Att 7 - Phyto.pdf

Guidelines for Minimizing Phytophthora Contamination at Midpeninsula Regional Open Space District Preserves

The goal of these guidelines is to minimize the contamination of Midpeninsula Regional Open

Space District (MROSD) preserves with Phytophthora, a soil pathogen that kills plants. Once a site is contaminated, this soil pathogen can spread farther into wildland areas and can be difficult to eradicate. Prevention is the lowest cost and easiest method to manage contamination.

The best way to prevent the spread of this disease is to not move soil from one location to another by cleaning tools, equipment, and footwear.

Part of the District’s mission is to protect and restore the natural environment. Within the last few years, planted restoration sites have unintentionally exposed preserves to soil pathogens brought in by nursery plants that were later found to be contaminated. Testing of former restoration sites on District preserves is now underway to determine which sites are contaminated and the necessary remedial actions.

Who should use these guidelines?

These guidelines are intended for use by field staff and Natural Resource (NR) staff who pose the highest chance of spreading soil Phytophthora via equipment and footwear. Several methods are provided on how and when to decontaminate tools and equipment depending on the site conditions (contaminated versus clean site) and staff activities (planting, other). Guidelines for contractors, consultants, volunteers and preserve visitors are under development. Consult NR staff (Amanda Mills, amills@openspace.org or x558, or Coty Sifuentes-Winter, csifuentes@openspace.org or x560) on which guidelines are best for your project.

When to use these guidelines?

Use these guidelines for any activity that contacts soil, water or plants on a known Phytophthora-contaminated site, on a formerly planted site, on a site with rare plants, or when preparing or planting a new restoration site.

mailto:amills@openspace.org iyeung Text Box Attachment 7

Table of Contents

1. Overview

1.1 What is Phytophthora?

1.2 General Steps:

1.3 Proper Disinfectants

2. Cleaning at the Field Office

2.1 Remove Soil from Equipment and Footwear

2.2 Disinfect Tools With Bleach

2.3 Disinfect Wheeled Equipment/ Vehicles

3. Cleaning at Field Site

3.1 Cleaning at Start of Field Day

3.2 Cleaning at End of Field Day

4. FAQ

5. Sources

6. Future Methods

1. Overview

Remember to Arrive Clean and Leave Clean. The best way to prevent the spread of

Phytophthora is to leave soil at its original location in the field. Equipment and footwear should be clean and sanitized before entering a site, especially for planting events where extra precautionary steps will be taken. Before leaving a site, especially at contaminated sites, it’s crucial to clean and sanitize footwear and equipment.

Definitions:

Clean - remove soil and organic debris from tools and footwear

Sanitize - Use disinfecting agent such as alcohol or chlorine bleach.

Phytosanitary- control of plant pests and diseases especially in agricultural crops

1.1 What is Phytophthora?

1.1.1 Phytophthora (Fie-tof-thora) is a group of water molds that infect plants. There are many species, mostly notably P. ramorm (Sudden Oak Death), P. infestans (potato blight/ Irish potato famine) and P. tentaculata (nursery root rot).

1.1.2 Symptoms are similar to drought, making diagnosis difficult without testing.

1.1.3 Symptoms include leaf spots, branch die-back, cankers, trunk bleeding and death of whole plant.

1.1.4 Hosts include many native and nursery plants including oaks, bay laurel, madrones, sticky monkeyflower.

1.1.5 Brought to California through imported camellia and rhododendron nursery plants.

1.1.6 Mainly spreads from contaminated nursery stock, pots and soil. Can spread by foot traffic from contaminated footwear.

1.2 General Steps:

1.2.1 What - Items to be cleaned: Anything that comes into contact with soil, water or plants.

This includes tools (shovels, hand trowels, hori-horis, rakes, tree cages, plant protection tubes etc.), footwear, equipment, wheeled equipment and vehicles.

1.2.2 When - Prior to the project day, field staff will be notified what items need to be cleaned and by which method. In general, tools and equipment should be cleaned at the field office before bringing them to the field site, and soil should be removed from footwear beforehand and more thoroughly cleaned at the entrance to the field site.

1.2.3 Transportation - Cleaned equipment should be transported in a truckbed from which all soil has been washed out, or cleaned equipment can be wrapped in a clean tarp before placed in a dirty truck.

