Poison-oak and poison-ivy (Toxicodendron spp.)

aminocyclopyrachlor + metsulfuron methyl (Streamline)

Rate 1.9 to 3.8 oz/A aminocyclopyrachlor + 0.6 to 1.2 oz/A metsulfuron (4.75 to 9.5 oz/A of product)

Time Apply to actively growing woody plants.

Remarks Adjuvants can be used; these include methylated seed oils 0.5 to 1% v/v, nonionic surfactants at 0.25 to 1% v/v, and crop oil concentrates at 1% v/v. Can be applied using an invert emulsion rather than water. There are several application methods that dictate the amount of product to be mixed with the carrier, so consult the label. Controls many herbaceous species, in addition to woody species.

Caution Even low rates can kill nontarget tree and shrub species, so avoid application within a distance equal to the tree height of the sensitive species. Conifers can be injured, these include ponderosa pine, Douglas fir, Norway spruce, and white pine. Other trees that can be injured include aspen, Chinese tallow, cottonwoods, honey locust, magnolia, poplars, redbud, silver maple, and willow. Applications to stressed plants may reduce control. Do not allow spray to drift off target.

Site of action (aminocyclopyrachlor) Group 4: Synthetic auxin; (chlorsulfuron) Group 2: ALS inhibitor

Chemical family (aminocyclopyrachlor) Pyrimidine carboxylic acid; (chlorsulfuron) Sulfonylurea

glyphosate (E-Z-Ject)

Rate Follow label instructions on number of capsules per stem.

Time Apply when plants are actively growing at or beyond early bloom stage.

Remarks The E-Z-Ject system of application will not harm desirable species.

Caution Capsules must penetrate woody bark for control.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted


Rate 3 to 3.75 lb ae/A broadcast or apply as a 2% solution with hand-held equipment.

Time Apply when plants are actively growing at or beyond early to full bloom stage. Results are best if applied after fruit forms. Make late summer or fall treatments before leaves lose their green color. Use higher rates for plants that have reached woody stage of growth.

Remarks Treat foliage when plants are growing rapidly. In orchards, prevent spray mist from contacting foliage, green bark, suckers, or fruit of crop trees or other desirable vegetation. If spray contacts immature bark on main trunk, serious localized or translocated damage can result. Roundup is a nonresidual herbicide requiring subsequent seedling control.

Caution Controls grasses and other vegetation in treated area.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepintsed

triclopyr ester (Garlon 4) or triclopyr amine (Garlon 3A) or triclopyr + 2,4-D ester (Crossbow)

Rate Spot treat: use 3 lb ae Garlon 4 or 2.25 lb ae Garlon 3A with 100 gal water; or 1 pint Crossbow in 12 gal water. Broadcast: use 4 to 8 lb ae/A Garlon 4, or 6 to 9 lb ae/A Garlon 3A, or 1 to 2 quarts/A of Crossbow.

Time Apply when plants are actively growing.

Remarks Foliage must be thoroughly wet.

Caution Garlon products are registered for use on rights-of-way, industrial sites, and forestry (release and site preparation). Crossbow can be used on permanent pastures and rangeland up to 1.5 lb ae/A. Observe all grazing and harvesting restrictions.

Site of action (all) Group 4: synthetic auxin

Chemical family (triclopyr) pyridine; (2,4-D) phenoxy acetic acid