POTATOES GROWN FOR SEED - PREEMERGENCE PARTIAL CONTROL

General Information

PRODUCT INFORMATION
DuPont MATRIX SG herbicide is a water soluble granule formulation that selectively controls certain broadleaf weeds and grasses in pome fruit, citrus fruit, tree nuts, stone fruit and grape crops which have been established for at least one full growing season. MATRIX SG herbicide also selectively controls certain broadleaf weeds and grasses in field corn (CA only), potatoes, potatoes grown for seed, and field grown tomatoes (direct seeded and transplant).

The best control is obtained when MATRIX SG is applied to young, actively growing weeds. The degree and duration of control may depend on the following:

- weed spectrum and infestation intensity
- weed size at application
- environmental conditions at and following treatment

BIOLOGICAL ACTIVITY AND ENVIRONMENTAL CONDITIONS
MATRIX SG is absorbed through the roots and foliage of plants, rapidly inhibiting the growth of susceptible weeds. For Preemergence weed control, rainfall or sprinkler irrigation is needed to move MATRIX SG into the soil. Weeds will generally not emerge from Preemergence applications. In some cases, susceptible weeds may germinate and emerge a few days after application, but growth then ceases and leaves become chlorotic three to five days after emergence. Death of leaf tissue and growing point will follow in some species, while others will remain green but stunted and noncompetitive.

One to three weeks after postemergence application to weeds, leaves of susceptible plants appear chlorotic, and the growing point subsequently dies. In warm, moist conditions, the expression of herbicide symptoms is accelerated; in cold, dry conditions, expression of herbicide symptoms is delayed. Death of leaf tissue and growing point will follow in some species, while others will remain green but stunted and noncompetitive.

MATRIX SG provides the best control of weeds in vigorously growing crops that shade competitive weeds. Weed control in areas of thin crop stand or seeding skips may not provide satisfactory control. However, a crop canopy that is too dense at application can intercept spray and reduce weed control.

The herbicidal action of MATRIX SG may be less effective on weeds stressed from adverse environmental conditions (including extreme temperatures or moisture), abnormal soil conditions, or cultural practices. In addition, weeds hardened- off by drought stress are less susceptible to MATRIX SG.

Postemergence weed control may be reduced if rainfall occurs soon after application. Several hours of dry weather are needed to allow MATRIX SG to be sufficiently absorbed by weed foliage (generally MATRIX SG is rainfast in 4 hours).

PRECAUTIONS

- Potato and tomato varieties may differ in their response to various herbicides. DuPont recommends that you first consult your state experiment station, university, or extension agent as to sensitivity to any herbicide. If no information is available, limit the initial use to a small area.

- Preemergence use on soils containing more than 6% organic matter may not provide adequate soil residual weed control and may result in reduced weed control.

- Preemergence and Postemergence use on rill irrigated potatoes and tomatoes (furrow or gravity) may not provide adequate weed control in the absence of rainfall.

- If sprinklers are used for frost protection, delay the application of MATRIX SG until stress from environmental conditions have passed.

- Avoid spray drift to any adjacent crops or desirable plants as injury may occur.

- Crop injury may occur following an application of MATRIX SG if there is a prolonged period of cold weather and/or cold weather in conjunction with wet soils caused by poor drainage or excessive use of sprinkler irrigation for frost protection.

- Draining or flushing equipment on or near desirable trees or other plants, or in areas where their roots may extend, or in locations where the chemical may be washed or moved into contact with their roots may injure these plants. Trees or other desirable plants whose roots extend into a treated crop use area may be injured.

- Carefully observe sprayer cleanup instructions, as spray tank residue may damage other crops.

- For best results, maintain spray tank solution at pH 5 to 7.

- If the selected companion herbicide has a ground or surface water advisory, consider the advisory when using the companion herbicide.

- Tank mixing DuPont MATRIX SG with organophosphate insecticides in tomatoes may result in crop injury.

