Rules and Regulations Colorado Certified Potato Seed
Charges To Cover The Cost Of The Certification Program
General Requirements Which Apply To All Classes Of Certified Seed Potatoes
Special Requirements For Limited Generation Seed Potatoes:
I. Seed Sources And Disease Tolerance Standards
II. Isolation For Limited Generation Seed Stock
III. Field Inspection Tolerances
IV. Sale Of Nuclear Material From Private Or Grower Operated Labs
Special Requirements For Non-Generation Class Seed Potatoes
Special Requirements For Grower Entry Program
Special Requirements For Experimental Class Seed Potatoes
Colorado Grade Standards For Certified Seed Potatoes
1. Potato Certification Service, Colorado State University, Fort Collins. A cooperative program of seed
improvement and inspection carried on by Colorado State University and the Colorado Certified Potato Growers'
Association, Inc.
2. Certified Seed means that the potatoes were inspected while growing in the field and again after being
harvested and were thereafter duly certified by the Potato Certification Service as provided in the Rules and
Regulations approved by the Colorado State Board of Agriculture.
3. Seed refers to the vegetatively propagated tuber used for reproduction of the potato rather than true seed that
is sexually produced from the potato flowers.
4. Limited Generation Seed refers to seed potatoes produced to meet the respective special requirements
outlined in the Limited Generation System regulations.
5. Experimental Seed refers to those seed potatoes produced to meet the respective special requirements
outlined in the Experimental Seed class regulations.
6. Lot refers to a field, or the potatoes harvested therefrom.
7. Official State Tag means the tag carrying the official seal of the Colorado State Board of Agriculture, cultivar,
grower and address, seed class, lot number and year of production, which must be attached to seed represented
to be "Colorado Certified Seed".
8. Bulk Certificate is an official document issued by the Potato Certificate Service to verify the certified status of
a specified quantity of Colorado Certified Seed potatoes which are shipped bulk.
9. Waiver of Grade Inspection - A statement which may be part of a sales contract or on a separate form wherein
the buyer agrees to accept grade without official inspection.
10. Disease tolerance - Certification rules make provisions to allow the presence of certain diseases at levels
sufficiently low as to preclude significant effect on seed value. In case of bacterial ring rot, there is zero
tolerance, and the discovery of a single ring rot infected plant in the field, or tuber in the bin, brings about
rejection of the lot from certification. Conversely, the lack of discovery of bacterial ring rot in any given seed lot
does not necessarily mean the seed is free from the disease.
11. U.S. Standards for Seed Potatoes is understood to be grades of potatoes as defined and issued by the U.S.
Department of Agriculture.
12. Inspector is a qualified person, approved by the Potato Certification Service as being capable of conducting
field, cellar, grade, and post harvest test plot inspections.
13. Rejected when applied to a field or lot of potatoes means that the potatoes fail to meet the standards
covering Generation or Non-Generation Certified seed potatoes, and cannot be sold as such without being
guilty of violation of the Seed Certification Law.
14. Roguing means the removal of all diseased or undesirable plants or tuber-units, and potatoes produced
thereon.
15. Tuber-Unit Planting is a method of dropping two or more seed pieces from one tuber consecutively in a row.
Tuber-unit field is a field: a) that is planted by tuber-unit method, and b) from which entire units are rogued if
any plant in a unit is found to have virus disease.
16. Mass or Straight Planting - as opposed to tuber-unit planting. May refer to whole or cut seed planted in a
conventional manner.
17. Field isolation is the physical separation between field plantings to minimize accidental mixing of tubers,
transmission of virus diseases and contamination by certain bacterial diseases.
18. Storage isolation is the physical separation between seed lots in storage to prevent the accidental mixing of
different lots or cultivars and minimize the tuber-to-tuber spread of disease.
19. Soft rot or wet breakdown means any soft, mushy, or leaky condition of the tissue.
20. Internal discoloration means any type of necrosis, stem-end browning, internal brown spot or other similar
types of discoloration not visible externally, except blackheart.
21. Farming Operation - A seed potato enterprise that includes all land, equipment, storage facilities, and labor
that are utilized in a common effort to produce certified seed potatoes. This includes all potato fields in the
enterprise whether actually grown by the applicant or under growing agreements with common equipment and
storages.
22. U.S. Plant Variety Protection Act - refers to the federal law administered by the USDA which outlines the
regulations and rules of practice for protecting sexually reproduced or tuber propagated plant varieties.
