General Information

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.

Herbicide Resistance

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.

Application Instructions

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 of the label, unless instructed differently in the Crop-Specific Information section. 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.

General Information Pertaining to Aerial and Ground Applications

Make aerial or ground application when the wind velocity favors on-target product deposition. Apply only when the wind speed is less than or equal to 10 mph. For all nonaerial applications, wind speed must be measured to the application site on the upwind side, immediately prior to application. DO NOT make aerial or ground applications into areas of temperature inversions. Inversions are characterized by stable air and increasing distance above the ground. Mist or fog may indicate the presence of an inversion in humid areas. When permissible by local regulations, the applicator may detect the presence of an inversion by producing smoke and observing a smoke layer near the ground surface.

All aerial and ground application equipment must be properly maintained and calibrated using appropriate carriers.

Aerial Application Methods and Equipment

Avoiding spray drift at the application site is the responsibility of the applicator. The interaction of many equipmentand weather-related factors determine the potential for spray drift. The applicator and the grower are responsible for considering all these factors when making decisions.

DO NOT apply under circumstances where possible drift to unprotected persons, to food, forage, or other plantings that might be damaged, or crops thereof rendered unfit for sale, use or consumption can occur.

Ground Application Methods and Equipment (Broadcast)

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.

Ground Application (Banding)

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. When applying Poast Plus by banding, determine the amount of herbicide and water volume needed using the formula on the label.

Spot or Small Area Application

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 to 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 herbicide and the amount of Dash HC, Sundance HC or oil concentrate in water according to Tables 5 and 6 of the label.

Limitations, Restrictions, and Exceptions



- 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 preemergence 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.

- DO NOT use UAN or AMS in California.

- 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.


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

Citrus - 15 days

Clover - 7 days before grazing, feeding, or cutting for (undried) forage

Clover hay - 20 days before grazing, feeding, or cutting for (dry) hay

Corn (Poast Protected field corn) - 60 days (grain or fodder) 45 days (forage and silage)

Corn (Poast Protected sweet corn) - 45 days (grain or fodder) 30 days (fresh sweet corn or forage and silage)

Cotton and Peanut - 40 days

Soybean - 75 days

Corn, field

Only Poast Protected field corn hybrids are tolerant to Poast Plus applications. Severe crop injury will occur to corn hybrids not designated as Poast Protected corn.

Not for use in California.

Over-the-top applications of Poast Plus in Poast Protected field corn may be made until the onset of pollen shed provided the appropriate preharvest intervals are met. DO NOT apply Poast Plus after pollination occurs.

Corn, sweet

Only Poast Protected sweet corn hybrids are tolerant to Poast Plus applications. Severe crop injury will occur to sweet corn hybrid’s not labeled as Poast Protected sweet corn.

Applications of Poast Plus in Poast Protected sweet corn may be made until the onset of pollen shed. DO NOT apply Poast Plus after pollination occurs. A second application of Poast Plus in Poast Protected sweet corn may be made 10 days or later following the first application.

Cotton and Peanut

Processed meal may be fed to animals.


In California, the maximum rate per acre per application is 3.0 pints.

Only processed meal from seed or hay may be fed to animals.

Alfalfa, Birdsfoot Trefoil, Clover, Sainfoin

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.


Pulp and waste may be fed to livestock.

For maximum height of specific weeds refer to the label.

Perennial Grass Control

Poast Plus effectively controls or suppresses perennial grasses, such as Bermudagrass, guineagrass, johnsongrass, quackgrass, wirestem muhly, perennial ryegrass, and torpedograss. See Table 2. However, their growth characteristics are such that they are more difficult to control than annual grasses, especially in a perennial crop such as established alfalfa or clover. A program of repeated applications is usually necessary for best results.

The most economical way of controlling perennial grasses is to do so in the year of stand establishment before rhizomes or stolons become large and difficult to kill. The field should be disked before seeding to thoroughly fragment rhizomes or stolons.

In summer and fall seedings, cool-season grasses (quackgrass, wirestem muhly, and perennial ryegrass) can become very competitive under cool fall conditions. Fall applications of Poast Plus will reduce late season grass growth and limit the ability of grasses to accumulate nutrient reserves in roots and rhizomes.

In established stands, it is important to begin applying in the spring when conditions favor active growth and before storage tissues have increased their nutrient reserves. Additional applications should be made on any grass regrowth in later cuttings.

Restricted Entry Interval

12 hours