Adjuvants are substances that enhance or modify the performance of pesticides when added to the spray tank.
Label rates and formulations of pesticides should be strong enough to handle some adverse conditions during the application process. However, in many instances during mixing, spraying, deposition and uptake of pesticides the losses can be so substantial that efficacy is compromised. Adjuvants can overcome these problems. Essentially, they make the application process more robust.
To optimise application it is important to choose the right adjuvant for a specific task.
Adjuvants: Functional Classification
Wetting / Spreading Agents
Anionic surfactant: a surface-acting agent that forms a negative ion (anion) at its lipophilic part when in solution with water
Cationic surfactant: a surface-acting agent that forms a positive ion (cation) at its lipophilic part when in solution with water
Non-ionic surfactants: a surface-acting agent that has no ionisable polar end groups, e.g. Activator®, Chemwet 1000
Petroleum or Mineral Oils:
a) containing >95% mineral oil and <5% emulsifier, e.g. D-C-Tron® (1-3%) or D-C-Trate® (<5%)
b) containing <85% mineral oil and >15% emulsifier, e.g. Bonza®, Uptake®, Supercharge®
a) Vegetable oil with <15% emulsifier, e.g. Synertrol
b) Chemically modified vegetable oils (methyl or ethyl esterfied) with emulsifier, e.g. Hasten™
Conventional surfactants at high dose (>0.15% v/v) e.g. Activator, Chemwet 1000
Organosilicones, e.g. Pulse
Sticker / Adhesion Agents
Wetter TX, Activator, Chemwet 1000, LI 700
Latex & resin type adjuvants
Water Management Agents
pH management buffers
a) Acidifier (e.g. LI 700)
b) True Buffer (e.g. Primabuff®)
c) Alkaline agents
Hard water management agents
Antifoam / de-foam agents
Suspension / re-suspension agent
Drift Reducing Agents
LI 700, Bonza, Activator
Prolongs the activity of chemicals in adverse weather conditions, e.g. Bond
The Spraywise Broadacre Application Handbook is 60+ pages of comprehensive, detailed information for all you need to know about spray application.