Influence of post-treatment irrigation timings and herbicide placement on bermudagrass and goosegrass (Eleusine indica) response to low-dose topramezone and metribuzin programs

Weed Science ◽  
2021 ◽  
pp. 1-23
Author(s):  
John R. Brewer ◽  
Jordan C. Craft ◽  
Shawn D. Askew
Keyword(s):  
Low Dose ◽  
Cynodon Dactylon ◽  
Post Treatment ◽  
Golf Course ◽  
High Dose ◽  
Insufficient Evidence ◽  
Eleusine Indica ◽  
Athletic Field ◽  
Minute Post ◽  
Herbicide Mixtures

Abstract Immediate, post-treatment irrigation has been proposed as a method to reduce hybrid bermudagrass [Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt Davy] phytotoxicity from topramezone. Immediate irrigation is impractical since it would take a turfgrass sprayer 10 to 15 minutes to cover an average golf course fairway or athletic field. There is also insufficient evidence regarding how post-treatment irrigation, immediate or otherwise, influences mature goosegrass [Eleusine indica (L.) Gaertn.] control from topramezone or low-dose topramezone plus metribuzin programs. We sought to investigate bermudagrass and E. indica response to immediate, 15-minute, and 30-minute post-treatment irrigation compared to no irrigation following topramezone at 12.3 g ae ha−1, the lowest labeled rate, or topramezone at 6.1 g ha−1 plus metribuzin at 210 g ai ha−1. We also evaluated placement of each herbicide and their combination on soil, foliage, and soil plus foliage to help elucidate the mechanisms involved in differential responses between species and herbicide mixtures. Responses were largely dependent on trial due to bermudagrass injury from high-dose topramezone being nearly eliminated by immediate irrigation in one trial and only slightly affected in another. When post-treatment irrigation was postponed for 15 or 30 minutes, topramezone alone injured bermudagrass unacceptably in both trials. Bermudagrass was injured less by low-dose topramezone plus metribuzin than by high-dose topramezone. All post-treatment irrigation timings reduced E. indica control compared to no post-treatment irrigation. The herbicide placement study suggested that topramezone control of E. indica is highly dependent on foliar uptake and phytotoxicity of both bermudagrass and E. indica is greater from topramezone than metribuzin. Thus, post-treatment irrigation likely reduces topramezone rate load with a concomitant effect on plant phytotoxicity of both species. Metribuzin reduced 21-d cumulative clipping wt and tiller production of plants, and this may be a mechanism by which it reduces foliar white discoloration from topramezone.

Tank-Mixed Herbicides on Large Crabgrass (Digitaria sanguinalis) and Goosegrass (Eleusine indica) Control in Common Bermudagrass (Cynodon dactylon) Turf

Weed Science ◽  
1994 ◽  
Vol 42 (2) ◽  
pp. 216-221 ◽  
Author(s):  
B. Jack Johnson
Keyword(s):  
Methyl Ester ◽  
Cynodon Dactylon ◽  
Golf Course ◽  
Digitaria Sanguinalis ◽  
Eleusine Indica ◽  
Combination Treatments ◽  
Common Bermudagrass ◽  
Large Crabgrass

Tank-mix combinations of PRE and POST herbicides were applied to control emerged large crabgrass and goosegrass in common bermudagrass turf. Large crabgrass control was better when MSMA at 2.2 kg ai ha-1was tank mixed with either pendimethalin at 1.7 kg ai ha-1(≤ 85%) or dithiopyr at 0.3 kg ai ha-1(≤ 94%), when compared with MSMA at 2.2 kg ai ha-1(≤ 50%) alone. When MSMA plus metribuzin at 2.2 + 0.14 kg ai ha-1was tank mixed with pendimethalin in 1992, large crabgrass control was better (≥ 96%) than when MSMA plus metribuzin was applied alone (≤ 73%). Quinclorac applied alone at 0.8 kg ai ha-1controlled ≥ 94% large crabgrass, but control with diclofop was 32%. There was no increase in control when either quinclorac or diclofop was tank mixed with any PRE herbicide. Methyl ester of diclofop applied alone at 1.1 kg ai ha-1provided 97% control of goosegrass at one location, but control was ≤ 62% at two other locations. Goosegrass control was better when diclofop at 1.1 kg ha-1was tank mixed with dithiopyr at 0.6 kg ha-1(≥ 77%) than when either diclofop (≤ 62%) or dithiopyr (≤ 50%) was applied alone. Goosegrass control was consistently better across years from combinations of dithiopyr plus diclofop at 0.6 + 1.1 kg ha-1(82%) than from combinations of MSMA plus metribuzin with dithiopyr (34%) or pendimethalin (53%). Common bermudagrass injury at Griffin-Spalding Golf Course in 1991 was higher at 1 wk after combination treatments of MSMA plus metribuzin with dithiopyr (46 to 54%) or pendimethalin (50%) than with MSMA plus metribuzin applied alone (26%). Injury from the combinations was higher from single MSMA plus metribuzin treatment for 4 wk. Similar results occurred at the Georgia Station in 1992 from combinations of dithiopyr with MSMA plus metribuzin.

