Dose–Response Curves of KIH-485 for Preemergence Weed Control in Corn

2009 ◽  
Vol 23 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Avishek Datta ◽  
Jon Scott ◽  
Peter J. Porpiglia
Keyword(s):  
Weed Control ◽  
Dose Response ◽  
Field Experiments ◽  
Response Curves ◽  
Tolerance Dose ◽  
Green Foxtail ◽  
Excellent Control ◽  
Dose Response Curves ◽  
Different Levels ◽  
Large Crabgrass

Field experiments were conducted in Nebraska with the experimental herbicide KIH-485 on soils with three different levels of organic matter (OM) to ascertain a dose response for weed control and corn tolerance. Dose–response curves based on the log-logistic model were used to determine the effective dose that provides 90% weed control (ED90 values) for three grasses (green foxtail, field sandbur, large crabgrass) and two broadleaf weeds (velvetleaf, tall waterhemp). The ED90 values for green foxtail control were 143, 165, and 202 g ai/ha for soils with 1, 2, and 3% OM, respectively at 28 d after treatment (DAT). The highest dose of 371 g ai/ha was needed for field sandbur control at 28 DAT, compared with 141 g ai/ha for large crabgrass, 152 g ai/ha for tall waterhemp, and 199 g ai/ha for velvetleaf. There was no significant corn injury observed. Grain yield increased with increasing doses of KIH-485; optimum yield was achieved at about 195 g ai/ha. From the dose–response curves it is clear that the proposed label rate of KIH-485 of 200 to 300 g ai/ha will provide excellent control of most grasses and certain broadleaf weeds in corn for at least the first 4 wk of the growing season on soils up to 3% OM in the state of Nebraska.

Adjuvants Influenced Saflufenacil Efficacy on Fall-Emerging Weeds

2009 ◽  
Vol 23 (3) ◽  
pp. 340-345 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Avishek Datta ◽  
Jon Scott ◽  
Leo D. Charvat
Keyword(s):  
Weed Control ◽  
Dose Response ◽  
Field Experiments ◽  
Weed Species ◽  
Response Curves ◽  
Wheat Field ◽  
Field Pennycress ◽  
Field Bindweed ◽  
Label Dose ◽  
Dose Response Curves

Saflufenacil is a new herbicide being developed for preplant burndown and PRE broadleaf weed control in field crops, including corn, soybean, sorghum, and wheat. Field experiments were conducted in 2006 and 2007 at Concord, in northeast Nebraska, with the objective to describe dose–response curves of saflufenacil applied with several adjuvants for broadleaf weed control. Dose–response curves based on log-logistic model were used to determine the effective dose that provides 90% weed control (ED90) values for six broadleaf weeds (field bindweed, prickly lettuce, henbit, shepherd's-purse, dandelion, and field pennycress). Addition of adjuvants greatly improved efficacy of saflufenacil. For example, the ED90values for field bindweed control at 28 d after treatment were 71, 20, 11, and 7 g/ha for saflufenacil applied alone, or with nonionic surfactant (NIS), crop oil concentrate (COC), or methylated seed oil (MSO), respectively. MSO was the adjuvant that provided the greatest enhancement of saflufenacil across all species tested. COC was the second-best adjuvant and provided control similar to MSO on many weed species. NIS provided the least enhancement of saflufenacil. These results are very similar to the proposed label dose of saflufenacil for burndown weed control, which will range from 25 to 100 g/ha with MSO or COC. We believe that such a dose would provide excellent burndown control of most broadleaf weed species that emerge in the fall in Nebraska.

Weed Management in Conventional- and No-Till Soybean Using Flumioxazin/Pyroxasulfone

2014 ◽  
Vol 28 (2) ◽  
pp. 298-306 ◽  
Author(s):  
Kris J. Mahoney ◽  
Christy Shropshire ◽  
Peter H. Sikkema
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Conventional Tillage ◽  
Common Ragweed ◽  
No Till ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Excellent Control ◽  
Almost All

Eleven field experiments were conducted over a 3-yr period (2010, 2011, and 2012) in conventional- and no-till soybean with a flumioxazin and pyroxasulfone premix. PRE and preplant applications were evaluated for soybean injury, weed control, and yield compared to standard herbicides. Early-season soybean injury from flumioxazin/pyroxasulfone ranged from 1 to 19%; however, by harvest, soybean yields were similar across labeled rates (160 and 200 g ai ha−1), standard treatments, and the nontreated control. Flumioxazin/pyroxasulfone provided excellent control (99 to 100%) of velvetleaf, pigweed species (redroot pigweed and smooth pigweed), and common lambsquarters across almost all rates tested (80 to 480 g ai ha−1). Common ragweed, green foxtail, and giant foxtail control increased with flumioxazin/pyroxasulfone rate. The biologically effective rates varied between tillage systems. The flumioxazin/pyroxasulfone rate required to provide 80% control (R80) of pigweed was 3 and 273 g ai ha−1under conventional- and no-till, respectively. For common ragweed, the R80was 158 g ai ha−1under conventional tillage; yet, under no-till, the rate was nonestimable. The results indicate that flumioxazin/pyroxasulfone can provide effective weed control as a setup for subsequent herbicide applications.

