Best Management Practices for Producing Clean Nursery Stock

6.4. Tools, surfaces, and the nursery environment

Objectives : use thought and care in all aspects of plant handling to prevent contamination in various plant production and maintenance activities

What you need to know:  If in doubt, sanitize surfaces, tools, and hands directly before they are used with clean materials.  Some redundancy in maintaining sanitation will not cause harm, whereas skipping sanitation because something is supposed to be clean can lead to accidental contamination. Do not allow water, soil, or debris from contaminated items and surfaces (including the ground) to be transferred to clean plants or surfaces.  Avoid moving soil or splashing water between plants.

Best practices:

6.4.1. Provide disinfectant footbaths or other decontamination supplies (brushes and disinfectant sprayers) for sanitizing footwear at all entrances to clean areas.  Workers may also use a separate set of sanitized shoes or boots that are used only in the clean area.  Sanitize these at least daily.

6.4.2. Items (including workers’ gloves or hands) that have been in contact with the ground or other potentially contaminated surfaces or materials must be sanitized before being placed in contact with clean plant materials, pots, soil, or benches.

6.4.3. Do not insert unsanitized items in the plant potting media (including your finger to check moisture).  If you need to probe in to the pots of multiple plants, use clean and sanitized tools, implements, fingers, etc., as you move from plant to plant.

6.4.4. Clean and sanitize hands, surfaces, and implements periodically when handling many plants successively in operations such as repotting.  Clean and sanitize hands, gloves, tools, etc., when switching between different blocks of plants.

6.4.5. Assign tools and equipment for exclusive use in the clean production area.  Heat-treated potting media should also have dedicated clean tools.  Provide clean storage areas where tools can be stored off the ground and away from splashing water.  Tools and equipment should be stored clean and sanitized before use.

6.4.6. Avoid unnecessary handling, rearranging, and moving of plants.  Handling increases chances for contamination.  Rearranging plants can obscure patterns that might indicate a disease or pest problem, and can also increase the chances for spread by giving infected plants new sets of neighbors.

6.4.7. Do not place container stock on the ground or unsanitized surfaces at any point.  Plants that are potentially contaminated though improper handling should be discarded or moved to a quarantine area and not left in clean areas.  It is better to lose one plant than to risk contaminating an entire block.

6.4.8. Place plants and other clean items only on clean or sanitized surfaces if it is necessary to move them.  Clean intact sheets of plastic or paper may be used as a clean working surface.

6.4.9. Clean and sanitize benches before placing a different set of plants or other clean items on them.

6.4.10. Remove suspected diseased plants as soon as problems are seen.  Transfer to a quarantine area for testing.  Note the locations on the bench by leaving empty spots and make notes indicating date, symptoms, and test results.  Monitor and test adjacent plants as appropriate (see 6.6. Inspection and testing below).

6.4.11. Promptly dispose of culls and disposable contaminated materials by placing them in a closed waste container.  Do not maintain containers of contaminated waste or culls in the clean area.  After use, take them to the waste disposal area and clean and sanitize the container before bringing it back to the clean area.  Alternatively, use disposable bags for waste collection, seal, and take directly to the waste disposal area.

6.4.12. Maintain general cleanliness in the nursery by removing plant debris and spilled potting media.  Avoid creating dust and splash when cleaning.