Differences in selectivity between bermudagrass and goosegrass (Eleusine indica) to low-rate topramezone and metribuzin combinations

Weed Science ◽  
2021 ◽  
pp. 1-28
Author(s):  
John R. Brewer ◽  
Whitnee L.B. Askew ◽  
Shawn D. Askew
Keyword(s):  
Low Dose ◽  
Cynodon Dactylon ◽  
Residual Activity ◽  
Field Studies ◽  
Differential Absorption ◽  
Eleusine Indica ◽  
Selective Control ◽  
Low Rate

Abstract Goosegrass [Eleusine indica (L.) Gaertn.] remains problematic for bermudagrass [Cynodon dactylon (L.) Pers.] turf managers due to the ineffective, selective control of mature plants with available POST herbicides and lack of sufficient residual activity from those herbicides to control seedling plants. Topramezone controls mature E. indica, but past efforts to suppress potential injury to bermudagrass turf have been inconsistent. We hypothesized that metribuzin at 210 g ai ha−1 in admixture with topramezone would improve bermudagrass tolerance while conserving mature E. indica control. In preliminary field studies, metribuzin mixed with topramezone at 1.2 or 2.5 g ae ha−1 applied twice at a 3-wk interval reduced bermudagrass injury and white discoloration compared to topramezone applied alone, but metribuzin did not safen bermudagrass to mesotrione. Topramezone at 3.7 g ha−1 plus 210 g ha−1 metribuzin applied twice at a 3-wk interval offered improved bermudagrass tolerance while it still controlled mature E. indica during fifteen field and two greenhouse studies in Virginia. This program offered a 10-fold decrease in suprathreshold duration of white-discoloration compared to topramezone alone at 6.1 g ha−1. Bermudagrass absorbed three times less radioactivity than E. indica at timings up to 48 h after treatment with 14C-topramezone. Bermudagrass also metabolized twice as much topramezone compared to E. indica at 48 h after treatment. Metribuzin reduced 14C absorption by approximately 25% in both species. These studies confirm the performance of a novel, low-dose topramezone plus metribuzin program for mature E. indica control in bermudagrass turf, and suggest that selectivity between bermudagrass and E. indica to topramezone is due to differential absorption and metabolism. The fact that metribuzin reduces topramezone absorption in both species suggests that it may help reduce bermudagrass phytotoxic response to topramezone, but its role in altering selectivity between bermudagrass and E. indica may be due to other factors.

scholarly journals Temperature Effects on the Speed and Completion of Germination of 19 Commercially Available Seeded Bermudagrass Cultivars

2013 ◽  
Vol 23 (1) ◽  
pp. 82-85 ◽  
Author(s):  
Michael T. Deaton ◽  
David W. Williams
Keyword(s):  
Cynodon Dactylon ◽  
Germination Rate ◽  
Early Summer ◽  
Golf Course ◽  
Science Laboratory ◽  
University Of Kentucky ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Athletic Field ◽  
The University

The use of seeded bermudagrasses (Cynodon dactylon) is increasing as athletic field and golf course turf. Anecdotal evidence indicates probable and important differences in germination rates among cultivars when established in late spring or early summer. Germination studies were completed in May 2011 in the Turfgrass Science Laboratory at the University of Kentucky on 19 commercially available seeded bermudagrass cultivars. Evaluations for germination rate and total germination under varying temperature regimes representing 20-year average day/night temperatures for seeding times from 15 May to 1 Aug. were conducted to quantify any differences in germination characteristics among cultivars as affected by temperature. There were highly significant differences (P < 0.0001) among cultivars in germination rate and total germination when grown under 20-year average day/night temperatures. The cultivars Casino Royale and Riviera consistently represented the fastest/slowest to germinate and highest/lowest total seeds germinated across all temperature regimes, respectively. Significant differences (P < 0.0001) were also observed within cultivars for total germination across the temperature regimes tested. The average temperatures of 15 May and 1 Aug. represented slowest/fastest to germinate and lowest/highest total seeds germinated across all temperature regimes, respectively.

