(a) Except as provided by Subsection (b) of this section, if the department determines following field inspection that the vegetable plants inspected are apparently free of injurious pests and of the diseases and insects listed in Sections 71.104-71.109 of this code, as applicable, the department shall issue a certificate tag or stamp for those plants. Plants certified under this section shall be known as “state certified plants.”
(b) In addition to field inspections of sweet potatoes, certification of that plant shall be based on prior inspection of seed potatoes in the field, treatment, and bedding inspections that the department considers necessary to provide clean slips for sale or shipment. Application for certification of sweet potato plants shall be made prior to harvesting time of the preceding season.

(c) The certificate tag or stamp shall be firmly affixed to each container or bundle of plants at the point of origin for shipment of the plants.