Rule Changes Needed

In recent years, there has been increased demand for rapid introduction of new potato varieties, often from out-of-state sources. Biotechnology has expanded disease-testing options, and has facilitated the creation of new potato varieties and new forms of propagative material. There has been increased cooperation between states, aimed at standardizing seed potato certification.

These developments have not replaced the traditional certification program based on college propagative material, field inspection and “limited-generation" plantings. However, they do require some program changes and adaptations.

This rule provides a clearer, more up-to-date framework for the seed potato certification program administered by the college. Among other things, this rule:

• Clarifies and, in some cases, changes current certification standards and procedures.

• Eliminates some outdated requirements, and strengthens some disease-control standards.

• Recognizes new laboratory testing capabilities.

• Expands the number of sources from which growers may obtain propagative material for certified seed potatoes, while minimizing disease risk.

• Allows for variances in certification standards to accommodate unusual situations.

• Clarifies how propagative material is regulated.

This rule does not substantially alter current standards or procedures for DATCP quality inspection of seed potatoes. However, it clarifies the respective roles of DATCP and the college, and spells out grading standards and procedures with greater clarity.

This rule applies to seed potato growers who wish to produce and sell certified seed potatoes (participation is voluntary, and there is nothing to prohibit sales of uncertified seed potatoes). It also applies to laboratories and greenhouses that provide propagative material used to grow certified seed potatoes. This rule does not apply to any of the following:

• Producers who grow potatoes only for consumption, and not for seed.

• Producers who grow potatoes for seed, but do not wish to have their seed potatoes certified and graded (participation is voluntary).

• Home gardens.

This rule reorganizes current rules into subchapters. This clarifies the distinction between certification by the college and grading by DATCP. This rule also redrafts the current rules, so they will be easier to read and understand.

This rule clarifies the procedure by which a seed potato grower may apply for and obtain certification of seed potatoes. Among other things, it clarifies the information that the grower must include on the application form, and the information that the college must include in the certification. This will make it easier for the college to process certification requests, and document certifications. It will also provide a better certification history and record, which is important for certification credibility, disease control and future certification.

Under this rule, if an applicant seeks certification of a protected (patented) variety of seed potatoes, the application must document that the applicant has permission to grow the protected variety. This is consistent with requirements under federal law.

Under this rule, as under current rules, the college may certify a “lot" of seed potatoes at the request of the seed potato grower. This rule clarifies that a “lot" includes all potatoes of the same variety and line that are grown from the same source seed on the same farm in the same year. Certification does not constitute a warranty by the college, and does not extend to any disease or condition that cannot be observed by visual inspection.

This rule clarifies minimum standards for the certification of seed potatoes, including standards for all of the following:

• Propagative material used to grow the certified seed potatoes.

• Field planting.

• Field and harvest inspections.

• Post-harvest testing.

This rule expands the number of sources from which growers may obtain propagative material for certified seed potatoes, while minimizing disease risk. Under this rule, certified seed potatoes must be grown from one of the following (no other propagative materials may be planted on a farm producing certified seed potatoes):

• Certified “foundation" seed potatoes produced, on the same farm, by the producer requesting certification.

• Certified “foundation" seed potatoes produced on another farm, if pre-approved by the college.

• Propagative material produced by the college.

• “Foundation" seed potatoes certified by another state, under standards equivalent to the standards in this rule, if pre-approved by the college.

• Propagative material produced in an approved laboratory or greenhouse (see below), if pre-approved by the college.

• Propagative material produced by a recognized breeding program and pre-approved by the college.

Under this rule, as under the current rules, the college must conduct field and harvest inspections of certified seed potatoes. The college must visually inspect a representative sample of growing potato plants, and a representative sample of harvested potatoes. The college must inspect for specified diseases and conditions, including leafroll, mosaics, spindle tuber, bacterial ring rot and variety mixture.

Under this rule, as under the current rules, the college must reject an entire “lot" of potatoes for certification if inspection samples exceed specified tolerances for the relevant diseases or conditions. This rule makes the following key changes to current tolerances, to make them more consistent with tolerances in other states:

• It specifies a zero tolerance for spindle tuber (which currently has a positive tolerance, but has not been detected for several decades).

