Antagonistic Effects of MCPA on Wild Oat (Avena fatua) Control with Diclofop

Weed Science ◽  
1981 ◽  
Vol 29 (5) ◽  
pp. 566-571 ◽  
Author(s):  
Wayne A. Olson ◽  
John D. Nalewaja
Keyword(s):  
Acetic Acid ◽  
Indole Acetic Acid ◽  
Treatment Temperature ◽  
Avena Fatua ◽  
Propanoic Acid ◽  
Controlled Environment ◽  
Wild Oat ◽  
Anisic Acid ◽  
Dichlorophenoxy Acetic Acid ◽  
Root Inhibition

Experiments were conducted in the field, greenhouse, and controlled environment chambers to determine the extent to which MCPA {[(4-chloro-o-tolyl)oxy] acetic acid} antagonizes wild oat (Avena fatuaL.) control with diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid}. Wild oat control with diclofop at 1 kg/ha was reduced from 96% when used alone to 76, 48, 31, and 14% by tank mixture with IAA (3-indole acetic acid), MCPA, 2,4-D [(2,4-dichlorophenoxy)acetic acid], or dicamba (3,6-dichloro-o-anisic acid), respectively. Wild oat control with diclofop applied alone at 1.1 kg/ha was similar to that of diclofop at 2.2 kg/ha applied as a tank mixture with MCPA at 0.15 or 0.3 kg/ha. MCPA antagonism of wild oat control with diclofop increased as the post-treatment temperature increased from 10 to 30 C. MCPA antagonism of wild oat control with diclofop was the same whether the herbicides were applied to the foliage only or to the foliage and soil. Approximately 20% of the wild oat root inhibition with diclofop applied postemergence, however, was from diclofop uptake from the soil. MCPA at 0.6 kg/ha did not reduce wild oat control when applied as a sequential treatment 2 days before or 1 day after diclofop at 1.1 kg/ha.

Influence of Picloram Alone or Plus 2,4-D on Control of Wild Oats (Avena fatua) with Four Postemergence Herbicides

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 889-891 ◽  
Author(s):  
P. Ashley O'Sullivan
Keyword(s):  
Acetic Acid ◽  
Weed Control ◽  
Broad Spectrum ◽  
Field Experiments ◽  
Avena Fatua ◽  
Propanoic Acid ◽  
Wild Oats ◽  
Commercial Mixture ◽  
Dichlorophenoxy Acetic Acid ◽  
Postemergence Herbicides

Field experiments were conducted for 2 yr to determine the influence of picloram (4-amino-3,5,6-trichloropicolinic acid) and a commercial mixture of picloram plus 2,4-D [(2,4-dichlorophenoxy)acetic acid] (1:16, w/w) on control of wild oats (Avena fatua L. # AVEFA) with four postemergence herbicides. The phytotoxicity to wild oats of barban (4-chloro-2-butynyl m-chlorocarbanilate) or difenzoquat (1,2-dimethyl-3,5-diphenyl-1H-pyrazolium) in 1981 and diclofop {2-[4-(2,4-dichlorophenoxy)-phenoxy] propanoic acid} or flamprop [N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine] in 1981 and 1982 was reduced when these herbicides were applied in a mixture with picloram plus 2,4-D. Consequently, the use of these mixtures for broad-spectrum weed control in one spray operation is not recommended. Picloram applied at a rate equivalent to the amount present in the picloram plus 2,4-D mixture did not influence the control of wild oats obtained with any herbicide, indicating that the antagonism was due to the 2,4-D component of the picloram plus 2,4-D mixture.

Amine Salts of Growth Regulator Herbicides Antagonize Paraquat

Weed Science ◽  
1982 ◽  
Vol 30 (6) ◽  
pp. 605-608 ◽  
Author(s):  
John T. O'Donovan ◽  
P. Ashley O'Sullivan
Keyword(s):  
Triticum Aestivum ◽  
Acetic Acid ◽  
Hordeum Vulgare ◽  
Growth Regulator ◽  
Avena Fatua ◽  
Fixed Rate ◽  
Wild Oats ◽  
Separate Treatment ◽  
Anisic Acid ◽  
Dichlorophenoxy Acetic Acid

Amine formulations of 2,4-D [(2,4-dichlorophenoxy) acetic acid] and MCPA {[(4-chloro-o-tolyl)oxy] acetic acid} caused a reduction in paraquat (1,1-dimethyl-4,4′-bipyridinium ion) phytotoxicity to barley (Hordeum vulgareL. 'Summit′), wheat (Triticum aestivumL. ‘Neepawa′), and wild oats (Avena fatuaL.). Dicamba (3,6-dichloro-o-anisic acid) reduced paraquat activity in barley only. Paraquat phytotoxicity was antagonized more by 2,4-D amine at high than at low rates. Higher rates of paraquat relative to a fixed rate of 2,4-D amine overcame the antagonism. Paraquat phytotoxicity was not antagonized by 2,4-D or MCPA amine applied as a separate treatment. The technical components of the 2,4-D- or MCPA-amine formulations were solely responsible for the antagonism. Ester formulations did not affect paraquat phytotoxicity.

