Last update: 09-FEB-2010


Herbicides

This publication is intended to serve as a reference guide for brush control and should not be used as a substitute for reading the label. Herbicide rates are not shown in this publication. Use rates vary according to the target brush species and the method of application. The appropriate herbicide label is the best source of current application information. Because herbicide labels are constantly updated or changed, you should read the label thoroughly before using any herbicide.

Access (picloram ester + triclopyr ester). Access is a prepackaged mixture of two herbicides used as a basal bark or thinline treatment. Access is mixed in diesel fuel, kerosene, or other approved penetrant before application. All treatments are most effective when basal diameters of stems are less than 6 inches. As a thinline treatment, Access has shown activity on hickory, sweetgum, and blackgum. The picloram component is a persistent, highly mobile herbicide that should not be used in areas where runoff water may contaminate surface water or groundwater. The product is a RESTRICTED USE material.

Accord (glyphosate). Accord is water soluble and is used mainly as a foliar spray. It is also very useful in injection and stump sprays. Spray coverage should be uniform and complete (spray-to-wet). It is subject to wash off and needs a 6-hour, rain-free period after application for maximum performance. An approved nonionic surfactant must be added to the spray mix to achieve best results from foliar spray. Accord is more effective when foliar application is made between August and early October. Accord is effective in the control of brush such as dogwood, sweetgum, blackgum, and some oaks.

Ally (metsulfuron). Ally is a 60% dry flowable herbicide which is applied as a foliar spray treatment. Add a nonionic surfactant (1 quart per 100 gallons) to spray mix. Apply after full leafout in the spring. Results may not be observed for 30 days after treatment. Ally has shown activity on blackberry, dewberry, multiflora rose, ash cherry, elm, and willow. It does not provide broad spectrum brush control alone. However, hay and grazing restrictions are minimal.

Arsenal (imazapyr). Arsenal can be used as a foliar spray, a hack and squirt treatment, or as a stump spray. For foliar sprays, a spray adjuvant must be applied to the spray mix before application. Apply from May through September. It is sold under the trade name Chopper for hack and squirt applications, and under the trade name Stalker for stump and basal bark sprays. Arsenal controls most woody species with the exception of elms and blackberries. Arsenal is especially effective in the control of sassafras, persimmon, sweetgum, oaks, sumac, and red maple. Do not use on food or feed crops, near irrigation water, or in domestic settings. This herbicide may persist for several years, depending on amount used.

Banvel (dicamba). Banvel is used as a foliar spray to control sensitive brush species after full leafout in the spring. It is effective in controlling wild rose and blackberries and suppresses the growth of persimmon. Do not treat areas where downward movement into water or surface water runoff can bring the herbicide into contact with roots of desirable plants. Use of Banvel is compatible with perennial grass forage crops. Remove meat animals 30 days before slaughter. Restrictions for lactating dairy cattle range from 7 to 60 days for grazing and 37 to 90 days for hay harvest, depending on rate used.

Crossbow (triclopyr ester + 2,4-D ester). Crossbow is a prepackaged mixture of two herbicides used as a foliar spray to control brush at full leafout from the spring through September. Crossbow plus diesel fuel is useful as a stump spray and a basal bark treatment. For best results from the basal bark treatment, apply to brush stems less than 6 inches in diameter during winter or early spring. For better control of regrowth from larger trees, cut larger trees and treat the stumps. Crossbow is a good general brush control product which controls or suppresses the growth of some oaks, locust, willow, blackberries, and mulberry. It provides poor foliar control of sassafras and persimmon.

Escort (metsulfuron). Escort is used as a foliar spay to control brush in fencerows and non-crop areas (not pastures and hayfields). See Ally remarks for additional information.

Garlon 3A (triclopyr amine). Garlon 3A is labeled for use as a foliar spray, a stem injection treatment, and a stump spray. Add nonionic surfactant to the spray mixture before making a foliar application. Apply to foliage from May to September. Time injection for dormant or growing season. Eye protection is required for applicators. Susceptible species include oak, ash, willow, and blackberry.

Garlon 4 (triclopyr ester). Garlon 4 is labeled for use as a foliar spray, thinline spray, stump spray, and basal bark treatment. The foliar spray should be made after full leafout in the spring. Make thinline applications from January through October to stems less than 6 inches in diameter. It may be mixed with diesel fuel or other approved petroleum based solvent for stump spray or basal bark treatment. Garlon 4 will control blackberry, sweetgum, osage orange, blackgum, locust, and hickory.

Grazon P+D (picloram amine + 2,4-D amine). Grazon P+D is labeled for use as a foliar spray to control certain brush species in perennial grass pastures and hayfields. Add a nonionic surfactant to the spray mixture before making a foliar application. Apply in the spring after full leafout. Do not apply more than 4 quarts of Grazon P+D per acre per year. This product can contaminate water through leaching or runoff, can flashback, and may persist in the soil for several years. Grazon is a RESTRICTED USE pesticide. Do not apply on or near areas to be planted to legumes.

