(1) A registration number approved by the department will be assigned to each registered seed tree.

(2) Only registered trees are permitted in a registered seed-block.

(3) Registered Prunus seed-blocks shall be located at least 300 feet from any nonregistered Prunus plants. The ground in a seed-block and for a distance of 20 feet surrounding the seed-block shall be kept clean cultivated or in an approved, controlled ground cover. Care shall be taken in the use of pollinating insects and pollen application to prevent the transmission and spread of virus diseases through the use of infected pollen and/or its application. Each tree shall bear a permanent registration number.

(4) The rootstock and top-stock sources of the seed-tree shall have originated from Generation 4 trees, from virus-tested trees originating through the NRSP-5, or other departmentally approved virus-tested sources. If the tree is scion-rooted, its source shall have met the above requirements.