It shall be unlawful for any person to sell, give away, carry, ship or deliver for carriage or shipment within this state any nursery stock unless such nursery stock has been officially inspected, at least annually, and a certificate issued by the state entomologist stating that the nursery stock has been inspected and found apparently free from harmful plant pests, and stating any other facts provided for in the rules made pursuant to sections 263.010 to 263.180. For such inspection and certification, the state entomologist may require the payment of a reasonable fee to cover the expenses of such inspection or certificate, or both, which cost in any event shall not exceed the actual cost of the inspection. If it shall be found at any time that a certificate of inspection, issued or accepted pursuant to the provisions of this section, is being used in connection with plants and plant products which are infested or infected with harmful plant pests, the certificate may be revoked and its further use may be prohibited, subject to such inspection and other disposition of the plants and plant products involved as may be provided for by the state entomologist. The provisions of this section shall not apply to farmers or other persons who may give away nursery stock from their own premises which was not grown specifically for commercial purposes.