Hyvar (bromacil). Hyvar is available as a wettable powder or water soluble liquid for use as a soil treatment for brush control. Effective in controlling brush species such as wild cherry, sweetgum, winged elm, and willow. It is water soluble, readily leachable, and persists for more than a year, depending on rate. Band application is helpful in reducing possible off-site contamination.

Krenite S (fosamine). Krenite is labeled for use as a foliar spray and is especially effective as a fall application. Apply in fall before leaves begin to change color. Does not cause rapid brown-out; brush fails to leaf out the next spring. To improve results, add a nonphytotoxic oil to the spray mixture before making a foliar application. It is very useful in areas adjacent to bodies of water. Effective on species such as locust, sumac, oaks, and sycamore.

Pathfinder II (triclopyr ester). Pathfinder is a ready-to-use formulation which contains a petroleum based penetrant. It is labeled for stump spray, basal bark treatment, and thinline applications. No additional mixing is required before application.

Pathway (2,4-D amine + picloram amine). Pathway is a ready-to-use formulation of two herbicides labeled for hack and squirt and stump spray applications. On hard to control species, make cuts edge to edge around the entire stem. Fresh cut stumps should be treated with this product. This product is a RESTRICTED USE material.

Remedy (triclopyr ester). Remedy is labeled for use as a foliar spray, basal bark treatment, thinline spray, and stump spray. Herbicide is also sold under the trade name Garlon 4. See remarks for Garlon 4 for additional information concerning use.

Rodeo (glyphosate). Rodeo is labeled for use as a foliar spray for brush control on or near aquatic sites. A proven program is using 7.5 pints of Rodeo per acre plus nonionic surfactant approved for aquatic use (X-77, Agri-Dex, Induce). Apply in the fall (September to early October) when most crops are mature or have been harvested. For handgun applications, use 1.5% Rodeo solution (1.5 gallons per 100 gallons of water) and 2 quarts of nonionic surfactant per 100 gallons of water. Spray to wet the foliage but not to runoff. The maximum allowable rates for Rodeo are 7.5 pints per acre or a 1.5% spray solution. The primary precaution is that Rodeo should not be applied within 0.5 mile of a drinking water intake.

Roundup Ultra (glyphosate). Roundup Ultra is labeled for use as a foliar spray, stump spray, and hack and squirt treatment. This herbicide is essentially the same as Accord and Rodeo, but with a surfactant already added. See remarks for Accord.

Spike (tebuthiuron). Spike is available as a wettable powder and granule. It is labeled as a lacing or spot soil treatment to control woody brush on noncrop land and fencerows. Spike can be applied at any time. Control symptoms appear slowly and depend on moisture and soil conditions. Spike should not be applied to poorly drained or saturated soils or to soils containing more than 30% clay (Control is difficult on clay soils). Application should not be made in domestic situations, near the root systems of desirable plants and trees, and on sites where potential water runoff could cause off- site plant injury. Effective on oaks, hickories, wild cherry, blackberries, and many other woody species. Will not control sassafras or persimmon. This herbicide will persist in the soil for several years.

2,4-D. The herbicide 2,4-D is used primarily as a foliar spray in amine or ester formulations. The ester formulation can be mixed with diesel fuel for stump and basal bark sprays. The amine formulation can be used undiluted for hack and squirt and injection applications. This herbicide is effective as a hack and squirt treatment, but it is rarely used alone for this purpose. See remarks for Pathway. Effective as a foliar spray on sumac, some oaks, willow, and poplar.

Velpar (hexazinone). Velpar is available as a dry flowable and a water dispersible liquid. Velpar is used as a basal soil spray to control individual or multi-stemmed brush. Make application just before or during active growth of brush species. Apply to soil within 3 feet of the root collar of target plants using an exact-delivery handgun applicator (spotgun). Apply 2 to 4 milliliters of Velpar solution per inch of stem diameter at breast height. For multi-stemmed brush, apply Velpar solution at the rate of 2 to 4 milliliters per 3 feet of brush canopy width. Effective in the control of small red cedar, honeylocust, oaks, hickories, and many other woody brush species. Velpar will not control sassafras and persimmon. Do not apply to soil containing more than 30% clay. Do not use on sites where runoff water will contact desirable trees or where desirable tree roots may extend.

Weedmaster (2,4-D amine + dicamba). Weedmaster is a prepackaged mixture of two herbicides. It is used undiluted as a hack and squirt or stump spray to control brush. A continuous cut or girdle around the tree must be made before spray treatment. Treat stumps within 6 hours of cutting.


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