scholarly journals Simulated Single Drift Events of 2,4-D and Dicamba on Pecan Trees

2019 ◽  
Vol 29 (3) ◽  
pp. 360-366 ◽  
Author(s):  
M. Lenny Wells ◽  
Eric P. Prostko ◽  
O. Wendell Carter
Keyword(s):  
Yield Loss ◽  
Genetically Modified Crops ◽  
Target Movement ◽  
Horticultural Crops ◽  
Field Corn ◽  
Auxin Herbicides ◽  
Serious Injury ◽  
New Generation ◽  
Significant Injury ◽  
Commercial Introduction

A large number of agronomic and horticultural crops are susceptible to injury and yield loss from drift-level exposures to synthetic auxin herbicides. A new generation of genetically modified crops including cotton (Gossypium hirsutum), field corn (Zea mays), soybean (Glycine max), and canola (Brassica napus) with resistance to dicamba and 2,4-D herbicides has been developed to address the problem of glyphosate-resistant weeds. In the few years since their commercial introduction, these technologies have been rapidly adopted. The objective of this study was to determine the potential effects of simulated, single drift events of 2,4-D and dicamba on pecan (Carya illinoinensis) trees. 2,4-D amine [3.8 lb/gal acid equivalent (a.e.)] or dicamba-Diglycolamine salt (4.0 lb/gal a.e.) were applied in 1.0%, 0.1%, and 0.01% by volume spray solutions to pecan trees in June 2013. In 2016 and 2017, 2,4-D choline (3.8 lb/gal a.e.) or dicamba-N,N-Bis-(3-aminopropyl) methylamine (5.0 lb/gal a.e.) were applied in 1.0%, 0.1%, and 0.01% by volume spray solutions to pecan trees in May. These results suggest that serious injury can occur to pecan trees receiving a drift application of 1.0% by volume dicamba or 2,4-D. This injury includes deformed foliage, dead foliage, dead limbs, and/or branches, and arrested nut development. There were no major differences in the response of pecan to either dicamba or 2,4-D at similar rates in this study. Pecan damage resulting from off-target movement of 2,4-D and dicamba at rates ≥1% by volume has the potential to cause significant injury. Yield was not negatively affected by any of the treatments, suggesting that pecan trees can compensate for the observed injury to some extent. The effect of treatments on percent kernel was variable.

Corn (Zea mays L.) response to sublethal rates of paraquat and fomesafen at vegetative growth stages

2019 ◽  
Vol 33 (04) ◽  
pp. 595-600
Author(s):  
Benjamin P. Sperry ◽  
Benjamin H. Lawrence ◽  
Jason A. Bond ◽  
Daniel B. Reynolds ◽  
Bobby R. Golden ◽  
...  
Keyword(s):  
Growth Stage ◽  
Yield Loss ◽  
Zea Mays L ◽  
Growth Stages ◽  
Corn Yield ◽  
Internode Elongation ◽  
Yield Losses ◽  
Target Movement ◽  
Significant Injury ◽  
Over Time

AbstractResearch was conducted from 2013 to 2015 across three sites in Mississippi to evaluate corn response to sublethal paraquat or fomesafen (105 and 35 g ai ha−1, respectively) applied PRE, or to corn at the V1, V3, V5, V7, or V9 growth stages. Fomesafen injury to corn at three d after treatment (DAT) ranged from 0% to 38%, and declined over time. Compared with the nontreated control (NTC), corn height 14 DAT was reduced approximately 15% due to fomesafen exposure at V5 or V7. Exposure at V1 or V7 resulted in 1,220 and 1,110 kg ha−1 yield losses, respectively, compared with the NTC, but yield losses were not observed at any other growth stage. Fomesafen exposure at any growth stage did not affect corn ear length or number of kernel rows relative to the NTC. Paraquat injury to corn ranged from 26% to 65%, depending on growth stage and evaluation interval. Corn exposure to paraquat at V3 or V5 consistently caused greater injury across evaluation intervals, compared with other growth stages. POST timings of paraquat exposure resulted in corn height reductions of 13% to 50%, except at V7, which was most likely due to rapid internode elongation at that stage. Likewise, yield loss occurred after all exposure times of paraquat except PRE, compared with the NTC. Corn yield was reduced 1,740 to 5,120 kg ha−1 compared with the NTC, generally worsening as exposure time was delayed. Paraquat exposure did not reduce corn ear length, compared with the NTC, at any growth stage. However, paraquat exposure at V3 or V5 was associated with reduction of kernel rows by 1.1 and 1.7, respectively, relative to the NTC. Paraquat and fomesafen applications near corn should be avoided if conditions are conducive for off-target movement, because significant injury and yield loss can result.