A. Acreage Fees: $18.00 per acre, all seed classes. ($17.00 for certification fees, $1.00 for CCPGA membership fees)
1. Minimum charge to any grower; $100.00 for 6 acres or less. Future Farmers of America and 4-H members;
minimum charge of $3.00 for 3 acres or less
2. Payment of acreage fees entitles the applicant to a one-year membership in the Colorado Certified Potato Growers'
Association (CCPGA).
3. Acreage entered may be voluntarily withdrawn at any time.
4. There are special fees for growers participating in the grower entry program. Please see page 15 for further
information.
CHECK OR MONEY ORDER, PAYABLE TO THE COLORADO CERTIFIED POTATO GROWERS' ASSOCIATION,
MUST ACCOMPANY THE APPLICATION FOR CERTIFICATION.
B. Tag and Bulk Certificate Fees:
1. Tag Fees: $0.08 per tag. A tag is required on each sack of certified seed. All unused tags must be returned
to the Potato Certification Office.
2. Bulk Certificates: $0.08 per hundred weight (cwt).
C. Disease Testing Fees:
1. A complete listing of disease testing fees is included in General Requirements.
D. Billing Policy
1. All charges for tags, bulk certificates, laboratory services and plant materials will be billed on a monthly
basis.
2. All checks or money orders must be made payable to the Colorado Certified Potato Growers' Association.
Mail or phone application, tag or bulk certificate orders to: Potato Certification Service
San Luis Valley Research Center
0249 East Rd. 9 North
Center, CO 81125
Phone (719) 754-3496
FAX (719) 754-2619
1. Application plus payment of fees for certification must be made on or before June 1st; applications
received later are accepted at the discretion of the Potato Certification Service. All growers will be assigned a
permanent grower identification number upon submitting an application for Certification.
2. Follow the recommendations and guidelines of Colorado State University for good seed potato
production.
3. Any disease or other condition seriously affecting seed quality, and its ability to sprout and grow
normally that is not mentioned herein, may be cause for rejecting a lot entered for certification.
4. Any lot of seed may be rejected at any time such lot is found not to meet the Certification standards.
5. All potato fields on the farm or in the farming operation must be eligible and entered for certification. A
farming operation means a seed potato enterprise that includes all land, equipment, storage facilities, and
labor that are utilized in a common effort to produce certified seed potatoes. This includes all potato fields in
the enterprise whether actually grown by the applicant or under growing agreements with common
equipment and storages.
6. If a member of the Colorado Certified Potato Growers' Association, Inc. violates the Rules and Regulations
for Certification of Seed Potatoes in Colorado, or engages or persists in practices which in the judgment of
the Board of Directors are likely to injure or discredit the Association, the member may be suspended or
expelled from membership by action of the Board at any regularly scheduled or special Board meeting. A
two-thirds vote of the Board shall be necessary for suspension of membership and a unanimous vote of the
Board necessary for expulsion from the Association.
7. Isolation
a. All potato fields entered for certification must be adequately isolated by a minimum of 60
feet from adjacent fields not entered for certification or lots rejected for serious seed-borne
diseases during the current season. Potato fields entered for certification not meeting
isolation requirements will be reduced in acreage accordingly.
b. Each lot of seed potatoes in storage must be adequately separated from other potatoes to
prevent mixture or contamination.
c. Each lot of certified seed potatoes must be kept in a storage building that contains only
potatoes approved by the Potato Certification Service. Potatoes from seed lots rejected for
certification due to bacterial ring rot will not be allowed under any circumstances.
8. Sacks
a. New sacks must be used if seed potatoes are harvested and/or stored in sacks.
b. New sacks must be used for the marketing of seed potatoes unless they are shipped in
bulk.
