980 likes | 2k Views
Characteristics of Pesticides. Basic concepts relating to the names, chemistry, behavior and fate of Pesticides including a review of the R8 Label Book summary pages. Pesticide Names. Chemical name *. There are three names associated with every pesticide. Common name *. Product name *.
E N D
Characteristics of Pesticides Basic concepts relating to the names, chemistry, behavior and fate of Pesticides including a review of the R8 Label Book summary pages
Pesticide Names Chemical name * There are three names associated with every pesticide Common name * Product name * Skip definitions
Pesticide Names: Chemical Name The systematic Name of a Chemical Compound according to the rules of nomenclature of the International Union of Pure and Applied Chemistry as adapted for indexing in Chemical Abstracts For example: 3,5,6-trichloro-2-pyridinyloxyacetic acid.. is a chemical name Return
Pesticide Names: Common Name A generic name for a chemical compound (see the Weed Science Society of America list of herbicide nomenclature) For example: The common name for 3,5,6-trichloro-2-pyridinoxyacetic acid.. is triclopyr The common name is the name generally used in discussing pesticidal toxicology and environmental behavior and fate Return
Pesticide Names: Product Name The trade name of a pesticide; that is the name on the container you purchase. It is also the name to which the EPA registration number is applied at the time of registration Triclopyr alone is sold as: Garlon 3A or Garlon 4
Names in the R8 Label Book Summary Sheets • Common names • Brand names • (If the chemical name is needed – see the label not the summary sheet)
Another Caution ---Pronunciation of Names FORAY 4-AA PHORATE
Some quick definitions Solution * Suspension * - Emulsion * - Invert Emulsion * Bypass definitions
Some quick definitions Solution A liquid or solid chemical which is dispersed completely (not suspended) in water or another fluid. For our purposes this includes water solutions and ester or other oil-soluble chemical dissolved in oil Return
Some quick definitions Suspension Finely divided solid particles or liquid droplets dispersed (but not dissolved) in another solid, a liquid or a gas. Return
Some quick definitions Emulsion A suspension of small droplets of an oil-based or an ester pesticide in water Return
Some quick definitions Invert Emulsion A suspension of small droplets of water in an oil. Some chemicals are now produced as invert emulsions
Some quick definitions Invert Emulsion Generally the formation of an invert emulsions is undesirable. Without special precautions during mixing and use they commonly form resulting, in a sludge of the approximate consistency of mayonnaise that clogs hoses and nozzles and creates a major problem of clean-up
Some quick definitions Solution Suspension Emulsion Invert emulsion Mixed – can separate Dissolved –Does not separate Oil droplets in water Water droplets in oil
Liquids Solutions Emulsifiable concentrates Ultra Low Volume Concentrates Low Volume Concentrates Aerosols Liquified gas Solids Dusts Granules Pellets Soluble Powders Wettable Powders Flowables Baits Types of Product Formulation
Gross Classification of Pesticides by Chemistry • Inorganic pesticides * • Organic pesticides * • Biological pesticides * Skip definitions
Gross Classification of Pesticides by Chemistry • Inorganics • Molecules do not contain carbon • Heavy metals – lead and arsenic • Copper products • Sulfur products Return
Gross Classification of Pesticides by Chemistry • Organics • Molecules contain carbon • May be chains or rings Return
Gross Classification of Pesticides by Chemistry • Biologicals • Viruses, bacteria, fungi, and plants • Nematodes, insects and other parasites or predators
Classification of Organic Herbicides by Chemistry • Phenoxy herbicides * • Triazines * • Imidazolinone * • Sulfonylureas * Bypass details
Classification of Organic Herbicides by Chemistry • Phenoxy herbicides • 2,4-D, 2,4-DP, 2,4,5-T • Behaves as an auxin causing hypertrophy • Sample structure Return
Classification of Organic Herbicides by Chemistry • Triazines • Hexazinone • Have extreme soil mobility • Structure Return
Classification of Organic Herbicides by Chemistry • Imidazolinone • Imazapyr • Structure Return
Classification of Organic Herbicides by Chemistry • Sulfonylureas • Metsulfuron & sulfometuron methyl • Sample structure
Classification of Organic Insecticides by Chemistry • Chlorinated hydrocarbons * • Organophosphates * • Carbamates * Skip definitions
