General Information


Poast Plus herbicide is a selective, broad spectrum, postemergence herbicide for control of annual and perennial grass weeds. Poast Plus does not control sedges or broadleaf weeds. Essentially, all grass crops, such as sorghum, corn, small grains, and rice, as well as ornamental grasses, such as turf, are susceptible to Poast Plus.


Poast Plus rapidly enters the target weed through its foliage and translocates throughout the plant. The effects range from slowing or stopping growth (generally within 2 days), to foliage reddening and leaf tip burn. Subsequently, foliage burnback may occur. These symptoms will generally be observed within 3 weeks depending on environmental conditions.


All labeled crops are tolerant to Poast Plus at all stages of growth.


Repeated use of Poast Plus (or similar postemergence grass herbicides with the same mode of action) may lead to the selection of naturally occurring biotypes with resistance to these products. If poor performance cannot be attributed to adverse weather conditions or improper application methods, a resistant biotype may be present. Consult your local representative or agricultural advisor for assistance.


In irrigated areas, it may be necessary to irrigate before treatment to ensure active weed growth.


DO NOT cultivate within 5 days before or 7 days after applying Poast Plus. Cultivating 7 days or later after treatment may help provide season-long control.


Applications can be made to actively growing weeds as aerial, broadcast, band, or spot spray applications at the rates and growth stages listed in Tables 1, 2 and 3, unless instructed differently in section VI. Crop-Specific Information. The most effective control will result from making postemergence applications of Poast Plus herbicide early, when weeds are small. Delaying application permits weeds to exceed the maximum size stated and may prevent adequate control.

Apply Poast Plus to the foliage of grasses uniformly and completely because large leaf canopies shelter smaller weeds and can prevent adequate spray coverage. DO NOT spray to the point of runoff.


For ground boom applications, apply with nozzle height no more than 4 feet above ground or crop canopy.

DO NOT apply when conditions favor drift from target area or when windspeed is greater than 10 mph.

Water Volume: Use 5-20 gallons of spray solution. In the West and in the High and Rolling Plains Region, (see regional descriptions in Table 1), DO NOT use less than 10 gallons of spray solution per acre.

Spray Pressure: Use 40-60 psi (measured at the boom, not at the pump or in the line). When crop and weed foliage are dense, use a maximum of 20 gallons of water and 60 psi.

Application Equipment: Use standard high-pressure pesticide flat fan or hollow cone nozzles spaced up to 20 inches apart. DO NOT use flood, whirl chamber, or controlled droplet applicator (CDA) nozzles as erratic coverage can cause inconsistent weed control. When tall weeds such as volunteer corn are to be controlled, the boom should be high enough to cover the entire plant. Refer to the nozzle manufacturer’s directions for recommended height. When a crop such as cotton is 24 inches or taller and the grasses are below the crop canopy, use drop nozzles to ensure good coverage of the grass species.

DO NOT use selective application equipment such as recirculating sprayers or wiper applicators.


Poast Plus herbicide may be applied by banding to control annual grasses. Banding is not recommended for perennial grasses.

Follow Ground Application (Broadcast) instructions for band applications.


DO NOT make spot treatments in addition to broadcast or band treatments. When using knapsack sprayers or high-volume spray equipment with hand guns or other suitable nozzle arrangements, prepare a 1-1.5% solution of Poast Plus in water unless otherwise specified under specific crops. Use a concentration of 0.5% for Dash HC and Sundance HC spray adjuvants, or 1% for oil concentrate. Prepare the desired volume of spray solution by mixing the amount of Poast Plus and the amount of Dash HC, Sundance HC or oil concentrate in water according to Tables 5 and 6.


If Poast Plus herbicide cannot be applied at the recommended time, larger annual grasses may be controlled with a later application by increasing the rate of Poast Plus (see Table 3). Do not exceed the maximum rate per acre, per season, for specific crops (see Table 7).


- Maximum seasonal use rate: See Table 7 for crop-specific maximum seasonal use rates.

- Preharvest Interval: See Table 7 for crop-specific preharvest intervals.

- Restricted Entry Interval (REI): 12 hours

- Avoid all direct or indirect contact with any desired grass crop unless otherwise recommended on the Poast Plus herbicide label.

