Herbicide incompatibility problems are usually the result of poor mixing techniques. Typically, people neglect to "pre-wet" the herbicide products. It is important to pre-wet all products whether liquid or solid formulation. The general quidelines for mixing herbicides include:

1) Refer to the specific herbicide label for exact mixing instructions.

2) Determine compatibility of herbicides and carriers with small containers rather than large spray tanks.

3) Pre-wet dry or suspension herbicide formulations, add to the spray tank and agitate. Pre-wet herbicides with an appropriate amount of water. This is especially important when fluid fertilizer is the intended carrier.

4) Pre-wet the EC formulated herbicide and add to the spray tank during filling. Use agitation during the process.

Herbicide labels will vary with the amount of carrier in the spray tank prior to the addition of the herbicides. Follow the instructions closely. Compatibility agents may be necessary if fluid fertilizer is the primary carrier. Another important compatibility problem is water temperature. Cold water may inhibit the proper mixing of some herbicide formulations. This is particularly a concern during the early spring when cool, cloudy conditions are common. It may be necessary to allow the water to warm slightly before adding the herbicides. It is illegal to mix herbicides near a well. One last consideration is when herbicide mixtures are allowed to set long periods of time. Some products tend to settle and cake at the bottom of the spray tank. Mechanical stirring, a compatibility agent or both may be necessary to resuspend the herbicide mixture. It is better to mix only as much herbicide as will be applied at one time.