Acetaminophen: Neonatal hepatotoxicity due to late pregnancy exposure

1987 ◽  
Vol 45 ◽  
pp. 718-719
Author(s):  
G.A. Miranda ◽  
M.A. Arroyo ◽  
C.A. Lucio ◽  
M. Mongeotti ◽  
S.S. Poolsawat
Keyword(s):  
Low Dose ◽  
Fetal Liver ◽  
Late Pregnancy ◽  
Toxic Chemicals ◽  
Control Group ◽  
High Dose ◽  
Over The Counter ◽  
Liver And Kidney ◽  
Neonatal Liver ◽  
Childbearing Women

Exposure to drugs and toxic chemicals, during late pregnancy, is a common occurrence in childbearing women. Some studies have reported that more than 90% of pregnant women use at least 1 prescription; of this, 60% used more than one. Another study indicated that 80% of the consumed drugs were not prescribed, and of this figure, 95% were “over-the-counter” drugs. Acetaminophen, the safest of all over-the-counter drugs, has been reported to induce fetal liver necrosis in man and animals and to have abortifacient and embryocidal action in mice. This study examines the degree to which acetaminophen affects the neonatal liver and kidney, when a fatty diet is simultaneously fed to the mother during late pregnancy.Timed Swiss Webster female mice were gavaged during late pregnancy (days 16-19) with fat suspended acetaminophen at a high dose, HD = 84.50 mg/kg, and a low dose, LD = 42.25 mg/kg; a control group received fat alone.

Evaluation of hippocampus in rhesus monkeys after chronic (1-year) inhalation exposure to marijuana: I. Electron microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 398-399
Author(s):  
A.M. Andrews ◽  
S.W. Wilson ◽  
A.C. Scallet ◽  
S.F. Ali ◽  
J. Bailey ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Rhesus Monkeys ◽  
Low Dose ◽  
Inhalation Exposure ◽  
Synaptic Cleft ◽  
High Dose ◽  
Withdrawal Time ◽  
Treatment Groups ◽  
Ultrastructural Evidence ◽  
Male Rhesus

Exposure of rhesus monkeys (Macaca mulatta) to marijuana via inhalation or to intravenous delta-9-tetrahydrocannabinol (THC), reportedly caused ultrastructural evidence of increased synaptic width. Chronic marijuana smoke in a single rhesus monkey examined after a six month withdrawal time caused ultrastructure changes in the septal, hippocampal and amygdala regions; the synaptic cleft was widened, electron opaque material was found in the cleft and in the pre- and postsynaptic regions, with some clumping of the synaptic vesicles. The objective of our study was to assess neuropathological alterations produced by chronic inhalation of marijuana smoke.Nineteen male rhesus monkeys, 3-5 years of age and weighing 3-8 kg, were divided into four treatment groups: a) sham control, b) placebo smoke (7 days/ week) c) low dose marijuana (2 times/week with 5 days/week sham) and d) high dose marijuana (7 times/week). A smoke exposure consisted of smoke from one cigarette (2.6% THC) burned down to 10 mm butt length. Smoke was administered via smoke generator (ADL II, Arthur D. Little, Inc. Cambridge, MA) and nose-mouth only masks (local production) equipped with one-way valves.

Benefit/Risk Profile of Combined Antiplatelet Therapy with Ticlopidine and Aspirin

1991 ◽  
Vol 65 (05) ◽  
pp. 504-510 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
Walter Bernini ◽  
Guido Lazzerini ◽  
Giuliana Buti Strata ◽  
...  
Keyword(s):  
Platelet Function ◽  
Low Dose ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Stable Coronary Artery Disease ◽  
High Dose ◽  
Single Drug ◽  
Before And After ◽  
Serum Thromboxane ◽  
Artery Disease

