Control of Woody Plants with Herbicide Mixtures

Weed Science ◽  
1973 ◽  
Vol 21 (5) ◽  
pp. 423-426 ◽  
Author(s):  
R. E. Meyer ◽  
R. W. Bovey

Honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell], huisache [Acacia farnesiana(L.) Willd.], Macartney rose (Rosa bracteataWendl.), live oak (Quercus virginianaMill.), and whitebrush (Aloysia lycioidesCham.) were sprayed with herbicides alone and in mixtures. Mixtures of picloram (4-amino-3,5,6-trichloropicolinic acid) + dicamba (3,6-dichloro-o-anisic acid) at 0.56 + 0.56 and 1.12 + 1.12 kg/ha were most effective for killing honey mesquite in July. Picloram or picloram + dicamba were more effective for defoliating huisache than 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], dicamba, or other mixtures of herbicides. On Macartney rose picloram as the salt or ester was most effective, but some mixtures of picloram plus either 2,4-D [(2,4-dichlorophenoxy)acetic acid] or 2,4,5-T were as effective as picloram alone. On live oak, the most effective treatments generally contained at least 1.12 kg/ha of picloram either alone or in mixtures with dicamba or 2,4,5-T. Picloram alone killed as many or more whitebrush plants than MCPA [[(4-chloro-o-tolyl)oxy]acetic acid], dicamba, 2,4,5-T, 2,4-D, or mixtures.

Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 358-362 ◽  
Author(s):  
R. E. Meyer ◽  
R. W. Bovey

Hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] was applied to honeylocust (Gleditsia triacanthosL.), honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell], huisache [Acacia farnesiana(L.) Willd.], live oak (Quercus virginianaMill.), Macartney rose (Rosa bracteataWendl.), post oak (Quercus stellataWangenh.), saw greenbrier (Smilax bona-noxL.), whitebrush (Aloysia lycioidesCham.), and yaupon (Ilex vomitoriaAit.). Bromacil (5-bromo-3-sec-butyl-6-methyluracil) and tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} were used for comparison in some experiments. Hexazinone was required at the following rates to kill at least 75% of the following species: 1.1 kg/ha for live oak, 2.2 kg/ha for post oak, 4.5 kg/ha for huisache (at Bryan, Texas) and whitebrush, and 9 kg/ha for honeylocust. Hexazinone was ineffective at 9 kg/ha for control of honey mesquite, huisache (at Washington, Texas), Macartney rose, saw greenbrier, and yaupon. Tebuthiuron at 1.1 kg/ha killed 80% of the live oak, and as a subsurface spray at 4.5 kg/ha, killed huisache (at Washington, Texas). Bromacil was effective on huisache at 9 kg/ha.


Weed Science ◽  
1972 ◽  
Vol 20 (4) ◽  
pp. 332-335 ◽  
Author(s):  
R. W. Bovey ◽  
R. E. Meyer ◽  
R. D. Baker ◽  
J. R. Baur

Polymerized and conventional (2,4-dichlorophenoxy)-acetic acid (2,4-D), (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T), 3,6-dichloro-o-anisic acid (dicamba), and 4-amino-3,5,6-trichloro-picolinic acid (picloram) were applied alone and in certain combinations to several brush species. Generally there were no significant differences in effectiveness between conventional and polymerized herbicides on honey mesquite(Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockrell), huisache(Acacia farnesianaL. Willd.), Macartney rose(Rosa bracteataWendl.), live oak(Quercus virginianaMill.), whitebrush(Aloysia lycioidesCham.), and winged elm(Ulmus alataMichx.). Conventional granular picloram was more effective on yaupon(Ilex vomitoriaAit.) than polymerized formulations.


Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 332-335 ◽  
Author(s):  
R. W. Bovey ◽  
F. S. Davis ◽  
H. L. Morton

We studied 4-amino-3,5,6-trichloropicolinic acid (picloram) alone and in combination with 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) or 1,1′-dimethyl-4,4′-bipyridinium salt (paraquat) for control of several greenhouse, nursery, and natural-grown, woody plant species. Picloram:paraquat combinations improved the control of some species such as yaupon (Ilex vomitoria Ait.) as compared to picloram alone at equal rates; but it had an antagonistic effect on huisache (Acacia farnesiana (L.) Willd.) and honey mesquite (Prosopis juliflora (Swartz) DC. var. glandulosa (Torr.) Cockerell). Evaluation of picloram: 2,4,5-T combinations suggested that 2,4,5-T sometimes could be added in equal amounts to picloram to increase control or reduce picloram rates proportionately on huisache, honey mesquite and live oak (Quercus virginiana Mill.).


