Cal. Food & Agric. Code § 64308

If any handler does not provide the information necessary to determine the amount of assessments due, when required, the secretary shall estimate the amount due from the records of the department or from any other source of information that is available. In any action by the secretary to recover assessments pursuant to this chapter, a certificate of the secretary that shows the amount determined by the secretary to be required to be paid by the person that is required to pay the assessments is prima facie evidence of the delinquency of the amount that is shown. The presumption established by this section is a presumption affecting the burden of proof.