“Pest control” means the use or application of any pesticide. It also means the use of any substance, method, or device to do any of the following:
(a) Control pests.
(b) Prevent, destroy, repel, mitigate, or correct any pest infestation or disorder of plants.
(c) Inhibit, regulate, stimulate, or otherwise alter plant growth by direct application to plants.
(Enacted by Stats. 1967, Ch. 15.)