Cal. Food & Agr. Code § 11761
Any person that alleges any loss, nonperformance, or damage as a result of the use or application of any pesticide, or of any substance, method, or device for pesticidal purposes; or for the purpose of preventing, destroying, repelling, mitigating, or correcting any disorder of plants; or for the purpose of inhibiting, regulating, stimulating, or otherwise altering plant growth by direct application to plants or soil shall, within 30 days from the time that the occurrence of such loss, nonperformance, or damage became known to such person, file with the commissioner of the county in which the loss, nonperformance, or damage, or some part of the loss, nonperformance, or damage, is alleged to have occurred, a verified report of the loss, nonperformance, or damage.
Ca. Food and Agric. Code § 11761