- Naturally occurring weed biotypes that are resistant to DuPont ALLY herbicide, DuPont GLEAN FC herbicide, DuPont EXPRESS herbicide, DuPont HARMONY EXTRA herbicide, or DuPont FINESSE herbicide will also be resistant to MATRIX SG (refer to Weed Resistance Management section)

RESTRICTIONS

- Do not apply more than 4 ounces (0.0625 lb ai) MATRIX SG per acre per year. Refer to Table 1 and the Application Information section for each crop/crop group for specific use restrictions.

- Injury to or loss of desirable trees or vegetation may result from failure to observe the following:

- Do not apply, drain, or flush equipment on or near desirable trees or other plants, or on areas where their roots may extend, or in locations where the chemical may be washed or moved into contact with their roots.

- Do not use on lawns, walks, driveways, tennis courts, or similar areas. Prevent drift of spray to desirable plants.

- Do not contaminate any body of water, including irrigation water that may be used on other crops.

- Do not apply to frozen or snow covered soil. Crop injury may occur from applications made to poorly drained soils.

- Do not apply using Air Assisted (Air Blast) field crop sprayers.

WEED RESISTANCE MANAGEMENT
MATRIX SG, which contains the active ingredient rimsulfuron, is a Group 2 herbicide based on the mode of action classification system of the Weed Science Society of America.

Proactively implementing diversified weed control strategies to minimize selection for weed populations resistant to one or more herbicides is a best practice. A diversified weed management program may include the use of multiple herbicides with different sites of action and overlapping weed spectrum with or without tillage operations and/or other cultural practices. Research has demonstrated that using the labeled rate and directions for use is important to delay the selection for resistance.

The continued effectiveness of this product depends on the successful implementation of a weed resistance management program. To aid in the prevention of developing weeds resistant to this product, users should:

- Scout fields before application to ensure herbicides and rates will be appropriate for the weed species and weed sizes present.

- Start with a clean field, using either a burndown herbicide application or tillage.

- Control weeds early when they are relatively small (less than 4 inches).

- Apply full rates of MATRIX SG for the most difficult to control weed in the field at the specified time (correct weed size) to minimize weed escapes.

- Scout fields after application to detect weed escapes or shifts in control of weed species.

- Control weed escapes before they reproduce by seed or proliferate vegetatively.

- Report any incidence of non-performance of this product against a particular weed to your DuPont representative, local retailer, or county extension agent.

- Contact your DuPont representative, crop advisor, or extension agent to find out if suspected resistant weeds to this MOA have been found in your region. If resistant biotypes of target weeds have been reported, use the application rates of this product specified for your local conditions. Tank mix products so that there are multiple effective sites of actions for each target weed.

- If resistance is suspected, treat weed escapes with an herbicide having a site of action other than Group 2 and/or use nonchemical methods to remove escapes, as practical, with the goal of preventing further seed production.

- 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.

Additionally, users should follow as many of the following herbicide resistance management practices as is practical:

- Use a broad spectrum soil-applied herbicide with other sites of action as a foundation in a weed control program.

- Utilize sequential applications of herbicides with alternative sites of action.

- Rotate the use of this product with non-Group 2 herbicides.

- Avoid making more than two applications of MATRIX SG and any other Group 2 herbicides within a single growing season unless mixed with an herbicide with a different site of action with an overlapping spectrum for the difficult-to-control weeds.

- Incorporate non-chemical weed control practices, including mechanical cultivation, crop rotation, cover crops and weed-free crop seeds, as part of an integrated weed control program.

- Use good agronomic principles that enhance crop development and crop competitiveness.

- Thoroughly clean plant residues from equipment before leaving fields suspected to contain resistant weeds.

- Manage weeds in and around fields, during and after harvest to reduce weed seed production.