Classification of Organic Insecticides by Chemistry • Chlorinated hydrocarbons • Dieldrin, aldrin, DDT, mirex, chlordane • Sample structure Return
Classification of Organic Insecticides by Chemistry • Organophosphates • Malathion, azinphos-methyl, naled • Sample structure Return
Classification of Organic Insecticides by Chemistry • Carbamates • Carbaryl (Sevin) • Structure
2 Basic Chemical Groups for Herbicides Amines * Esters * Skip details
AmineGeneral Characteristics • Organic salt • Water soluble • Low volatility • Low in its toxicity to fish • Used for injection & cut-surface treatments Return
Esters(General Characteristics) • Oil based • Oil soluble / can be emulsified in water • Generally highly volatile • Highly toxic to fish • Used for bark & foliar applications
Organic salt Oil based Amine Ester • Water soluble • Oil soluble or can be emulsified in water • Low volatility • High volatility • Low toxicity for fish • High toxicity for fish • Bark or foliar applications • Injection & cut-surface treatments
LD50s of field formulations Triclopyr – LD50 630 mg/kg Garlon 4 --LD50 1,419 mg/kg
LD50s of field formulations Garlon 4 --LD50 1,419 mg/kg Streamline uses a 17% solution of Garlon 4 => 1,419 / 0.17 = 8,347 mg/kg Foliar spray is normally done as a 3% solution => 1,419 / 0.03 = 47,300 mg/kg
Mode of action Selectivity Soil activity and mobility Persistence and breakdown Toxicity to humans and wildlife Application timing Weaknesses or limitations Environmental behavior: Several categories of environmental behavior are included in the summaries which precede each chemical presented in the Region-8 Label Book Information includes:
The following slides discuss these and several other properties of pesticides in generalDiscussion in the “R-8 Label Book” section (later this week) presents chemical specific information
Mode of Action: Herbicides • Movement in the plant • Contact * • Translocated * • Action in the plant • Inhibit protein synthesis, photosynthesis, or growth Bypass definitions
Mode of Action: Contact Herbicide One which causes injury to only the plant tissue to which it is applied, or one which is not appreciably translocated within a plant Return
Mode of Action: Translocated Herbicide One which is moved within a plant from the point of application to the point of action; may be either phloem-mobile or xylem-mobile The term is often misapplied to include only foliar applied herbicides which move downward from the leaves to the roots Return
Mode of Action: Animal Poisons (incl. Insecticides) Contact poison * Systemic poison * Attractants * • Pheromones • Baits Repellants * Bypass definitions
Mode of Action: Contact Insecticide Pesticide which causes injury or death of insect through the touch rather than through inhalation or ingestion Return
Mode of Action: Systemic Insecticide Pesticide which is moved within a plant from the point of application to the point where the insect will contact or ingest it Return
Mode of Action: Attractants Pesticide which lures animals to a predetermined spot • Pheromones are biochemicals either released by the animal or synthesized which are sex attractants • Baits are chemicals which entice animals for reasons other than sex (smells like food) Return
Mode of Action: Repellants Pesticide which discourages animals from coming to a specific area • Many chemicals unrelated to sexual activity (due to smell or other physical characteristic) are repellant to animals • Pheromones in low concentration are attractive to animals but, often, in high concentration become repellant
Mode of Action: Life Stage Affected Ovicide * Larvicide * Adulticide * Bypass Definitions
Mode of Action: Life Stage Affected Ovicide • Kills eggs Return
Mode of Action: Life Stage Affected Larvicide • Kills larval stage (immature) insects Return
Mode of Action: Life Stage Affected Adulticide • Kills adult insects
Mode of Action: Selectivity • Many products express a degree of selectivity • Extremely variable from product to product • Biologicals often more selective than chemicals • Despite claims, selectivity is generally limited • Often based on rate • Many newer products are more selective • Application method also influences selectivity
Soil Activity Soil Active Herbicide: applied to or present in the soil, these chemicals are readily absorbed by plant roots and subsequently negatively affects the plant in some manner