Weed Science ◽  
1974 ◽  
Vol 22 (4) ◽  
pp. 384-388 ◽  
Author(s):  
H. G. Mccall ◽  
C. J. Scifres ◽  
M. G. Merkle

Three blended foam adjuvants increased 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] uptake from aqueous solutions by detached live oak (Quercus virginianaMill.) leaves as compared to uptake from water alone. There were no differences in honey mesquite [Prosopis juliflora(Swartz.) D.C. var.glandulosa(Torr.) Cockerell] control with 2,4,5-T or 1:1 combinations of 2,4,5-T with picloram (4-amino-3,5,6-trichloropicolinic acid) or with dicamba (3,6-dichloro-o-anisic acid) at 0.56 kg/ha whether applied in water + 0.5% (v/v) foam adjuvant or in a diesel oil: water (1:4, v/v) emulsion. Residual life of picloram in native forages was not extended by foam carrier as compared to water, water and surfactant, and diesel oil:water emulsion as carrier. Foam generation from adjuvants with expansion ratios (ER) of two to four was less susceptible to alteration from addition of commercially-formulated herbicides than was an adjuvant with an ER of seven. Foam adjuvant ER's increased in a curvilinear fashion as water temperature was increased from 5 to 50 C.


Weed Science ◽  
1969 ◽  
Vol 17 (4) ◽  
pp. 538-541 ◽  
Author(s):  
R. W. Bovey ◽  
H. L. Morton ◽  
J. R. Baur ◽  
J. D. Diaz-Colon ◽  
C. C. Dowler ◽  
...  

Granular 4-amino-3,5,6-trichloropicolinic acid (picloram) was effective in controlling live oak(Quercus virginiana(Mill.), huisache)(Acacia farnesiana(L.), Willd.), and yaupon(Ilex vomitoriaAit.), but not honey mesquite(Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell) in south Texas. Granular 5-bromo-3-sec-butyl-6-methyluracil (bromacil) controlled live oak and huisache. Herbicides applied to soil were usually most effective in spring and fall during periods of active brush growth. Picloram granules applied in May to a mixed stand of woody plants in Puerto Rico usually were effective. However, rates up to 30 lb/A were ineffective on some species.


Weed Science ◽  
1974 ◽  
Vol 22 (3) ◽  
pp. 276-279 ◽  
Author(s):  
R. W. Bovey ◽  
R. E. Meyer

Picloram (4-amino-3,5,6-trichloropicolinic acid), 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] and dicamba (3,6-dichloro-o-anisic acid) were sprayed at 0.28 kg/ha on honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell] and huisache [Acacia farnesiana(L.) Willd.] seedlings 1, 2, 4, 8, 12, and 16 weeks after emergence from seed under greenhouse conditions. Picloram or 2,4,5-T killed 73% or more of the honey mesquite up to 8 weeks after emergence, but the percent killed declined thereafter. Picloram killed more than 90% of the huisache seedlings when applied from 1 to 8 weeks after emergence. Less than 60% of the honey mesquite or huisache seedlings were killed with dicamba at any treatment date. Clipping the plants at the soil level resulted in high mortality (96 to 100%) of both species 1 to 2 weeks after emergence. Treating regrowth of clipped 1-year-old honey mesquite and huisache with 0.28 kg/ha of picloram, dicamba, or 2,4,5-T produced results similar to those obtained from plants grown from seed.


Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 373-378 ◽  
Author(s):  
Robert E. Meyer ◽  
Rodney W. Bovey

Tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} in various formulations and placements was applied to honey mesquite (Prosopis glandulosaTorr. # PRCJG), huisache [Acacia farnesiana(L.) Willd. # ACAFA], live oak (Quercus virginianaMill.#QUEVI), Macartney rose (Rosa bracteataJ. C. Wendl. # ROSBC), and Texas whitebrush [Aloysia gratissima(Gillies & Hook.) Troncoso # ALYLY]. There was little difference in a species response to the various tebuthiuron formulations. Pellets (20%) at 2 g ai/tree base reduced the canopy 85% and killed 50% of the honey mesquite. At 1 g ai/plant, two briquettes at 0.5 g ai each or pellets (5.14 g, 20%) killed 37 and 80% of the huisache, respectively. Pellets were no more effective at 2 g than at 1 g ai on huisache. Basal treatments of 0.25, 0.5, 0.5, 1, and 2 g ai tebuthiuron/tree killed from 8 to 22, 48 to 62, 62 to 85, and 92% of the live oak, respectively. Pellets at 2 g ai placed at the base reduced the canopy 83% and killed 59% of the Macartney rose. On Texas whitebrush, 0.25, 0.5, 1, and 2 g ai tebuthiuron/tree killed from 68 to 85, 75 to 100, 90, and 100% of the plants, respectively. Tebuthiuron persisted mainly in the upper 30 cm of soil for at least 15 months.