Response of Sweet Corn to Pyroxasulfone in High-Organic-Matter Soils

2013 ◽  
Vol 27 (2) ◽  
pp. 341-346 ◽  
Author(s):  
Dennis C. Odero ◽  
Alan L. Wright
Keyword(s):  
Organic Matter ◽  
Weed Control ◽  
Dose Response ◽  
Sweet Corn ◽  
Corn Yield ◽  
Response Curves ◽  
Common Lambsquarters ◽  
High Organic Matter ◽  
Dose Response Curves ◽  
Common Purslane

Field experiments were conducted in 2011 and 2012 in Belle Glade, FL to evaluate the response of sweet corn and weed control to pyroxasulfone on high-organic-matter soils in the Everglades Agricultural Area (EAA) of southern Florida with the use of dose-response curves. Pyroxasulfone was applied PRE at 31.25, 62.5, 125, 250, 500, and 1,000 g ai ha−1 on soil with 80% organic matter. Dose-response curves based on a three-parameter log-logistic model were used to determine pyroxasulfone rate required to provide 90% control (ED90) of spiny amaranth, common lambsquarters, and common purslane in sweet corn. The ED90 values for spiny amaranth, common lambsquarters, and common purslane control were 209, 215, and 194 g ha−1 of pyroxasulfone, respectively, at 21 d after treatment (DAT). At 42 DAT, the ED90 values for spiny amaranth, common lambsquarters, and common purslane control were 217, 271, and 234 g ha−1 of pyroxasulfone, respectively. Sweet corn yield increased with increasing rates of pyroxasulfone. An estimated 214 g ha−1 of pyroxasulfone was required to maintain sweet corn yield at 90% level of the weed-free yield. In addition, pyroxasulfone did not result in sweet corn injury. These results indicate that pyroxasulfone can provide effective weed control in sweet corn on high-organic-matter soils of the EAA.

scholarly journals First report of Amaranthus viridis resistance to herbicides

2014 ◽  
Vol 32 (3) ◽  
pp. 571-578 ◽  
Author(s):  
A.C. Francischini ◽  
J. Constantin ◽  
R.S. Oliveira JR. ◽  
G. Santos ◽  
G.B.P. Braz ◽  
...  
Keyword(s):  
Weed Control ◽  
Dose Response ◽  
Response Curves ◽  
Mato Grosso ◽  
First Report ◽  
Resistance To Herbicides ◽  
Dose Response Curves ◽  
Als Inhibitors ◽  
Mato Grosso Do Sul ◽  
Selection Of

Due to the limited number of herbicides registered for the control of dicot weeds in cotton crops, ALS inhibitors have been used on an intensive and recurrent basis. Given that, cases of poor weed control have been described after application of these herbicides in the main cotton producing areas in Brazil, the purpose of the present work was to evaluate the occurrence of resistance to ALS herbicides in Amaranthus viridis biotypes from those areas. Dose-response curves were prepared after pre-emergence applications of trifloxysulfuron-sodium (0; 1.8; 3.7; 7.5; 15 and 30 g ha-1) and pyrithiobac-sodium (0; 35; 70; 140; 280 and 560 g ha-1), equivalent to 0, ¼, ½, 1, 2 and 4 times the recommended commercial rates. The selection of trifloxysulfuron-sodium resistant biotypes of A. viridis was confirmed in samples from Bahia (BA 7, BA 8, BA 9 and BA 11). However, no resistance to pyrithiobac-sodium was found for biotypes either from Bahia or from Mato Grosso do Sul.

