Module Two Chap. 4, 5 , & 6

1. Module TwoChap. 4, 5, & 6

2. Chapter 4Soil and Pest Factors ThatInfluence Fumigant Activity

3. Factors that Influence Soil Fumigation • Pest Factors: • What are they (pest identification)? • Where are they (how deep)? • When to fumigate (application timing) ? • How much gas to use (fumigation rate)?

4. Factors that Influence Soil Fumigation Correct diagnosis is the first step in successful disease management!

5. Factors that Influence Soil Fumigation: Application Depth

6. Factors that Influence Soil Fumigation:Application Timing • Fumigating when soil temperatures are higher also catches pest & pathogens at growth stages when pests & pathogens are more active, when they are more susceptible to soil fumigants.

7. The appropriate fumigant, its application rate, application method, & timing are determined by: • The crop to be planted; • The target soil-borne organism(s) – “pests”; • Level of infestation; • Soil characteristics, such as texture; • Environmental conditions.

8. Fumigator Set-up, Repair & Maintenance • Check fittings and tubing to ensure all are made of materials compatible with the fumigant to be used; never aluminum; • Filters in all systems, check valves in pressurized systems.

9. Factors that Influence Soil Fumigation:Soil Characteristics Soil Water Film Soil Fumigant Soil Water Film Soil Particle Soil Particle Nematode Soil Particle Soil Pore Air Space

10. Factors that Influence Soil Fumigation:Soil Temperature • Soil temperature influences how fast fumigants change from a liquid into a gas; • Gases move through soil faster than liquids; • The higher the soil temperature, the faster fumigants vaporize into a gas; Soil Water Film Soil Fumigant Soil Water Film Soil Particle Soil Particle Nematode Soil Particle Soil Pore Air Space

11. Factors that Influence Soil Fumigation:Soil Temperature • The higher the soil temperature, the further the fumigant often moves – through soil, but also potentially into the air above the ground. • Acceptable soil temperatures at the point of injection usually between 40o and 90o F. • If air temperatures have been above 100o for within 72 hr of application, soil temperatures at application must be recorded.

12. Factors that Influence Soil Fumigation:Soil Texture

13. Factors that Influence Soil Fumigation:Soil Texture • Coarser soils (sands, sandy loams) have larger soil particles & larger spaces between them (pores); • Fumigants can move through larger soil pores faster; • The coarser the soil, the faster & further fumigants move, both through soil and into the air; Soil Water Film Soil Fumigant Soil Water Film Soil Particle Soil Particle Nematode Soil Particle Soil Pore Air Space

14. Factors that Influence Soil Fumigation:Soil Moisture • Soil moisture influences how far & how fast fumigants move; • Soil moisture requirements vary for fumigants depending upon their vaporization rate and water solubility; • The coarser the soil, the faster & further fumigants move through soil; Soil Water Film Soil Fumigant Soil Water Film Soil Particle Soil Particle Nematode Soil Particle Soil Pore Air Space

15. Factors that Influence Soil Fumigation:Soil Moisture • Soil moisture influences how far & how fast fumigants move; • Coarser textured (sandier) soils typically require higher moisture contents than finer-textured soils (clays, silts). • Soil moisture requirements vary for fumigants depending upon their vaporization rate and water solubility; Soil Water Film Soil Fumigant Soil Water Film Soil Particle Soil Particle Nematode Soil Particle Soil Pore Air Space

16. Factors that Influence Soil Fumigation:Soil Moisture • The coarser the soil, the faster & further fumigants move through soil; • Determine soil moisture with a tensiometer or by the USDA feel & appearance method. Soil Water Film Soil Fumigant Soil Water Film Soil Particle Soil Particle Nematode Soil Particle Soil Pore Air Space

17. “USDA Feel & Appearance Method”or “Clod Method” • 50-75% Moisture in Fine Sands/Loamy Sands: When darkened soil forms a moist ball with loose & clustered sand grains on fingers, with moderate water staining on fingers; will not ribbon. Photo courtesy USDA-NRCS

18. “USDA Feel & Appearance Method”or “Clod Method” • 50-75% Moisture in Sandy Loams: when Darkened soil forms a ball with defined finger marks, very light soil/water staining on fingers, not sticky. Photo courtesy USDA-NRCS

19. “USDA Feel & Appearance Method”or “Clod Method” • 50-75% Moisture in Sandy Clays & Clay Loams:when darkened soil forms a ball, very light staining on fingers, pliable, & forms a weak ribbon between thumb & forefinger. Photo courtesy USDA-NRCS

20. Soil Tilth = the physical condition of soil Factors = clods, moisture content, aeration, water infiltration, & drainage; Clods & hardpans have less pore space, slowing and reducing fumigant movement, but increasing off-gassing; Best soil tilth for fumigation = physical condition that allows the fumigant to diffuse through soil but not escape when the soil surface is sealed properly. Factors that Influence Soil Fumigation:Soil Tilth

21. Factors that Influence Soil Fumigation:Crop Residues • Slow fumigant movement by absorbing some fumigants; • Break the seal at the soil surface, providing avenues for gas to escape from the soil; • Hang-up on fumigator shanks, plugging outlets. Pi = ~844 eggs/500 cc soil

22. Factors that Influence Soil Fumigation:Soil Sealing • For less volatile fumigants, by compacting soil or irrigation (~1/4” water)

23. Factors that Influence Soil Fumigation:Soil Sealing • By tarping for more volatile fumigants (methyl bromide, some chloropicrin applications).

