Herbicide Terms

From American Society for Testing and Materials (ASTM) Standard Terms and Definitions


[A B C D E F H M N O P S V W]

Acidifier

A material that can be added to spray mixtures to lower the pH.

Activator

A material that increases the biological efficacy of agrichemicals.

Active Ingredient

A component of the formulation that produces a specific effect for which the formulation is designed.

Adjuvant

A material added to a tank mix to aid or modify the action of an agrichemical, or the physical characteristics of the mixture.

Anionic Surfactant

A surface-active agent in which the active portion of the molecule containing the lipophilic segment forms exclusively a negative ion (anion) when placed in aqueous solution.

Antifoaming Agent

A material used to inhibit or prevent the formation of foam.

Attractant

A material that attracts specific pests.

Buffer or Buffering Agent

A compound or mixture that, when contained in solution, causes the solution to resist change in pH. Each buffer has a characteristic limited range of pH over which it is effective.

Canopy Penetrating Agent

An adjuvant that increases the penetration of the spray material into the crop canopy. See deposition aid.

Cationic Surfactant

A surface-active agent in which the active portion of the molecule containing the lipophilic segment forms exclusively a positive ion (cation) when placed in aqueous solution.

Colorant

A material used to alter the color of the tank mix.

Compatibility Agent

A surface-active agent that allows simultaneous application of liquid fertilizer and agrichemical, or two or more agrichemical formulations, as a uniform tank mix, or improves the homogeneity of the mixture and the uniformity of the application.

Crop Oil Concentrate

An emulsifiable, petroleum oil-based product containing 15% to 20% w/w surfactant and a minimum of 80% w/w phytobland oil.

Crop Oil (Emulsifiable)

An emulsifiable, petroleum oil-based product containing up to 5% w/w surfactant and the remainder of a phytobland oil.

Crop Oil (Nonemulsifiable)

See phytobland oil.

Defoaming Agent

A material that eliminates or suppresses foam in the spray tank.

Deposition Aid

A material that improves the ability of agrichemical sprays to deposit on target surfaces.

Dormant Oil

A horticultural spray oil applied during the dormant phase of the targeted plant.

Drift Control Agent

A material used in liquid spray mixtures to reduce spray drift.

Emulsifier

A surfactant that promotes the suspension of one immiscible liquid in another.

Esterification

The process of reacting fatty acids with an alcohol. Although methanol is the most commonly used alcohol (methylated), ethanol (ethylated), n-butanol and isopropyl alcohol could be used.

Evaporation Reduction Agent

A material that reduces the evaporation rate of a spray mix during, after, or both during and after, application.

Extender

A material that increases the effective life of an agrichemical after application.

Foam Suppressant

See defoaming agent.

Foaming Agent

A material that increases the volume or stability of the foam formed in a spray mixture.

Humectant

A material which increases the equilibrium water content and increases the drying time of an aqueous spray deposit.

Modified Vegetable Oil

An oil extracted from seeds that has been chemically modified (for example, methylated).

Modified Vegetable Oil Concentrate

An emulsifiable, chemically modified vegetable oil product containing 5% to 20% w/w surfactant and the remainder chemically modified vegetable oil.

Naphtha-Based Oil

A petroleum oil containing a majority of the naphtha fraction.

Nonionic Surfactant

A surface-active agent having no ionizable polar end groups but comprised of hydrophilic and lipophilic segments.

Oil

See petroleum, vegetable, paraffinic and so forth.

Paraffinic Oil

A petroleum oil (derived from paraffin crude oil) whose paraffinic-carbon type content is typically greater than 60%.

Penetrant

A material that enhances the ability of an agrichemical to enter a substrate or penetrate a surface.

Petroleum Oil

Oil derived from petroleum: contains a mixture of hydrocarbons that are broadly classified as paraffins, naphthenes, aromatics, or other unsaturates, or combinations thereof.

Phytobland Oil

A highly refined paraffinic material with minimum unsulfonated residue of 92% v/v.

Spreader

A material which increases the area that a droplet of a given volume of spray mixture will cover on a target.

Spreader/Sticker

A material that has the properties of both a spreader and a sticker.

Sticker

A material that assists the spray deposit to adhere or stick to the target and may be measured in terms of resistance to time, wind, water, mechanical action or chemical action.

Surface Agent

A material that when added to a liquid agent medium, modifies the properties of the medium at a surface or interface. This is a general term that includes soluble detergents in liquid medium, dispersing agents, emulsifying agents, foaming agents, penetrating agents and wetting agents.

Surfactant

See surface agent.

Vegetable Oil

Oil extracted from seeds; typically those of corn, cotton, peanut, rapeseed, sunflower, canola or soybean.

Vegetable Oil Concentrate

An emulsifiable vegetable oil product containing 5% to 20% w/w surfactant and a minimum of 80% w/w vegetable oil.

Wetting Agent

Wetting agents can be considered synonymous with spreading agents in function.