COTTON - HARVEST AID AND POST HARVEST APPLICATIONS - SUPPRESSION OF REGROWTH
Gramoxone SL 3.0 is a contact Group 22 herbicide used to control or suppress a broad spectrum of emerged weeds. It controls most small annual weeds – both broadleaves and grasses, and suppresses perennial weeds by destroying green foliage. For most effective control, apply to weeds less than six inches tall. Gramoxone SL 3.0 can also be used as a desiccant/defoliant at harvest. It will cause damage to nontarget crops and plants if off-target movement occurs.
Gramoxone SL 3.0 is rapidly absorbed by green plant tissue and interacts with the photosynthetic process to produce superoxides which destroy the plant cells. Gramoxone SL 3.0 requires actively growing green plant tissue to function. Thorough coverage of all green foliage is essential for effective weed control and for effective crop desiccation/ defoliation. Gramoxone SL 3.0 is not as effective on drought-stressed weeds, weeds with little green foliage (i.e., mowed or cut weeds), or mature woody bark of trees and vines. Because Gramoxone SL 3.0 is rapidly absorbed by the weed foliage, typically rain occurring 15-30 minutes or more after application will have no effect on the activity of Gramoxone SL 3.0.
Gramoxone SL 3.0 is active over a wide range of environmental conditions. Cool weather (below 55°F) will slow the activity of Gramoxone SL 3.0, as will cloudy, overcast weather, but will not affect performance.
Clay and organic matter rapidly tie up Gramoxone SL 3.0. As a result, Gramoxone SL 3.0 has no residual soil activity to affect later-planted crops or later germinating weeds. Gramoxone SL 3.0 is formulated as a liquid which contains 3.0 pounds of active ingredient per gallon. The formulation contains a nontoxic odor and an emetic (an agent which will induce vomiting if the product is swallowed). The odor is included in the formulation to help prevent accidental ingestion of Gramoxone SL 3.0.
Some naturally occurring weed biotypes resistant to paraquat dichloride may exist through normal genetic variability in any weed population. The repeated use of herbicides with the same mode of action is known to lead under certain conditions to a selection of resistant weeds.
The active ingredient in Gramoxone SL 3.0 is paraquat dichloride, a mechanism of action Group 22 herbicide, which inhibits Photosystem I (PSI). Any weed population may contain or develop plants naturally resistant to paraquat dichloride and other Group 22 herbicides. The resistant biotypes may dominate the weed population if these herbicides are used repeatedly in the same field.
Within the USA specific biotypes of a number of species, including horseweed/marestail (Conyza canadensis), hairy fleabane (Conyza bonariensis), Italian ryegrass (Lolium perenne ssp. multiforum), goosegrass (Eleusine indica), dotted duckweed (Landoltia punctate), and American black nightshade (Solanum americanum) have become resistant to paraquat.
PRINCIPLES OF HERBICIDE RESISTANT WEED MANAGEMENT
Scout and know your field
- Know weed species present in the field to be treated through scouting and field history. An understanding of weed biology is useful in designing a resistance management strategy. Ensure the weed management program will control all weeds present.
- Fields should be scouted prior to application to determine species present and growth stage. Always apply this herbicide at the full labeled rate and correct timing for the weeds present in the field.
Utilize non-herbicidal practices to add diversity
- Use diversified management tactics such as cover crops, mechanical weed control, harvest weed seed control, and crop rotation as appropriate.
Use good agronomic practices, start clean and stay clean
- Use good agronomic practices that enhance crop competitiveness.
- Plant into weed-free fields utilizing tillage or an effective burndown herbicide for control of emerged weeds.
- Sanitize farm equipment to avoid spreading seed or vegetative propagules prior to leaving fields.
Difficult to control weeds
- Fields with difficult to control weeds should be planted in rotation with crops that allow the use of herbicides with an alternative mode of action or different management practices.
- Difficult to control weeds may require sequential applications, such as a broad spectrum preemergence herbicide followed by one or more postemergence herbicide applications. Utilize herbicides containing different modes of action effective on the target weeds in sequential applications.
Do not overuse the technology
- Do not use more than two applications of this or any other herbicide with the same mode of action in a single growing season unless mixed with an herbicide with a different mode of action which provides overlapping spectrum for the difficult to control weeds.
Scout and inspect fields following application
- Prevent an influx of weeds into the field by controlling weeds in field borders.
- Scout fields after application to verify that the treatment was effective.
- Suspected- herbicide resistant weeds may be identified by these indicators
- Failure to control a weed species normally controlled by the herbicide at the dose applied, especially if control is achieved on adjacent weeds;
- A spreading patch of non-controlled plants of a particular weed species; and
- Surviving plants mixed with controlled individuals of the same species.
