managing pesticide drift mary beth henry aquatic weed short … of onsite ppts... · 2012-05-18 ·...
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Managing Pesticide Drift Mary Beth Henry
Aquatic Weed Short Course Coral Springs Marriott
• The use of trade names in this presentation is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition.
• Pesticide users must review and comply with all conditions set forth in the pesticide label.
Disclaimer:
Learning Objectives
• What spray drift is
• How environmental factors affect drift
• The effects of droplet size
• How your decisions can affect spray drift
UF/IFAS PIO
What is Drift?
Unknown Photo Source
The physical movement of pesticide through the air at the time of pesticide application or soon thereafter from the target site to any non- or off-target site.
Types of Drift
• Vapor Drift - associated with volatilization, gases, fumes
• Particle Drift - movement of spray particles
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Why All the Interest in Drift? • Because drift can cause injury to:
– Adjoining crops – Livestock – Wildlife – Humans
• Because drift costs money: – Restitution for damaged crops – Reduced control of intended target pest(s) – Increased regulations because of drift
problems
Detrimental Effects of Drift Applying pesticides in a manner that
allows drift to occur is a label violation
What are the major factors in managing drift?
a. Droplet size
b. Wind speed and direction
c. Chemical and formulation
d. All of the above
8
What are the major factors in managing drift?
a. Droplet size
b. Wind speed and direction
c. Chemical and formulation
d. All of the above
9
Factors Affecting Drift
• Chemical
• Formulation
• Additives
• Drop size
• Evaporation
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Factors Affecting Drift
• Environmental Factors –Wind speed and direction
–Temperature and humidity
–Air stability/inversions
–Topography
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Factors Affecting Drift
• Equipment & Application
–Nozzle type
–Nozzle size
–Nozzle orientation
–Nozzle pressure
–Height of release
–Technology
UF/IFAS PIO
Droplet Size • Large droplets have less potential
to drift because they: – Fall more quickly – Evaporate more slowly – Are less affected by wind
• Small droplets often result from: – High spray pressure – Small nozzle tips – Wind shear across the nozzles
UF/IFAS PIO
Droplet size Droplet diameter is measured in microns
(μm) 1 μm = 0.001 mm = 0.0001 cm
Type of droplet Diameter (μm) Smoke <1
Fog 15 Mist 50
Grain of salt 100 Rain 500
0 50 100 150 200 250 300 350 Drift distance (feet)
200 μm droplet 100 μm droplet 50 μm droplet 20 μm droplet
3 mph wind D
ropl
et re
leas
e: 3
ft. a
bove
gro
und
Small droplets
Large droplets
Droplet size Droplet size is influenced by nozzle
orifice size and spray pressure At a given pressure, droplet size
decreases as nozzle orifice size decreases
At a given nozzle orifice size, droplet size decreases as spray pressure increases
What is the target minimum droplet size to reduce drift:
a. 50 µm
b. 100 µm
c. 200 µm
d. 350 µm
18
What is the target minimum droplet size to reduce drift:
a. 50 µm
b. 100 µm
c. 200 µm
d. 350 µm
19
Labels and Droplet Size
CDMS
Droplet size Nozzle orifice size and spray pressure
should maximize droplet size but still provide adequate coverage
Droplets too big: Poor coverage
Good droplet size: Adequate coverage
Droplet spectrum1
Contact insecticide & fungicide
Systemic insecticide & fungicide
Contact foliar herbicide
Systemic foliar herbicide
Soil-applied herbicide
Incorpor-ated soil-applied herbicide
Very fine (VF)
Fine (F) X
Medium (M)
X X X X
Coarse (C) X X X X
Very coarse (VC)
X X X
Extremely coarse (XC)
X
1Based on Volume Mean Diameter (VMD) designation.
Category (symbol) Color code Very fine (VF) Red Fine (F) Orange Medium (M) Yellow Coarse (C) Blue Very coarse (VC) Green Extremely coarse (XC) White
ASABE Spray Quality Categories
Very fine
Fine Medium Coarse Very coarse
Extr. coarse
Increasing pressure Increasing
orifice size
Droplet size Use nozzles with the largest orifice size
that is appropriate for the application
Use a spray pressure near the middle of the range for a given nozzle
Low Drift Nozzle Types
UF/IFAS PIO
Which Size is Best?
Western Crop Protection Association
Factors You Can’t Control • Weather
– Wind (speed & direction)
– Temperature
– Humidity
• Susceptible crops or other non-target areas of concern near your application site
Western Crop Protection Association
The range of wind speed to avoid drift is:
a. 0-3 mph
b. 2-5 mph
c. 3-10 mph
d. 6-12 mph
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The range of wind speed to avoid drift is:
a. 0-3 mph
b. 2-5 mph
c. 3-10 mph
d. 6-12 mph
30
Wind
Kansas State University
Drift potential is lowest at wind speeds between 3 and 10 miles per hour
Evaporation of Droplets Humidity effects on droplet size
70% RH 30% RH
Wind
Factors Affecting Drift
• Temperature inversions
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Radiant cooling of the ground
Factors the Applicator can Control
• You can control… – The selection of the applicator/operator
– Equipment selection and setup
– Field conditions
– The choice of the product
UF/IFAS PIO
Strategies to Reduce Drift: Equipment Setup
• Select nozzle to increase drop size • Increase flow rates - higher application volumes • Use lower pressures • Use lower spray (boom) heights • Drift reduction nozzles
UF/IFAS PIO
Strategies to Reduce Drift: Drift Reduction Additives
• Polyvinyl
• Polyacrylamide
• Linear alkyl epoxide
• Polymide copolymers
UF/IFAS PIO
Strategies to Reduce Drift: Buffer Zones
CDMS
Drift and the Law
Drift and the Law
• 2,4-D
• MCPA
• 2,4-DP
• MCPP
• MCPB
• Dicamba
• Triclopyr
UF/IFAS PIO
Drift and the Law
UF/IFAS Agronomy
Drift and the Law
UF/IFAS PIO
FDACS-13345
FDACS-13345
FDACS-13328
http://www.doacs.state.fl.us/onestop/forms/13328.pdf
A major ag insurance company categorized 1996 payouts due to misapplication. What percentage were due to drift?:
a. 33%
b. 48%
c. 17%
d. 68%
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Why All the Interest?
33%
33%
24%
8% 2%
Drift
Improper tank mix
Application Equipment
Off label application
Causes of the Drift
13%
26%
38%
23%
NozzleApplicatorPhysicalOtherApplicator
Photo/Diagram Credits • Many slides from Fred Fishel “Pesticide Drift-Keeping it on Target “ (included slides from) • University of Florida/IFAS • Florida Depart. of Agriculture and Consumer Services • Kansas State University • University of Nebraska • US EPA • CDMS • National Coalition on Drift Minimization • Spraying Systems Co. • Western Crop Protection Association
• Additional Slides from Brandon Fast “Pesticide Drift "University of Florida,
Fred Fishel, Ph.D. Department of Agronomy University of Florida/IFAS Copyright 2009 University of Florida
Mention of trade names in this presentation is solely for providing specific information. It is not a guarantee or warranty of the products named, and does not signify that they are approved to the exclusion of others of suitable composition. Use pesticides safely. Read and follow directions on the manufacturer’s label.
Thanks! Mary Beth Henry [email protected]