9. Tags, Bulk Certificates, Seals
a. No potatoes are recognized as officially certified unless properly tagged or identified with a
bulk certificate. Illegal use of tags or bulk certificates will be prosecuted.
b. Tags or bulk certificates will be issued only to the applicant or his agent. NO
MUTILATION OF TAGS OR BULK CERTIFICATES, BY WRITING OR MARKING OVER,
OR OTHERWISE ALTERING ORIGINAL INFORMATION PRINTED THEREON, WILL BE
PERMITTED. The responsibility of proper use of tags and bulk certificates is placed on the
person (CCPGA member) to whom such articles have been issued.
c. A metal seal shall be placed on the conveyance doors of bulk shipment containers
identified by a bulk certificate.
d. Special permission may be granted by the CCPGA Board of Directors to imprint a duplicate
image of an official Colorado Certified Tag on a small plastic bag (3 lbs. to 10 lbs.) to be used
for marketing small quantities of certified seed potatoes. The art work layout must be
approved by the Potato Certification Service prior to printing. Information normally printed on
the Colorado seed tag (i.e., seed grower's name, cultivar, crop year, seed class, lot number,
and maximum tuber size) will be printed on the bag in order that the reader can readily identify
the seed source. One completed copy of a bag bearing all of the above mentioned information
related to a given shipment must be filed with the Potato Certification Service. All such
shipments must comply with designated grade inspection requirements. A bulk certificate will
accompany each load.
10. Grades And Grade Inspection
a. All Certified Seed Potatoes must be graded to conform with the Colorado standard grades
and sizes for seed potatoes unless a signed waiver of grade inspection has been obtained
from the purchaser as outlined in Section 10-d or 10-g.
b. All classes must be shipped under tags or bulk certificates that represent the grade to
which they have been sorted. Potatoes failing to meet the grade specified on the tag or bulk
certificate will be; (1) resorted to meet the grade requirements, (2) retagged with new tags or
re-issued a new bulk certificate representative of the grade of the potatoes, or (3) the tags
must be removed.
c. All shipments out of any Marketing Order Area must be inspected by a Federal/State
Inspector at the time of shipment. The Federal/State Inspection Service is responsible for
inspecting seed shipments to verify that proper grade standards have been met. If a "zero
tolerance" disease such as bacterial ring rot or root knot nematode is suspected or any other
condition which may disqualify a seed lot from certification is discovered during the
inspection, the Potato Certification Service will be notified by the seed grower so additional
procedures can be implemented to identify and confirm the true nature of the problem. Seed
cut prior to shipment out of any Marketing Order Area will not be eligible for tags or bulk
certificates under any circumstances.
d. Each lot sold within a Marketing Order Area shall be inspected by a Federal/State Inspector
or a waiver of grade inspection must be secured from the purchaser at the time of delivery or
acceptance.
e. All Certified Seed Potatoes marketed in bags and carrying a tag must meet the highest
grade requirements indicated by either the bag or the colored tag. U.S. No. 1 Seed Grade is not
strictly a U.S. No. 1 grade, and may not be marketed in bags branded as U.S. No. 1.
f. All Certified Seed Potatoes exported outside of the U.S. shall meet the U.S. EXPORT "SEED
POTATOES" standards for the given class being shipped.
g. Certified Seed Potatoes marketed expressly for use as garden seed and shipped in
quantities less than 10 cwt per cultivar or clone within the same load shall be exempt from
Federal/State grade inspection. However, a certificate of privilege shall be obtained from the
Marketing Order (Colorado Potato Administrative Committee - Area II) verifying the load's
use as garden seed and the quantity shipped, and a waiver of grade inspection must be
secured from the purchaser at the time of delivery or acceptance.
11. Field And Storage Inspections
a. Each field entered for certification shall receive at least two inspections. A third inspection
may be made if growing conditions permit. Three or more inspections may be made on any
field at the discretion of the inspector. Each inspection shall consist of a visual examination of
the growing plants in each field. At least 100 plants per acre shall be counted on the first and
second inspections to determine disease percentages. When individual seed lots consist of
less than 10 acres, at least 1000 plants or 100% of the lot shall be counted. A third inspection
shall consist of a visual survey of plants that normally does not include a plant count unless
a disease condition or other problem is discovered that requires a numerical estimate of
affected plants. All disease diagnoses or problem identifications shall consist of visual
examination of the plants in question, except in the case of latent viral infections, where a
serological test such as ELISA may be used to supplement the visual inspection. In the case
of bacterial ring rot caused by Clavibacter michiganensis subsp. sepedonicus, the visual
diagnosis shall be supplemented with the gram stain procedure as described by Glick, Ark,
and Racicot in the American Potato Journal, Vol.21:311-14, 1944 and an appropriate laboratory
serological test as outlined in the "Protocol for Indexing and Confirmation of Diagnosis of
Bacterial Ring Rot of Potato" (accepted 12/3/98 by the U.S. Seed Potato Certification
Agencies). Field inspectors shall observe at least 4600 plants or 100% of the lot during the
time that bacterial ring rot symptoms, if expressed, should be visible. When seed lots are
rejected prior to final field inspection for reasons other than bacterial ring rot such lots will be
re-inspected.