- Stress: DO NOT apply to grasses or crops under stress due to lack of moisture, hail damage, flooding, herbicide injury, mechanical injury, or widely fluctuating temperatures, as unsatisfactory control may result. In irrigated areas, it may be necessary to irrigate before application to insure active weed growth.

- DO NOT apply to crops that show injury (leaf phytotoxicity or plant stunting) produced by any other prior herbicide applications, because this injury may be enhanced or prolonged.

- DO NOT apply as a preplant or pre-emergence treatment before planting grass crops, such as corn, millet, or sorghum, unless otherwise specified on supplemental labeling.

- DO NOT use selective application equipment such as recirculating sprayers, wiper applicators, or shielded applicators.

- Rainfast Period: Poast Plus is rainfast 1 hour after application.

- DO NOT apply through any type of irrigation equipment.

- DO NOT plant other crops to be harvested for 30 days after application unless Poast Plus is registered for use on that crop.

Limitations, Restrictions, and Exceptions



Alfalfa, birdsfoot trefoil, and sainfoin - 14 days before cutting for (dry) hay

Alfalfa, birdsfoot trefoil, and sainfoin (Undried): 7 days before grazing, feeding, or cutting for undried) forage

Poast Plus herbicide may be applied to seedling or established alfalfa and clover grown for hay, silage, green chop, direct grazing, or for seed.

Mowing: The best control of annual grasses can be achieved by applying Poast Plus before grass weeds are mowed. Once a grass is mowed it becomes tougher to control, as much of the leaf surface may be removed, putting the grass under stress. In areas without a killing frost, some annuals can over-winter after having been mowed a number of times. These grasses can form large crowns and contain many viable buds. A large crown, even if it is an annual grass, may require repeated applications of Poast Plus for partial or complete control.


Irrigation practices can be very critical to the successful use of Poast Plus and may be necessary to start grass weeds growing again. Generally, applications 2-4 days after an irrigation are most effective because:

- grasses resume active growth,

- grasses have less chance to grow too large,

- by waiting later, the clover or alfalfa begins to canopy and interferes with spray coverage.

Irrigation shortly after application (2 days) can be effective, but more consistent grass control is obtained when the irrigation is made before the application.

Annual Grass Control

Apply Poast Plus at the grass sizes and rates indicated in Tables 1 and 3. If grass has been cut, apply Poast Plus after the regrowth reaches the minimum height (so there will be enough leaf area for absorption) and before it exceeds the maximum height indicated. Apply before the clover or alfalfa canopies cover the grasses and interfere with the spray coverage. Also, applications after a clover or alfalfa cutting may need to be timed to follow an irrigation or rainfall which will allow the grasses to regrow to a treatable size. Some annual grasses are spring- and summer germinating plants, while others are fall-germinating plants, and the time they are actively growing and most susceptible to Poast Plus may vary from area to area. Also, some annuals germinate over a long time, and because control of small grasses is desired, applications after each weed flush may be needed. As a general guideline, spray spring- and summer-germinating grasses as early in the season as possible. The optimum application timing may occur very early in the spring after initial green-up. Spray fall-germinating weeds in the fall soon after they begin growing but before any killing frosts. Late fall applications may be less effective due to environmental changes, such as frosts or the onset of flowering.

West & High and Rolling Plains: An area of the Western United States, including Western Texas, Oklahoma and Kansas; west of a line running north from Del Rio to Gainesville, Texas, and extending along Interstate 35 to the Oklahoma-Kansas border, then west along border to Highway 83 and then north to the Kansas-Nebraska border, west to Colorado, all of Colorado to the Continental Divide, then West of the Continental Divide North to the U.S.-Canada border.

Crabgrass Large, Smooth, Oats Wild, Red Rice, Shattercane/Wildcane, Barley Volunteer, Corn Volunteer, Oats Volunteer, Rye Volunteer, Wheat Volunteer, Witchgrass: Add nitrogen to the crop oil concentrate to improve grass control on indicated species.

Barley Volunteer: Apply Poast herbicide before tillering.

Sprangletop, Red: Poast is not recommended for use on red sprangletop in California, Arizona, or western New Mexico.

Barley Volunteer: In the West Region, volunteer cereals that emerge from late spring through early summer (May through July) may be partially or incompletely controlled because of unfavorable conditions at application time.

Refer in the label for specific information and rates recommendation.

Restricted Entry Interval

12 hours