OAR 603-051-0857: Requirements and Conditions for Certification

Certification by the Department shall not imply or be construed as any warranty of the Department or their employees as to the condition of nursery stock. The following requirements and conditions shall be met in order to qualify for consideration of certification of nursery stock: (1) The applicant for certification shall be responsible for the selection of the location and the proper maintenance of all plantings being grown. The applicant shall also be responsible for maintaining the identity of all nursery stock. Any planting entered in this certification program shall be kept in a thrifty growing condition and free of plant pests. (2) Trees may be registered for certification as rootstock, interstock, and top-stock sources for the propagation of Oregon Certified Nursery Stock when inspected, tested and found to be discernably free from harmful virus and virus-like diseases of regulatory concern and having varietal purity, in accordance with the procedures prescribed in OAR 603-051-0855 to 603-051-0859. (3) No budding, grafting, or top-working of registered G2 and G3 trees in a scion-block, seed-block, or stool bed shall be permitted. Use of a certified G2 and G3 nursery stock for scionwood shall only be allowed upon receiving permission from the Department and shall be subject to departmental supervision. (4) Any plant found to be infected by a virus or virus-like disease and officially confirmed by the Department, or found to be off-type, or in root or foliar contact with a confirmed infected plant shall be removed immediately from any planting and destroyed after notification is rendered by the Department. For scion blocks, if a positive plant is present the following growing season, all plants growing within 30-feet of the infected plant within the same block will not be certified. For stool beds, if a positive plant is present the following growing season, all plants growing within 10-feet of the infected plant within the same block will not be certified. The certification of these plants may be regained if Departmentally-approved corrective action is taken. (5) Prior to planting, all registered plant growing areas and their contiguous border areas of not less than ten feet shall be tested for the presence of soil-inhabiting nematodes known to transmit viruses of concern to the Program. Growing areas found free of nematode vectors will not require chemical fumigation. Growing areas found infested with nematode vectors are required to be fumigated in accordance with the rates and practices recommended by Oregon State University. The growing areas will then be re-tested. Such tests and treatments shall be carried out under the supervision of the Department. (6) Applicants shall be responsible for maintaining trueness to type of certified G4 nursery stock produced from registered G2 and G3 plants. The applicant shall develop a written program, in cooperation with the Department, so as to provide for monitoring of each cultivar for trueness to type. (7) A participating nursery must maintain the following records for all registered G2 and G3 nursery stock in this program for a minimum of four (4) years: (a) Records indicating the Latin name, variety or cultivar, rootstock, origin, date of introduction of the G1 or G2 plant materials to the facility, date of propagation in the registered G2 or G3 block, and field location including nursery row and planting; (b) Records of sale and copies of all phytosanitary certificates issued; (c) Maps of the facility or nursery indicating the growing areas and a detailed inventory for the registered G2 and G3 plants. (8) The following requirements specifically apply to scion-blocks: (a) A scion-block shall be located not less than 100 feet from any nonregistered cultivated plant of the Rosaceae family. The ground in a scion-block, and for a distance of 20-feet surrounding it, shall be kept either clean-cultivated or in an approved, properly controlled ground cover. Registered scion-block G2 and G3 trees shall be planted and maintained in a manner, and at sufficient distances, so that branches of different varieties do not overlap. Each tree shall bear a permanent registration number; (b) The rootstock and top-stock sources of the G2 and G3 scion-block trees shall have originated from G2 or G3 trees established under this certification program or from virus-tested G1 trees originating through the Clean Plant Center of the Northwest or other departmentally approved virus-tested sources. If the tree is scion-rooted, its source shall have met the above-mentioned requirements. Only registered G2 and G3 trees shall be permitted in the scion-block. (9) The following requirements specifically apply to stool beds: (a) Existing stool beds that index clean on the commonly used virus indicators or via testing approved by the Department shall qualify as registered G3 stool beds. New stool beds (those planted after July 1, 1980) shall have originated from G2 or G3 stock established under this certification program, or from virus-tested G1 plants originating through the Clean Plant Center of the Northwest or other departmentally approved virus-tested sources, and shall be located not less than 50 feet from nonregistered rosaceous hosts and not less than ten (10) feet from registered rosaceous plants. If the tree is scion-rooted, its source shall have met the requirements of this certification program. Only registered trees shall be permitted in the stool bed. (b) A registered G2 or G3 stool bed shall be located not less than 50-feet from any nonregistered cultivated plant of the Rosaceae family. However, nonregistered stool beds may be located not less than ten feet from registered G2 or G3 stool bed plantings if such plantings were in production when they became subject to this certification program. The ground in a registered stool bed, and for a distance of ten feet surrounding it, shall be kept clean-cultivated; (10) The following requirements specifically apply to seed-blocks: (a) A Prunus seed-block shall be located not less than 100-feet from any nonregistered plant of the Prunus species. 