Weed Science ◽  
1981 ◽  
Vol 29 (4) ◽  
pp. 376-378 ◽  
Author(s):  
P. W. Jacoby ◽  
C. H. Meadors ◽  
M. A. Foster

The herbicide 3,6-dichloropicolinic acid was more effective than 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] or equal-ratio combinations of 2,4,5-T with picloram (4-amino-3,5,6-trichloropicolinic acid) or dicamba (3,6-dichloro-o-anisic acid) when aerially applied as broadcast sprays for control of honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell]. Applied at 0.56 kg/ha, 3,6-dichloropicolinic acid controlled 60 and 68% of the honey mesquite at two locations; whereas, the mixture of 2,4,5-T and picloram controlled only 21 and 30% of the honey mesquite at the same rate of application. The herbicide 3,6-dichloropicolinic acid was equally effective when applied alone or in 1:1 mixtures with 2,4,5-T, picloram, or triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid} at equivalent rates. Applying 3,6-dichloropicolinic acid at 1.12 kg/ha resulted in an absolute increase in mortality of 26% over the 0.56-kg/ha rate.


Weed Science ◽  
1982 ◽  
Vol 30 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Robert E. Meyer

Soil-applied herbicides were evaluated for control of blackjack oak (Quercus marilandicaMuenchh.), huisache [Acacia farnesiana(L.) Willd.], honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell], live oak (Quercus virginianaMill.), Macartney rose (Rosa bracteataWendl.), winged elm (Ulmus alataMichx.), and yaupon (Ilex vomitoriaAit.) in Texas. Various spacing of spot treatments of pelleted tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} on huisache and live oak and picloram (4-amino-3,5,6-trichloropicolinic acid) on Macartney rose up to a 2.7-m square grid did not change herbicide effectiveness. Pelleted tebuthiuron at 2.2 kg/ha reduced the canopy of live oak and killed a significant percentage of plants; however, differences among herbicide formulations and distance of placement in a grid were small. On unburned plots, 2.2 kg/ha of tebuthiuron applied as pellets at 2.7-m centers and as a broadcast wettable-powder treatment killed fewer yaupon than pellets applied in most broadcast treatments. In individual-plant treatments, bromacil (5-bromo-3-sec-butyl-6-methyluracil) and picloram solutions at 2 g/plant killed 45% of the yaupon 1.5 to 2 m tall on a fine sandy loam, whereas 0.5 g/plant of either herbicide killed 70% or more of the yaupon plants 1 m tall on a loamy fine sand. Both bromacil and picloram at 1 g/plant killed all blackjack oak and winged elm sprouts 1 to 2 m tall. On a clay soil, 1 g of bromacil/plant killed 79% of the live oak and 88% of the winged elm plants, whereas picloram killed only 38 and 45%, respectively. Neither bromacil nor picloram was effective as soil treatments for killing honey mesquite.


Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 349-352 ◽  
Author(s):  
Rodney W. Bovey ◽  
Robert E. Meyer

Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) was superior to 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], dicamba (3,6-dichloro-o-anisic acid), picloram (4-amino-3,5,6-trichloropicolinic acid), and triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid} for control of honey mesquite (Prosopis glandulosaTorr. ♯ PRCJG) in the field. However, equal ratio mixtures of clopyralid + picloram or triclopyr (0.28 + 0.28 or 0.56 + 0.56 kg ae/ha) were as effective for honey mesquite control as clopyralid at rates of 0.56 and 1.12 kg/ha. Equal mixtures of picloram + 2,4,5-T, picloram + triclopyr, picloram + dicamba, triclopyr + 2,4,5-T, or triclopyr + dicamba were less effective in controlling honey mesquite than clopyralid alone or clopyralid + picloram or triclopyr in 1:1 mixtures. In the greenhouse, mixtures of clopyralid + 2,4,5-T, picloram, or triclopyr were highly effective for the control of honey mesquite. Mixtures of 2,4,5-T + picloram, 2,4,5-T + triclopyr, or triclopyr + picloram were also effective when applied at 0.28 + 0.28 kg/ha.


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