Pesticide Formulations, Adjuvants, and Compatibility
Pesticide Formulations, Adjuvants, and Compatibility
This domain tests how formulation affects mixing, handling, and performance, and how adjuvants and compatibility checks prevent tank failures.
Core rules
- Formulation types include emulsifiable concentrate (EC), wettable powder (WP), water-dispersible granule (WDG), suspension concentrate (SC), soluble liquid (SL), microencapsulated, bait, dust, and fumigant.
- ECs use solvents and emulsifiers; WPs can leave visible residue; WDGs dissolve more cleanly; microencapsulated products release slowly and can be hazardous to bees.
- Adjuvants: surfactants (wetting/spreading), stickers, spreader-stickers, drift-control agents, defoamers, compatibility agents. Use only when the label allows or requires them.
- Compatibility: do a jar test before tank-mixing unfamiliar products. Add products in a standard order (fill water, compatibility agent, dry formulations, suspensions, ECs, solutions, adjuvants) and keep agitation.
- Hard water, pH, and temperature can inactivate some products.
Worked example
You plan to tank-mix a WP and an EC. In a jar with the same water, the WP goes in first and disperses; then the EC is added. If the mixture forms oily flakes or a thick sludge, it is incompatible. Reasoning: the visible failure in a small jar predicts a tank failure; do not add it to the sprayer. Try a compatibility agent or apply separately.
Traps
- Adding adjuvant before the product.
- Assuming "compatible" because both are pesticides.
- Using a jar test with different water than the spray tank.
- Over-agitating a product that foams.
- Ignoring label restrictions on surfactants near aquatic sites.