Keep it in the Field : Management of Off-Target Pesticide Drift

1. Keep it in the Field:Management of Off-Target Pesticide Drift

2. What is Pesticide Drift? • The movement of a pesticide away from its intended target. • Easy to define but harder to control

3. Why is Managing Spray Drift Important? • Because drift can cause injury to: • Adjoining crops • Livestock • Wildlife • Humans

4. Why is Managing Spray Drift Important? • Because drift costs money: • Restitution for damaged crops • Reduced control of intended target pest(s) • Increased regulations because of drift problems ARKANSAS REGULATIONS ON PESTICIDE USE SECTION I. Title The following regulations of the Arkansas State Plant Board, written pursuant to the Arkansas Pesticide Use and Application Act, Act 389 of 1975, as amended, and the Arkansas Pesticide Control Act, Act 410 of 1975, as amended, shall be known as “The Arkansas Regulations On Pesticide Use”. Promulgation of these regulations repeals all provisions of the Plant Board’s current regulations entitled “Arkansas Regulations On 2,4-D, 2,4-DB, MCPA, And Other State Restricted Use Herbicides” effective December 31, 2002

5. What causes Pesticide Drift? • Equipment setup (droplet size, boom height, gpa, pressure, etc.) wind, weather, temperature inversions are all important. • But nothing is more important than the judgment YOU make in the field. • Know when to say “NO” to an application.

6. Pesticide Drift

7. Types of Pesticide Drift? • Vapor drift • Volatility • 2,4-D on cotton • Physical drift • Wind • Temperature inversion • Poor judgment

8. Commonly Seen Drift? • Glyphosate (Roundup) • Yellowing, stunting • 2,4-D • Twisting (epinasty), elongation • Diaquat/paraquat • Necrosis or rapid “burning” of the leaves All pesticides can drift. It is usually just more obvious when herbicides drift.

9. Factors Affecting Drift • Spray characteristics • Droplet size • Chemical • Volatility • Formulation • Additives • Evaporation

10. Factors Affecting Drift • Equipment and Application • Nozzle type • Nozzle size • Pressure • Boom height http://www.teejet.com/MS/TeeJet/product_Detail.asp?ID=23&SUB=true

11. Factors Affecting Drift • Weather • Air movement • Wind speed • Wind direction • Temperature and humidity • Air stability/temperature inversions • Topography

12. Product Selection • Must control target pest(s) • Options may be limited • Choose product least likely to cause drift problems • Understand product label and chemistry!

13. Droplet Size • Large droplets have less potential to drift because they: • Fall more quickly • Evaporate more slowly • Are less affected by wind

14. Droplet Size • Small droplets often result from: • High spray pressure • Small nozzle tips • Wind shear across the nozzles (for high speed applications like an airplane).

15. Equipment Selection and Setup • Various types of suitable spray equipment, so make sure that… • Equipment is in good operating condition • Calibrated properly and regularly • Use the expertise and publications available from your county Extension agent for calibrating your equipment. • There are also excellent resources available on the internet.

16. Equipment Selection and Setup • Select equipment to produce the largest droplet size possible (greater than 150 microns is best). • But be aware that some products require relatively smaller droplets to ensure good coverage.

17. Equipment Selection and Setup • Droplet size effects on drift: • Application speed = 3 mph • Spray nozzle height = 10 feet • Cross wind of 5 mph • 20 microns -------- 1056 feet • 50 microns -------- 178 feet • 100 microns ------ 48 feet • 150 microns ------ 22 feet • 400 microns ------ 8 feet Recommended minimum droplet size 100 micron = human hair 500 micron = one grain table salt 1000 micron = thickness of a dime http://www.bae.uky.edu/smcneill/Pesticides/PesticideDrift.pdf

18. Is the weather good? I’ve got to spray!

19. Factors You Can’t Control • Weather • Wind (speed & direction) • Temperature • Humidity • Temperature inversions • Surrounding area near application site • Susceptible crops • Non-target areas

20. Wind • Drift potential usually increases with increasing wind speed. • However, many factors (ex., droplet size and boom height) can influence drift.

21. Wind • The effects of wind are reduced if small droplets are minimized and the application is made at the proper height. Correct boom height Boom height is high If the boom height is too high you also get skips as well as increased drift potential. 30% overlap

22. Wind • Use a wind gauge and avoid gusty conditions (avoid applications in winds over 8 mph – check the label for wind restrictions).

23. Temperature Inversions • Some of the worst drift incidents we have ever had in Arkansas were due to applications made during temperature inversions. • Most likely during dead calm conditions in early morning or late afternoon. • Can result in spray drift moving 10 or more miles.

24. Recognizing Inversions • Under clear to partly cloudy skies and lightwinds, a temperature inversion can form as the sun sets.

25. Recognizing Inversions • Applications made during temperature inversions can concentrate pesticide droplets and lead to drift and damage over long distances.

26. To Avoid Temperature Inversions: • Avoid making applications in “dead calm” conditions. Light, steady winds blowing away from sensitive areas are best. Label statements like this are common.

27. To Avoid Temperature Inversions: • Wait until temperatures have risen at least 3 degrees from the morning low before making application. • Don’t make applications late in the afternoon if temperatures have dropped more than 5 degrees from the daytime high.

28. To Avoid Temperature Inversions: • Use a legal smoke generating device to check for the presence of temperature inversions (burning tires is not legal).

29. To Avoid Temperature Inversions: • Always check the product label for additional temperature inversion precautions.

30. Other things to watch out for to reduce the potential for drift.

31. Field Conditions to Consider • Is the field close to houses or a town? • What are the adjacent crops (GMO vs Conventional)? Consider adopting: “Flag the Technology” to help identify the type of crop (GMO/conventional) grown in a field.

34. In Summary: Strategies to Reduce Drift • Select nozzle to increase drop size. • Use lower pressures. • Correct boom height. • Avoid adverse weather conditions. • Consider using buffer zones. • Use the gallons per acre specified on label. Standard nozzles on right side of boom (same gpa as left side, but many more small droplets produced) Drift reduction nozzles on left side of boom. Notice the reduction in fine droplets.

35. Strategies to Reduce Drift • Air induction nozzles create extra large drops for reduced spray drift by adding air. The resulting larger droplet contains small bubbles of air that bursts on contact with the leaf, spreading out the drop contents after contact.

36. Strategies to Reduce Drift • "Turbo" or pre-orifice nozzles, create larger drops with the turbulence chamber, but also maintain a consistent droplet size throughout a wider range of pressures. • Can be combined with air induction technology.

37. Other technologies for minimizing drift • shields, electrostatics, air-assist • drift reduction additives • Flag the Technology program

38. In Conclusion • Try not to fall into the trap of declaring “I need to spray RIGHT NOW!”. • Forcing a job under poor conditions almost always leads to drift or other errors.

39. Questions?