b. Each storage building shall be inspected following completion of harvest and prior to
removal of the certified seed potatoes to determine the suitability of the structure and bins to
provide reasonable security against contamination and/or cultivar mixing. The grower shall be
responsible for proper disinfection of the storage building, bins and equipment utilized. Also,
the grower shall identify the location of each seed lot by means of a label attached to the
storage bin. The label information shall include the grower's name, seed lot number, cultivar,
and number of hundred weight stored. In the event two or more seed lots are combined, the
status of the entire lot shall be downgraded to the lowest generation (or class) concerned,
and if a varietal mix has occurred, all seed lots which have been mixed shall be denied
certification unless the varieties are capable of being visually separated and sorted, and such
separation and sorting has in fact taken place to the satisfaction of officials of the Potato
Certification Service.
c. Any lot of seed potatoes proven to be infected with bacterial ring rot will be rejected for
certification regardless of the time or place of inspection. A grower who has any lot of
potatoes rejected because of bacterial ring rot will have an * printed in front of his seed lot
number(s) in the Seed Directory; also on certified tags and bulk certificates. Any seed lot with
an * in its designation shall not be eligible for recertification. However, any seed lot identified
by an * may be replanted for certification the following year on the original grower's farm.
d. In the event a farming operation has more than one field planted from the same seed lot
source and bacterial ring rot is discovered in at least one of the fields, the remaining fields
(planted with the same seed source) will be automatically rejected unless the pattern of
infected plants observed by the inspector provides clear evidence that the cause of
contamination was equipment used exclusively in connection with seed cutting, handling
and/or planting the seed lot in question.
e. Field inspection may be refused and seed lots rejected for certification if the inspector
believes the field cannot be properly inspected due to: 1) excess weeds, 2) hail or frost
damage, 3) damage caused by insects or disease, 4) chemical injury, or 5) any other condition
that prevents visual identification of diseases or other factors affecting seed quality and
performance. Any lot rejected due to hail and frost may be retained by the original grower for
recertification on his farm the following year provided post harvest test requirements are met.
f. Seed fields must be marked so that the inspector can tell at all times where the different seed
lots are located. (For example, blank rows separating the lots or brightly colored stakes at
least 4 feet tall spaced about 600 feet apart).
g. Any grower of Certified Seed may appeal the decision of an inspector by making such
appeal in writing to the Potato Certification Service, San Luis Valley Research Center, 0249
East Rd. 9 North, Center, CO 81125. Such appeal must be received within one week following
the inspection and must state clearly the reason for the appeal and show cause why a
re-inspection should be given. Roguing or sorting will not be permitted between the time of
inspection and examination following appeal.
12. Post Harvest Testing. All Colorado Certified Seed Potatoes must be subjected to a post harvest test and
meet prescribed standards to be eligible for recertification.
a. Purpose: Because of inability to detect certain virus diseases at all times under Colorado
field conditions, samples from seed lots eligible for recertification are planted where these
diseases can be observed in the greenhouse or in the south during the winter months.
b. Method: Samples are to be selected so as to represent all field areas of any given seed lot.
Tubers must be in the 2-3 ounce size range.
c. For Southern Post Harvest Test:
1. Generation 1 (stocks for sale only) - Not less than 25 tubers or 1.0% of the
population, not to exceed 400 tubers in a given seed lot, shall be sampled.
Growers may elect to have laboratory testing for leafroll and PVY prior to vine
kill conducted in lieu of a southern post harvest test at similar sampling rates.
Actual number selected will be established by Potato Certification Service
personnel.
2. Generation 2 - In any given seed lot, not less than 100 tubers or 1.0% of the
population, not to exceed 400 tubers or the levels established for Generation
3-6, shall be sampled. Actual number selected will be established by Potato
Certification Service personnel.
3. Generation 3-6
- 400 tubers per seed lot for lots up to 40 acres.
- 800 tubers per seed lot for lots 41-80 acres.
- An additional 200 tubers will be required for each 40 acres or portion thereof
beyond 80 acres.
- Exceptionally small lots - Not less than 100 tubers or 1.0% of the population.
