Drift Management. Tim Stock Integrated Plant Protection Center Oregon State University

Transcription

1 Drift Management Tim Stock Integrated Plant Protection Center Oregon State University

2 Many thanks to those who contributed slides and/or information for this presentation: Steve Castignoli, OSU Extension, Hood River Len Coop, OSU Integrated Plant Protection Center Paul Jepson, Director, OSU Integrated Plant Protection Center Mark Mellbye, OSU Extension, Linn County Myron Shenk, retired, OSU Integrated Plant Protection Center Tom Wolf, Ag & Agri-Food Canada

3 Where do pesticides go after they leave the nozzle? Some estimates have suggested that up to 80 per cent of the total pesticide applied to plants may eventually reach the soil

4 Pesticide utilization efficiency is poor (Graham-Bryce, 1977) Pesticide Application method Target Efficiency of utilization Demeton-Smethyl Foliar spray Aphids on sugar beet % Dieldrin Seed treatment Wheat bulb fly larvae % Dimethoate Foliar spray Aphids on field beans 0.03% Lindane Foliar spray Capsids on Cocoa 0.02% Dieldrin Aerial swarm spray Locusts 6.0%

5 The complex processes of pesticide transfer and deposition Drift takes place between atomization and impaction Image from Brian Young, formerly ICI, UK

6 Factors Affecting Drift Weather: Droplet Transport can occur in still, windy, and unstable conditions Droplet Evaporation is highest at low humidity and high temperatures

7 Factors Affecting Drift From Baythroid 2 label: Do not apply when wind speed favors drift beyond the area intended for treatment. The interaction of many equipment and weather related factors determine the potential for spray drift. The applicator is responsible for considering all of these factors when making application decisions. Drift potential increases at wind speeds of less than 3 mph (due to inversion potential) or more than 10 mph. However, many factors, including droplet size, canopy and equipment specifications determine drift potential at any given wind speed.

8 Factors Affecting Drift Droplet Size: nozzle orifice spray pressure/volume angle of application

9 Factors Affecting Drift Distance between nozzle and target Speed of tractor Volatility of product (especially herbicides)

10 Crossbow in pastures #1 drift complaint Courtesy Mark Mellbye, OSU Cooperative Extension

11 Things we can do to avoid drift What can be done. Before During After an application?

12 Before an Application Know where sensitive sites are Establish buffer zones Choose your pesticide Select your nozzles Check your equipment Use NOAA Graphical Forecast Keep records Involve applicator in IPM program Develop drift response plan just in case

13 Before [Know where sensitive sites are] Residential areas Public roads Schools Courtesy Steve Castagnoli

14 Before [Protect the Pollinators!]

15 Before [Watch out for the Winegrapes!]

16 Before [Establish buffer zones] Specific ruling for salmon: Some pesticides near certain waterways require buffers See:

17 Cultural Practices - Unsprayed Buffer Outside tree row Larger buffers are required for some pesticides near certain waterways. Stream Oregon Washington Unsprayed buffer planted to cover crop

18 Cultural Practices - Windbreaks

19 Cultural Practices - Windbreaks Windbreaks can have significant, but unpredictable, impacts on reducing spray drift.

20 Drift reduction values from Dutch authorization procedure for orchard spraying (from van de Zande (2004) Drift reducing measure Drift reduction % Dormant Full leaf Windbreak Tunnel sprayer Sensor-equipped sprayer Netting on ditch bank (2.5m) Sprayer with reflection shield 6m crop-free zone Spraying orchards at full leaf, at 3m/s gives deposition of 6.8% of application rate at m from orchard

21 Before [Choose your pesticide] Check label for any special precautions for preventing drift Determine optimum rate of application Adjuvants poor substitute for good management (see next slide)

22 Adjuvants: poor substitute for good management WSU research: In-Place effective with airblast sprayers Research on other adjuvants not as positive Nothing works for thermal drift URBAN INTERFACE: Even if the pesticide does not volatilize, many additives can volatilize. These can often be smelled even if there is no pesticide drift.

23 Use Non-Volatile Formulations To Reduce Vapor Drift An LV ester: 33 times more volatile than an amine formulation.

24 Herbicide LV Ester Products (33 times more volatile) 2,4-D LV ester MCPA LV ester Crossbow Bronate Curtail M Garlon 4

25 Before [Choose your pesticide]

26 Before [Select your nozzles] Match nozzle to target Avoid spraying outside recommended pressure / flow rates Product catalogs have a wealth of information

27 Before [Nozzle Selection] Gallons per minute at different pressure settings Gallons per 1000 sq ft at different pressure settings and speeds

28 Before [Nozzle Selection] Changes in droplet size as pressure changes

29 Before [Nozzle Selection] Nozzle Selection Guide

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31 Courtesy Mark Mellbye, OSU Cooperative Extension, and Tom Wolf, Ag & Agri-Food Canada TeeJet XR 40 psi in 12 mph crosswind Turbo Drop 11003@ 70 psi in 12 mph crosswind

32 Driftable Fines Comparison of Nozzles % Driftable fine droplets <105.5 Pressure (PSI) Extended Range Turbo Flat Fan AirMix TurboDrop