24. Review Questions

25. Which of the following soil factors has little or no effect on the fumigant’s movement through the soil? • Tilth • pH • Texture

26. A fumigant handler is intending to apply a 1,3-D/chloropicrin product to a sandy loam field. Soil temperature at the depth of the application is 45°F, and the soil forms a weak ball using the “feel method.” Which of the following may limit the success of this fumigation? • Soil texture • Soil moisture • Soil temperature

27. Which of the following pest factors has the greatest impact on the timing of a soil fumigant application? • Pest density • Difficult-to-control pests • Growth stage of an insect.

28. Chapter 5Personal Protective Equipmentand Respirators

29. Personal Protective Equipment (PPE) • Fumigants are distinct from other pesticides • fumigants are volatile • may result in inhalation exposure. • Therefore PPE required differs from non-fumigants • Check the pesticide label PPE directions in the Precautionary Statements section of the pesticide label.

30. Differences in PPE for Fumigants • Examples of how PPE for various fumigants may differ from non-fumigants: • Respirators are always required to be kept on site • Loose-fitting work clothes • Often no chemical-resistant apron or spray suit • May not allow Chemical-resistant gloves or boots • May require wearing cotton gloves • Others may specify chemical-resistant gloves and footwear just for certain tasks. • Specific about the type of eye or respiratory protection to wear and when

31. Respirators • Medical Evaluation Before Respirator Fit Testing • preliminary screening, • a medical practitioner may determine that a physical exam is required. • Re-examined if • health status, • respirator style, • use conditions change.

32. Respirators • May be required for: • Any handling task • Triggered by sensory irritation • Not required: • Prior to application of the fumigant • When transporting unopened cylinders

33. Respirator Fit and Care • After being cleared for: • Air-purifying respirator (APR) • Fumigant handlers must be • Fit tested and trained on how to use each specific respirator • Fit testing is required and repeated annually.

34. Respirator Fit and Care • Follow-up fit testing is required if: • The style of the face piece has changed. • The respirator size, model, or brand has changed. • There is a physical change in the person’s face due to weight change or dental work. • Fit is unacceptable. • At request of the user. • Employer policy. • Fit check before each use (user seal check)

35. Respirator Training • Adequate training is required before handling a fumigant, including: • Fit and use of the respirator • Even if it is for emergency response only • Must establish a formal respiratory protection program, including: • Written operating procedures for • maintenance, • cleaning, • storage

36. Respirator Types • APR (Air Purifying Respirator) • replaceable organic vapor cartridge or • canister(gas mask) • half-face/fullface • PAPR (powered) • SCBA (Self-Contained Breathing Apparatus)

37. Selection • Carefully review the respirator requirements on the label to determine: • Whether you need respiratory protection. • Correct type of respirator for that fumigant. • Situations when respiratory protection is needed. • Never substitute another type of respirator

38. Cartridge or canister life • The type of cartridge. • The size of the cartridge. • The type and concentration of vapors in the surrounding air. • The length of exposure. • The rate of breathing. • Whether more than one contaminant is present. • The temperature and humidity at the time of use.

39. Cartridge Replacement (also a WPS Requirement) • At the first indication of odor, taste, or irritation. • According to the pesticide label or manufacturer instructions, whichever is more frequent. • When the end of service life indicator (ESLI) shows a color change indicating the unit has expired. • In absence of any of the above instructions or indications of service life, at the end of each day’s work period.

40. SCBA • SCBA respirators are only used • For emergency situations and • Not permitted for routine handler tasks.

41. Review Questions

42. Who must undergo a medical evaluation before using respiratory equipment? • Fumigant handlers with known heart problems. • Fumigant handlers who will be removing tarps. • Any fumigant handler or certified applicator who might need to wear a respirator.

43. Which type of respirator may never be worn during routine fumigant handler tasks? • Half-face air purifying respirator (APR) • Powered air-purifying respirator (PAPR) • Self-contained breathing apparatus (SCBA)

44. How do soil fumigant labels differ from nonfumigant labels regarding personal protective equipment (PPE) statements? • Respirators are always required on site • Different products have different PPE requirements • PPE requirements will vary depending on the handling task

45. Chapter 6Protecting People

46. “Stop Work” Trigger Levels and Respiratory Protection • Fumigant labels specify trigger levels whichrequire fumigant handlers to • Continue work using a respirator, or • Stop work and leave the application block and buffer zone. • Prevents fumigant handlers from being exposed to the maximum-use concentration (MUC) (capacity of the respirator cartridge)

47. Examples of Label Requirements • An APR with the appropriate cartridges or canisters must be available for each fumigant handler who may be required to wear a respirator. • For methyl bromide formulations with more than 20% chloropicrin, 100% chloropicrin formulations, dazomet, metam sodium, and metam potassium, fumigant handlers only need to wear full-face or gas-mask type respirators when they experience sensory irritation. If this happens, fumigant handlersmust either stop work and leave the area, or use a full-face APR to complete the task.

48. Minimum number of fumiganthandlers and respirators that mustbe on site: • Methyl bromide, chloropicrin only, and other products with chloropicrin: • At least two fumigant handlers must be on site. • At least two APRs must be on site. • Metam Sodium & Metam Potassium: • One fumigant handler on site. • One full-face APR must also be on site.

49. Stop Work Triggers • Trigger levels and air-monitoring requirements are found on labels under the “Respiratory Protection and Stop Work Triggers” section.

50. Sensory Irritation • A physical reaction to a certain fumigant air concentration, including… • burning or irritation of the • eyes, • nose, or • mucous membranes. • If at any time there is sensory irritation handler must: • Use an APR to complete the task, or • Stop work and leave the application block and buffer zone.