- Report non-performance of this product to your Syngenta retailer, Syngenta representative, or call 1-866-Syngent(a) (866-796-4368). If resistance is suspected ensure weed escapes are controlled using an herbicide with an effective mode of action and/or use non-chemical means to prevent further seed production.
Prevent weed escapes before, during, and after harvest
- Do not allow weed escapes to produce seed or vegetative structures such as tubers or stolons which contribute to spread and survival. Consider harvest weed seed management and control weeds post-harvest to prevent seed production.
- Contact your local Syngenta representative, retailer, crop advisor or extension agent to determine if weeds resistant to this mode of action are present in your area. If resistant biotypes have been reported, use the full labeled rate of this product, apply at the labeled timing, and tank-mix with a different mode of action product so there are multiple effective modes of application for each suspected resistant weed.
Methods of Application
- Applications with Gramoxone SL 3.0 alone or in tank mixtures are permitted by ground and by air.
- This product may only be applied with a backpack sprayer if the backpack equipment allows the product to be transferred into the sprayer from the original product container using a closed system as specified in the Use Restrictions Section (Section 6.1) of this label and the application rate does not exceed 0.5 lb ai/A (1.3 pts of this product) in 30 gallons of spray solution per acre.
- Preplant, preemergence, postemergence, and burndown applications are allowed as specified in Crop Use Directions, Non-agricultural Crop Use Directions, and 13.0 unless otherwise restricted in Restricted and Precautions.
- Configure spray equipment to provide accurate and uniform coverage of the target area and minimize potential for spray drift.
- To ensure accuracy, calibrate sprayer before each use. For information on spray equipment and calibration, consult spray equipment manufacturers and/or state recommendations.
- Use sprayers that provide accurate and uniform application with nozzles designed to minimize drift and provide uniform coverage.
- Avoid using screens and strainers finer than 50 mesh.
- All equipment must be properly maintained.
- Gramoxone SL 3.0 is corrosive to aluminum. Aluminum and all other spray equipment must be washed to remove product residues after use.
- Prolonged exposure of this product to uncoated steel surfaces may result in corrosion and possible failure of the part.
For aerial application equipment:
- Gramoxone SL 3.0 is corrosive to aluminum. Aluminum aircraft structures that are exposed to spray solution or spray drift should be flushed thoroughly with water immediately after use.
- The maintenance of an organic coating (paint) which meets aerospace specification MIL-C-38413 may prevent corrosion.
- To prevent corrosion of exposed parts, thoroughly wash aircraft after each day of spraying to remove residues of this product accumulated during spraying or from spills.
- Landing gear are most susceptible.
Application Volume and Spray Coverage
- Since Gramoxone SL 3.0 is a contact-type herbicide, it is essential to obtain complete coverage for control of target weeds and thorough desiccation/defoliation of crops.
- Improper application technique will usually result in unacceptable weed control and unacceptable crop desiccation/defoliation.
- For ground application apply in a minimum of 10 gal/A of spray mixture. Increasing the carrier volume will likely result in improved control. For aerial application apply in a minimum of 5 gal/A of spray mixture.
- When spot spraying, spray to thoroughly wet the foliage, but not to the point of runoff.
When only small areas are to be sprayed with labeled applications, it is advantageous to mix small quantities of Gramoxone SL 3.0.
All rotational crops may be planted immediately after the last application of Gramoxone SL 3.0.
RESTRICTIONS AND PRECAUTIONS
- For containers less than 120 gallons, this product must only be removed from the original container with a closed transfer system. Any subsequent transfer of this product must utilize a closed transfer system. Any attempt to circumvent the closed transfer system prior to complete removal of the product and rinsing of the product container as described in the Storage and Disposal Section of this label is prohibited.
- NEVER PUT INTO FOOD, DRINK OR OTHER CONTAINERS.
- DO NOT USE OR STORE IN OR AROUND THE HOME.
- DO NOT REMOVE CONTENTS EXCEPT FOR IMMEDIATE USE.
- DO NOT apply this product through any type of irrigation system.
- DO NOT use this product in residential or public recreational settings (e.g. home, home gardens, schools, recreational parks, golf courses, and/or playgrounds.
- DO NOT apply under conditions involving possible drift to food, forage, or other plantings that might be damaged or the crops thereof rendered unfit for sale, use, or consumption.
- DO NOT apply when weather conditions favor drift from treated areas.
- For broadcast applications of this product using backpack sprayers, the application rate must not exceed 0.50 lb ai/A (1.3 pts of this product) in a minimum of 30 gallons of spray solution per acre.
- In dry areas, dust stirred up by high winds or equipment can coat weed or plant leaves and reduce Gramoxone SL 3.0 activity. Avoid applying Gramoxone SL 3.0 in extremely dusty conditions.
