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Pesticide Drift Management

Dr. Eric P. Prostko
Extension Weed Specialist
University of Georgia
Tifton, GA

• Slide Presentation (PowerPoint, 6.3 MB)

TABLE OF CONTENTS

Pesticide Drift Management Pesticide Drift Management: Topics For Discussion What is pesticide drift?? Spray drift is undesirable!! Corn and Grain Sorghum Yield Loss From Simulated Staple Drift, College Station, 1994 Physical Drift Studies have shown that equipment and its operation are responsible for 68-90% of the physical drift problems while weather accounts for 10-32% Physical Drift: Droplet Size Fall Rate of Various Size Droplets Relationship of Particle Size to Drift Physical Drift: Droplet Size Physical Drift: Spray Boom Height Physical Drift: Weather Physical Drift: Temperature Inversions Physical Drift: Other Factors to Consider Physical Drift: Nozzle Orientation Influence of Spray Pressure on Droplet Size: Flat Fan Nozzle - 0.6 GPM Physical Drift: Spray Volume Vapor Drift Vapor drift can occur even days after the application Vapor Pressure Values of Various Chemicals Pesticide Drift Management: Equipment Modifications Pesticide Drift Management: Drift Control Agents Drift Fallout As Influenced By Pressure and Nalcotrol Top 10 Tips For Reducing Pesticide Drift References used in the development of this slide set

SLIDE CONTENTS

Pesticide Drift Management Dr. Eric P. Prostko Extension Weed Specialist University of Georgia Pesticide Drift ManagementTopics For Discussion definition types of drift factors affecting drift equipment management What is pesticide drift?? the movement of the pesticide away from the target area. physical drift vapor drift Spray drift is undesirable!! inefficient use of equipment and time under-application/ineffective control litigation concerns unintentional contamination of foodstuffs air/water pollution livestock and human health/safety Corn and Grain Sorghum Yield Loss From Simulated Staple Drift, College Station, 1994. Applied 30 DAP Physical Drift movement of pesticide away from target during application droplet size boom height weather Studies have shown that equipment and its operation are responsible for 68-90% of the physical drift problems while weather accounts for 10-32%. D. B. Smith et al., 1982 Physical DriftDroplet Size measured in microns hair - 50 microns 20-370 micron range 200 micron average smaller drops increase drift potential (< 100) Fall Rate of Various Size Droplets Relationship of Particle Size to Drift Based upon 10’ fall in 3 MPH winds Physical DriftDroplet Size nozzle selection Drift Guard Nozzles * reduces volume of droplets below 200 microns up to 65% Raindrop Nozzles * 0.7% - 200 microns or less Physical DriftSpray Boom Height Spacing * Wide-angle nozzles can be placed lower to the ground but also produce smaller droplets. * Easy and inexpensive Physical DriftWeather wind speed/direction * most important temperature humidity inversions Physical DriftTemperature Inversions Normal Inversion Physical DriftOther Factors to Consider nozzle orientation spray pressure spray volume Physical DriftNozzle Orientation ground speeds > 10 MPH 450 or more from perpendicular 30% < 100 microns 88% < 100 microns Influence of Spray Pressure on Droplet SizeFlat Fan Nozzle - 0.6 GPM Physical DriftSpray Volume most effective means to increase spray volume is to increase nozzle orifice size i.e. 8002 vs. 8003 vs. 8004 Vapor Drift the volatilization or evaporation of a pesticide from the soil or crop surface that occurs after application. Factors that influence vapor drift include: * vapor pressure/volatility * temperature * wind speed Vapor drift can occur even days after the application Non-Target Sensitive Crop Wind Drift Vapor Vapor Pressure Values of Various Chemicals@ 770F Note: The higher the number the more volatile the chemical. Pesticide Drift ManagementEquipment Modifications shielded spray boom covered boom hooded-sprayers air-assist systems electrostatic spraying Pesticide Drift ManagementDrift Control Agents “thickeners” increase droplet size of pesticide/water mixes $0.10-$1.00/A 38F, Anchor, Array, Border, Chem-Trol, Corsair, Direct, Drifgon, Driftgard, Drop Zone, Get Down, Lo-Drift, More, Nalcotrol, Submerge, Sta-Put, Windfall Drift Fallout As Influenced By Pressure and Nalcotrol Source: W. Bowers. 1975. Ohio State Univ. Extension, Facts #1203. Top 10 Tips For Reducing Pesticide Drift nozzle selection reduce pressure lower boom height increase nozzle size avoid spraying when winds exceed 10 MPH lookout for inversions use additives calibrate sprayer keep records use common sense References used in the development of this slide set include the following: Reducing Spray Drift. Ohio State Univ. Extension Bulletin 816, H. Erdal Ozkan. Herbicide Application Management. Sandoz Crop Protection, 1993.