Adjuvants and Surfactants
Additives that improve pesticide coverage, penetration, and effectiveness - spreaders, stickers, wetting agents, and drift reducers.
Detailed Overview
Adjuvants are tank-mix additives that enhance pesticide performance. Types: (1) Surfactants/Spreaders: reduce surface tension allowing spray to spread evenly rather than beading up. Critical for waxy leaf surfaces and hard-to-wet surfaces. (2) Stickers: help product adhere to surfaces and resist wash-off from rain or irrigation. Important for outdoor treatments. (3) Penetrants: help active ingredient penetrate plant tissues or pest cuticles. (4) Drift control agents: thicken spray reducing airborne drift. (5) Buffering agents: adjust pH for optimal pesticide stability. (6) Compatibility agents: help tank mixing of incompatible products. Most modern formulations include built-in surfactants - read label to determine if additional surfactant needed. Some labels prohibit adjuvants. Common mistake: adding unnecessary surfactant to product already containing it - can cause excessive foaming or phytotoxicity. When useful: waxy ornamental plants resisting spray coverage, situations requiring extended residual despite rain, very hard water interfering with product performance. Follow label directions: some labels specify adjuvant types and rates; others prohibit. Test tank mix compatibility before large batches - combine small amounts, let sit 30 minutes, check for separation or clumping.
When to Use
Add adjuvants only when label permits or recommends. Use spreaders for hard-to-wet surfaces, stickers for rain-prone outdoor treatments. Most modern formulations include adequate adjuvants - do not add unnecessarily.
Required Skill Level
Requires some training and experience in pest management
Benefits
- Improves spray coverage and uniformity
- Enhances rainfall resistance
- Can improve penetration and efficacy
- Reduces drift in windy conditions
- Solves hard water compatibility issues
Limitations
- Many products already contain adequate adjuvants
- Overuse can cause phytotoxicity or foaming
- Some labels prohibit adjuvants
- Additional cost and mixing complexity
- Must verify label compatibility
Related Concepts
Other product types that may be useful
Reduced-Risk Pesticides
Low-toxicity pesticide products that pose minimal risk to humans, pets, and the environment while remaining effective against target pests.
Insect Growth Regulators (IGRs)
Pesticides that disrupt insect development and reproduction by mimicking or blocking growth hormones - providing long-term population suppression.
Non-Repellent vs Repellent Chemistry
Understanding the difference between insecticides pests cannot detect (non-repellent) versus those they avoid (repellent) - critical for colony elimination.