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Efficacy of α-(cyanomethoximino)-benzacetonitrile (CGA-43089), ((1,3-dioxolan-2-yl-methyl)imino)benzeneacetonitrile (CGA-92194), and 5-thiazolecarboxlic acid,benzl ester,2-chloro-4-(trifluoro-methyl) (MON-4606) as antidotes for acetanilide herbicides and effect of antidotes on grain sorghum (Sorghum bicolor (L.) moench) germination and development / by Daniel L. Devlin.Devlin, Daniel L. January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
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Differential tolerance of corn hybrids to metolachlor and its regulation by the safener benoxacor /Cottingham, Charles K., January 1991 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 137-139). Also available via the Internet.
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ACTIVATED CARBON: ITS NEUTRALIZING EFFECTS ON A PREEMERGENT HERBICIDETabo, Ramadjita January 1982 (has links)
No description available.
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Rattail fescue (Vulpia myuros) control in Italian ryegrass (Lolium multiflorum) grown for seedReyes, Carlos C. 23 January 1991 (has links)
Italian ryegrass growth and production from
positionally selective applications and sublethal rates of a
nonselective herbicide were compared to growth and
production when treated with diuron applied preemergence as
a broadcast treatment and safened by activated carbon
applied over the crop row. In the positionally selective
treatments, herbicide spray was directed to leave an
untreated zone over the crop row at planting. Growth
analysis indicated no detectable differences when Italian
ryegrass safened by directed spray was compared to Italian
ryegrass safened by activated carbon. The major difference
between systems was greater weed control in the crop row for
carbon-safened treatments.
The non-safened application superimposed sublethal
diuron rates over Italian ryegrass and rattail fescue grown
in varying densities and proportiors. Growth analysis of
monoculture stands indicated differences due to planted
density, species, and herbicide, whereas growth analysis of
plants grown as space-planted individuals indicated
difference due to species only. Diuron at the rates applied
did not affect seed yield or above ground dry weight.
Soil samples were taken in crop rows where diuron was
applied as directed spray or broadcast spray safened by
carbon. Samples were assayed and soil profile
concentrations mapped. To assist future investigators'
understanding of the role rainfall plays in herbicide
movement from directed applications, elementary rainfall
depth and occurrence models were examined. The Markov and
mixed-exponential models adequately described rainfall
occurrence and depth patterns for Corvallis, Oregon. / Graduation date: 1992
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Studies on the mechanisms of action of the herbicide safener CGA- 92194Zama, Paul January 1985 (has links)
CGAr92194 {α-[1,3-dioxolan-2-yl-methoxy)imino]benzeneacetonitrile} is a herbicide safener that is used as a seed dressing agent (1.25 g ai/kg seeds) to protect grain sorghum [<i>Sorghum bicolor</i> (L.) Moench] against metolachlor [2-chloroi-<u>N</u>-(2-ethyl-6-methylphenyl-<u>N</u>-(2-methoxy1-methylethyl)acetamide] injury. The potential adverse phytotoxic effects and the mechanisms of the protective action of this safener were studied in laboratory experiments.
Adverse phytotoxicity was assessed by comparing CGA-92194 and the herbicide safeners cyometrinil {(Z)-α[(cyanomethoxy)imino]benzeneacetonitrile} and flurazole [phenylmethyl 2-chloro-4-(trifluromethyl)-5-thiazolecarboxylate] for their effects on CO₂ fixation, protein, DNA, RNA and lipid syntheses of enzymatically isolated leaf cells of soybean [<u>Clycine max</u> (L.) Merr]. At physiological concentrations of less than 10 μM, CGA-92194, cyometrinil and flurazole were stimulatory of all metabolic processes. At 100 μM, the safeners were inhibitory of the five processes with flurazole being the most potent.
The mechanisms of the safening action of CGA-92194 were studied by examining the potential interactions of this safener with metolachlor at the levels of uptake and macromolecular syntheses in enzymatically isolated leaf mesophyll protoplasts of grain sorghum. The influence of CGA-92194 on the <i>in vitro</i> reactivity of metolachlor with glutathione (GSH) and it metabolism by sorghum seedlings were also examined. When CGA-92194 and metolachlor were given simultaneously, CGA-92194 enhanced the uptake of ¹⁴C-metolachlor into the sorghum protoplasts in a concentration-dependent pattern. Thus, interference with herbicide uptake is not involved in the protective action of this safener Treatments with metolachlor and CGA-92194 in combination inhibited the incorporation of ¹⁴C-uracil, ³H-thymidine and ¹⁴C-acetate into sorghum protoplast macromolecules less than metolachlor given alone, suggesting the potential involvement of a competitive antagonism in the mechanism of action of CGA-92194.
The metabolic activity and growth of sorghum seedlings grown from CGA-92194-pretreated seeds was significantly lower than that of seedlings grown from untreated seeds at 10 or 20 days after planting, The relationship of these effects of CGA-92194 to its safening action is unclear at the present time.