• It increases (slightly) the current tolerance for variety mixture.

Field and harvest inspection tolerances, as revised by this rule, are shown in Table 1:

Table 1
Field and Harvest Inspection Standards

Condition	1st Field Inspection	Subsequent Field or Harvest Inspections
		Foundation Seed Potatoes	Other Seed Potatoes
Leafroll	1.5%	0.25%	1.0%
Mosaics	2.0%	0.25%	1.0%
Spindle tuber	0.0%	0.0%	0.0%
Total leafroll and mosaics	3.0%	0.25%	2.0%
Bacterial ring rot	0.0%	0.0%	0.0%
Variety mixture	1.0%	0.1%	0.1%

This rule, like the current rules, specifies higher standards for the certification of “foundation" seed potatoes (which may be used to grow other certified seed potatoes, not just commercial potatoes or uncertified seed potatoes). “Foundation" seed potatoes are subject to more rigorous disease tolerances (see Table 1 above and Table 2 below), and more rigorous inspection and control for bacterial ring rot (see below). The college may not certify “foundation" seed potatoes until it has completed its post-harvest testing of the potatoes (see below).

The current rules and this rule specify a zero tolerance for bacterial ring rot. Under the current rules and this rule, the college must reject for certification any “lot" of seed potatoes in which bacterial ring rot is found. The college may certify other lots on the same farm, but not as “foundation" class seed. The farm must produce 2 annual crops free of bacterial ring rot before the college can again certify “foundation" class seed from that farm. There is no exception to this requirement.

Under current rules, if bacterial ring rot is found in 2 “lots" from the same farm within 3 years, the college may not certify any other “lots" from that farm (regardless of whether bacterial ring rot is actually found in those “lots"). This rule allows the college to certify the other “lots," but not as “foundation" seed (until the farm produces 2 annual crops free of bacterial ring rot).

Under current rules and this rule, the college must conduct a post-harvest test on every “lot" of certified seed potatoes. The college may not certify a “lot" that fails a post-harvest test, except that in some cases this rule allows certification based on lab testing (see below).

To conduct a post-harvest test, the college collects a sample of potatoes from the “lot" to be certified, and plants those potatoes in a winter growing location. The college then inspects the potatoes grown in the winter location for disease and variety mixture. The inspection must show compliance with specified tolerances (this rule revises some of the current tolerances). The tolerances (as revised by this rule) are shown in Table 2:

Table 2
Post-Harvest Test Standards

Condition	Foundation seed potatoes	Other certified seed potatoes
Leafroll	0.5%	5.0%
Mosaics	0.5%	5.0%
Spindle tuber	0.0%	0.0%
Total leafroll and mosaics	0.5%	5.0%
Bacterial ring rot	0.0%	0.0%
Variety mixture	0.25%	2.0%

This rule allows for greater use of laboratory testing in lieu of traditional post-harvest testing. Under this rule, the college may certify a “lot" of seed potatoes that passes field and harvest inspection, regardless of any post-harvest testing, if laboratory testing by the college shows that the “lot" meets the post-harvest test standards in Table 2.

Under this rule, the college may certify a “lot" of seed potatoes that fails to comply with applicable tolerances in Table 1 or Table 2, if the college documents all of the following:

• Special conditions justify the certification, and there is a reasonable likelihood that the next generation of seed potatoes grown from the non-complying lot will meet applicable tolerances.

• No bacterial ring rot has been found in the lot.

• The certification will not jeopardize seed potato quality, or pose a significant risk of harm to the potato industry or consumers.

• The certified seed potatoes will not be planted on any farm other than the farm where they are produced.

Under current rules and this rule, the college gives each “lot" of certified seed potatoes a classification number based on generation (with each year of field planting the classification drops one level, reflecting increased disease risk). Under current rules, seed potatoes may be certified for 5 generations (4 generations as “foundation" seed), except that “Elite" seed potatoes produced by the college may be certified for up to 7 generations (6 generations as “foundation" seed).

