Understand How Pesticides Impact the Environment

Pesticide Characteristics: Solubility Tordon – 200,000 ppm Milestone – 205,000 ppm Gramoxone – 620,000 ppm Lorsban - emulsifiable

Pesticide Characteristics Adsorption Tordon - slightly Milestone – moderately Gramoxone – rapidly & tightly Lorsban – rapidly & tightly

Leaching

Pesticide Characteristics Persistence (Soil) Tordon – moderately (20 – 300 days) Milestone – moderately low( days) Gramoxone – Highly (1000 day) Lorsban – Highly (soil) days (H2O)

Pesticide Carry-over

Carry-over

Volatility Tordon – low Milestone – negligible Gramoxone – low Lorsban – MSDS no data available Pesticide Characteristics:

Pesticide Degradation Microbial Chemical Photodegradation Tordon Milestone Gramoxone Lorsban

Pesticide Movement By air Vapor, particle, spray drift By water Surface runoff Movement through soil By other objects Residues on plants and animals

DRIFT

Particle Drift Tordon Milestone Gramoxone Lorsban

WSDA

Factors That Influence Drift

Applicator Attitude Assess what sensitive sites are near the application area No-spray buffer necessary? Assess weather conditions: air stability, wind direction and speed Set up equipment with appropriate boom height, nozzles, and pressure Make decision to spray or not to spray

Droplet Size The Larger the Spray Droplet Size The Less Distance the Droplet Drifts

Viscosity A liquid’s resistance to flow – drift retardants

– Read the Wind What’s downwind? Direction How far will it move? Speed 0-3 mph: could be very stable with airflow, just not sure which direction the air is moving 3-7 mph: manage for off-target movement downwind >7 mph: carries more material off-target Weather Conditions

G.Thomasson and C. Ramsay, WSU Stable Air Conditions: Temperature Inversion air at ground has cooled (heavier air) warm air has risen (lighter air) result is stagnant, stable air = inversion long distance drift can result from applications made during inversions

Temperature Inversion Can occur anytime Usually develops at dusk May continue through night Breaks up when ground warms up in morning It may appear ideal, but is not

Pesticide Movement in Water Pesticides can move into water from a identifiable occurrence or from general contamination Point Source identifiable source Non-point Source wide area contamination Maintain an Air Gap

Which is most likely to move in water and why? Tordon Milestone Gramoxone Lorsban Tordon – Persistent Highly soluble weakly adsorbed to soil

Runoff is dependent on: soil moisture amount and timing of irrigation/rainfall pesticide characteristics grade or slope of the area soil texture vegetation

Leaching Geology – how permeable is the soil? Soil texture and structure Sandy: fast percolation, few binding sites Silt, clay or organic matter: slower percolations and many binding sites Depth to groundwater: shallow water tables pose a concern Amount and timing of rainfall or irrigation

Leaching/Runoff & Groundwater High Annual Precipitation Cool Soil Temperature Shallow Groundwater Sandy or Gravely Soil Soluble Pesticide Concern for leaching or the site is vulnerable select a product that does not pose a concern Little or no concern for leaching product selection is not a concern

Schools, playgrounds, parks, hospitals Wildlife refuges, bee hives Yards, gardens, crop fields Indoors: homes, offices, stores, clinics, restaurants, factories, animal facilities Endangered/threatened species and their habitats Protect Sensitive Areas

Protect Non-target Organisms Plants Bees, other pollinators Other beneficial insects Fish and other wildlife Humans Jerry Stein, Nev. DOW Virgin River Chub

Special Environmental Concerns Tordon Milestone Gramoxone imidicloprid

Which of the following techniques would reduce spray drift? 1. Increasing the nozzle orifice size. 2. Decreasing pressure. 3. Lowering your booms. 4. Increasing the viscosity of your spray 5. All of the above.

You need to control aphids in a blooming alfalfa field and the label has a bee toxicity hazard. What application precautions can you take to reduce bee mortality? 1. Apply mid morning when temperatures are warming. 2. Apply a dust formulation instead of an EC. 3. Use a systemic granule formulation 4. Move the hives to greater than 300 yards from the field to be sprayed.

Temperature Inversions are the product of: 1. Warm air trapped above colder denser air. 2. Usually occur in mid- day 3. Only occur in summer 4. Are dependant on temperature and humidity

Teaching Environmental Fate Use examples from your own experience. Keep the concepts simple Use analogies Use brain science Use activity based learning

Questions??