WSDA Looks To Ad Soil to Apple Maggot Quarantine List

Washington has long had an apple maggot quarantine in place in several counties to control the spread of apple maggot into pest-free areas of the state.  After months of meetings with the tree fruit industry, the Washington state Department of Agriculture is proposing to add soil and growing medium to the list of apple maggot quarantine regulated materials.

The rule change would regulate the movement of soil and growing medium, in pots or root balls of both plants that can host apple maggot and some non-host plants.  Under the proposal, plants with soil that originate from a quarantined area must have a phytosanitary certificate stating the following if they will be moved out of the quarantined area

Host Plants (Apple, crabapple, hawthorn, cherry, pear, plum, prune, and quince)  

Have not produced fruit and were not located in the drip line of host plants that have fruited or

Originated in an area where apple maggot is not considered established based on official  trapping surveys or

Had soil or growing medium treated with an appropriate pesticide treatment just prior to shipping.

Non-host plants grown within the drip line of fruiting host plants in the quarantine area

Originated in an area where apple maggot is not considered established based on official  trapping surveys or

Had soil or growing medium treated with an appropriate pesticide treatment just prior to shipping.

As a reminder, moving fruit attached to host plants is currently prohibited under the apple maggot quarantine.

The following remain unregulated, even under the proposed rule change:

• Bare root plants (host and non-host) – host plants cannot have fruit attached
• Plants (host and non-host) originating from the WSDA pest-free area
• Non-host plants that were not grown in the drip line of fruiting host plants

In addition to adding soil and growing media to the list of regulated materials, WSDA is also proposing to change the rule to reflect how plants may enter the pest-free area if the risk is mitigated.

The rule change was first suggested by the Washington State Tree Fruit Association after WSDA trapping discovered that apple maggot had likely been moved into the pest-free area in the soil of a potted nursery fruit tree.  WSDA identified soil on nursery plants as a probable pathway for the introduction of apple maggot into pest-free areas.

Public hearings for the proposed rule change are expected to take place sometime in January, with exact dates to be determined.

Check out the WSDA's Website to learn more about the rule change and other apple maggot quarantine issues.

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