scholarly journals Prehospital shock index outperforms hypotension alone in predicting significant injury in trauma patients

2021 ◽  
Vol 6 (1) ◽  
pp. e000712
Author(s):  
Tareq Kheirbek ◽  
Thomas J Martin ◽  
Jessica Cao ◽  
Benjamin M Hall ◽  
Stephanie Lueckel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Missing Values ◽  
Injured Patient ◽  
Injury Pattern ◽  
Long Bone ◽  
Shock Index ◽  
Level Of Evidence ◽  
Emergent Operation ◽  
Serious Injury ◽  
Significant Injury

BackgroundThe American College of Surgeons Resources for Optimal Care of the Injured Patient recommends using hypotension, defined as systolic blood pressure ≤90 mm Hg, as an indicator of a full team trauma activation. We hypothesized that an elevated shock index (SI) predicts significant traumatic injuries better than hypotension alone.MethodsThis is a retrospective cohort study analyzing full team trauma activations between February 2018 and January 2020, excluding transfers and those who had missing values for prehospital blood pressure or heart rate. We reviewed patients’ demographics, prehospital and emergency department vitals, injury pattern, need for operation, and clinical outcomes. The primary outcome was rate of significant injury defined as identified injured liver, spleen, or kidney, pelvis fracture, long bone fracture, significant extremity soft tissue damage, hemothorax, or pneumothorax.ResultsAmong 544 patients, 82 (15.1%) had prehospital hypotension and 492 had normal blood pressure. Of the patients with prehospital hypotension, 34 (41.5%) had a significant injury. There was no difference in age, gender, medical history, or injury pattern between the two groups. There was no difference between the two groups in rate of serious injury (41.5% vs. 46.1%, NS), need for emergent operation (31.7% vs. 28.1%, NS) or death (20.7% vs. 18.8%, NS). On the other hand, SI ≥1 was associated with increased rate of serious injury (54.6% vs. 43.4%, p=0.04). On a logistic regression analysis, prehospital hypotension was not associated with significant injury or need for emergent operation (OR 0.83, 95% CI 0.51 to 1.33 and OR 1.32, 95% CI 0.79 to 2.25, respectively). SI ≥1 was associated with both increased odds of significant injury and need for emergent operation (OR 1.57, 95% CI 1.01 to 2.44 and OR 1.64, 95% CI 1.01 to 2.66).DiscussionSI was a better indicator and could replace hypotension to better categorize and triage patients in need of higher level of care.Level of evidencePrognostic and epidemiologic, level III.

Using Estimates of Weed Pressure to Establish Crop Yield Loss Equations

1994 ◽  
Vol 8 (1) ◽  
pp. 114-118 ◽  
Author(s):  
R. Gordon Harvey ◽  
Clark R. Wagner
Keyword(s):  
Linear Regression ◽  
Crop Yield ◽  
Yield Loss ◽  
Sweet Corn ◽  
Crop Yields ◽  
Yield Reduction ◽  
Weed Species ◽  
Field Corn ◽  
Efficacy Trials ◽  
Total Crop

Herbicide efficacy trials in field corn, sweet corn, and soybean were conducted at three locations in Wisconsin over a 6-yr period. Percent weed pressure (WP) was determined by visually estimating the contribution of all weed species present to the total crop and weed volume in each plot. Crop yields in each plot were measured. Percent crop yield reduction (YLDRED) was calculated by comparing mean yields of individual treatments with those of the highest yielding treatment in each trial. Linear regression analyses of YLDRED and WP data from 1640 field corn and 138 sweet corn treatments were significant. Nonlinear regression analysis of YLDRED and WP data from all 1374 soybean treatments was significant; however, a linear regression of those 1154 soybean treatments with WP ratings of 30 or less produced a more easily interpreted regression equation.

Response of Rice (Oryza sativa) to Low Rates of Glyphosate and Glufosinate

2011 ◽  
Vol 25 (2) ◽  
pp. 198-203 ◽  
Author(s):  
Brad Davis ◽  
Robert C. Scott ◽  
Jason K. Norsworthy ◽  
Edward Gbur
Keyword(s):  
Yield Loss ◽  
Flag Leaf ◽  
Field Studies ◽  
Leaf Length ◽  
University Of Arkansas ◽  
Yield Losses ◽  
Time Of Application ◽  
Flag Leaf Length ◽  
The University ◽  
Significant Injury