- In preplant and preemergence (to the crop) uses, do not apply to soils lacking clay minerals, e.g., peat, muck, pure sand, artificial planting media.
- To reduce germination of new weeds, seeding or transplanting should be done with a minimum amount of soil disturbance.
- Gramoxone SL 3.0 used for preplant weed control over the top of plastic mulch may damage transplants which come in contact with the plastic. Sufficient rainfall or sprinkler irrigation to cause wash-off prior to planting may be needed to prevent damage to the crop.
- Weeds emerging after application of Gramoxone SL 3.0 will not be controlled or suppressed.
- Unless otherwise indicated, crop plants emerged at time of application may be severely injured or killed if contacted by sprays of Gramoxone SL 3.0.
- Do not release spray at a height greater than 10 ft above the vegetative canopy, unless a greater application height is necessary for pilot safety.
- For applications prior to the emergence of crops and target weeds, applicators are required to use a coarse or coarser droplet size (ASABE S572.1).
- The boom length must not exceed 65% of the wingspan for airplanes or 75% of the rotor blade diameter for helicopters.
- Applicators must use 1/2 swath displacement upwind at the downwind edge of the field.
- Nozzles must be oriented so the spray is directed toward the back of the aircraft.
- Do not apply when wind speeds exceed 10 miles per hour at the application site.
- Do not apply during temperature inversions.
BOOM-LESS GROUND APPLICATION
- Applicators are required to use a Medium or coarser droplet size (ASABE S572.1) for applications.
- Do not apply during temperature inversions.
GROUND BOOM APPLICATIONS
- Apply with the nozzle height recommended by the manufacturer, but no more than 3 feet above the ground or crop canopy unless making a pasture, or rangeland application, in which case applicators may apply with a nozzle height no more than 4 feet above the ground.
- For applications prior to the emergence of crops and target weeds, applicators are required to use a Coarse or coarser droplet size (ASABE S572.1).
- Do not apply during temperature inversions.
WEEDS CONTROLLED OR PARTIALLY CONTROLLED BY GRAMOXONE SL 3.0
Gramoxone SL 3.0 should be applied to emerged weeds when they are small. Weeds 1-6 inches in height are the easiest to control. Larger weeds may be more difficult to control. When weeds have been grazed or mowed, thus removing much of the green foliage, allow the weeds to regrow to a height of 2-4 inches before spraying if possible. Similarly, when forage or grain crops have been harvested prior to spraying, weeds present in the field will also have been cut. To allow for adequate green foliage to remain on weeds in this situation, raise cutter bars as high as possible from the ground to cut stubble and weeds at a greater height.
Difficult weeds can often be controlled by tank mixing Gramoxone SL 3.0 with other herbicides. The addition of herbicides which are photosynthetic inhibitors herbicide (Groups 5, 7) will slow the activity of Gramoxone SL 3.0, allowing Gramoxone SL 3.0 to thoroughly distribute itself within the treated leaf. The resulting level of control is usually greater than if Gramoxone SL 3.0 was applied alone.
When perennial broadleaf weeds such as Canada thistle, bindweed, dandelion, etc. or difficult to control annual broadleaf weeds such as giant ragweed or morningglory are present, tank mixes with 2,4-D ester (Low Volatile), 2,4-DB, dicamba, Boundary, Acuron, Acuron Flexi, Lexar EZ, Lumax EZ where labeled, will help improve control. Tank mixing the amine formulation of 2,4-D with Gramoxone SL 3.0 may result in reduced grass control.
Tank Mix Options:
- Refer to for tank-mix options.
- Refer to Resistance Management.
- When applying to Stripper or Spindle cotton or for late season cotton desiccation, it is advisable, because of extremes in environmental and plant conditions, to apply the rage of rates on a small block of cotton to determine the rate that best fits your needs.
- NOTE: Nodes above cracked bolls (NACB) timing is for guidance and is not intended to restrict the local expert in their use of the product.
1. Refer to Use Restrictions for additional product use restrictions.
2. Maximum Single Application Rate: 1.3 pt/A
3. REI: 24 hours
4. Minimum Application Interval: 7 days
5. Maximum Annual Rate 1.3 pt/A/year
a. DO NOT exceed 0.50 lb ai/A/year of paraquat-containing products for harvest aid uses.
b. DO NOT exceed 3.0 lb ai/A/year of paraquat-containing products for all combined uses.
6. DO NOT make more than 4 harvest aid applications per year.
7. DO NOT pasture livestock in treated fields or feed treated foliage.
8. Pre-Harvest Interval (PHI):
a. western cotton: 7 days
b. all others: 3 days