Effect of MCPA on14C-Diclofop Uptake and Translocation

Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Wayne Olson ◽  
J. D. Nalewaja
Keyword(s):  
Acetic Acid ◽  
Avena Fatua ◽  
Propanoic Acid ◽  
Distilled Water ◽  
Wild Oat ◽  
Sucrose Uptake ◽  
Acid Pretreatment ◽  
Dark Treatment ◽  
Treated Leaf ◽  
Constant Dark

Experiments were conducted to determine the influence of the dimethylamine salt of MCPA {[(4-chloro-o-tolyl)oxy] acetic acid} pretreatment, darkness from 1 day prior to treatment until harvest, and exogenous sucrose on diclofop {2-[4-(2,4-dichlorophenoxy)phenoxyl] propanoic acid} glucose, and sucrose uptake and translocation by wild oat (Avena fatuaL.). Uptake of14C-diclofop label by wild oat foliage was not influenced by MCPA pretreatment, constant dark treatment, or the addition of exogenous sucrose. Total14C-diclofop and14C-glucose label uptake and translocation were similar whether 5 cm of the treated leaf tip were placed in distilled water or 1% (w/v) sucrose. Downward translocation of14C-diclofop,14C-sucrose, and14C-glucose label in the phloem of wild oat was reduced similarly by MCPA, constant dark treatments, or a combination of the two. Upward translocation of14C-diclofop label was greater and exudation of14C-diclofop label into the ‘tip’ solution was less than that of14C-sucrose or14C-glucose label, regardless of MCPA or constant dark treatments. Downward translocation of14C-diclofop label was reduced as much by MCPA topically applied to the wild oat leaf 1 cm above, 1 cm below, or with the diclofop as with the MCPA broadcast pretreatment.

Barban Selectivity for Wild Oat in Wheat

Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 476-480 ◽  
Author(s):  
Robert W. Neidermyer ◽  
John D. Nalewaja
Keyword(s):  
Triticum Aestivum ◽  
Air Temperature ◽  
Leaf Blade ◽  
Plant Morphology ◽  
Treatment Temperature ◽  
Avena Fatua ◽  
Post Treatment ◽  
Wild Oat ◽  
Wheat Growth ◽  
Wild Oats

The response of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.) to barban (4-chloro-2-butynyl-m-chlorocarbanilate) was studied as influenced by plant morphology and air temperature after application. Growth of wheat and wild oat seedlings was reduced by barban at 0.3 μg and 0.6 μg applied to the first node, respectively. Barban application to the base and midpoint of the first leaf blade required a lower dose to reduce wild oat growth than wheat growth. Increased tillering occurred from barban injury to the main culm in wheat. Wheat and wild oat susceptibility to barban increased as the post-treatment temperature decreased from 32 to 10 C. Barban selectivity for wild oats in wheat was greater at 27 and 21 C than at 16 and 10 C.

SPRAY DROPLET DISTRIBUTION AND HERBICIDE UPTAKE IN SEQUENTIAL APPLICATIONS OF DICLOFOP-METHYL AND MCPA FOR WEED CONTROL IN BARLEY

1979 ◽  
Vol 59 (1) ◽  
pp. 93-98 ◽  
Author(s):  
F. A. QURESHI ◽  
W. H. VANDEN BORN
Keyword(s):  
Acetic Acid ◽  
Leaf Surface ◽  
Avena Fatua ◽  
Wild Oat ◽  
Spray Application ◽  
Spray Droplet ◽  
Wild Oats ◽  
Droplet Distribution ◽  
Spray Droplets ◽  
Spray Volume

Uptake of 14C-diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy propanoate]} by leaves of wild oats (Avena fatua L.) was reduced significantly in the presence of MCPA {[(4-chloro-o-tolyl)oxy]acetic acid]}, especially the dimethylamine formulation. If the herbicides were applied separately, the degree of interference with uptake depended on the extent of overlap of droplets of the two spray preparations on the leaf surface. Spray volume and direction of spray application were important factors in minimizing the mixing of spray droplets on the leaves if the two herbicides were applied separately with a tandem arrangement of two sprayers. Such a sequential application of MCPA ester and diclofop-methyl in a field experiment provided significantly greater wild oat control than could be obtained with a tank mix of the same two herbicides, but the results were not consistent enough to recommend the procedure for practical use.

