The commissioner shall have the power to refuse to issue an inspection certificate or to recall or to revoke any certificate already issued when he shall have reasonable cause to believe that the applicant for or holder of said certificate may tend to introduce into the state or disseminate within this state plant pests or noxious weeds injurious to plants and plant products of this state, or if an applicant or holder of said certificate is selling, offering to sell, distributing or offering to distribute nursery stock in violation of this article or the rules and regulations promulgated thereunder.

The commissioner may also refuse to certify or revoke or suspend existing certification of any nursery stock or plant product when it has been determined that plant pests and/or noxious weeds exist on said stock or product, or that the nursery or site is in such condition with regard to growth and cultivation that an adequate inspection for plant pests cannot be made.