1.3 Proper Disinfectants

All recommended disinfectants are considered pesticides. Personal protective equipment required by the State of California for anyone using disinfectants is eye protection with wrap-around and brow protection and 14 mil chemical resistant gloves. You can use smaller mil gloves if handling chemicals for 15 minutes or less.

1.3.1 The disinfectants listed in Table 1 are recommended by standard phytosanitary guidelines.

1.3.2 Other disinfecting agents or methods, such as Lysol or heat treatments, must be reviewed and approved by NR staff before use.

1.3.3 Disinfectants are most effective when surfaces are clean of soil and user follows label instructions.

Disinfecting

Agent

Active ingredient Contact time

Product shelf life

Proper

Disposal

Health

Risk

Personal

Protective

Equipment

Granular Chlorine

Bleach (Leslies

Chlor Brite, EZ

Chlor)

Sodium dichloroisocyanurate dihydrate

2 min Long if undiluted

Neutralizer

(Vita-D-

Chlor)

High

Eyewear, gloves; do not inhale

Liquid Bleach

(Clorox)*

Sodium chloride 2 min 3-5 months

TBD High Eyewear, gloves; do not inhale

Rubbing Alcohol Ethanol or Isopropyl

Alcohol

1 min Long TBD Med Eyewear, gloves;

flammable

Quaternary ammonium compounds (Quat

128 or Physan 20)

Dodecyl dimethyl ammonium chloride

10 min Long if undiluted

TBD Med Eyewear, gloves; toxic to fish

Table 1: List of approved disinfecting agents. Always follow chemical label instructions.

*Liquid bleaches are generally not recommended as a disinfectant because they lose potency in storage.

2. Cleaning at the Field Office

Clean equipment, tools and footwear at the field office before arriving to the project site. This is the easiest way to prevent soil contamination. For those occasions where equipment and footwear must be cleaned at a field site, see Cleaning at Field Site (page 7).

2.1 Remove Soil from Equipment and Footwear

2.1.1 At the field office, scrape, brush, and wash off any soil or organic material. Take care to remove soil trapped in treads or cracks.

2.1.2 Pathogens can survive inside soil clods even after soaking because disinfectants may not completely penetrate large or clayey masses. Therefore, it is important to remove large clods of soil before soaking or otherwise treating with disinfectants.

2.2 Disinfect Tools With Bleach

Several disinfecting agents are available for treating Phytophthoras (Table 1). When many tools need treatment, use granular chlorine bleach at the field office. Spraying with rubbing alcohol is more appropriate for spot treatment at remote field locations.

NEVER MIX DIFFERENT DISINFECTING AGENTS.

ALWAYS FOLLOW LABEL DIRECTIONS.

FOLLOW REQUIREMENTS FOR PERSONAL PROTECTIVE EQUIPMENT WHEN USING

DISINFECTING AGENTS.

List of Equipment for Disinfecting Tools:

Disinfectant – most frequently, we expect to be using granular chlorine bleach such as

EZ Chlor or Leslie’s Chlor Brite when cleaning multiple tools at the field office.

Carefully follow the directions below when using any [?] of the bleach disinfectants.

Vita-D-Chlor (chlorine neutralizer) - This neutralizing product is only required if you used chlorine bleach as a disinfectant.

Waterproof container - A large [minimum size?] plastic trashcan or waterproof pop-up garden trimming container in which to mix the water-based disinfectant and soak the tools.

Hard bristled scrub brushes and paint scrapers - Grill brushes with scrapper attachment are handy tools to loosen soil from both flat surfaces and narrow cracks.

Personal Protective Equipment Close-toed shoes, apron or coveralls, protective eyewear, 14 mil chemical resistant gloves (not leather or cloth).

Clean water source - should not be cloudy or with a lot of organic material in it.

Pressure washers or nozzles are helpful to remove soil quickly and get into small cracks.

2.2.1 Before using the disinfectant, remove soil as described in above section.

2.2.2 Fill waterproof container with 10 gallons of water. Use label instructions to add the right amount of disinfecting agent. For granular bleach, use one teaspoon in 10 gallons to get the desired 0.525% dilution.

2.2.3 Dunk tools in solution for required soaking time (see Table 1). For granular bleach, this is 2-minutes. Just getting tools wet does not mean they will be disinfected. Think of it as chemical cooking.

2.2.4 If you used chlorine bleach as a disinfectant, it needs to be neutralized after soaking.

This ‘rinse cycle” will deactivate the bleach so it does not corrode metal and so that it is safer to dispose of the soak water. Equipment sprayed with alcohol does not require this neutralization step.