Actual number selected will be established by Potato Certification Service
personnel.
d. Under certain circumstances a greenhouse grow-out will be substituted for the field test to
meet eligibility requirements for recertification. Sample size shall be 200 tubers of 2-3 ounce
size range per seed lot.
e. Representative post harvest test samples of suitable size will be collected by the grower.
They must be delivered to a designated assembly point by the grower. The samples of seed
tubers from all lots eligible for recertification are grown in a post harvest test either in the
greenhouse or in a southern test plot during the winter months to observe the plants for
evidence of disease spread or chemical damage that may have occurred the previous growing
season. Each plant in each seed lot sample is visually observed for disease symptoms. The
stand count in each lot is recorded and disease content is calculated by dividing the number
of diseased plants observed by the total number of tubers planted. Seed lots found to contain
tuber-borne diseases in excess of prescribed tolerances will be ineligible for certification the
following season. If the tubers of any seedlot sample submitted for post harvest testing do
not produce plants of adequate size due to dormancy problems or the plants are destroyed
due to weather, pests or other unforeseen problems at the test plot site, the respective
seedlots will be evaluated by Potato Certification Service personnel for recertification
eligibility on the basis of appropriate field inspection data.
f. Post Harvest Testing Disease Tolerances: In addition to the general requirements for post
harvest testing, the following special requirements must be met by each class of seed:
| Disease | Seed Class | |
| G1 - G5 | G6 | |
| Leafroll | 1.0 % | 1.5 % |
| Spindle Tuber | 0 % | 1.0 % |
| Mosaic (severe) | 1.0 % | 3.0 % |
| Mild Mosaic | 2.0 % | 5.0 % |
| Other Viruses | 0.5 % | 1.0 % |
| Haywire | 2.0 % | 2.0 % |
| Bacterial Ring Rot | 0 % | 0 % |
13. Any potato cultivar or numbered clone brought in from out-of-state whose disease symptom expression
resulting from infection with the ring rot bacterium (Clavibacter michiganensis subsp. sepedonicus) or
potato leafroll virus is unknown under Colorado growing conditions shall be eligible for certification under
the following conditions: a) If test results demonstrate adequate symptom intensity, that will normally permit
inspectors to visually detect the presence of these diseases under field conditions, the seed lot will be
allowed to proceed through the certification process and be approved provided other requirements are met.
Testing to determine disease reaction will be concurrent with field production of the cultivars or numbered
clones in question. Growers who intend to enter such stocks in the current year's certification program must
provide a minimum of 75 tubers of each cultivar or numbered clone to the Potato Certification Service by
May 1st of any given growing season. b) In the event disease expression is totally latent or mild to the
degree which prevents detection during field inspection an affidavit must be signed by the buyer which
acknowledges the limitations to disease detection.
See Seed Sources and Disease Tolerance section below for details involving required laboratory testing for nuclear and
G1-3 seed lots. All of the expenses for virus testing will be paid by the individual grower. Standard disease testing fees are
listed below. Other testing which may be needed by the CCPGA membership will be billed to recover cost of labor and
materials.
| Class | Test | # Samples | Cost $ | Time |
| Mother Plants * | 1PVX,S,Y,A,M,PLRV,PSTV, Cms &Erw | Individual | $10.00/test PSTV
$3.00/test |
2 wks |
| Nuclear * | PVX,S,Y,Cms & Erw | Individual - Combined 5/test | $5.00/test | 2 wks |
| Greenhouse Foliage * | PVX,S or all viruses | Individual - Combined 5/test - 10 min. to 1 % of plant population | $0.50/test | 3 days |
| Greenhouse Tubers * | Erw(lenticel), Cms(IFAS and or ELISA) | Individual with 10
min. to 0.5 % of plant
population
Up to 100 per group with 10 min. to 1 % of plant population |
Erw $0.50/test
Cms $15.00/test |
2 wks |
| Field Foliage * | G1 - PVX,S
G2,G3 - PVX plus PVY 0n cultivars with latenet reactions such as Russet Norkotah, Shepody, etc |
G1 - Individual - 25
min. to 1 % of plant
population
G2 - Individual - 200/ac. With 200 min. G3 - Individual - 20/ad. With 100 min. G1 - 3 combined 5/test |
$0.50/test
$48.00/ELISA plate |
3 days |
| Cms Tuber Test
(Post Harvest) |
Cms (IFAS and or ELISA) | Individual - Combined 200 tuber cores/test with 400 tubers min. per lot | $30.00/test | 2 wks |
| Erw Tuber Test | Erw (lenticel) | Individual with 25 min. | $0.50/test | 2 wks |
| Late Blight Tuber Screening | Tuber Incubation, high humidity, 68-72oF, 21 days, visual inspection | See late blight requirement for the San Luis Valley | $50.00/50 tubers | 25 days |
1Potato viruses X, S, Y, A and M, PLRV (potato leafroll virus), PSTV (potato spindle tuber viroid), Cms (Clavibacter michiganensis subsp.
