Control of Horseweed (Conyza canadensis) with Growth Regulator Herbicides

2010 ◽  
Vol 24 (4) ◽  
pp. 425-429 ◽  
Author(s):  
Greg R. Kruger ◽  
Vince M. Davis ◽  
Stephen C. Weller ◽  
William G. Johnson
Keyword(s):  
Field Study ◽  
Growth Regulators ◽  
Dose Response ◽  
Growth Regulator ◽  
The Other ◽  
Conyza Canadensis ◽  
Appropriate Use ◽  
Dose Response Study

The growth regulator herbicides 2,4-D and dicamba are used to control glyphosate-resistant horseweed before crops are planted. With the impending release of 2,4-D–resistant and dicamba-resistant crops, use of these growth regulator herbicides postemergence will likely increase. The objective of this study was to determine the effectiveness of various growth regulators on Indiana horseweed populations. A greenhouse dose–response study was conducted to evaluate the effectiveness of 2,4-D ester, diglycolamine salt of dicamba, and dimethylamine salt of dicamba on control of four populations of horseweed in the greenhouse. Population 66 expressed twofold levels of tolerance to 2,4-D ester and diglycolamine salt of dicamba. Population 43 expressed an enhanced level of tolerance to diglycolamine salt of dicamba but not to the other herbicides. Diglycolamine salt of dicamba provided the best overall control of populations 3 and 34. Additionally, a field study was conducted to evaluate standard use rates of 2,4-D amine, 2,4-D ester, diglycolamine salt of dicamba, and dimethylamine salt of dicamba on control of various sized glyphosate-resistant horseweed plants. Control of plants 30 cm or less in height was 90% or greater for all four herbicides. On plants greater than 30 cm tall, diglycolamine salt of dicamba provided 97% control while 2,4-D amine provided 81% control. Diglycolamine salt of dicamba provided the highest level of control of glyphosate-resistant horseweed, followed by dimethylamine salt of dicamba, 2,4-D ester and 2,4-D amine, respectively. This research demonstrates that horseweed populations respond differently to the various salts of 2,4-D and dicamba, and it will be important to determine the appropriate use rates of each salt to control glyphosate-resistant horseweed.

Short Communication: Effect of silymarin (Silybum marianum) treatment on prolactin concentrations in cyclic sows

2013 ◽  
Vol 93 (2) ◽  
pp. 227-230 ◽  
Author(s):  
F. Loisel ◽  
H. Quesnel ◽  
C. Farmer
Keyword(s):  
Dose Response ◽  
Short Communication ◽  
The Other ◽  
Milk Thistle ◽  
Silybum Marianum ◽  
Blood Samples ◽  
Communication Effect ◽  
Dose Response Study ◽  
Estradiol 17Β

Loisel, F., Quesnel, H. and Farmer, C. 2013. Short Communication: Effect of silymarin (Silybum marianum) treatment on prolactin concentrations in cyclic sows. Can. J. Anim. Sci. 93: 227–230. An extract (silymarin) from the plant Silybum marianum (milk thistle) was shown to increase circulating concentrations of prolactin in cycling rats. A dose-response study was undertaken to determine if silymarin does have hyperprolactinemic properties in cycling swine. Forty-four weaned sows were allotted to four groups receiving 0, 1, 2 or 4 g d−1 of silymarin over a period of 8 d. Blood samples were obtained on days 1 (first day of treatment starting 24 to 48 h after the onset of the standing estrus), 2, 3, and 9. Prolactin, progesterone, estradiol-17β and leptin concentrations were determined. Silymarin did not increase prolactin concentrations at any of the doses studied, nor did it affect concentrations of the other hormones (P>0.1).

scholarly journals The Response of Wheat Cultivars Triticum aestivum L. to Various Growth Regulators Under Thi-Qar Province Condition

2018 ◽  
Vol 7 (1) ◽  
pp. 49-56
Author(s):  
Haitham A. Ali ◽  
Salih Hadi Farhood AL-Salim ◽  
Ragheb Hadi A. AL-burky
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Growth Regulators ◽  
Combination Treatment ◽  
Growth Regulator ◽  
Growing Season ◽  
Triticum Aestivum L ◽  
The Other ◽  
Wheat Cultivars ◽  
1000 Grain Weight

