(a) Scion Tree Requirements. Scion trees shall meet all of the following requirements.
  (1) Budwood for propagating scion trees shall be obtained from a foundation tree.
  (2) Scion trees shall be propagated and grown in a certified citrus nursery as specified in Subchapter D of this chapter (relating to Citrus Nursery Stock Certification Program).
  (3) Scion trees shall be budded on nursery rootstock which has not been budded previously. If re-budding is necessary, buds from the same source as the original shall be used.
  (4) Scion trees shall be vigorous, productive, and horticulturally true-to-type and shall have borne fruit.
(b) Scion Tree Structures. Scion trees must be held exclusively in an approved pest exclusionary structure designated for scion trees.
  (1) At no time shall any uncertified citrus nursery stock be inside the approved pest exclusionary structure.
  (2) Scion trees may be grown in containers or planted in the ground.
  (3) Scion trees of different varieties and selections shall be kept distinctly apart and clearly identified to avoid the mixing of scion trees originating from different source trees.
(c) Labeling of Scion Trees.
  (1) Each lot of scion trees produced from the same lot of budwood from a specific foundation block tree shall be labeled for traceability with a unique identification number. The permanent label or tag shall include the variety, source tree identification number, and the month and year of budding.
  (2) Each lot of scion trees must be of the same cultivar, originating from the same foundation block source tree(s) and budded in the same month and year.
  (3) A scion tree identification map shall be maintained on-site. The map shall be made available during an inspection or upon request by the Department. The map must include the location of each group of scion trees by selection in the approved pest exclusionary structure, the name of the selection, the number of trees in each lot, source tree identification number, and the month and year of budding.
(d) Inspection.
  (1) Scion trees shall be inspected and tested at a minimum of once prior to 12 months post-budding and at an interval not to exceed 12 months for citrus tristeza and citrus greening or any other pest of regulatory concern. The Department shall collect samples for testing according to the sampling plan, "Survey Protocol in Exclusionary Facilities for the Interstate Movement of Citrus and Other Rutaceous Plants for Planting from Areas Quarantined for Citrus Greening, Asian Citrus Psyllid, and Citrus Canker," developed by the CPHST Plant Epidemiology and Risk Analysis Laboratory of the Plant Protection and Quarantine branch of USDA-APHIS. The cost of the laboratory analysis of the samples shall be borne by the owner of the nursery. The Department will inspect trees for citrus canker and other pests of regulatory concern during facility inspection.
  (2) The scion block must be routinely inspected and treated to prevent pests and diseases. The Department may issue a seizure order if a pest or disease is found. If an Asian citrus psyllid or other disease vector is found, the contents of the structure are subject to a seizure order based on risk assessment. The Department may consult with a panel of experts for additional mitigation measures necessary to ensure the integrity of scion trees.
(e) Disposition of scion trees. Upon discontinuing use of a scion tree, the scion tree must be removed from the scion block and may be sold, planted, or destroyed.

Source Note: The provisions of this §21.44 adopted to be effective March 22, 2018, 43 TexReg 1629