Field studies were conducted in 2007 and 2008 at the University of Arkansas at Pine Bluff farm near Lonoke to evaluate and compare the effects of low rates of glufosinate and glyphosate on rice. Two rice cultivars were seeded, and glyphosate and glufosinate were applied at 1/2, 1/4, and 1/8 of the labeled use rate of 870 g ae ha−1and 616 g ai ha−1, respectively, at the three- to four-leaf, panicle initiation (PI), and boot stages. Rice canopy height reductions, reduction in flag leaf length, prolonged maturity, and yield losses were caused by both herbicides at all evaluated application timings. Although both herbicides caused significant injury, symptoms varied greatly between the two herbicides. Glufosinate injury to rice was more rapid and visually intense than with glyphosate. Glufosinate symptoms, which consisted of rapid necrosis, were visible in 1 to 2 d, whereas glyphosate symptoms, stunting and chlorosis, became visible after 7 to 10 d or not at all depending on time of application. Glyphosate applied at the 1/2× rate to rice in the boot growth stage caused less than 10% injury at 3 wk after treatment but resulted in 80% yield loss. Glufosinate at boot caused 80% injury and 80% yield loss. Glyphosate symptoms from PI and boot timings were typically only visible at heading and included malformed panicles and shortened flag leaves. Harvested grain seed weights were reduced as much as 14% by either herbicide applied at PI and boot. Germination of harvested grain was not affected by any treatment. At the rates evaluated in this research, glufosinate-induced injury to rice can be just as detrimental as glyphosate in reducing yield.

scholarly journals The Influence of Nozzle Type on Peanut Weed Control Programs

2017 ◽  
Vol 44 (2) ◽  
pp. 93-99 ◽  
Author(s):  
O.W. Carter ◽  
E.P. Prostko ◽  
J.W. Davis
Keyword(s):  
Weed Control ◽  
Palmer Amaranth ◽  
Annual Grass ◽  
Weed Species ◽  
Target Movement ◽  
Herbicide Resistant ◽  
Control Programs ◽  
The Past ◽  
Auxin Herbicides ◽  
Nozzle Type

ABSTRACT The increase in herbicide-resistant weeds over the past decade has led to the introduction of crops that are resistant to auxin herbicides. Strict application procedures are required for the use of auxin herbicides in auxin-resistant crops to minimize off-target movement. One requirement for application is the use of nozzles that will minimize drift by producing coarse droplets. Generally, an increase in droplet size can lead to a reduction in coverage and efficacy depending upon the herbicide and weed species. In studies conducted in 2015 and 2016, two of the potential required auxin nozzle types [(AIXR11002 (coarse) and TTI11002 (ultra-coarse)] were compared to a conventional flat-fan drift guard nozzles [DG11002 (medium)] for weed control in peanut herbicide systems. Nozzle type did not influence annual grass or Palmer amaranth control in non-crop tests. Results from in-crop tests indicated that annual grass control was 5% to 6% lower when herbicides were applied with the TTI nozzle when compared to the AIXR or DG nozzles. However, Palmer amaranth control and peanut yield was not influenced by coarse-droplet nozzles. Peanut growers using the coarse-droplet nozzles need to be aware of potential reduced grass control.

In-Line Inspection Tools for Crack Detection in Gas and Liquid Pipelines

1998 ◽  
Author(s):  
H. H. Willems ◽  
O. A. Barbian ◽  
N. I. Uzelac
Keyword(s):  
Crack Detection ◽  
Oil And Gas ◽  
Fatigue Cracks ◽  
Data Comparison ◽  
Detection Tool ◽  
The World ◽  
Oil And Gas Pipelines ◽  
Axial Crack ◽  
New Generation ◽  
Commercial Introduction

The occurrence of stress corrosion cracking (SCC) has become a serious matter for many pipeline operators around the world. Advanced in-line inspection technology using nondestructive methods is considered the most promising approach to detect and size this kind of damage. Considerable progress has been achieved with the UltraScan CD (Crack Detection), a new generation of internal inspection device especially designed for the detection of axial crack-like defects in pipelines. Since its commercial introduction in October 1994, the crack detection tool has successfully inspected over 2,000 km of operating oil and gas pipelines. The inspection runs were followed by verification excavations at specific locations selected from the collected data. Comparison of the findings with corresponding verifications from excavations illustrate the sensitivity and reliability of the inspection concept and the ability of the tool to safely discriminate between injurious crack-like defects and different non-injurious reflectors such as e.g. inclusions. The performance has proved the tool to be a reliable internal inspection device for the detection and sizing of cracks (SCC, fatigue cracks and crack-like defects) in pipelines.