Effect of 2,4-D on the Hydrolysis of Diclofop-Methyl in Wild Oat (Avena fatua)

Weed Science ◽  
1980 ◽  
Vol 28 (6) ◽  
pp. 725-729 ◽  
Author(s):  
B. D. Hill ◽  
B. G. Todd ◽  
E. H. Stobbe
Keyword(s):  
Enzyme Preparation ◽  
Avena Fatua ◽  
Wild Oat ◽  
Enzymic Hydrolysis ◽  
Standard Assay ◽  
Rate Of Hydrolysis ◽  
Dichlorophenoxy Acetic Acid ◽  
Hydrolysis Of ◽  
Assay Conditions

The basis for 2,4-D [(2,4-dichlorophenoxy)acetic acid] antagonism of diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy) phenoxy] propanoate} toxicity to wild oat (Avena fatuaL.) was investigated by studying changes in the metabolism of diclofop-methyl in vitro. An esterase from wild oat, which hydrolyzes diclofop-methyl to the acid diclofop, was extracted, partially purified, and the reaction characterized. The rate of hydrolysis of14C-diclofop-methyl was 0.14 ηmoles/2 h at standard assay conditions of 0.25 mg lyophilized enzyme preparation (19.6% protein) in 0.1 ml phosphate buffer (0.1 M, pH 7.0), substrate 5 μM. The addition of 2,4-D to this reaction did not inhibit14C-diclofop formation. Higher levels of 2,4-D stimulated enzymic hydrolysis.14C-diclofop-methyl was rapidly metabolized to14C-diclofop and polar14C-conjugates when vacuum-infiltrated into wild oat leaf segments. The addition of 2,4-D caused small increases in the rates of both14C-diclofop-methyl de-esterification and14C-diclofop conjugation. It is concluded that 2,4-D does not inhibit the in vitro de-esterification of diclofop-methyl.

Effect of Herbicides on the Production of Common Buffelgrass (Cenchrus ciliaris)

Weed Science ◽  
1984 ◽  
Vol 32 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Rodney W. Bovey ◽  
Hugo Hein ◽  
Robert E. Meyer
Keyword(s):  
Acetic Acid ◽  
Cenchrus Ciliaris ◽  
Shoot Production ◽  
Anisic Acid ◽  
Growth Production ◽  
Dichlorophenoxy Acetic Acid ◽  
Relative Differences

Dicamba (3,6-dichloro-o-anisic acid), 2,4-D [(2,4-dichlorophenoxy)acetic acid], 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], 3,6-dichloropicolinic acid, picloram (4-amino-3,5,6-trichloropicolinic acid), triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid}, tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea}, and hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] were applied at rates of 0.3, 0.6, 1.1, and 2.2 kg/ha pre- and postemergence to greenhouse-grown common buffelgrass (Cenchrus ciliarisL. ♯3PESCI). Buffelgrass tolerated preemergence sprays of 3,6-dichloropicolinic acid up to and including 1.1 kg/ha. All other treatments except picloram and 2,4,5-T at 0.3 kg/ha were phytotoxic to emerging buffelgrass. Buffelgrass tolerated early postemergence applications of 2,4-D, picloram, and tebuthiuron at 0.3 kg/ha; dicamba and 2,4,5-T at 0.6 kg/ha; and 3,6-dichloropicolinic acid at 2.2 kg/ha based on oven-dry shoot production 1 month after treatment. Regrowth of buffelgrass from stubble 1 month after original harvest of the early postemergence treatment occurred only with all rates of 3,6-dichloropicolinic acid and 2,4,5-T at 0.3 kg/ha. When treated at 45 days after planting, buffelgrass tolerated dicamba, 2,4-D, 2,4,5-T, 3,6-dichloropicolinic acid, and picloram at 2.2 kg/ha, but top growth production was significantly reduced by most rates of hexazinone and tebuthiuron. Relative differences in regrowth of buffelgrass 1 month after the original harvest were similar to those of the original harvest. Mature buffelgrass (90 or 150 days old) responded similarly to herbicides as the 45-day-old buffelgrass.

Influence of Nitrogen on Recovery of Bermudagrass (Cynodon dactylon) Treated by Herbicides

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 819-823 ◽  
Author(s):  
B. Jack Johnson
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Cynodon Dactylon ◽  
Turf Quality ◽  
Herbicide Treatment ◽  
Anisic Acid ◽  
Dichlorophenoxy Acetic Acid

Bermudagrass [Cynodon dactylon(L.) Pers. ‘Tifway’] injured by MSMA (monosodium methanearsonate) plus metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] or 2,4-D [(2,4-dichlorophenoxy)acetic acid] plus mecoprop {2-[(4-chloro-o-tolyl)oxy] propionic acid} plus dicamba (3,6-dichloro-o-anisic acid) recovered more rapidly when nitrogen (N) was applied in sequence with the herbicides than when no N was applied. Bermudagrass recovery was faster with less injury within 2 weeks after herbicide treatment when N was applied at the first MSMA plus metribuzin treatment or when N was applied at 2 weeks after the first 2,4-D plus mecoprop plus dicamba treatment. Turf quality at 4 weeks or later was consistently as good or better in plots where N was applied at 2 weeks after the first application of either herbicide combination than when N was applied earlier.

Environment and Herbicide Effects on Canada Thistle Ecotypes

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 163-167 ◽  
Author(s):  
James H. Hunter ◽  
Leon W. Smith
Keyword(s):  
Acetic Acid ◽  
Root Development ◽  
Leaf Damage ◽  
Cirsium Arvense ◽  
Temperature Dependent ◽  
Canada Thistle ◽  
Anisic Acid ◽  
Herbicide Effects ◽  
Increasing Temperature ◽  
Dichlorophenoxy Acetic Acid

Root sections of seven Canada thistle(Cirsium arvense(L.) Scop.) ecotypes were grown under 8, 12, 14, and 16-hr photoperiods at 16, 21, and 27 C. Flowering occurred in all ecotypes under a 16-hr photoperiod. At the 14-hr photoperiod five ecotypes flowered; flowering in three of them was temperature-dependent. Shoot and root development and plant height varied with ecotype. Both the root-to-shoot ratios and the number of shoot buds formed on the roots were inversely related to temperature and length of photoperiod. Herbicides tested for their effects on Canada thistle were 4-amino-3,5,6-trichloropicolinic acid (picloram), 3,6-dichloro-o-anisic acid (dicamba), and (2,4-dichlorophenoxy)acetic acid (2,4-D). Control of top growth increased with increasing temperature. Similarly, root control was maximum at 27 C, at which temperature there were few fleshy roots. Picloram, unlike 2,4-D and dicamba, caused little leaf damage but completely destroyed the root system.

The Basis of the Antagonistic Effect of 2,4-D on Diclofop-Methyl Toxicity to Wild Oat (Avena fatua)

Weed Science ◽  
1980 ◽  
Vol 28 (4) ◽  
pp. 371-377 ◽  
Author(s):  
B. G. Todd ◽  
E. H. Stobbe
Keyword(s):  
Degradation Products ◽  
Membrane Damage ◽  
Antagonistic Effect ◽  
Avena Fatua ◽  
Wild Oat ◽  
Meristematic Activity ◽  
Leaf Necrosis ◽  
Dichlorophenoxy Acetic Acid ◽  
Control Application ◽  
Methyl Propanoate

The interaction between diclofop-methyl {2-[4-(2,4-dichlorophenoxy)phenoxy] methyl propanoate} and 2,4-D [(2,4-dichlorophenoxy)acetic acid] was evaluated. Foliar applications of the two herbicides in a tank mixture were antagonistic with respect to wild oat (Avena fatuaL.) control. Application of mixtures of the two herbicides to wild oat roots resulted in an additive herbicidal effect. The acid form of 2,4-D was determined to be the component of the 2,4-D formulation that reduced the toxicity of foliar-applied diclofop-methyl to wild oat. Analysis of diclofop-methyl solutions with and without added 2,4-D revealed no degradation products of dichlofop-methyl, nor any evidence of complexing between diclofop-methyl and 2,4-D. Addition of 2,4-D to the diclofop-methyl spray solution did not affect diclofop-methyl spray retention by, or penetration into, wild oat leaves. Movement of radioactivity to roots and to shoot apices following application of14C-diclofop-methyl to wild oat leaves was reduced by addition of 2,4-D to the treatment solution. Deesterification of diclofop-methyl was inhibited by 2,4-D. The accumulation of diclofop-methyl in these wild oat leaves resulted in membrane damage and leaf necrosis. Symplastic movement of the des-methyl acid, diclofop, to sensitive meristematic areas was reduced. As insufficient toxicant reached meristematic areas to permanently interrupt meristematic activity, the wild oat plants were able to outgrow the contact damage to their leaves.

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