Wis. Stat. § 94.44

Each person whose name is required to appear on the label as the labeler of agricultural or vegetable seeds pursuant to s. 94.39 shall maintain complete records of each lot of seed sold or labeled for a period of 2 years after final sale or disposition thereof, except that a file sample of such seed need be kept for only one year. This section shall not be construed as requiring a record of the sale or disposal of each portion of a lot sold at retail in quantities of less than 40 pounds. All records and samples pertaining to any lot of seed shall be accessible for inspection by the department during customary business hours.