This rule allows certification for up to 7 generations (6 generations as “foundation" seed), and eliminates the separate classification of “Elite" seed. This will make Wisconsin's classification system more consistent with the system in other states. The new classification system is shown below (FY1 is the highest classification):

Under this rule, the college may authorize a seed potato grower to use experimental propagative material from a breeding farm. This makes it possible for growers to experiment with new varieties. However, seed potatoes grown from the experimental material may be certified for only 3 generations (“Ex5 Foundation," “Ex6 Foundation" and “Certified"), not 7 generations.

Table 3
Classification

Year of Field Propagation on Seed Potato Farm (Generation)	Standard Classification	Experimental* Classification
1	FY1 Foundation	Ex5 Foundation
2	FY2 Foundation	Ex6 Foundation
3	FY3 Foundation	Certified**
4	FY4 Foundation
5	FY5 Foundation
6	FY6 Foundation
7	Certified**

* Applies to lines of seed potatoes grown from experimental field-grown propagative material from recognized breeding programs.

** “Certified" (non-foundation) class seed may not be replanted to produce other certified seed potatoes, but may be used to produce commercial potatoes or uncertified seed potatoes.

Under this rule, “foundation" seed potatoes certified by another state have the same classification assigned by that state, provided that the other state certifies seed potatoes under standards equivalent to the standards in this rule. If the other state does not provide field year information, the seed will be classified as FY5.

Once for each line of certified seed potatoes, the college may renew a classification by doing one of the following (contrary to the normal classification progression):

• The college may classify, as “FY5" rather than “certified," certified seed potatoes produced from seed potatoes classified as “FY6."

• The college may classify, as “Ex5" rather than “certified," certified seed potatoes produced from seed potatoes classified as “Ex6."

A seed potato grower seeking such a renewal must show that the seed potatoes meet the standards for the renewed classification. The college may require verification in the form of laboratory testing. “Tuber unit planting" is no longer required, in order to qualify for a renewal classification, because most seed potato growers no longer have the necessary equipment.

Historically, the college has provided disease-free propagative material used to grow lines of certified seed potatoes in this state. But in recent years, there has been increased demand for new potato varieties, often from out-of-state sources.

This rule expands the sources from which a seed potato grower may obtain propagative material used to start a line of certified seed potatoes. However, this rule includes safeguards to prevent the introduction of disease, and to maintain the credibility of the certification process.

This rule allows a seed potato grower to obtain propagative material from, among other places, a laboratory or greenhouse approved by the college. “Propagative material" may include tissue culture plantlets, microtubers, minitubers or tubers that are produced under rigorous laboratory or greenhouse conditions to ensure that they are free of disease.

The college may approve a laboratory or greenhouse in this state if all of the following apply:

• The college inspects the laboratory or greenhouse before granting approval, and at least annually after granting approval. The college must also inspect minitubers, if any, produced by a greenhouse.

• The laboratory or greenhouse uses testing, propagation, isolation and sanitation procedures equivalent to those used by the college.

• The laboratory or greenhouse operator does all of the following:

• Applies to the college for approval, and provides information reasonably required by the college for purposes of evaluation and approval.

• Agrees to pay the college's reasonable costs to inspect, evaluate and approve the laboratory or greenhouse.

• Keeps complete records of laboratory or greenhouse operations, and of propagative material produced by the laboratory or greenhouse. The operator must make the records available to the college upon request.

• Labels propagative material as directed by the college, consistent with this rule.

The college may approve a laboratory or greenhouse in another state if the seed potato certification agency in the other state approves that laboratory or greenhouse for the same purpose, using standards and procedures that are equivalent to the standards and procedures that the college uses to approve in-state laboratories and greenhouses under this rule.

This rule spells out basic standards for storing, shipping and handling certified seed potatoes, to prevent disease contamination. This rule modernizes current standards. For example, this rule eliminates the current requirement that “foundation" seed potatoes be shipped in bags (it allows bulk shipments) and addresses shipment in totes. This rule also eliminates the current requirement that bags or trucks be sealed with a metal seal.

Under this rule, no person may do any of the following: