General Information


Local conditions, crop varieties, and application method may affect performance of this product. User should consult local Extension Service, agricultural experiment station, or university weed specialists, and State regulatory agencies for recommendations in your area.

NOTE: Certain counties in California may have specific permit requirements and restrictions that need to be adhered to prior to and during the application of phenoxy herbicides. It is the responsibility of the end user, applicator, and/or pest control advisor (PCA) to be fully aware of any and all county permit conditions regarding the use and application of phenoxy herbicides. All restrictions dates, buffer zones to sensitive crops, required drift control measures and any other requirements are the sole responsibility of the purchaser, end user, applicator or PCA.

Best results are obtained when product is applied to young succulent weeds that are actively growing. Application rates lower than recommended will not be satisfactory on susceptible annual weeds. For perennial weeds and conditions such as the very dry areas of the western states, where control is difficult, the higher recommended rates should be used. When product is used for weed control in crops, the growth stage of the crop must be considered. Some plants and weeds, especially woody varieties, are hard to control and may require repeat applications. Application rates should be 1 to 5 gallons of total spray by air or 5 to 25 gallons by ground equipment unless otherwise directed. In either case, use the same amount of UNISON per acre. UNISON should not be allowed to come into contact with desirable, susceptible plants such as beans, cotton, fruit trees, grapes, legumes, ornamentals, peas, tomatoes and other vegetables.

UNISON should not be used in greenhouses. If stored below freezing, it may be necessary to warm product to 40ºF and agitate before using. This does not affect the efficiency of the product. Spray equipment used to apply UNISON or other products containing 2,4-D should not be used for any other purpose until thoroughly cleaned with a suitable chemical cleaner.

NOTE: California Aerial Restriction: In California, aerial application is allowed on small grains only. All other crops application by air is prohibited.

Western States Aerial Restrictions: Application of UNISON is prohibited between February 1st and September 15th in the following Western United States (AZ, NM, NV).


Use calibrated spray equipment for all types of applications to assure applying the recommended amount of spray mixture per acre. Use sufficient spray volume within the ranges specified to obtain good coverage of weeds. UNISON is absorbed sufficiently within 1 hour after application to provide adequate weed control.

Ground Broadcast Spray: Unless otherwise specified in the appropriate crop or non-crop directions, apply in 5 or more gallons of spray solution per acre. Use enough spray volume to provide uniform coverage of weeds, taking into account the amount of vegetation present and the type of application equipment to be used. As crop canopy and weed density increase, a higher spray volume may be needed for equivalent coverage and weed control. Typical crop applications utilize 10 to 50 gallons of spray solution per acre, while certain high volume non-crop applications may utilize more than 100 gallons per acre. Use coarse sprays to minimize potential spray drift. Do not apply with hollow cone nozzles or other nozzles that produce fine spray droplets. Boom spraying with flat fan or low volume nozzles is generally most suitable for ground broadcast applications.


Labeled Crops: Within 29 days following an application of this product, plant only those crops named as use sites on this or other registered 2,4-D labels. Follow more specific limitations, if any, provided in the directions for individual crops. Labeled crops may be at risk for crop injury or loss when planted soon after application, especially in the first 14 days. Degradation factors described below should be considered in weighing this risk.

Other Crops: All other crops may be planted 30 or more days following an application without concern for illegal residues in the planted crop. However, under certain conditions, there may be a risk of injury to susceptible crops. Degradation factors described below should be considered in weighing this risk. Under normal conditions, any crop may be planted without risk of injury if at least 90 days of soil temperatures above freezing have elapsed since application.

Degradation Factors: When planting into treated areas, the risk of crop injury is less if lower rates of product were applied and conditions following application have included warm, moist soil conditions that favor rapid degradation of 2,4-D. Risk is greater if higher rates of product were applied and soil temperatures have been cold and/or soils have been excessively wet or dry in the days following application. Consult your local Agricultural Extension Service for information about susceptible crops and typical soil conditions in your area.

Limitations, Restrictions, and Exceptions

POME FRUITS (Apples and Pears)

Apply broadcast for the control of unwanted vegetation on the orchard floors. It is important to avoid contact with the fruit, fruit foliage, and tree trunks, lowers limbs and exposed brace roots. Two applications 75 days apart are permitted.

- Minimum of 75 days between applications.

- Do not cut orchard floor forage for hay within 7 days of application.

NOTE: Aerial application in California is prohibited.

Pre-Harvest Interval

14 days

Restricted Entry Interval

48 hours