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; (b) The rootstock and top-stock sources of the seed-tree shall have originated from G2 or G3 trees established under this program or from virus-tested G1 trees originating through the Clean Plant Center of the Northwest or other Department approved virus-tested sources. If the tree is scion-rooted, its source shall have met the above requirements. Only registered trees shall be permitted in the seed-block. (11) The following requirements specifically apply to scion blocks of containerized Malus, Pyrus, Cydonia, Chaenomeles, or Prunus species. All other requirements for growing scion blocks also apply (see (8)): (a) The roots of trees being containerized must be free of soil prior to planting in the containers; (b) The growing medium must consist of non-soil material, including but not limited to, expanded or baked clay pellets, ground coconut husks, coffee hulls, cocoa pods or rice husks, peat, perlite, sawdust, sphagnum, volcanic ash, cinder or vermiculite. The components of the growing medium must not have been previously used for growing plants or other agricultural purposes. The components of the growing medium must be mixed and maintained under conditions which preclude soil contamination or contamination by water run-off. Samples of the growing medium may be taken to verify the absence of soil; (c) The containers must be set on a barrier that prevents the roots of the plants from permeating the soil or prevents direct contact with the soil, such as plastic, hard-packed clay, pavement, or a minimum of two (2) inches of coarse gravel. The site must be located so as to preclude soil contamination, either directly or through water run-off from drainage, flooding, irrigation, or other means. (12) The following requirements apply specifically to tissue culture plant materials grown for scion and for rootstock. These requirements are in addition to the requirements specifically for scion blocks described in (8) and for stoolbeds as described in (9): (a) Plants (explants) used to produce callus for tissue culture must be tested or indexed annually as required by this program; (b) Plantlets (rooted shoots) regenerated from the tissue culture callus must be grown in a greenhouse or growth chamber and all measures and precautions must be taken to prevent the presence of any vectors in the greenhouse or growth chamber. Records of such measures taken, if they include pesticide use, must be maintained as required by OAR 603-057-0405 through 603-057-0410 and other Oregon Administrative Rules for licensed pesticide applicators as applicable; (c) One regeneration of plantlets from the tissue culture callus will be certified under this program as G4 level material with no further testing or indexing provided all other requirements are met. This certification will last one (1) year from the date of introduction of the plantlets into the greenhouse. Plantlets may be planted as G3 level registered plants provided all other requirements, including testing, are met for scion as described in (8) and for stool beds as described in (9). (13) The following requirements specifically apply to Oregon certified nursery stock, also known as G4 level material: (a) A participating nursery must maintain the following records of all G4-level materials in this program for at least two (2) years. (i) Records indicating the Latin name, variety or cultivar, rootstock, origin, date of introduction of the G2 materials to the facility, date of propagation in the registered G2 or G3 block, and field location including nursery row and planting. (ii) Records of sale and copies of all phytosanitary certificates issued. (iii) Maps of the facility or nursery indicating locations of Oregon certified nursery stock. (b) All nursery stock grown for G4 certification shall be on rootstocks from registered G2, G3, or G4 trees except for stone fruit trees grown on peach seedlings. Such peach root-stocks shall be acceptable only if the seed transmissible virus content does not exceed five percent, and upon the prior approval of the Department being obtained. Clonal rootstocks used in the production of Oregon Certified Nursery Stock shall originate from registered stool beds; (c) Nursery stock grown for G4 certification shall be planted sufficiently apart to maintain its identity and shall be kept clean-cultivated. Such nursery stock shall be designated as to rootstock, top-stock, and interstock sources. Rebudding or regrafting of nursery row stock shall not be allowed unless such stock is reworked with budwood from the same registered scion-block; (d) An official certification tag shall be utilized to designate G4-level trees produced from registered scion-source trees and which have been propagated on rootstocks produced from registered seed sources or stool bed trees, or which are self-rooted. Official certification tags must be attached to G4-level trees at time of sale.