INTEGRATED PEST MANAGEMENT
This product may be used as part of an Integrated Pest Management (IPM) program, which can include biological, cultural, and genetic practices, aimed at preventing economic pest damage. Application of this product should be based on IPM principles and practices including field scouting or other detection methods, correct target pest identification, population monitoring, and treating when target pest populations reach locally determined action thresholds. Consult your state cooperative extension service, professional consultants or other qualified authorities to determine appropriate action treatment threshold levels for treating specific pest/crop or site systems in your area.

MANDATORY SPRAY DRIFT MANAGEMENT

Ground Boom Applications:

- Apply with the nozzle height specified by the manufacturer, but no more than 3 feet above the ground or crop canopy unless making a 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).

- For all other applications, applicators are required to use a Medium or coarser droplet size (ASABE S572.1).

- Do not apply when wind speeds exceed 10 miles per hour at the application site.

- Do not apply during temperature inversions.

Aerial Applications:

- Do not release spray at a height greater than 10 feet 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).

- For all other applications, applicators are required to use a Medium 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 one-half 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 Applications:

- Applicators are required to use a Medium or coarser droplet size (ASABE S572.1) for all applications.

- Do not apply when wind speeds exceed 10 miles per hour at the application site.

- Do not apply during temperature inversions.

Limitations, Restrictions, and Exceptions

POTATOES GROWN FOR SEED

APPLICATION INFORMATION
MATRIX SG may be used on potatoes grown for seed that use field grown tubers as the planted seed piece, and are at least the progeny of the first field planting*.
Apply MATRIX SG by any of the following methods:
- Preemergence 1.5 oz (0.0234 lb ai) per acre
- In a sequential application Preemergence at 1.0-1.5 oz (0.0156-0.0234 lb ai) per acre, followed by Postemergence at 1.0 oz (0.0156 lb ai) per acre.
- Postemergence at 1.0 oz (0.0156 lb ai) per acre followed by second Postemergence at 1.0 oz (0.0156 lb ai) per acre.

To activate MATRIX SG preemergence, supply moisture by a single rainfall event, or apply sprinkler irrigation of 1/3 to 1" (sandy soils apply at least 1/3", sandy loams apply at least 1/2", silt soils apply at least 3/4", clay soils apply at least 1"), within 5 days after application, to move MATRIX SG 2" to 3" deep into the soil profile.

Use Precautions
- The rotational crop interval listed in the MATRIX SG label may need to be extended to 18 months if seed potato production practices decrease water and/or time for MATRIX SG breakdown. Practices that may shorten the breakdown are late planting or less frequent irrigations as compared to commercial production practices. Potatoes can be planted at anytime.

- Consider informing your state seed certification agency or inspector that MATRIX SG has been applied. Under growing conditions that promote crop stress (including drought, frost, cold temperatures, high temperatures, or extreme temperature variations), temporary chlorosis (lime green color) may occur after application. These symptoms may appear similar to virus like symptoms (including chlorosis, leaf crinkling, pinching of terminal leaflet) but will usually disappear within 5 to 15 days of application.

Use Restrictions

- Do not make more the 2 applications of MATRIX SG per year.

- Do not exceed 2.5 oz (0.0391 lb ai) of MATRIX SG per acre per year.

- Do not apply to plants suffering stress from lack of moisture, cold, herbicide injury, and insect or disease injury.

- Do not use on potatoes grown for seed if these are grown from microtubers or transplants. Depending on geography, these may be referred to as Generation 1, Nuclear, Elite 1, or Pre-Elite.

- The rotational crop interval for Spring Barley is extended to 18 months due to the shorter growing seasons and different cultural practices in seed production in the states of California, Idaho, Oregon, Montana, South Dakota, Washington, Colorado, and parts of North Dakota**.

* First field planting utilizes laboratory tested stocks which may be tissue cultured plantlets, greenhouse produced microtubers, minitubers, stem cuttings, or line selections.

**All counties in North Dakota except Pembina, Towner, Walsh, Grand Forks, Trail and Cass.

AERIAL APPLICATION
(Also read SPRAY DRIFT MANAGEMENT section)
- Use nozzle types and arrangements that will provide optimum spray distribution and maximum coverage at a minimum of 5 GPA. In California use a minimum of 10 GPA.