SummaryTiclopidine (T) and aspirin (ASA) are two antiplatelet drugs both capable of prolonging bleeding time (BT), with a different mechanism of action. A synergism in BT prolongation has been reported and is currently considered an argument for not recommending their combination. However, a profound suppression of platelet function might be a desirable counterpart of a marked prolongation of BT, with a possible use in selected clinical situations. We therefore studied ex vivo platelet function (aggregation by ADP 0.5-1-2.5 μM; adrenaline 0.75-2.5 μM; collagen 1.5-150 μg/ml; arachidonic acid 1 mM; PAF 1 μM; adrenaline 0.17 μM + ADP 0.62 μM; serum thromboxane ([TX]B2 generation) and BT (Mielke) in 6 patients with stable coronary artery disease receiving such combination. Patients underwent sequential laboratory evaluations at baseline, after 7 days of T 250 mg b.i.d., before and after the intravenous administration of ASA 500 mg, respectively, and, finally, after a minimum of 7 days of sole ASA oral administration (50 mg/day). The experimental design, therefore, allowed a comparison of T and ASA effects (2nd and 4th evaluation), and an assessment of the combination effect (3rd evaluation). Platelet aggregation in response to all doses of ADP was depressed more by T than by ASA. Conversely, responses to adrenaline, and arachidonate were affected more by ASA than by T. For all other agents, differences were not significant. T + ASA combination was more effective (p <0.05) than either treatment alone in depressing responses to high-dose collagen (% over control, mean ± SEM: T: 95 ± 3; ASA: 96 ± 5; T + ASA: 89 ± 4). Serum TXB2 (basal, ng/ml: 380 ± 54) did not change with T (372 ± 36), dropped to <1 ng/ml on ASA injection and slightly re-increased to 9.1 ± 3.1 ng/ml on oral low-dose ASA. BT (basal 7.4 ± 0.6 min) was affected similarly by T (9.2 ± 0.8) or ASA (9.7 ± 0.9) alone, but increased to 15.0 ± 0.7 min on combination treatment (106% increase over control). Thus, the strong synergism in BT prolongation by ASA-T combination has a counterpart in the inhibition of platelet function in response to strong stimuli such as high-dose collagen, not otherwise affected significantly by single-drug treatment. This effect is a possible rationale for the clinical evaluation of T + ASA combination.

Intensive Initial Oral Anticoagulation and Shorter Heparin Treatment in Deep Vein Thrombosis

1984 ◽  
Vol 52 (03) ◽  
pp. 276-280 ◽  
Author(s):  
Sam Schulman ◽  
Dieter Lockner ◽  
Kurt Bergström ◽  
Margareta Blombäck
Keyword(s):  
Deep Vein Thrombosis ◽  
Oral Anticoagulation ◽  
Dose Group ◽  
Low Dose ◽  
Clinical Signs ◽  
Coagulation Factor ◽  
High Dose ◽  
Vein Thrombosis ◽  
Heparin Treatment ◽  
Deep Vein

SummaryIn order to investigate whether a more intensive initial oral anticoagulation still would be safe and effective, we performed a prospective randomized study in patients with deep vein thrombosis. They received either the conventional regimen of oral anticoagulation (“low-dose”) and heparin or a more intense oral anticoagulation (“high-dose”) with a shorter period of heparin treatment.In the first part of the study 129 patients were randomized. The “low-dose” group reached a stable therapeutic prothrombin complex (PT)-level after 4.3 and the “high-dose” group after 3.3 days. Heparin was discontinued after 6.0 and 5.0 days respectively. There was no difference in significant hemorrhage between the groups, and no clinical signs of progression of the thrombosis.In the second part of the study another 40 patients were randomized, followed with coagulation factor II, VII, IX and X and with repeated venograms. A stable therapeutic PT-level was achieved after 4.4 (“low-dose”) and 3.7 (“high-dose”) days, and heparin was discontinued after 5.4 and 4.4 days respectively. There were no clinical hemorrhages, the activity of the coagulation factors had dropped to the same level in both groups at the time when heparin was discontinued and no thromboembolic complications occurred.Our oral anticoagulation regimen with heparin treatment for an average of 4.4-5 days seems safe and reduces in-patient costs.

Effects of Aspirin and Sulfinpyrazone on Thromboxane and Prostacyclin Synthesis in Rabbits

1979 ◽  
Author(s):  
J McDonald ◽  
A Cerskus ◽  
M Ali
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Low Dose ◽  
High Dose ◽  
Prostacyclin Synthesis

Arachidonic acid (AA) or collagen were infused into rabbits causing intravascular platelet aggregation with thrombocytopenia, hypotension and death. Thromboxane and prostacyclin synthesis were measured by radioimmunoassay of plasma TXB2 and 6-keto-PGF1α. The effects of pretreatement with aspirin (ASA) or sulfinpyrazone(SPZ) were assessed.Death in drug-treated rabbits was always associated with elevations of plasma TXB2(1-40 ng/ml) and of 6-keto-PGF1α(1-20 ng/ml). Collagen produced only small elevations of plasma TXB2 compared to AA but protection by ASA correlated better with inhibition of TXB2 and 6-keto-PGF1α synthesis than with inhibition of aggregation. Low dose ASA produced less inhibition of prostacyclin synthesis than high dose ASA but was less effective in preventing thromboxane synthesis and death.

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