ATCP 156.04(3)(a) (a) Except as provided in par. (b) or s. ATCP 156.03 (4) (b), the college shall conduct a post-harvest test on each lot of certified seed potatoes. The college shall conduct the post-harvest test according to par. (c). The college may not certify foundation seed potatoes until it completes the post-harvest test, but may certify other seed potatoes before completing the post-harvest test.

ATCP 156.04 Note Note: The college must perform a post-harvest test before certifying foundation seed potatoes. The college may certify other seed potatoes before completing a post-harvest test, but must withdraw the certification if the post-harvest test shows a violation of standards under s. ATCP 156.03 (4).

ATCP 156.04(3)(b) (b) No post-harvest test is required under par. (a) if the certified lot will be planted in the following season on fewer than 0.25 acres and only on the grower’s own farm.

ATCP 156.04(3)(c) (c) For a post-harvest test under par. (a), the grower shall deliver to a location specified by the college a representative sample of 400 tubers for every 50 acres from each lot to be certified, with a maximum of 4 samples per lot. Each tuber shall be 1¾ to 2¼ inches in diameter and no more than 2½ inches long. The college shall plant the tubers in a winter growing location chosen by the college. The college shall inspect the potato plants and potatoes grown from those tubers for compliance with the standards under s. ATCP 156.03 (4) (a).

ATCP 156.04(3)(d) (d) The college shall deny or withdraw its certification of a seed potato lot if the seed potato grower impedes or fails to permit a post-harvest test under this subsection. If the college is unable to perform a post-harvest test because of conditions outside the control of the seed potato grower or the college, the lack of a post-harvest test does not affect the validity of a certification under s. ATCP 156.02 (1).

ATCP 156.04 History History: CR 06-085: cr. Register April 2007 No. 616, eff. 5-1-07.

ATCP 156.05 ATCP 156.05 Classifying certified seed potatoes.

ATCP 156.05(1) (1) General.

ATCP 156.05(1)(a) (a) The college shall classify certified seed potatoes according to Table 3. The college shall use the standard classification except that, if the seed potatoes are descended from propagative material approved under s. ATCP 156.03 (1) (f), the college shall use the experimental classification.

- See PDF for table

ATCP 156.05(1)(b) (b) In Table 3:

ATCP 156.05(1)(b)1. 1. “F” means foundation seed potatoes.

ATCP 156.05(1)(b)2. 2. “Ex” means experimental foundation seed potatoes.

ATCP 156.05(1)(b)3. 3. “Certified” means certified seed potatoes other than foundation seed potatoes.

ATCP 156.05(1)(b)4. 4. In each column, classifications are listed from highest (top) to lowest (bottom).

ATCP 156.05(2) (2) Classification based on years of field propagation.

ATCP 156.05(2)(a) (a) Except as provided in sub. (3), the college may not do any of the following:

ATCP 156.05(2)(a)1. 1. Certify, under the standard classification, seed potatoes from a line with more than 7 generations of field propagation.

ATCP 156.05(2)(a)2. 2. Certify, under the experimental classification, seed potatoes from a line with more than 3 generations of field propagation. The college shall classify the first field-propagated generation as “Ex5.”

ATCP 156.05 Note Note: “Field propagation” does not include outdoor production of propagative material at a breeding farm, prior to time that the college approves that propagative material under s. ATCP 156.03 (1) (f) for use at a seed potato farm. See s. ATCP 156.01 (10) (b).

ATCP 156.05(2)(b) (b) The college shall downgrade the classification of certified seed potatoes by one step for each year of field propagation, except that no potatoes may be certified as foundation seed potatoes unless they meet the standards under s. ATCP 156.03.

ATCP 156.05 Note Note: Pathogen populations in seed potatoes normally increase with each year (generation) of field propagation. Under the standard classification system, seed potatoes may be certified for up to 6 generations as “foundation” seed potatoes (for use as seed for other certified seed potatoes). The 7th generation may be certified as seed for commercial potatoes, but not for growing other certified seed potatoes.
  Seed potatoes are normally downgraded by one step for each year of field propagation. But if they fail to meet standards under s. ATCP 156.03 (5) for “foundation” seed potatoes, they must be downgraded to “certified” class even if they have been propagated in the field for fewer than 7 years. If they fail to meet the basic standards for certification under s. ATCP 156.03, they may not be certified at all.

ATCP 156.05(2)(c) (c) Foundation seed potatoes certified by another state shall be treated as having an equivalent classification under Table 3 based on years of field propagation. If the seed potatoes do not bear a classification showing the year of field propagation, they shall be treated as FY5.

ATCP 156.05 Note Note: Under s. ATCP 156.03 (1) (e), foundation seed potatoes certified by another state may be used to grow certified seed potatoes in this state if the other state uses equivalent certification standards and the college pre-approves the use.

ATCP 156.05(3) (3) Classification renewal.

ATCP 156.05(3)(a) (a) The college may grant one of the following classification renewals one time for any line of certified seed potatoes:

ATCP 156.05(3)(a)1. 1. The college may classify, as “FY5” rather than “certified,” certified seed potatoes produced from seed potatoes classified as “FY6.”

ATCP 156.05(3)(a)2. 2. The college may classify, as “Ex5” rather than “certified,” certified seed potatoes produced from seed potatoes classified as “Ex6.”

ATCP 156.05 Note Note: Among other things, a classification renewal under par. (a) may allow continued production of a minor or experimental variety for which there may be a limited seed supply. A renewal gives seed potato growers another 3 years to find a new seed source for that variety.