CGA-92194 increased the <i>in vitro</i> chemica1 reactivity of metolachlor for GSH in a concentration-dependent pattern, Sorghum seedlings grown from safener-pretreated seeds enhanced ¹⁴C-metolachlor absorption and stimulated its metabolism <u>via</u> conjugation to GSH. This stimulation was reduced by tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethy1)- oxirane] a potent inhibitor of plant GSH-<u>S</u>-transference enzymes, These results indicate that a safener-induced stimulation of the spontaneous or enzymatic conjugation of metolachlor with GSH is most likely involved in the protective action of CGA-92194.
It is suggested that the safening mechanism of action of CGA—92194 involves a sequence of multilevel interactions which together contribute to the overall protection of grain sorghum from metolachlor injury. / Ph. D. / incomplete_metadata
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Differential tolerance of corn hybrids to metolachlor and its regulation by the safener benoxacorCottingham, Charles K. 28 July 2008 (has links)
Determining the basis of intraspecific herbicide tolerance was expected to be a useful way of revealing factors which are regulated by safeners in providing their protective effect. Differential tolerance to the chloroacetanilide herbicide metolachlor and the thiocarbamate herbicide EPTC was examined in 11 corn hybrids. Tolerance to one of these herbicides does not imply similar tolerance to the other. Detoxication of these herbicides in plants is mediated via conjugation with glutathione (GSH). GSH levels from 1.8 to 2.4 µmol/g fresh weight were determined for the eleven corn hybrids tested. There was no correlation between GSH content and herbicide tolerance. The monooxygenase inhibitor piperonyl butoxide (PBO) acted synergistically with EPTC on 8 of the tested corn hybrids. A Similar antagonism by the oxygen evolving compound calcium peroxide provided additional evidence for the importance of oxidative processes in EPTC tolerance which were not important in determining metolachlor tolerance. The more rapid absorption and greater accumulation of ¹⁴C-metolachlor by 'Northrup-King 9283' corn relative to 'Cargill 7567' corn at least partially explains the increased susceptibility of the former hybrid to metolachlor. The in vitro metabolism of ¹⁴C-metolachlor was similar for both hybrids. A lag in the expression of glutathione S-transferase (GST) activity during early seedling development of 'Northrup-King 9283' corn may be of additional significance in its limited tolerance to metolachlor. The safener benoxacor was effective in protecting 'Northrup-King 9283' and other susceptible corn hybrids from metolachlor injury. Benoxacor had no effect on metolachlor uptake or the rate of non-enzymatic conjugation of metolachlor. Seedlings of 'Cargill 7567' and 'Northrup-King 9283' treated with 1 µM benoxacor metabolized metolachlor to the GS-conjugate at a rate 1.7 times that of untreated seedlings. GST activity was stimulated by 35% by similar treatment. GST isozymes with metolachlor conjugating activity (GST-metolachlor activity) were found in the cytosol and microsomal fractions of corn extracts. At least two GST-metolachlor isozymes were separated by DEAE-Sepharose chromatography. The activity of both isozymes was increased by benoxacor treatment. It appears that benoxacor regulates metolachlor tolerance by inducing GST isozymes that consequently increase the rate of metolachlor detoxication. / Ph. D.
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Investigations on the mechanism of action of the oxime ether safeners for the protection of grain sorghum against metolachlorYenne, Samuel P. January 1989 (has links)
Herbicide safeners (protectants, antidotes) are used to protect crop plants from herbicide injury. Currently our understanding of the mechanisms involved in the protection of plants by safeners is not well defined; therefore, investigations were conducted to elucidate the mechanism(s) of action of the oxime ether safeners. Molecular comparisons of selected herbicide-safener combinations using computer-aided molecular modeling revealed that the chemical structures of safeners and herbicides are very similar at the molecular level; and, indicate that these compounds could bind at the same active site of the target protein or they may serve as inducers of metabolic enzymes which detoxify herbicides. Metolachlor at 10 μM and seed-applied CGA-133205 had no effect on germination while treatment with seed-applied oxabetrinil significantly reduced germination of grain sorghum. Results from experiments on ¹⁴C-acetate incorporation into lipids indicate that metolachlor and the oxime ether safeners influence lipid metabolism causing a redistribution of carbon in the lipid fractions of germinating sorghum roots. Results from studies with acetyl-CoA carboxylase indicate that this enzyme is not a target site for either metolachlor or the oxime ether safeners. Metolachlor and the oxime ether safeners enhanced glutathione levels in grain sorghum seedlings at 12 to 48 hr after imbibition was initiated with oxabetrinil being more stimulatory than metolachlor or CGA-133205. Glutathione reductase activity was also stimulated in safener-treated grain sorghum seedlings. Both safeners slightly enhanced nonenzymatic and enzymatic conjugation of metolachlor with reduced glutathione. Oxabetrinil conjugated enzymatically or nonenzymatically with reduced glutathione at a slow rate, but CGA-133205 did not. These data suggest that during the early stages of seed germination and seedling development of grain sorghum, safeners can enhance the detoxication of metolachlor by enhancing glutathione levels and enzymatic and nonenzymatic conjugation of metolachlor with glutathione. It appears that oxabetrinil and CGA-133205 are conferring protection to grain sorghum by increasing the rate of metolachlor metabolism. / Ph. D.
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