Pesticide Formulations and Adjuvants Montana State University Pesticide Safety Education Program
What is a formulation? How a pesticide is packaged. Contains: Active Ingredient Inert Ingredient
Active Ingredients Has the pesticidal effect Its on the label Properties of the a.i. influences the type of formulation
Inert Ingredients Inactive ingredients mixed with a.i. To make formulation easier to handle or store. Toxic or non-toxic
Can you get the same reaction from the same active ingredients regardless of inert ingredients? NO, Inert Ingredients are often patented and are only known to the company. Many times this is the difference between a product working effectively and not at all. BANDED, SEED, FOLIAR applications all different yet the same!
Types of Formulations Wet More easily absorbed Dry More easily inhaled
Liquid Formulations (Wet) EC emulsifiable concentrate S soluble M or ME Micro-Encapsulated ULV ultra low volume
Soluble Advantage: Will not separate or settle out when mixed with water. Not as harmful to non-target plants and animals Disadvantage: Not many disadvantages. Readily absorbs into skin
Emulsified Concentrates ADVANTAGES Little agitation required. Won t settle out when equipment is turned off. Relatively non-abrasive. Easy to handle, store and transport DISADVANTAGES Because of the solvents and emulsifiers, EC s are a hazard to non-target plants and animals. Easily absorbed through skin of plants and humans. Solvents may cause rubber or plastic hoses & gaskets to deteriorate.
Dry Formulations WP Wettable powder F or DF Dry Flowable WDG Water Dispersible Granule D -Dust P or G Pellets or Granules
Wettable Powders ADVANTAGES Easy to store & transport. Smaller packaging. Won t freeze. Less inert ingredients in formulation. Lower toxicity to plants than liquid formulations. The inert ingredients, clay or talc, are generally harmless to plants DISADVANTAGES Inhalation hazard when pouring and mixing. It s dry! Needs vigorous & constant agitation in the spray tank. Abrasive to many pumps and nozzles.
Flowable ADVANTAGES Easy to handle and apply Seldom clogs nozzles. Finer ground carrier. DISADVANTAGES May leave visible residue. Requires agitation
Granules or Pellets ADVANTAGES Ready to Use (RTU); no mixing Low drift hazard as particles settle quickly. In most cases, don t need to mix with water first. DISADVANTAGES May need to be incorporated into the soil. Dust from application equipment might present hazard to applicator. Easy to over apply
Effects of Different Formulations Formulations Hazards Phytox Equipment Agitate Compactable M or ME Dermal Safe ok Yes Fair G or P Inhale Safe NA NA NA D Inhale Safe NA NA NA S Dermal Safe Non-abrasive No Fair F or FL Dermal Maybe abrasive Yes Fair EC Dermal Maybe Seals, gaskets No Fair WP Inhale Safe abrasive Yes High
Testing Compatibility Using 1 qt jar Wear your PPE! Add to jar in same proportions as you use in the field ( 1 teaspoon = 1 quart of pesticide added to 50 gallons of water). Add half of diluent to jar then add pesticide according to plan. Add Wettable & other powders & Water-dispersible granules Agitate and add remaining diluent Add the Liquid products, such as solutions, surfactants and flowables. Add Emulsifiable concentrates last. Shake jar vigorously and feel sides of jar for heat. Check for lumps, scum and clumps
continued Let the jar sit for 5 minutes. Check for any flakes, sludge, gels or other precipitants. Also see if there is any separation or layering, or small oil particles in solution. If separate layers are formed after sitting up to 30 minutes but can be resuspended by shaking, application may be possible but make sure you have agitation in the sprayer. If there is layering, an emulsifiable concentrate will normally go to the top. Wettable powders will either settle to the bottom or float on top.
Interaction problems with combining Formulations Additive effects Synergistic responses Antagonism Enhancement
Additive Effect SAVES TIME WITH NO CHANGE IN EFFECT! Ease of mixing Reduces # of field passes Example: root absorbed herbicide with a foliar absorbed or Tordon with Escort
Synergistic Response Confused with Additive effects Greater response when mixed. True interaction between chemicals Reduced rates often the result
Antagonism Less control when 2 or more chemicals are mixed May also increase phytotoxicity Example: mixing of some grass and broadleaf herbicides (Diclofop and 2,4-D)
Enhancement When a pesticide is mixed with an additive to provide greater response. Example: adjuvants
Adjuvants Additives that are added to a spray solution in order to enhance or modify the performance of the spray mixture. #1 - Surfactants/wetting agents #2 - Oils #3 - Fertilizers #4 - Utility
#1 - Surfactants A broad category of adjuvants that facilitate and enhance the absorbing, emulsifying, dispersing, spreading, sticking, wetting and penetrating properties of pesticides. Some pesticides like Roundup Pro already have surfactants added. (14.5 %)
Why Surfactants Because of the high surface tension of water, spray mixture droplets maintain their roundness and can sit on the leaf hairs or leaf surface without much of the mixture actually contacting the leaf. Surfactants reduce angle and promote more absorption
Classes of Surfactants/Wetting Agents #1a - Nonionic Surfactants (no charge) Reduces surface tension Improves spreading, sticking and herbicide uptake All purpose #1b - Silicone compounds (Silicone based) More reduction in surface tension. Spread more than conventional surfactants Maximum rainfastness due to increased absorption. Can usually use at lower rates
#2 - Oils Crop Oil Concentrates (COC) Blend of paraffin based petroleum oil and surfactants Used primarily with grass herbicides Esterified Seed Oils (ESO) often referred as MSO Produced by reacting fatty acids from seed oils(corn, soybean, canola) with an alcohol to form an ester All purpose type of surfactant
#3 - Fertilizers -(Nitrogensurfactant Blends) Improves herbicide uptake with hard to-kill weeds Neutralizes or gives hard water mineral ions something to bind to instead of the herbicide. Used primarily with broadleaf herbicides.
#4 - Utility Acidifiers -neutralize alkaline solutions & lower ph. Buffering agents -stabilize the ph of spray solutions. Anti-foaming agents Compatibility agents Drift control agents Emulsification aids Suspension aids -added to a suspension in order to keep pesticide particles dispersed or to resuspend particles.
Tips continued Costs Generally, non-ionic surfactants and crop oil concentrates are the least expensive Nitrogen surfactants, esterified crop oils, organosilicones (most expensive) What conditions follow an application? Max rainfastness: esterified seed oils, organosilicones, nitrogen surfactants Not all surfactants have the same amount of rainfastness
What formulation is this? FLOWABLE DERMAL ABSORPTION Examples: Bravo 720 F fungicide Furadan 4 F insecticide
Question #2 What formulation is this? Powdered Hand Soap Wettable Powder Easily Inhaled Examples: Sevin 50 W insecticide Kerb 50 W herbicide Sniper 50 W insecticide
READ THE LABEL This will give you an idea of what type of adjuvant if any should be used.
Questions