General Information


Bolero 8 EC Herbicide is a Group 8 herbicide. Any weed population may contain or develop plants naturally resistant to Bolero 8 EC Herbicide and other Group 8 herbicides. Weed species with acquired resistance to Group 8 herbicides may eventually dominate the weed population if Group 8 herbicides are used repeatedly in the same field or in successive years as the primary method of control for targeted species. This may result in partial or total loss of control of those species by Bolero 8 EC Herbicide or other Group 8 herbicides.

To delay herbicide resistance consider:

- Avoiding the consecutive use of Bolero 8 EC Herbicide or other target site of action Group 8 herbicides that might have a similar target site of action, on the same weed species.

- Using tank mixtures or premixes with herbicides from different target site of action Groups as long as the involved products are all registered for the same use, have different sites of action and are both effective at the tank mix or prepack rate on the weed(s) of concern.

- Basing herbicide use on a comprehensive Integrated Pest Management (IPM) program.

- Monitoring treated weed populations for loss of field efficacy.

- Contacting your local extension specialist, certified crop advisors and/ or manufacturer for herbicide resistance management and/or integrated weed management recommendations for specific crops and resistant weed biotypes.

For further information or to report suspected resistance, you may contact Valent U.S.A. Corporation at the following toll-free number: 800-682-5368.


Bolero 8 EC Herbicide applied preplant, delayed preemergence or postemergence will control many weeds in rice. Bolero 8 EC Herbicide will provide residual control of some weeds up to 5 weeks following application. Temporary injury to seedling rice may occur under certain conditions.

Restrictions and Limitations

- Do not apply Bolero 8 EC Herbicide to fields with exposed seed as exposed seed will be killed.
- Do not apply to stressed rice.

- Do not apply Bolero 8 EC Herbicide as a preemergence treatment to cracked soil.

- Do not apply more than 2-1/2 pt of Bolero 8 EC Herbicide per acre when using aerial application equipment east of the Rocky Mountains.

- Do not apply more than 4 Ib active ingredient per acre per year.

- See “Engineering Control Statements” when making aerial application of Bolero 8 EC Herbicide.

- Do not apply Bolero 8 EC Herbicide through any type of irrigation system.

- Do not apply to rice paddies where commercial catfish or crayfish farming is practiced.

- Do not apply this product on rice fields adjacent to catfish or crayfish ponds.

- When applying to rice fields, do not release permanent flood water within 14 days of application of this product (where weather permits).

- Avoid application of this product within 24 hours of rainfall or when heavy rain is expected to occur within 24 hours.

- Do not mix/load or otherwise handle Bolero 8 EC Herbicide within 100 feet of aquatic habitat.

- Do not apply under conditions involving possible drift to food, forage or other plantings that might be damaged or the crops rendered unfit for sale, use or consumption.

- Avoid drift to non-target areas.

- Do not overlap or double spray ends of field.

- Do not apply to a second stubble rice crop.

- Water drained directly from treated fields must not be used to irrigate other crops.

- Do not apply Bolero 8 EC Herbicide plus propanil mixture within 14 days before or after organophosphate or carbamate insecticide application.

- Do not mix zinc with Bolero 8 EC Herbicide.

- Do not use Bolero 8 EC Herbicide on rice grown in fields which have been land leveled resulting in severe cuts and heavily filled areas (does not apply to normal maintenance leveling) in the past 18 months.

- Do not use Bolero 8 EC Herbicide on water-seeded rice grown in fields which have received chicken litter or had large amounts of green vegetative residue incorporated in the past 10 months.

Environmental Conditions and Biological Performance

Bolero 8 EC Herbicide should be used as an integral part of a weed control program in conjunction with a resistance management strategy (see “Resistance Management Recommendations” statement in this label). The mode of action is the inhibition of lipid synthesis. Bolero 8 EC Herbicide will, in most cases, prevent the emergence of susceptible weeds if application is made to a clean well-prepared seedbed. For optimum results from an application made prior to the emergence of susceptible weeds, rainfall or irrigation is needed to move Bolero 8 EC Herbicide into the soil.

Application Equipment

Application equipment should be clean and functioning properly. Proper sprayer calibration is required. Nozzles should be spaced to provide even, complete coverage and calibration should frequently be checked for accuracy. Select nozzles that deliver the recommended gallonage. Use the pressure range recommended by the manufacturer for the selected nozzle.


Do not plant subsequent crops in treated fields within 6 months of last application.


After application, flush the fields as necessary to prevent crusting and drying of the soil. Fields should be flooded as soon as the rice plants will tolerate permanent flooding. Do not release permanent flood water within 14 days after application.


