Pesticide Formulations and Adjuvants Flashcards
7 cards from real CPA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pesticide Formulations and Adjuvants flashcards as text
A surfactant molecule has both a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail. This dual nature allows surfactants to:
Answer: Bridge the interface between water and oil or waxy surfaces
The dual hydrophilic/hydrophobic structure of surfactant molecules lets them sit at the oil-water or wax-water interface, reducing surface tension and improving coverage.
An applicator notices the spray tank mix has separated into layers despite mixing. This MOST likely indicates a:
Answer: Physical incompatibility between the tank-mixed products
Layer separation in a tank mix typically signals a physical incompatibility between formulations, which can reduce efficacy and cause application problems.
Which pesticide formulation is MOST likely to cause phytotoxicity (plant injury) if applied at high temperatures or to stressed plants?
Answer: Emulsifiable concentrate (EC)
The solvents and emulsifiers in emulsifiable concentrates can damage plant tissues, especially under heat stress or when plants are drought-stressed.
What is the purpose of an 'antifoaming agent' used as a pesticide adjuvant?
Answer: To suppress foam formation during tank filling and mixing
Antifoaming agents (defoamers) are added to the spray tank to reduce excessive foam generated during filling or mixing, which can interfere with accurate measurement.
Ready-to-use (RTU) pesticide formulations are advantageous for homeowners primarily because they:
Answer: Require no mixing or dilution before application
Ready-to-use formulations are pre-diluted to application strength, requiring no additional mixing, which reduces handling errors and exposure risk.
When tank mixing pesticides, which component should generally be added to the water FIRST according to standard mixing order guidelines?
Answer: Wettable powders (WP) or water-dispersible granules (WDG)
Standard tank mixing order places wettable powders and water-dispersible granules first (after filling halfway with water) to ensure they disperse properly before other formulations are added.
Why are some pesticide active ingredients formulated as microencapsulated products rather than as emulsifiable concentrates?
Answer: Microencapsulation reduces mammalian toxicity and provides longer residual activity
The polymer capsule reduces immediate dermal and inhalation exposure and provides slow release of the active ingredient for extended residual activity.