Each person whose name appears on the label as handling agricultural, vegetable or other seeds subject to this Act shall keep for a period of 2 years complete records of each lot of agricultural, vegetable or other seeds designated by the Department of Agriculture. A file sample of each lot of seed must be kept for one year after final disposition of that lot. All such records and samples pertaining to the shipment or shipments involved shall be accessible for inspection by the Director of the Department of Agriculture, or his agents, during customary business hours.