Aircraft: Apply Bolero 8 EC Herbicide in no less than 10 gal spray mix per acre. Do not apply more than 2-1/2 pt of Bolero 8 EC Herbicide per acre when using aerial application equipment east of the Rocky Mountains.

Ground Sprayers: Apply in a minimum of 10 gallons of total spray mix per acre. The following herbicide products may be tank mixed with Bolero 8 EC Herbicide for delayed preemergence use in rice. Always read and follow label instructions for all products tank mixed with Bolero8 EC Herbicide.


Bolero 8 EC Herbicide use in rice fields which develop anaerobic (low oxygen content) soil conditions following planting, in the presence of certain fungi that dechlorinate benzene rings (i.e. Bolero 8 EC Herbicide, propanil, 2,4-D, etc.), may reduce plant stand and yield. Anaerobic soil conditions are likely to occur when:

1. Green matter and crop residue is plowed down or worked into the soil prior to planting.

2. Internal soil drainage is slow (poor percolation).

3. There is a continuous flood.

4. There are areas in the field which retain water during periods of prescribed flood removal.

Management practices which will help to minimize these situations and thereby promote good soil conditions for the production of healthy rice treated with Bolero 8 EC Herbicide are:

1. Destruction of previous crop and weed residues by:

a. Burning where state regulations allow.

b. Fall and winter plowing.

c. Use of glyphosate or paraquat as a “burndown” to prevent vegetation buildup after initial ground preparation and prior to final seedbed preparation.

2. Application of fertilizer according to soil test results:

a. Do not apply excess phosphorous.

3. Uniform leveling practices which eliminate low spots in the field and insure that the field is entirely drained for prescribed flood removal periods. This is far more difficult to achieve with the use of contour levees. Fields which have been precision leveled for perimeter ditches or straight levees are more suited to the intense water management practices required for the red rice suppression, pinpoint flood program.

4. Uniform flood depth of 2” to 4”.

5. Not exceeding labeled rates of Bolero 8 EC Herbicide, accurate calibration of application equipment and eliminating application overlap.

Water-seeded rice fields treated with Bolero 8 EC Herbicide preplant or post flood should be inspected regularly through the stand establishment and seedling growth stages. If any of the following phytotoxic symptoms (associated with low oxygen soil conditions) occur:

1. dark green foliage

2. reduced plant height

3. plant deformation

Immediately drain the flood and allow the soil to oxygenate (no standing water for 3 to 5 days) then reflood. Low spots which do not drain completely may continue to display phytotoxic symptoms.

Limitations, Restrictions, and Exceptions

Special Instructions

Water-Seeded Rice – Red Rice Suppression and Sprangletop Control (Preplant, non-incorporated)

- Apply Bolero 8 EC Herbicide to a well prepared seedbed which preferably has been mechanically ridged and has had drains plowed.

- Make application immediately after soil preparation (before any weed germination). If rain should occur after soil preparation, Bolero 8 EC Herbicide should not be applied until the soil is dry enough to support tillage operations. Red Rice or Sprangletop plants which are not killed by seedbed preparation and Red Rice or Sprangletop seed which have germinated before Bolero 8 EC Herbicide application will not be controlled.

Application to stressed rice can result in stand reduction, chlorosis, growth inhibition, delayed maturity and/or leaf desiccation. Stress factors include but are not limited to the following: Daily temperatures below 65°F or above 95°F, problem soils, (i.e., Zn deficiency, high salt content, high pH), excessive moisture, (i.e., above field capacity while rice seed is germinating), drought conditions, poor field drainage or deep water after application.

- Flood the field between 2 and 3 days after the Bolero 8 EC Herbicide application.

- Do not drag the field or disturb the treated seedbeds after flooding.

- Seeding should not occur before 24 hours after the field has been brought to flood level. Refer to and follow State Extension Service recommendations regarding seeding rate, seeding time after flood and drainage of seeding flood.

- Supplemental herbicides may be needed for season long weed control.

- Rice in areas which do not completely drain when the seeding flood is removed may be injured or killed. Refer to “Restrictions and Limitations section”. Begin drainage when the first leaf is about 1/4 to 1/2 inch long. For red rice suppression normal pin-point flood cultural practices (not flush or continuous flood culture) should be followed with the post seeding drainage period not to exceed 3 to 5 days. Preplant nitrogen enhances the program by promoting fast growth. The planting of early season varieties of rice as soon as possible after soil temperatures are favorable; fall preparation of rice land involving deep-plowing and subsequent shallow cultivations; and rotational schemes involving fallow, pasture and/or other non-crops, are essential for long-term integrated management of Red Rice, Sprangletop and other rice weeds. Rice injury and/or stand thinning may be evident, especially when germinating rice is subjected to stress conditions.

Restricted Entry Interval

7 days