Response of Non–Dicamba-Resistant Soybean to Dicamba As Influenced by Growth Stage and Herbicide Rate

2018 ◽  
Vol 32 (5) ◽  
pp. 513-519 ◽  
Author(s):  
Spencer McCown ◽  
Tom Barber ◽  
Jason K. Norsworthy
Keyword(s):  
Seed Yield ◽  
Weed Management ◽  
Yield Loss ◽  
Soybean Seed ◽  
Growth Stages ◽  
Target Movement ◽  
Visible Injury ◽  
Leaf Injury ◽  
Resistant Varieties ◽  
Wide Range

AbstractIntroduction of the Roundup Ready® Xtend system (Monsanto Co., St. Louis, MO) provides an alternative weed management option for growers, but of concern is the risk of dicamba injury to sensitive crops, particularly soybean from off-target movement and tank contamination. Experiments were conducted to determine the response of soybean to low rates of dicamba over a wide range of application timings. Two glufosinate-resistant varieties (HBK 4950LL–indeterminate and HALO 5.45LL–determinate) commonly grown in Arkansas were chosen for these studies. Two rates of dicamba, 2.18 and 8.75 g ae ha–1(1/256× and 1/64× of the POST labeled rate for dicamba-resistant soybean), were applied at two vegetative (V4, V6) and six reproductive (R1 to R6) growth stages. Compared to the nontreated control, dicamba applied during late vegetative and early reproductive growth of soybean caused leaf injury, plant height reduction, and seed yield loss for both soybean cultivars. Averaged across dicamba rates applied at R1, soybean seed yield was reduced 14% for the HBK 4950LL cultivar and 19% for the HALO 5.45LL cultivar. Averaged over rates, dicamba applied at R1 to the HALO 5.45LL and HBK 4950LL soybean resulted in 48% and 43% visible injury 4 wk after treatment, respectively. Grain yield was similar to that of the nontreated control when dicamba was applied at the later reproductive stages averaged across rates.

Influence of Application Timings and Sublethal Rates of Synthetic Auxin Herbicides on Soybean

2014 ◽  
Vol 28 (3) ◽  
pp. 454-464 ◽  
Author(s):  
Craig B. Solomon ◽  
Kevin W. Bradley
Keyword(s):  
Yield Components ◽  
Seed Weight ◽  
Yield Loss ◽  
Field Trials ◽  
Synthetic Auxin ◽  
Stages Of Growth ◽  
General Order ◽  
Auxin Herbicides ◽  
Production Areas ◽  
Near Future

Synthetic auxin herbicides have long been utilized for the selective control of broadleaf weeds in a variety of crop and noncrop environments. Recently, two agrochemical companies have begun to develop soybean with resistance to 2,4-D and dicamba which might lead to an increase in the application of these herbicides in soybean production areas in the near future. Additionally, little research has been published pertaining to the effects of a newly-discovered synthetic auxin herbicide, aminocyclopyrachlor, on soybean phytotoxicity. Two field trials were conducted in 2011 and 2012 to evaluate the effects of sublethal rates of 2,4-D amine, aminocyclopyrachlor, aminopyralid, clopyralid, dicamba, fluroxypyr, picloram, and triclopyr on visible estimates of soybean injury, height reduction, maturity, yield, and yield components. Each of these herbicides was applied to soybean at the V3 and R2 stages of growth at 0.028, 0.28, 2.8, and 28 g ae ha−1. Greater height reductions occurred with all herbicides, except 2,4-D amine and triclopyr when applied at the V3 compared to the R2 stage of growth. Greater soybean yield loss occurred with all herbicides except 2,4-D amine when applied at the R2 compared to the V3 stage of growth. The only herbicide applied that resulted in no yield loss at either stage was 2,4-D amine. When applied at 28 g ae ha−1at the V3 stage of growth, the general order of herbicide-induced yield reductions to soybean from greatest to least was aminopyralid > aminocyclopyrachlor = clopyralid = picloram > fluroxypyr > triclopyr > dicamba > 2,4-D amine. At the R2 stage of growth, the general order of herbicide-induced yield reductions from greatest to least was aminopyralid > aminocyclopyrachlor = picloram > clopyralid > dicamba > fluroxypyr = triclopyr > 2,4-D amine. Yield reductions appeared to be more correlated with seeds per pod than to pods per plant and seed weight. An 18- to 26-d delay in soybean maturity also occurred with R2 applications of all synthetic auxin herbicides at 28 g ae ha−1except 2,4-D. Results from this research indicate that there are vast differences in the relative phytotoxicity of these synthetic auxin herbicides to soybean, and that the timing of the synthetic auxin herbicide exposure will have a significant impact on the severity of soybean height and/or yield reductions.

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