A field experiment is conducted at Thi-Qar Province in AL-Shatra District located about 30 Km North AL-Nassiria City to study the response of three wheat Cultivars Triticum  aestivum L. to Growth regulators during 2014-2015 growing Season. The Cultivars are Latifia , AL-Rasheed and Iba 99. The growth regulators are Alga600, Atonik and Azomin32%. Factorial experiment in R.C.B.D.  with three replicates is used . The results showed that Iba 99  Cultivar gives the highest plant height , Spikes/m2 and grain yield , with a means 80.83 cm , 272.25 spike/m2 and 3.06 Ton/h) Respectively . Azomin32%  growth regulator gives the highest grain /spike , 1000 grain weight and grain yield , with a means 66.00 seed/spike ,43.55 gm , 272.33 spike/m2  respectively. In addition the interaction between Iba 99 Cultivar  and Azomin32% growth regulator gives the highest Leaf Area , number of grain/spike and grain yield with means 45.10 cm2 , 70.00 grain/spike and 3.16 ton/ha respectively.The combination treatment Iba 99 with Atonik growth regulator gives the highest number of spike/m2  with a mean 279.66 spike/m2  . In the other hand, the same cultivar with Atonik and Azomin32% gives the highest mean of grain yield with a amount 3.16 ton/ha.

Response and Survival of Rosette-Stage Horseweed (Conyza canadensis) after Exposure to 2,4-D

Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 748-752 ◽  
Author(s):  
Greg R. Kruger ◽  
Vince M. Davis ◽  
Stephen C. Weller ◽  
William G. Johnson
Keyword(s):  
Dose Response ◽  
Growth Suppression ◽  
Conyza Canadensis ◽  
Visible Injury ◽  
Susceptible Population ◽  
Soybean Production ◽  
No Till ◽  
Dose Response Study

2,4-D is often used as a preplant burndown herbicide to help control horseweed and other broadleaf weeds before planting in no-till corn and soybean production. Isolated instances of poor horseweed control have occurred in production fields. The objective of this research was to evaluate the response of various horseweed populations to 2,4-D. In the first study, 478 horseweed populations from Indiana were subjected to 280 g ae ha−1of 2,4-D amine in the greenhouse. This rate of 2,4-D caused visible injury and prevented all biotypes from forming new leaves for 28 days. There were specific populations where all plants sprayed were alive at 28 days after treatment (DAT), and approximately 10% of all populations had a least one plant that survived 280 g ae ha−12,4-D, resumed growth, and produced seed. In a dose-response study, we observed populations with three-fold more tolerance to 2,4-D. The most tolerant population had a GR90of 513 g ae ha−1and the most susceptible population had a GR90of 121 g ae ha−1based on dry weights. Growth suppression with 2,4-D was not affected by rosette size for rosettes between 0.5 and 10 cm in width.

Reduction of insulin clearance during hyperglycemic clamp. Dose-response study in normal humans

Diabetes ◽  
1988 ◽  
Vol 37 (10) ◽  
pp. 1351-1357 ◽  
Author(s):  
H. Tillil ◽  
E. T. Shapiro ◽  
A. H. Rubenstein ◽  
J. A. Galloway ◽  
K. S. Polonsky
Keyword(s):  
Dose Response ◽  
Insulin Clearance ◽  
Hyperglycemic Clamp ◽  
Normal Humans ◽  
Dose Response Study

Long-term Effects of Triazol Growth Regulators on Stem Elongation of Rhododendron and Kalmia

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 436E-436
Author(s):  
Martin P.N. Gent
Keyword(s):  
Dose Response ◽  
Growth Regulator ◽  
Stem Elongation ◽  
Spray Application ◽  
Long Term Effects ◽  
Potted Plants ◽  
Response Coefficient ◽  
Wide Range ◽  
Second Year