sepedonicus), Erw (Erwinia carotovora subspp. atroseptica and carotovora)
* Required testing to qualify for certification.
Introduction: Each lot of seed potatoes entered for certification shall be classified as Limited Generation, Non-Generation
Certified or Experimental. Each class must meet all General Requirements and applicable Special Requirements mentioned
herein.
ANY SEED LOT BROUGHT INTO THE COLORADO LIMITED GENERATION SYSTEM FROM
OUT-OF-STATE WILL HAVE ITS ENTRY CLASSIFICATION DETERMINED BY THE POTATO CERTIFICATION
SERVICE.
Limited Generation System For Colorado Certified Seed Potatoes
The major goal of all seed potato improvement is to maximize the productivity of marketable potatoes through: a) elimination
of disease organisms and b) selection of superior clones within any cultivar. The Nuclear phase of seed improvement will be
the focal point of insuring that the best seed stocks are introduced into the Colorado seed potato program. The methods of
disease elimination and cultivar improvement may vary somewhat since new laboratory and greenhouse techniques to
control diseases are constantly being developed. Colorado State University, the Potato Certification Service and research
personnel will cooperate with producers of Nuclear seed stocks to maintain the highest level of technology available. Listed
below are the various steps that any given seed stock will pass through in the Limited Generation System:
Nuclear (Lab and/or greenhouse produced)
Generation 1 (1st year in field)
Generation 2 (2nd year in field)
Generation 3 (3rd year in field)
Generation 4 (4th year in field)
Generation 5 (5th year in field)
Generation 6 (6th year in field)
A. Nuclear
1. Seed source must be from single hill field selections obtained from certified seed of Generation 5 or earlier
generations or from a source approved by the Potato Certification Service.
2. Must be free of all visible disease symptoms. Testing for Clavibacter michiganensis subsp. sepedonicus
will be handled as outlined in the "Protocol for Indexing and Confirmation of Diagnosis of Bacterial Ring Rot
of Potato" (accepted 12/3/98 by the U.S. Seed Potato Certification Agencies).
3. Mother plants: Those units (plantlets) initiated from field selected plants or tubers. All mother plants to be
used for subsequent propagation must be tested and proven negative for the following disease organisms:
Clavibacter michiganensis subsp. sepedonicus, Erwinia carotovora subspp. atroseptica and carotovora,
potato viruses X, S, Y, A and M (hereafter referred to as PVX, PVS, PVY, PVA and PVM), potato leafroll virus
(PLRV), and potato spindle tuber viroid (PSTV).
4. Nuclear stocks: Those stocks derived from mother plants. These include material used in maintaining a
clone bank, plantlets increased for use in production of in-vitro microtubers, microtubers, plantlets increased
for use in field production of tubers, and minitubers produced in a greenhouse.
4. Clone bank: The clone bank in-vitro stocks will be tested on an annual basis and proven negative for
PVX, PVS, PVY, Clavibacter michiganensis subsp. sepedonicus, and Erwinia carotovora subspp.
atroseptica and carotovora.
Plantlet/greenhouse production: Representative samples of micropropagated materials for use in field or
greenhouse plantings, of not less than 10 units and not to exceed 1.0% of the planting stock, must be tested
for PVX and PVS to verify that such material still tests negative for these pathogens. In the case of
greenhouse production, the testing will take place between the time of first and second visual inspections. In
the event that trace amounts of virus are detected, the grower will be informed of the results and have the
seed lot in question classified accordingly upon completion of the Generation 1 field testing. Greenhouse
stocks will have an additional test for the presence of Erwinia carotovora completed at the same rate as
above on the minitubers. A positive test for presence of Erwinia carotovora will result in downgrading of
the stocks to Generation 2 for sale outside the originating grower's program. However, the contaminated
stocks may be replanted for certification and entered as Generation 1 on the original grower's farm.
