Food and Agricultural Code § 5801
ARTICLE 6. Grafts and Buds from Plants Generally Infected
If the director, after investigation and hearing, determines that any kind or variety of plant is generally infected with a virus or mycoplasma-like disease that is dangerous or detrimental to the production of fruit, nut, or vine crops in this state, he may adopt regulations which prohibit or restrict the propagation by cuttings and the budding, grafting, or otherwise joining of tissue of such kind or variety of plant with any kind or variety of fruit or nut tree or vine.