2.2.5 In addition to tools, remember to disinfect the sanitation kit, gloves, tarps, or other miscellaneous items that have come into contact with soil.

2.2.6 Let tools dry. The hose lay is great for drying tarps.

2.3 Disinfect Wheeled Equipment/ Vehicles

Anything with wheels, including wheel barrels, ATV’s, motorized carts that will be used at the field site needs to be cleaned and this is best done at the field office before the project. Vehicles that stay at the staging area do not have to be cleaned and sanitized. However, it is good phytosanitary practice to remove soil from wheels every time you leave a site.

2.3.1 Scrub down tires either by hand scrubbing or using a pressure spray wash.

2.3.2 Sanitize using disinfecting spray such as bleach (must be made weekly) or rubbing alcohol.

3. Cleaning at Field Site

Remember to Arrive Clean and Leave Clean. If equipment was cleaned and treated with a disinfectant at the field office and delivered in a clean truck, then on-site cleaning of equipment will only be required when leaving at the end of a work day. We recommend that everyone be encouraged to thoroughly clean their footwear of soil before arrival at the site, and then footwear be treated with alcohol upon arrival. Volunteers may not always be aware of this recommendation and may arrive with boots that need to be cleaned of foreign soil at the field site. Scraping all soil off equipment and footwear is required before leaving site, and sanitation of all footwear is usually recommended when leaving a site, especially for known contaminated sites. Rubbing alcohol is usually the preferred disinfectant in the field. Bleach products can be used in the field, but it is harder to mix and dispose of them properly in the field. See details below.

3.1 Cleaning at Start of Field Day

Tools:

Portable sanitation kits include the following items in a bin: 2 tarps, boot brush with scraper, 2 spray bottles of 70% isopropyl alcohol, 2 long-handled brushes, 2 paint scrapers, and instructions. On muddy days, also bring a basin and 2 jugs of water.

Alcohol 70% Ethyl alcohol (Ethanol) or 90% Isopropyl alcohol is fine. Called rubbing alcohol at drug stores.

Spray bottle - we take the nozzles from chemical resistant spray bottles and screw them directly into the rubbing alcohol bottle. Sometimes the stem needs to be trimmed. This allows you to have a spray bottle that is properly labeled with rubbing alcohol information and precautions.

3.1.1 Any equipment or footwear not cleaned and sanitized at the field office must be cleaned and sanitized before entering the site. Off-site soil should be considered contaminated.

3.1.2 Using the items in the portable sanitation kit, set up a staging area where equipment and footwear will be cleaned and sanitized. A paved parking lot or surface near the entrance to the work site is preferred.

3.1.3 Lay out 2 tarps, one labeled ‘dirty’ and one labeled ‘clean’.

Remove any off-site soil from footwear and equipment onto the ‘dirty’ tarp. Try not to use water. If water is used, DO NOT dump potentially contaminated water onto on-site soil. Water can be dumped onto non-permeable pavement such as a road or parking lot in a low traffic area. This will UV-sterilize the dirty water (24 hr daylight cycle) as long as no clumps exist. Potentially contaminated soil in the ‘dirty’ tarp should be bagged in a trash bag and thrown away. DO NOT dispose of off-site soil at the new site.

3.1.4 Use the ‘clean’ tarp to sanitize soil-free footwear and equipment. Standing on the tarp, spray cleaned footwear and tools with 70% isopropyl alcohol, thoroughly wetting the surface. If the surface of your footwear or tools is already wet, spray extra alcohol to displace the water and allow the alcohol to soak the surface. Spray the footwear from the top down to avoid contamination.

3.1.5 Allow alcohol to evaporate (approx. 1 min) before starting work. You can stand on the tarp until your shoes are dry.

3.1.6 Footbath Alternative - we are investigating sanitizing mats where sanitizing only requires stepping on the mat. Gemplers.com, sanistride.com, and nelsonjameson.com sell both sponge mats and footbath mats for disinfecting shoes. Either chlorine bleach or non-evaporating disinfectants are used in these footbaths and the solution is changed weekly or as needed. Chemical strips are available to test if disinfectants are still effective.

Caution should be taken if footbaths and solutions are transported to avoid spills.

3.1.7 Bleach alternative in the field. We are currently recommending that the bleach alternative be used at the field office and alcohol be used in the field. Bleach may be a better alternative in the field under some circumstances (large amounts of tools that must be disinfected in field), but will require special processes for safety and to properly dispose of the chlorine treatment water. Consult with the NR Department to determine best methods under these conditions.

