Take Advantage Of Adjuvants

Adjuvants are substances used to aid or modify the action of an agrichemical or the physical characteristics of mixtures in order to enhance performance. Adjuvants include surfactants, compatibility agents, anti-foaming agents, spray colorants such as dyes and drift control agents. Adjuvants can be added to the agrichemical product at the time it is formulated by the manufacturer or by the applicator to the spray mix just prior to treatment. Adjuvants are used for numerous different reasons. Adding adjuvants can potentially increase the efficacy of the pesticide being applied or reduce off target implications. However adjuvants can easily cause crop injury or have reduced activity if label instructions are not followed. Pesticide labels usually will state if a specific adjuvant is required and the amount of active ingredient the product should contain.

Surfactants Or Surface Agents

The word “surfactant” is a general term that includes soluble detergents in liquid, and other agents that improve emulsifying, dispersing, spreading or wetting spray mixes. Surfactants increase the spray coverage on foliages and help plants absorb the spray mix or increase the exposure of a pest to the spray mix. Surfactants include extenders, compatibility agents, buffers or pH modifiers, drift retardants, defoaming agents, thickeners, emulsifying agents, wetting agents (spreaders), crop oil concentrates, and stickers.

Emulsifying Agents

These are surfactants that promote the suspension of one liquid in another. There are two types of emulsions used in the applications of pesticides. One is “oil-in-water”, these are used to allow oil-soluble pesticides to be applied as water spray. The second type is “water-in-oil” emulsion; these are usually viscous and are used to improve resistance of spray mixes to rain, improve accuracy of delivery of the pesticide and enhance activity.

Wetting Agents

These materials are also known as spreaders. They improve the ability of a given pesticide to increase the area of contact and spread evenly over surfaces of leaves or fruits. There are four types of wetting agents: anionic, cationic, non-ionic and amphoteric. Anionic and cationic surfactants have electrical charges in water while non-ionic surfactants do not have an overall electrical charge. Amphoteric may have positive or negative charges depending on the pH of the solution. Most herbicides will recommend the use of non-ionic surfactants. It is essential to read the pesticide label to determine what type of wetting agent to use.

Crop Oil Concentrates

A crop oil concentrate refers to products that contain 80 to 85% petroleum or vegetable oil plus 15 to 20% surfactant and emulsifiers. An emulsifiable oil generally refers to products that contain about 98% oil and 1 to 2% emulsifiers. This group is often called nonphytotoxic oils and phytobland oils.

Comments (3)

William R. Carr (Tue Sep 25 15:03:23 2012)

I completed series 38 test on 9/9/2012 but have not received notificiation from anyone regarding completion of test and or results. Kindly let me know when I can expect to be awarded the core points as my renewal is coming up in November, 2012. Thank you Wm. R. Carr

Chris W. Lundy (Tue Jul 31 20:27:12 2012)

I completed this test on July 26, 2012 but have not received notificiation of completion from you. Kindly let me know when I can expect to receive notification. If, for some reason, there was a problem with my submission and you do not have it, please let me know that as well and I will resubmit. Thanks

PEDRO E MALABET (Fri Apr 13 13:00:54 2012)

very good and interesting article

Learn how to enhance pesticide performance with these helpful farm aids.