B. Generation 11
1. Seed source must be Nuclear class stocks approved by the Potato Certification Service. All nuclear class
seed stocks must have a Certificate of Origin, tag, or similar document available for inspection by the Potato
Certification Service prior to being accepted into the certification program.
2. Tubers must be planted in identifiable family units. If greenhouse or laboratory production methods
preclude this possibility consult with Potato Certification Service personnel.
3. Each family unit will be lab tested for PVX and PVS and, at the growers option, for potato leafroll virus. At
least 1.0% of the plants must be sampled. If there are indications that viral infection has taken place, then, at
the grower's option, at least one leaflet from each plant in the infected family unit will be sampled to identify
and aid in removal of the infected plants, or blocks of samples will be tested to determine the extent of the
infection. If the grower refuses additional testing or the level of virus found in the stocks is too high for
removal of infected plants, the lot will be downgraded to the next appropriate class. Trace PVX or PVS
infections, as determined by the Potato Certification Service, will not result in downgrading of the lot if
replanted for certification on the original grower's farm the following year.
C. Generation 21
1. Seed source must be Nuclear or Generation 1.
2. Family units may be maintained.
3. Representative samples of at least 200 leaflets per acre will be tested for PVX and, at the grower's option,
tested for PVS.
D. Generation 31
1. Seed source must be Generation 2 or earlier generations.
2. Representative samples of at least 20 leaflets per acre and not less than 100 leaflets from any given seed lot
will be tested for PVX and, at the grower`s option, tested for PVS.
1See Tables 1 and 1A for disease tolerances.
E. Generation 41,2
1. Seed source must be Generation 3 or earlier generations.
F. Generation 51,2
1. Seed source must be Generation 4 or earlier generations.
G. Generation 61,2
1. Seed source must be Generation 5 or earlier generations.
2. May be tagged and sold as Generation 6 but is not eligible for certification the following year.
1See Tables 1 and 1A for disease tolerances.
2At the grower's option, Generations 4-6 seed lots may be tested for PVX and/or PVS. The Potato Certification Service will
be notified at the time of application. Sampling procedures will be those used for Generation 3. Results will not be published
in the Seed Directory, however, PVX content of the tested lots may be listed on the tag or bulk certificate at the grower's
option. Tolerances do not apply.
A. Field Isolation
1. Generations 1-3 potatoes must be separated from Generations 4-6, Non-Generation Certified and
Experimental class lots by a minimum distance of at least two blank row widths.
B. Storage Isolation
1. Generation 1 potatoes must be isolated from all other certified potatoes in the same storage. Emphasis
should be directed toward intensive sanitation and physical separation by solid wall partitions.
2. All certified seed lots must be kept in a storage building which contains only seed entered for certification.
Non-certified stocks and potatoes rejected due to blackleg or zero tolerance diseases such as bacterial ring
rot will not be allowed in the storage building; the presence of such potatoes will result in rejection of the
certified seed lots present.
| Table 1. Percentages Allowed - First Inspection | |||||
| Item | G11 | G21 | G31 | G4&5 | G6 |
| Potato Leafroll Virus | 0 | 0.1 | 0.1 | 0.5 | 0.8 |
| Spindle Tuber Viroid | 0 | 0 | 0 | 0 | 0.4 |
| Mosaic Virus | 0 | 0.1 | 0.2 | 1.0 | 1.5 |
| Other Viruses | 0 | 0.1 | 0.1 | 0.5 | 1.0 |
| Total Virus Allowed | - | - | - | 1.5 | 3.0 |
| Haywire | 0 | 0.2 | 0.2 | 1.0 | 1.0 |
| Giant Hill | 0 | 0.5 | 0.5 | - | - |
| Variety Mix | 0 | 0.1 | 0.1 | 0.25 | 0.5 |
| Bacterial Ring Rot | 0 | 0 | 0 | 0 | 0 |
| Blackleg2 | 0 | 0.05 | 0.05 | 0.1 | 4.0 |
| Table 1. Percentages Allowed - Second Inspection | ||||||
| Item | G11 | G21 | G31 | G4 | G5 | G6 |
| Potato Leafroll Virus | 0 | 0.5 | 0.07 | 0.1 | 0.2 | 0.4 |
| Spindle Tuber Viroid | 0 | 0 | 0 | 0.1 | 0.1 | 0.1 |
| Mosaic Virus | 0 | 0.05 | 0.1 | 0.2 | 0.3 | 0.5 |
| Other Viruses | 0 | 0.05 | 0.05 | 0.5 | 0.5 | 0.5 |
| Total Virus Allowed | - | - | - | 0.5 | 0.5 | 1.0 |
| Haywire | 0.1 | 0.1 | 0.1 | 0.5 | 0.5 | 0.5 |
| Giant Hill | 0 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Variety Mix | 0 | 0.05 | 0.07 | 0.125 | 0.125 | 0.25 |
| Bacterial Ring Rot | 0 | 0 | 0 | 0 | 0 | 0 |
| Blackleg2 | 0 | 0.05 | 0.1 | 2.0 | 3.0 | 4.0 |
| PVX (lab test) | 0 | 1.0 | 2.0 | - | - | - |
All Generation 2 and 3 seed lots exceeding PVX tolerances will be downgraded to the next appropriate class.
