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rotting apples and apple maggots Whitney Cranshaw, Colorado State University,
APPLE CHALLENGE: Washington state is working to stop apple maggot in its tracks, and that now includes soils and growing medium, which are not regulated under the state’s rules for quarantine.

Adding soils to apple maggot quarantine

Washington state now includes soils and growing medium as a regulated material as part of the apple maggot quarantine.

The apple maggot is a yield- and profit-robbing pest that the Washington State Department of Agriculture is working to keep in check. A new rule went into effect July 11 that adds certain soils and growing medium to the list of regulated materials as part of the apple maggot quarantine.

This quarantine regulates the movement of fruits, green waste — and now some soils — from apple maggot-quarantined areas to pest-free areas of Washington. The new rule change regulates movement of soil and growing medium, in pots or on root balls, of apple maggot host plants and nonhost plants grown within the drip line of hosts that have fruited. Soil not associated with plants is not regulated as part of the rule.

This change was developed through years of meetings with partners in the tree fruit industry, according to WSDA. The work involved developing a small business economic impact statement, holding public hearings and receiving feedback from the nursery industry. The tree fruit industry first proposed the change after recognizing that the movement of soil — specifically soil in pots and attached to root balls of host and some nonhost plants — could move maggots into pest-free areas.

Under the revised rule, plants containing soil from the quarantine area must have a phytosanitary certificate if moving into the pest-free area in eastern Washington. The change will affect nurseries in any location quarantined for apple maggot, whether in Washington or in another state.

Moving apple maggot host fruit, attached to plants or not, is already regulated under the existing rule.

A little apple maggot history

The apple maggot was first detected in Washington in 1980. It spread quickly along the Interstate-5 corridor and throughout western Washington, and moved into some parts of several eastern Washington counties as well.

Despite the spread of the pest, most of the state’s main apple-growing areas have very low levels of the pest, or remain pest-free. This is the result of WSDA trapping and monitoring efforts, along with the work of local county pest boards that manage the maggot when detected.

Combined state, local and industry efforts have also prevented apple maggot from ever being detected in commercial apples. The spread of apple maggot into pest-free areas of the state could have far-reaching effects, especially for trade. Preventing apple maggot’s spread is critical to the state’s $1 billion apple industry.

You can learn more at

Source: WSDA, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.



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