Addressing the Mixing Challenge: A recent survey conducted among producers who visited Rizobacter's Laboratory for Adjuvant and Formulation Evaluation (LEAF) revealed that over 90% cited tank mixing as a primary concern in agrochemical applications. A poorly mixed solution not only results in high operational costs but can also lead to losses of up to $3,000, considering the average tankful's value. These potential losses underscore the significance of achieving a well-mixed solution for successful applications.
Identifying Incompatibilities: Achieving a proper mixture involves more than just combining ingredients. Incompatibilities can arise, such as phase separation, foam formation, and solid precipitation. While some incompatibilities are visually apparent, others may not be detectable, emphasizing the importance of considering five fundamental factors:
1. Water Quality Matters: Understanding the quality of the water used in mixing is essential for successful applications. Murky or hard water can adversely affect mixture stability. While there aren't always effective chemical treatments for turbidity due to its diverse nature, best practices like using closed tanks, drawing water from wells, and employing filters and floaters can help reduce its presence. High water hardness, caused by calcium and magnesium cations, can impact formulation stability. Adjuvants with strong cation-sequestering capacity and pH buffers in their formulation can provide a solution to this challenge.
2. Formulation Compatibility: Different formulation types require varying handling methods and exhibit varying compatibility when mixed. Soluble products should not result in turbidity, unlike insoluble products that can introduce suspended solids and cloudiness. Additionally, the quality of the products utilized plays a pivotal role in mixture stability.
3. The Sequence of Addition: The order in which products are added is paramount. A recommended sequence involves starting with insoluble products and proceeding to soluble ones. This sequence helps prevent issues like precipitation. Adjusting pH gradually by adding neutral products first and acid products later (primarily herbicides) is crucial, given that Argentina's average water pH is 8.1. The pH information for formulations can be found in safety data sheets.
4. Agitation, Temperature, and Volume: Effective agitation is necessary to achieve proper product integration, especially for products like dispersible granules and suspension concentrates. Lower temperatures reduce water's solvent capacity and slow down chemical reactions, making the waiting time between successive additions critical. Concentrated formulations may require increased application volume per hectare to ensure stability.
5. Equipment Maintenance: Clean and properly functioning spray equipment is vital. Pre-application cleansing removes stubborn pesticide molecules, preventing incompatibilities in the mixture. Consider using comprehensive cleaners that can dissolve, solubilize, and deactivate even the most challenging pesticide formulations.
Conclusion: Achieving a stable, well-mixed solution is vital for successful agrochemical applications. By addressing water quality, formulation compatibility, addition sequence, agitation, temperature, and equipment maintenance, producers can maximize the effectiveness of their treatments. Adjuvants rich in surfactants can serve as valuable tools to achieve a successful mixture, translating into efficient applications and effective pest control. As the agricultural industry evolves, mastering the art of mixing remains pivotal for sustainable and productive crop management.