Tank mixing herbicides involves combining multiple herbicides (and potentially other products like adjuvants) in a sprayer tank to achieve broader weed control, reduce application costs, and/or improve herbicide efficacy. The key is to follow a specific mixing order and ensure compatibility to avoid clogging nozzles or reducing effectiveness.
Here's a step-by-step guide on how to properly tank mix herbicides:
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Start with Clean Equipment: Before beginning, ensure your sprayer tank and equipment are clean and free of any residue from previous applications. Rinse thoroughly with clean water. This is crucial to prevent unintended chemical reactions.
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Fill the Sprayer Partially: Fill your sprayer tank with approximately half the total volume of water you intend to use. This allows for proper mixing and dilution as you add each product.
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Begin Agitation: Start the sprayer's agitation system and maintain continuous agitation throughout the entire mixing and application process. Proper agitation ensures a uniform mixture and prevents settling of chemicals.
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Add Compatibility Agents (If Required): If you suspect compatibility issues between the herbicides or other products you plan to mix, add a compatibility agent at this stage according to the product label instructions. Jar tests are crucial for determining compatibility.
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Add Dry Formulations First: If you're using any dry formulations like wettable powders (WP), dry flowables (DF), or water-dispersible granules (WDG), add these to the tank before liquid formulations. These typically take longer to dissolve and disperse thoroughly. Let each dry product fully dissolve before adding the next.
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Add Liquid Formulations: Next, add liquid formulations in the following order, generally (always refer to the product label for specific instructions):
- Suspension Concentrates (SC) or Flowables (F): These are finely ground particles suspended in a liquid.
- Emulsifiable Concentrates (EC): These are oil-based formulations that form an emulsion when mixed with water.
- Solutions (S): These are completely dissolved in the liquid carrier.
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Add Adjuvants: After the herbicides are thoroughly mixed, add any required adjuvants such as:
- Surfactants: These improve the spreading and wetting of the herbicide on the plant surface.
- Drift Control Agents: These reduce the potential for spray drift.
- Deposition Aids: These improve the deposition of the spray droplets on the target weeds.
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Complete Filling the Tank: Add the remaining water to bring the tank to its final desired volume.
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Continue Agitation: Maintain continuous agitation throughout the spraying process to ensure the mixture remains uniform.
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Perform a Jar Test: Before mixing large volumes, perform a jar test. Mix small quantities of each chemical in a jar at the correct proportions. Observe for any signs of incompatibility, such as:
- Precipitation (formation of solids)
- Separation (layering of the mixture)
- Gel formation
- Excessive foaming
Important Considerations:
- Always read and follow the product labels for all herbicides and adjuvants you are using. The label is the law! Pay attention to any specific mixing instructions or warnings.
- Know your water quality: Water pH and hardness can affect the efficacy of some herbicides. Consider testing your water and using a water conditioner if necessary.
- Avoid mixing products that are known to be incompatible. Check product labels or consult with a crop advisor.
- Tank mixing can increase the risk of crop injury if not done properly. Use caution when applying tank mixes to sensitive crops.
By following these steps carefully, you can safely and effectively tank mix herbicides to achieve optimal weed control.