The persistence of effects of paclobutrazol or uniconazol on stem elongation was determined for several years after large-leaf Rhododendron and Kalmia latifolia were treated with a single-spray application of these triazol growth-regulator chemicals. Potted plants were treated in the second year from propagation, and transplanted into the field in the following spring. The elongation of stems was measured in the year of application and in the following 2 to 4 years. Treatments with a wide range of doses were applied in 1991, 1992, or 1995. For all except the most-dilute applications, stem elongation was retarded in the year following application. At the highest doses, stem growth was inhibited 2 years following application. The results could be explained by a model of growth regulator action that assumed stem elongation was inversely related to amount of growth regulator applied. The dose response coefficient for paclobutrazol was less than that for uniconazol. The dose that inhibited stem elongation one-half as much as a saturating dose was about 0.5 and 0.05 mg/plant, for paclobutrazol and uniconazol, respectively. The dose response coefficient decreased exponentially with time after application, with an exponential time constant of about 2/year. The model predicted a dose of growth regulator that inhibited 0.9 of stem elongation immediately after application would continue to inhibit 0.5 of stem elongation in the following year.

scholarly journals Application of Plant Extracts in Micropropagation and Cryopreservation of Bleeding Heart: An Ornamental-Medicinal Plant Species

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 542
Author(s):  
Dariusz Kulus ◽  
Natalia Miler
Keyword(s):  
Tissue Culture ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Plant Extracts ◽  
The Other ◽  
White Gold ◽  
Natural Extracts ◽  
Other Hand ◽  
The Impact

Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts in the tissue culture systems of plants other than orchids. The aim of this study is to compare the utility of traditional plant growth regulators (PGRs) and natural extracts—obtained from the coconut shreds, as well as oat, rice, and sesame seeds—in the micropropagation and cryopreservation of L. spectabilis ‘Gold Heart’ and ‘White Gold’. The biochemical analysis of extracts composition is also included. In the first experiment related to micropropagation via axillary buds activation, the single-node explants were cultured for a 10-week-long propagation cycle in the modified Murashige and Skoog medium fortified either with 1.11 µM benzyladenine (BA) and 1.23 µM indole-3-butritic acid (IBA) or with 10% (v/v) plant extracts. A PGRs- and extract-free control was also considered. In the cryopreservation experiment, the same 10% (v/v) extracts were added into the medium during a seven-day preculture in the encapsulation-vitrification cryopreservation protocol. It was found that the impact of natural additives was cultivar- and trait-specific. In the first experiment, the addition of coconut extract favoured the proliferation of shoots and propagation ratio in bleeding heart ‘Gold Heart’. Rice extract, on the other hand, promoted callus formation in ‘White Gold’ cultivar and was more effective in increasing the propagation ratio in this cultivar than the conventional plant growth regulators (4.1 and 2.6, respectively). Sesame extract suppressed the development of the explants in both cultivars analysed, probably due to the high content of polyphenols. As for the second experiment, the addition of plant extracts into the preculture medium did not increase the survival level of the cryopreserved shoot tips (sesame and oat extracts even decreased this parameter). On the other hand, coconut extract, abundant in simple sugars and endogenous cytokinins, stimulated a more intensive proliferation and growth of shoots after rewarming of samples. Analysing the synergistic effect of conventional plant growth regulators and natural extracts should be considered in future studies related to L. spectabilis.

Dose–response study of myo-inositol as an inhibitor of lung tumorigenesis induced in A/J mice by benzo[a]pyrene and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone

2001 ◽  
Vol 167 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Stephen S. Hecht ◽  
Patrick M.J. Kenney ◽  
Mingyao Wang ◽  
Pramod Upadhyaya
Keyword(s):  
Dose Response ◽  
Lung Tumorigenesis ◽  
Dose Response Study

scholarly journals A randomized, fixed-dose, dose–response study of ropinirole prolonged release in advanced Parkinson's disease

2017 ◽  
Vol 7 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Theresa A Zesiewicz ◽  
Stephen Chriscoe ◽  
Theresa Jimenez ◽  
James Upward ◽  
Maria Davy ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dose Response ◽  
Fixed Dose ◽  
Prolonged Release ◽  
Advanced Parkinson’S Disease ◽  
Dose Response Study
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