Cal. FAC § 6032

As used in this article “handler” means any person that engages in the operation of selling, marketing, or processing any of the crops vulnerable to damage from curly top virus, as covered by this chapter, which he or she has purchased, or acquired from a producer or which he or she is marketing, selling or processing on behalf of a producer, whether as owner, agent, employee, broker, or otherwise. A producer-handler is a producer who operates as a handler as to any such crop produced by him or her. Every producer or producer-handler of agricultural crops susceptible to curly top virus as determined by the secretary, may include, but is not limited to, tomatoes, sugar beets, melons, beans, cucumbers, spinach, and peppers shall pay to the department an assessment on all those crops sold or delivered by him or her to a handler or, in the case of a producer-handler, on those crops marketed by the producer-handler. The full amount of the assessment shall be collected from the producer by the handler at the point and time that the crop is purchased or received by the handler as provided by regulations of the secretary.