Aerial Application Restrictions:
- Do not apply during a temperature inversion, when winds are gusty, or when conditions favor poor coverage and/or off-target spray movement.

- Do not apply by air in the state of California, except in Modoc or Siskiyou counties.
- Do not apply by air in the state of New York.

CHEMIGATION - POTATOES ONLY
DuPont MATRIX SG can be applied using center pivot, lateral move, solid set, or hand move irrigation systems in potatoes. Do not apply MATRIX SG using any other type of irrigation system. Check irrigation systems to insure uniform application of water to all areas. Failure to apply MATRIX SG uniformly may result in crop injury and/or poor weed control.

For best results, use the highest labeled rate and apply preemergence to early postemergence to the weeds (weeds less than 1" tall). If weeds are present at application, add a nonionic surfactant containing at least 80% active ingredient to the spray mix at 1 to 2 pt/acre.

MATRIX SG may be mixed in a supply tank with water, fertilizer, or other appropriate agricultural chemicals. Maintain continuous agitation in the injection nurse tanks during application.

For solid set and hand move irrigation systems, apply MATRIX SG at the beginning of the set and then apply 1/3 to 1" of water for activation (sandy soils apply at least 1/3", sandy loams apply at least 1/2", silt soils apply at least 3/4", clay soils apply at least 1").

For center pivot and lateral move irrigation systems, apply MATRIX SG in 1/3 to 1" of water for activation as a continuous injection (sandy soils apply at least 1/3", sandy loams apply at least 1/2", silt soils apply at least 3/4", clay soils apply at least 1").

If you have questions about calibrating chemigation equipment, contact State Extension Service specialists, equipment manufacturers, or other experts. If the chemigation equipment needs adjustment, only the custodian responsible for its operation, or someone under the supervision of that custodian, can make the necessary adjustments.

IRRIGATION SYSTEM REQUIREMENTS

The irrigation system must contain the following:
- a functional check valve
- vacuum relief valve
- a low pressure drain (to prevent water source contamination from backflow; must be located on the irrigation pipeline)
- functional interlocking controls (to automatically shut-off the pesticide injection pump when the water pump motor stops)
- a metering pump, including a positive displacement injection pump (e.g., diaphragm pump) effectively designed and constructed of materials that are compatible with pesticides and capable of being fitted with a system interlock

The pesticide injection pipeline must contain the following:
- a functional, automatic, quick-closing check valve (to prevent the flow of fluid back toward the injection pump)
- a functional, solenoid-operated valve (normally closed) located on the intake side of the injection pump (should be connected to the system interlock to prevent fluid from being withdrawn from the supply tank when the irrigation system is shut down either automatically or manually)

The irrigation line or water pump must include a functional pressure switch that will stop the water pump motor when pesticide distribution is adversely affected by a decrease in water pressure.

USE PRECAUTIONS FOR CHEMIGATION - POTATOES
Distributing treated water in an uneven manner can result in crop injury, lack of effectiveness, or over-tolerance pesticide residues in the crop. Therefore, to ensure that the mixture is applied evenly at the labeled rate, use sufficient water, and apply the mixture for the proper length of time.

USE RESTRICTIONS FOR CHEMIGATION -POTATOES
- Do not permit run-off during chemigation.
- Do not apply when wind speed favors drift beyond the area intended for treatment.
- Do not connect an irrigation system (including greenhouse systems) used for MATRIX SG application to a public water system.

MATRIX SG ROTATIONAL CROP RESTRICTIONS - POTATO
For crops listed below, planting prior to the interval shown may result in crop injury when using MATRIX SG. Rotation intervals may need to be extended to 18 months if drought conditions prevail after application and before the rotational crop is planted, unless supplemental sprinkler irrigation has been applied and totals greater than 15" during the growing season. For tank mixtures, follow the most restrictive rotational crop guideline

Restricted Entry Interval

4 hours