In cases where the director may perform sampling, grading, testing, inspection, or certification services in relation to any agricultural product, or identification services in relation to root or top stock of any fruit or nut trees, and fix reasonable fees to pay the costs necessary to perform the services he may collect such fees in advance of performing the services. He need not, however, do so if, in his opinion, the benefit of such services would be lessened by advance payment.
Ca. Food and Agric. Code § 282