3.2 Cleaning at End of Field Day

Tools:

Portable sanitation kits include the following items in a bin: 2 tarps, boot brush withscraper, 2 spray bottles of 70% isopropyl alcohol, 2 long-handled brushes, 2 paint scrapers, and instructions. On muddy days, also bring a basin & 2 jugs of water.

3.2.1 Sanitation of equipment and shoes is important for known or suspected contaminated sites. More leniency can be given for ‘clean’ sites.

3.2.2 Remove all soil and organic material from footwear and equipment. Leave soil onsite.

Use the boot scraper, paint scraper and a stiff brush to remove any soil and plant material on both the top and bottom of footwear and from tools including the digging ends and handles. Make sure to clean out crevices. On muddy days, fill the basin with water to assist in rinsing off excess soil once the majority of debris has been removed.

3.2.3 Water helps in removing dried clods of soil. This water can be dumped on-site only if the soil originates from on-site.

3.2.4 Standing on the ‘clean’ tarp, spray cleaned footwear and tools with 70% isopropyl alcohol, thoroughly wetting the surface and allowing it to dry (approx. 1 min). If the surface of your footwear or tools is already wet, spray extra alcohol to displace the water and allow the alcohol to soak the surface.

3.2.5 Before leaving the site, shake soil off the scrapers, brushes and tarp.

3.2.6 At the field office, thoroughly clean the portable sanitation kit by washing out, spraying with alcohol and drying the container and all contents before storage. The portable sanitation kit must be clean before moving to a new site.

4. FAQ

Q. What do we do with left over soil?

A. Depends on the soil. Soil from off-site should be disposed of in a trash bag and thrown away--there’s no knowing if off-site soil is contaminated or not. On site soil can be disposed of on-site back where it came from.

Q. What do we do with dirty water?

A. Pouring on pavement or another non-porous surface should disperse the contaminated soil enough to UV (sun) sterilize the water. If using bleach, use neutralizer and the water can be considered clean and safe enough to pour out anywhere. Don’t pollute! Other disinfectants need proper disposal that isn’t safe for dumping on the ground. Contact Natural Resources Department

(Amanda Mills/Coty Sifuentes-Winter) or EH&S for safe disposal procedures.

Q. How do we use the tarps?

A. Two tarps, two purposes. Dirty tarp: use as a containment area to clean off soil clogs, especially offsite soil, for later disposal. Clean tarp: provides users a clean surface to sterilize

(with alcohol or other sanitation liquid) shoes and equipment not cleaned at the Field offices.

Q. When will we need to sanitize or use the kits?

A. 1. Contaminated sites (list TBD) 2. Planting events-NR staff lead 3. When NR Staff recommend sanitation. Most of these will be NR staff lead, otherwise a leading crew member will advise on Phytosanitary BMP.

Q. Can we use hot water to sterilize?

A. Hot water can be used only if equipment bathes in 120-125° water for 30 minutes in order to be effective at killing both surface contaminants and internal infections.

Q. What about large equipment and Ranger lead projects?

A. TBD. Field staff will be trained on phytosanitary measures. For field crew lead projects, a crew member should be in charge of facilitating phytosanitary compliance.

Q. Why does this take so much time?

A. It’s best to prevent rather than respond to contamination by Phytophthora. Once a natural area has been exposed to this soil disease, it can slowly spread and kill other plants. It is very difficult and expensive to kill all the pathogens in the soil of a natural area.

5. Sources

CalPhytos.org. “Guidelines to minimize Phytophthora Pathogens in Restoration Nurseries”.

Suddenoakdeath.org. http://www.suddenoakdeath.org/wp-content/uploads/2016/04/Restoration.Nsy_.Guidelines.final_.092216.pdf

Kurowki, Chet. “Control Pathogen Spread through use of Disinfectants”. Calseed.org.

http://www.calseed.org/documents/Disinfectants%2004-22-14a.pdf

Cornell University Institutional Animal Care and Use Committee “Cleaning and sanitizing equipment used in the transport of animals.”

https://ras.research.cornell.edu/care/documents/ACUPs/ACUP532.pdf http://agriculture.mo.gov/animals/pdf/animalag_guide4.pdf

6. Future Methods

Let us know how these guidelines worked for your project! We may adjust guidelines based on feedback.