33 Boom sprayers: nozzle selection NOZZLE CATEGORIES CONVENTIONAL FLAT FAN PRE-ORIFICE LOW-PRESSURE AIR INDUCTION HIGH PRESSURE AIR-INDUCTION COMMENTS Fine spray, reliable, but drift prone 50% drift reduction, reliable at low volumes 50-70% drift reduction 70-90% drift reduction USE GUIDE 20-60psi, >3gpa psi, >5gpa psi, >5gpa psi, >7gpa

34 Before [Check your equipment] Check the following: Nozzle discharge All hoses & connections for splits, cracks, leaks Missing, damaged, blocked filter elements and seals Tank damage Tank sits firmly on mount Agitator working properly Valves for leaks Pump for leaks, lubrication levels Pump rotates freely without friction or noise Fan drive gearbox oil level Replace nozzles at least once per season

35 Sprayer Tune-Up Results (Aldrich-Markham, Pirelli & Shenk) 44 Sprayers checked (only 6 were okay) 28 Worn nozzles 12 Dripping check valves 9 Boom heights too low or uneven 8 Excessive pressure 5 Unequal nozzle spacing or height 3 Mismatched nozzles

36 Before [Use NOAA Graphical Forecast] National Weather Service

37 NOAA s Graphical Forecasts Up to date forecasts for Precipitation Temperature Wind speed & direction

38 Pacific Northwest

39 Oregon

40 Pendelton Region

41 Weekly View 12Hr Prob of Precip (%)

42 Weekly View Dewpoint Temp (F)

43 Weekly View Wind Speed & Direction Feb 14 10PM

44 Weekly View Wind Speed & Direction Feb 15 4AM

45 Weekly View Wind Speed & Direction Feb 15 4PM

46 Weekly View Wind Speed & Direction Feb 16 4AM

47 Weekly View Wind Speed & Direction Feb 16 4PM

48 NOAA Graphical Forecast

49 Before Use Forecast to Predict Inversions

50 Use Forecast to Determine Likely: Wind speed and direction during application Humidity and temperature

51 Before [Planning Your Application] Use Forecast to determine when and where you should be able to spray Prioritize sensitive sites when looking at when you will spray

52 Check out

53 Do you really need to spray? Think about Degree Days Degree-days: a unit of accumulated heat, used to estimate development of insects, fungi, plants, and other organisms which depend on temperature for growth. Eggs start developing: 0 DDs cumulative: 20 daily: o(avg) - 50 o(threshold) =20 DD Eggs hatch: 152 cumulative DDs

54 Why weather-driven models for IPM? Pest models provide quantitative estimates of pest activity and behavior (often hard to detect): they can take much of the guess work out of timing control measures Pest models are expected to become NRCS cost share approved practices for certain crops and pests, proper spray timing is a recognized pesticide risk mitigation practice Models can be tied to local biological and weather inputs for custom predictions, and account for local population variations and terrain differences Models can be tied to forecasted weather to predict future events

55 IPPC weather data homepage ( Degree-day maps Degree-day calculator and models

56 Watch Your Boom Height Drift potential doubles for higher boom Consider using auto boom-height controller Courtesy Mark Mellbye, OSU Cooperative Extension, and Tom Wolf, Ag & Agri-Food Canada

57 Drift at 6m increases by 75% when boom height increases from 0.5m to 0.7m above target surface

58 Auto-Boom on CNH 4410 Courtesy Mark Mellbye, OSU Cooperative Extension, and Tom Wolf, Ag & Agri-Food Canada

59 Before [ Donuts on airblast sprayers]

60 Increase size of Donut hole as canopy gets fuller

61 During [Monitor Weather] (e.g. use pocket weather meter)

62 During Use pocket weather meter Do not spray if inversion conditions exist - very low wind speed with cool air, and/or smoke indicates low surface mixing (to avoid inversion drift) Be extra cautious as wind speed approaches 9mph (to avoid wind drift) Be very wary if humidity goes below 50% and temperature nears 70F (to avoid thermal drift)

63 Inversion Drift Often follows clear, cold nights Little or no wind, low surface mixing Courtesy Steve Castagnoli

64 Thermal Drift High heat, low humidity, unstable conditions Courtesy Steve Castagnoli

65 Wind Drift Be wary of thresholds Likelihood increased by high temperature and low humidity Other influences include droplet size, equipment type, and local terrain s influence on wind patterns Courtesy Steve Castagnoli

66 You need some wind No wind is an indication of an inversion (drift potential is high) No wind means no mixing of air (low penetration to middle of trees)

67 During - Orchards Spray in on edges Turn off sprayers at corners Buffers needed? When spraying last three rows upwind of sensitive sites, use nozzles on one side only, with spray directed away from the sensitive sites

68 Time to show video clip of inversion drift

69 After Keep records (add weather data) Check borders to see if drift occurred If drift occurred, follow response plan

70 Summary An ounce of prevention Nozzle wear is the most common oversight NOAA Graphical Forecast is your friend A pocket weather meter can also be your friend What is the most important part of the sprayer? The part that is about to break What is the best way to avoid drift? Don t spray! - Think about Degree-Days & IPM

71 If you can t be a good example, then you ll just have to serve as a horrible warning. * Catherine Aird

72 Tim Stock Integrated Plant Protection Center Oregon State University (541)

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