Herbicide Effectiveness in Response to Season of Application and Shrub Physiology

Weed Science ◽  
1982 ◽  
Vol 30 (5) ◽  
pp. 467-475 ◽  
Author(s):  
W. Thomas Lanini ◽  
Steven R. Radosevich
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Moisture Stress ◽  
Stages Of Development ◽  
Phenological Stages ◽  
Shrub Species ◽  
Arctostaphylos Patula ◽  
Dichlorophenoxy Acetic Acid

The selectivity of five foliage-applied herbicides, 2,4-D [(2,4-dichlorophenoxy)acetic acid], dichlorprop [2-(2,4-dichlorophenoxy)propionic acid], glyphosate [N-(phosphonomethyl)glycine], fosamine [ethyl hydrogen (aminocarbonyl)phosphonate], and triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid}, applied at three phenological stages of development to five Sierran shrub species, deerbrush [Ceanothus integerrimusvar.californicus(Kell.) G. T. Benson.], greenleaf manzanita (Arctostaphylos patulaGreene), bearmat (Chamaebatia foliolosaBenth.), snowbrush ceanothus (Ceanothus velutinusDougl.), and whiteleaf manzanita (Arctostaphylos viscidaParry), was compared. Treatments in the summer and fall were less effective than spring applications. Periods of herbicide susceptibility generally corresponded to times when moisture stress was low and photosynthesis was high.

Chemical Control of Canada Thistle

Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 116-118 ◽  
Author(s):  
A. G. Carson ◽  
J. D. Bandeen
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Chemical Control ◽  
Field Studies ◽  
Cirsium Arvense ◽  
Canada Thistle ◽  
Stages Of Development ◽  
Anisic Acid ◽  
Dichlorophenoxy Acetic Acid

Field studies were conducted to evaluate the effectiveness of one, two, and three annual applications of atrazine [2-chloro-4-(ethylamino) −6-(isopropylamino)-s-triazine], 2,4-D [(2,4-dichlorophenoxy) acetic acid], dicamba (3,6-dichloro-o-anisic acid), and a three way mix of dicamba, mecoprop [2-[(4-chloro-o-tolyl) oxy]propionic acid], and 2,4-D at a ratio of 7:5:20 at different stages of development for the control of Canada thistle [Cirsium arvense(L.) Scop.]. Two consecutive annual applications in all atrazine treatments achieved the same level of control as cultivation every 5 weeks. In the year of the last treatment, Canada thistle was controlled with two or more consecutive annual applications of the hormone-type herbicides (2,4-D, dicamba, and the three way mix); however, in the year following the last treatment, regrowth occurred.

Geyer Larkspur Phenology and Response to 2,4-D

Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 31-33 ◽  
Author(s):  
D. N. Hyder ◽  
L. D. Sabatka
Keyword(s):  
Acetic Acid ◽  
Root Growth ◽  
Plant Development ◽  
Mortality Rates ◽  
Flowering Plants ◽  
Poisonous Plant ◽  
Single Application ◽  
Stages Of Development ◽  
Dichlorophenoxy Acetic Acid ◽  
Late Stages

Mortality rates of Geyer larkspur(Delphinium geyeriGreene), a poisonous plant, were determined after spraying with (2,4-dichlorophenoxy)acetic acid at various stages of plant development in 1967 to 1969. Sprays of 2,4-D at 2.2 kg/ha were more effective at early than at late stages of development, but seldom exceeded 40% mortality. Uneven-aged stands and early drying (dormancy) of small non-flowering plants often prevented the exposure of all plants to a single application of spray; treated plants contorted but continued growth for 5 to 8 weeks after spraying; residual seed provided a source of new plants; and previously dormant rootstock buds gave rise to new shoot and root growth the year after spraying. These characteristics and escape mechanisms direct attention to possibilities of improving effectiveness by spraying two or three times in a single season.

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.

EFFECTS OF HERBICIDE RATES AND TIME OF APPLICATION ON THE CONTROL OF TANSY RAGWORT IN PASTURES

1976 ◽  
Vol 56 (3) ◽  
pp. 605-610 ◽  
Author(s):  
W. N. BLACK
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Active Ingredient ◽  
White Clover ◽  
Senecio Jacobaea ◽  
Time Of Application ◽  
Trifolium Repens L ◽  
Dichlorophenoxy Acetic Acid ◽  
Acetic Acids ◽  
Tansy Ragwort

The ester of 2,4-D [(2,4-dichlorophenoxy) acetic acid] at 1.1 kg active ingredient (a.i.)/ha failed to control tansy ragwort (Senecio jacobaea L.) in the late-rosette, bud, and flowering stages of development. Sprays of 2,4-D ester at 2.2 kg/ha were more effective than when applied at 1.1 kg/ha, but repeated treatments were necessary for optimum tansy ragwort control. Comparative dosage levels of the esters of 2,4-D and of 2,4-DB [4-(2,4-dichlorophenoxy) butyric acid] showed 2,4-D giving better control of tansy ragwort when applied at equivalent rates. Control of relatively immature tansy ragwort plants with 2,4-D was not significantly different at the 1.1, 2.2, and 4.5 kg/ha levels, but injury to grasses and white clover (Trifolium repens L.) increased at the higher rates. The ester of 2,4-DB at 2.2 and 4.5 kg/ha effectively controlled seedling and early-rosette tansy ragwort plants only. The quantity of water applied as a spray was critical since the frond-type leaves which fold over one another prevented thorough wetting of the entire foliage with spray volumes under 275 liters/ha. Data obtained over a 4-yr period showed that CMPP (±) 2-[(4-chloro-1-tolyl) oxy) propionic acid], CP 1815 (chlorinated benzoic and cresoxy-acetic acids), 2,3,6-TBA (dimethylamine salt of 2,3,6-trichlorobenzoic acid), 2,4-D acid [weedone 638, emulsifiable concentrate-(2,4-dichlorophenoxy) acetic acid], and fenoprop [2-(2,4,5-trichlorophenoxy) propionic acid] were as effective as the ester of 2,4-D for tansy ragwort control but caused more injury to components of the sward.

Effect of Timing of Spring Applications of Herbicides on Quality of Bermudagrass (Cynodon dactylon) Turf

Weed Science ◽  
1985 ◽  
Vol 33 (2) ◽  
pp. 238-243 ◽  
Author(s):  
B. Jack Johnson ◽  
Robert E. Burns
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Cynodon Dactylon ◽  
Turf Quality ◽  
Anisic Acid ◽  
Dichlorophenoxy Acetic Acid

Oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-δ2-1,3,4-oxadiazolin-5-one] applied to dormant bermudagrass [Cynodon dactylon(L.) Pers. ‘Tifway’ ♯ CYNDA] retarded early foliar growth more than other herbicides evaluated. When bensulide [O,O-diisopropyl phosphorodithioateS-ester withN-(2-mercaptoethyl)benzenesulfonamide] treatments were delayed until after bermudagrass initiated spring growth, foliar growth and quality were generally lower than when the treatments were applied to dormant turf. Retardation of early foliar bermudagrass growth by 2,4-D [(2,4-dichlorophenoxy)acetic acid] + mecoprop {2-[(4-chloro-o-tolyl)oxy] propionic acid} + dicamba (3,6-dichloro-o-anisic acid) was generally the same whether applied to dormant or semidormant turf. This combination of herbicides reduced the quality and density of bermudagrass when applied to growing but not to dormant turf. Atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] did not retard bermudagrass growth or affect density whether applied to dormant or semidormant turf, but turf quality was slightly lower when atrazine was applied to semidormant turf.

Response of Weeds in Bermudagrass (Cynodon dactylon) Turf to Tank-Mixed Herbicides

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 883-888 ◽  
Author(s):  
B. J. Johnson
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Cynodon Dactylon ◽  
Digitaria Sanguinalis ◽  
Anisic Acid ◽  
Dichlorophenoxy Acetic Acid ◽  
Large Crabgrass

Tank mixtures of herbicides for control of emerged winter weeds and preemergence control of large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA] were evaluated on bermudagrass [Cynodon dactylon(L.) Pers. ‘Common’ # CYNDA] fairways over a 2-yr period. Glyphosate [N-(phosphonomethyl)glycine] applied at 0.28 kg ai/ha in tank mixtures with DCPA (dimethyl tetrachloroterephthate) at 11 kg ai/ha controlled a higher percentage of parsley-piert (Alchemilla microcarpaBoiss. Reut. # APHMI) than either herbicide alone. When applied for spur weed (Solivaspp.) control, DCPA was antagonistic in the tank mixture with simazine [2-chloro-4,6-bis(ethylamino)-s-txiazine]. During one yr of the 2-yr study period, control of large crabgrass was less in plots treated with combination of DCPA and glyphosate than in plots treated with DCPA alone. Less large crabgrass control was obtained in plots treated with bensulide [O,O-diisopropyl phosphorodithioateS-ester withN-(2-mercaptoethyl)benzenesulfonamide] at 11 kg ai/ha in combinations with either paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) 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) than when treated only with bensulide.

Movements of Herbicides through Isolated American Pondweed (Potamogeton nodosus) Epidermal Tissues

Weed Science ◽  
1980 ◽  
Vol 28 (4) ◽  
pp. 419-424
Author(s):  
John C. Pringle ◽  
Lars W. J. Anderson
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Copper Sulfate ◽  
Tissue Layer ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Dichlorophenoxy Acetic Acid ◽  
Rate Of Movement ◽  
Potamogeton Nodosus

Enzymatically isolated American pondweed (Potamogeton nodosusPoir.) epidermal tissues were exposed to14C-labeled dichlobenil (2,6-dichlorobenzonitrile), diquat (6,7-dihydrodipyrido[1,2-α: 2′, 1′-c] pyrazinediium ion), silvex [2-(2,4,5-trichlorophenoxy) propionic acid] or 2,4-D [(2,4-dichlorophenoxy)acetic acid] at concentrations of 5 × 10−4, 5 × 10−5, and 5 × 10−610M, and the amount of herbicide crossing the tissue layer was measured. Rates of herbicide movement were compared to those found when copper sulfate pentahydrate was added as a potential synergist at concentrations of 5 × 10−5M (12.5 ppm), 5 × 10−6M (1.25 ppm), and 5 × 10−7M (0.125 ppm). Copper sulfate at 5 × 10−6M increased the rate of movement of all herbicides. However, diquat and dichlobenil exhibited the most enhanced movement in the presence of copper sulfate. Without copper sulfate, 0.1 nmoles of 5 × 10−6M14C diquat penetrated the tissue within 24 h, compared to 1.3 nmoles following the addition of 5 × 10−7M of copper sulfate.

Degradation of Dicamba, Picloram, and Four Phenoxy Herbicides in Soils

Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 556-560 ◽  
Author(s):  
J. D. Altom ◽  
J. F. Stritzke
Keyword(s):  
Acetic Acid ◽  
Linear Regression ◽  
Propionic Acid ◽  
Half Life ◽  
The Other ◽  
Degradation Rates ◽  
Anisic Acid ◽  
Herbicide Concentration ◽  
Phenoxy Herbicides ◽  
Dichlorophenoxy Acetic Acid

The degradation rates of 2,4-D [(2,4-dichlorophenoxy)acetic acid], dichlorprop [2-(2,4-dichlorophenoxy)propionic acid], 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], silvex [2,(2,4,5-trichlorophenoxy)propionic acid], dicamba (3,6-dichloro-o-anisic acid), and picloram (4-amino-3,5,6-trichloropicolinic acid) were determined in three soils. Herbicide breakdown was proportional to herbicide concentration, so half life of the various herbicides was calculated from linear regression of the logarithm transformed residue data. The average half life for 2,4-D, dichlorprop, silvex, 2,4,5-T, dicamba, and picloram were, respectively, 4 days, 10 days, 17 days, 20 days, 25 days, and greater than 100 days. The rate of degradation of 2,4-D was the same in all three soils, but for the other herbicides it was consistently faster in soil removed from under grass vegetation than from under trees.

Influence of Phenoxy Herbicides on Picloram Uptake and Phytotoxicity

Weed Science ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 226-229 ◽  
Author(s):  
A. S. Hamill ◽  
L. W. Smith ◽  
C. M. Switzer
Keyword(s):  
Acetic Acid ◽  
Phaseolus Vulgaris ◽  
Propionic Acid ◽  
Plant Part ◽  
Foliar Uptake ◽  
Treated Leaf ◽  
Red Kidney Bean ◽  
Phenoxy Herbicides ◽  
Dichlorophenoxy Acetic Acid ◽  
Bean Weight

The foliar uptake of 4-amino-3,5,6-trichloropicolinic acid (picloram) and its phytotoxicity in mixtures with several phenoxy herbicides were studied using bean (Phaseolus vulgaris L. ‘Red Kidney’). The greatest accumulation of picloram occurred in the growing point, stem, and axillary buds. Transport from the treated leaf occurred within 6 hr and continued for at least 7 days. The effectiveness of herbicide combinations containing picloram was related to the particular plant part measured. A synergistic reduction in fresh and dry red kidney bean weight was obtained with (2,4-dichlorophenoxy) acetic acid (2,4-D) or 2-[(4-chloro-o-tolyl)oxy]propionic acid (mecoprop) when applied in combination with picloram, whereas 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) and picloram gave an antagonistic response. An investigation of the antagonistic reaction of 2,4-DB with picloram indicated that picloram prevented the movement of 2,4-DB, while 2,4-DB increased both the distribution and the amount of picloram translocated from the point of application.

Control of Green Sagewort in the Nebraska Sandhills

Weed Science ◽  
1975 ◽  
Vol 23 (6) ◽  
pp. 465-469
Author(s):  
L. A. Morrow ◽  
M. K. McCarty
Keyword(s):  
Acetic Acid ◽  
Weed Control ◽  
Propionic Acid ◽  
Nitrogen Fertilizer ◽  
Herbicide Treatments ◽  
Nebraska Sandhills ◽  
Anisic Acid ◽  
Artemisia Campestris ◽  
Dichlorophenoxy Acetic Acid

Plots were established in 1970 in the Nebraska Sandhills for the control of green sagewort (Artemisia campestris L.). Herbicides were applied in 1970; 1970 and 1971; 1970, 1971, and 1972; and 1970 and 1972. Nitrogen fertilizer at 45 kg/ha was applied in 1973. Herbicide treatments included 2,4-D amine [(2,4-dichlorophenoxy)acetic acid], 2,4-D ester, 2,4,5-T [(2,4-5-trichlorophenoxy)acetic acid], silvex [2-(2,4,5-trichlorophenoxy)propionic acid], and mixtures of picloram (4-amino-3,5,6-trichloropicolinic acid) or dicamba (3,6-dichloro-o-anisic acid) and 2,4-D amine. Herbicides were most effective for the control of broadleaf weeds when they were applied in 3 consecutive years or in alternate years. Herbicides applied only once did not effectively control broadleaf weeds. When nitrogen was applied after weed control treatments, weed production increased if herbicide applications were not effective. If weed control treatments were effective, nitrogen did not affect weed production.

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