effects on fruiting in sensitive cotton Weed Technol. (IF 1.259) Pub Date : 2020-07-09 Kyle R. Russell; Peter A. Dotray; Irish L.B. Pabuayon; Glen L. Ritchie
Since the release of dicamba-tolerant cotton in 2016, preplant and POST applications of dicamba to control glyphosate-resistant Palmer amaranth have increased. With the increase in area treated with dicamba, the risk of off-target movement to nontarget crops has increased. A field study was conducted at the Texas Tech University New Deal Research Farm equipped with subsurface drip irrigation in 2017
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Resistance of Inzen™ grain sorghum to multiple PRE- and POST-applied acetolactate synthase–inhibiting herbicides Weed Technol. (IF 1.259) Pub Date : 2020-06-30 Hunter D. Bowman; Tom Barber; Jason K. Norsworthy; Trenton L. Roberts; Jason Kelley; Edward E. Gbur
A non-GMO trait called Inzen™ was recently commercialized in grain sorghum to combat weedy grasses, allowing the use of nicosulfuron POST in the crop. Inzen™ grain sorghum carries a double mutation in the acetolactate synthase (ALS) gene Val560Ile and Trp574Leu, which potentially results in cross-resistance to a wide assortment of ALS-inhibiting herbicides. To evaluate the scope of cross-resistance
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Effect of dicamba rate and application parameters on protoporphyrinogen oxidase inhibitor-resistant and -susceptible Palmer amaranth (Amaranthus palmeri) control Weed Technol. (IF 1.259) Pub Date : 2020-06-09 Wyatt Coffman; Tom Barber; Jason K. Norsworthy; Greg R. Kruger
Throughout eastern Arkansas, Palmer amaranth resistant to protoporphyrinogen oxidase (PPO)-inhibiting herbicides (Group 14 herbicides) has become widespread. Most PPO-resistant Palmer amaranth biotypes possess a target-site mutation, but a metabolic resistance mechanism to fomesafen (Group 14) has also been identified. Once metabolic resistance manifests, plants may also be tolerant to other herbicides
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Characterization of rice cultivar response to florpyrauxifen-benzyl Weed Technol. (IF 1.259) Pub Date : 2020-07-21 Hannah E. Wright; Jason K. Norsworthy; Trenton L. Roberts; Robert Scott; Jarrod Hardke; Edward E. Gbur
Many factors such as environment, herbicide rate, growth stage at application, and days between sequential applications can influence the response of a crop to herbicides. Florpyrauxifen-benzyl is a new broad-spectrum, POST herbicide that was commercialized for use in U.S. rice production in 2018. Field experiments were conducted in 2018 at the Pine Tree Research Station (PTRS) near Colt, AR, and the
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Chemical control of suckers in hazelnut orchards of western Oregon Weed Technol. (IF 1.259) Pub Date : 2020-07-20 Larissa Larocca de Souza; Marcelo L. Moretti
Hazelnut naturally grows as a multi-stemmed tree. The basal sprouts, known as suckers, grow throughout the season. Suckers are removed to promote a single trunk that facilitates production mechanization and increased yield. In western Oregon, herbicides are the most common method of sucker control, and at least four applications per season are performed in the spring and summer seasons. This study