Dose-response Curves in the Fibrin Plate Assay Fibrinolytic Activity of Proteases

1974 ◽  
Vol 32 (02/03) ◽  
pp. 356-365 ◽  
Author(s):  
F Haverkate ◽  
D. W Traas
Keyword(s):  
Dose Response ◽  
Fibrinolytic Activity ◽  
Enzyme Concentration ◽  
Response Curves ◽  
Agar Gel ◽  
Porcine Tissue ◽  
Plate Assay ◽  
Fibrin Plate ◽  
Different Types ◽  
Dose Response Curves

SummaryIn the fibrin plate assay different types of relationships between the dose of applied proteolytic enzyme and the response have been previously reported. This study was undertaken to determine whether a generally valid relationship might exist.Trypsin, chymotrypsin, papain, the plasminogen activator urokinase and all of the microbial proteases investigated, including brinase gave a linear relationship between the logarithm of the enzyme concentration and the diameter of the circular lysed zone. A similar linearity of dose-response curves has frequently been found by investigators who used enzyme plate assays with substrates different from fibrin incorporated in an agar gel. Consequently, it seems that this linearity of dose-response curves is generally valid for the fibrin plate assay as well as for other enzyme plate bioassays.Both human plasmin and porcine tissue activator of plasminogen showed deviations from linearity of semi-logarithmic dose-response curves in the fibrin plate assay.

OVARIAN ASCORBIC ACID DEPLETION TEST FOR LUTEINIZING HORMONE

1967 ◽  
Vol 56 (4) ◽  
pp. 619-625 ◽  
Author(s):  
Hans Jacob Koed ◽  
Christian Hamburger
Keyword(s):  
Ascorbic Acid ◽  
Luteinizing Hormone ◽  
Dose Response ◽  
Response Curve ◽  
Dose Response Curve ◽  
Human Origin ◽  
Response Curves ◽  
Significant Difference ◽  
The Mean ◽  
Different Levels

ABSTRACT Comparison of the dose-response curves for LH of ovine origin (NIH-LH-S8) and of human origin (IRP-HMG-2) using the OAAD test showed a small, though statistically significant difference, the dose-response curve for LH of human origin being a little flatter. Two standard curves for ovine LH obtained with 14 months' interval, were parallel but at different levels of ovarian ascorbic acid. When the mean ascorbic acid depletions were calculated as percentages of the control levels, the two curves for NIH-LH-S8 were identical. The use of standards of human origin in the OAAD test for LH activity of human preparations is recommended.

BIOASSAY OF THYROID HORMONE USING HYPOTHYROID TADPOLES

1962 ◽  
Vol 41 (1) ◽  
pp. 143-153 ◽  
Author(s):  
U. Henriques
Keyword(s):  
Thyroid Hormone ◽  
Dose Response ◽  
Developmental Rate ◽  
Response Curves ◽  
Sodium Salts ◽  
Dose Response Curves

ABSTRACT A bioassay of thyroid hormone has been developed using Xenopus larvae made hypothyroid by the administration of thiourea. Only tadpoles of uniform developmental rate were used. Thiourea was given just before the metamorphotic climax in concentrations that produced neoteni in an early metamorphotic stage. During maintained thiourea neotoni, 1-thyroxine and 1-triiodothyronine were added as sodium salts to the water for three days and at the end of one week the stage of metamorphosis produced was determined. In this way identical dose-response curves were obtained for the two compounds. No qualitative differences between their effects were noted except that triiodothyronine seemed more toxic than thyroxine in equivalent doses. Triiodothyronine was found to be 7–12 times as active as thyroxine.

Dose Response Curves for Microwave Ablation in the Cardioplegia-Arrested Porcine Heart

2005 ◽  
Vol 8 (4) ◽  
pp. E269-E274 ◽  
Author(s):  
Sydney L. Gaynor ◽  
Gregory D. Byrd ◽  
Michael D. Diodato ◽  
Yosuke Ishii ◽  
Anson M. Lee ◽  
...  
Keyword(s):  
Dose Response ◽  
Microwave Ablation ◽  
Response Curves ◽  
Porcine Heart ◽  
Dose Response Curves

Modeling Nonmonotonic Dose-Response Curves

2001 ◽  
Author(s):  
Quinton J. Nottingham ◽  
Jeffrey B. Birch ◽  
Barry A. Bodt
Keyword(s):  
Dose Response ◽  
Response Curves ◽  
Dose Response Curves

scholarly journals Comment Concerning the Effects of Light Intensity on Melatonin Suppression in the Review “Light Modulation of Human Clocks, Wake, and Sleep” by A. Prayag et al.

2021 ◽  
Vol 3 (1) ◽  
pp. 181-188
Author(s):  
Peter Bracke ◽  
Eowyn Van de Putte ◽  
Wouter R. Ryckaert
Keyword(s):  
Phase Shift ◽  
Light Intensity ◽  
Dose Response ◽  
Light Modulation ◽  
Response Curves ◽  
Practical Applications ◽  
Circadian Phase ◽  
Melatonin Suppression ◽  
Dose Response Curves ◽  
Circadian Phase Shift

Dose-response curves for circadian phase shift and melatonin suppression in relation to white or monochromatic nighttime illumination can be scaled to melanopic weighed illumination for normally constricted pupils, which makes them easier to interpret and compare. This is helpful for a practical applications.

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