WAC 16-350-025. Requirements for registered scion blocks

(1) The department will assign a registration number to each registered scion tree. (2) Only registered G2 or G3 trees are permitted in a registered scion block. (3) Isolation requirements. Prunus trees must be at least 100 feet from any nonregistered Prunus tree and any nonregistered members of the Rosaceae family. (a) Plant genera Amelanchier, Chaenomeles, Cydonia, Crataegus, Malus, Pyrus, and Sorbus trees must be at least 60 feet from any nonregistered plant of the Rosaceae family. (b) The department may waive the isolation distance for registered trees of these genera, if the trees are separated by a physical barrier that would prevent the intermingling of roots. (c) The department may waive the isolation distances for registered tissue culture lines of these genera, if kept under sterile laboratory conditions or an indoor insect proof facility. (4) The ground in a scion block and for a distance of 20 feet on all sides around it shall be kept clean cultivated or in grass ( Gramineae ) or another approved cover in which broad-leaved weeds are actively controlled. (5) The rootstock and scion sources of the G2 and G3 scion-block trees shall have originated from G2 trees established under this certification program or from virus-tested G1 trees originating through the National Clean Plant Network-FT or other department-approved virus-tested sources. If the tree is scion-rooted, its source shall have met the above-mentioned requirements. (6) Registered scion trees may be propagated with scionwood from other registered trees, if all of the following conditions are complied with: (a) No registered tree utilized is more than two generations from the foundation source. (b) The registered tree providing scionwood for a second-generation registered tree is identified and its location is known. (c) The department monitors the propagation of second-generation registered scion trees.