1Inspection policy: Growers of Generations 1-3 seed lots may be given one additional opportunity to restore the seed lot to tolerance
following the first and second scheduled inspections providing the following conditions are met: 1) The grower agrees to complete roguing
of the field as soon as possible and 2) Field conditions, plant development and other factors such as presence of insect vectors would not
in the judgement of the inspector limit the accuracy and effectiveness of the roguing effort.
2Generations 1-3 seed lots exceeding specified blackleg tolerances will be downgraded to the next level of tolerance eligibility. Roguing of
these lots to restore them to blackleg tolerance will not be allowed.
1. Rules governing the seed sources and disease tolerance standards (as outlined on pages 10-11) for
Nuclear stocks must be followed. All stocks not initiated in the year of production or sale must have an
annual testing for the presence of disease organisms and a grow-out or other test approved by the Potato
Certification Service to verify trueness to type and varietal identification.
2. Accurate and complete accession records must be kept on all nuclear stocks and be available for review if
requested by the Potato Certification Service. Information should include year of initiation into tissue
culture, source of the line, general increase data, pertinent field performance characteristics, and disease
testing history.
3. All greenhouse produced stocks (minitubers) shall have at least two inspections during their growth. At
the time of the second inspection, prior to vine death, plants will be examined to verify trueness to type and
varietal identification. Minitubers will be examined in storage for any apparent problems prior to shipment or
subsequent field growth.
4. All nuclear stocks must be kept in a clone bank with accurate identification on each tube or vessel. These
stocks shall be kept in the clone bank no less than one year from the date of any sale.
5. Nuclear stock production in Colorado can be contracted for out-of-state growers providing that the
arrangements made fall within the capacity of the Potato Certification Service to carry out. If requested, a
copy of the contract shall be made available to the Potato Certification Service prior to actual tissue culture
increase and sale. Nuclear stocks under contract must meet minimum Colorado standards as described within
this document.
6. Nuclear stocks sold will not be tagged with an official tag or bulk certificate used on other certified seed
stocks. Instead, there will be an affidavit included with the nuclear material which carries information relating
to its accession, disease testing records, varietal identification, numbers sold, and product identity (i.e.,
minitubers, tissue culture plantlets, microtubers, etc.). The stocks will be recorded as eligible for certification
as Generation 1 under the Colorado Rules and Regulations.
This class of certified seed is intended to provide limited opportunity for a grower to produce certified stocks of cultivars
for which micropropagated, laboratory-tested seed sources are temporarily not available. Growers who intend to produce
Non-Generation Certified seed must verify to the Potato Certification Service prior to April 1st of any given growing season
that the cultivar in question is not available from a Limited Generation seed program, and furthermore have each request
reviewed and approved by the CCPGA Board of Directors Executive Committee. However, any prospective seed lots must
have been post harvest tested and meet qualifications for recertification. Non-Generation Certified seed lots will be
inspected and classified according to the disease tolerances and all of the applicable Rules and Regulations established for
Generation 6. These stocks will be identified in the Seed Directory and when sold will be inspected for grade and properly
identified with tags or bulk certificates. The symbols "NGC" shall be printed in the Seed Directory and on the tags and bulk
certificates to denote their class.
The grower entry program is designed for growers who wish to enter the certification program, but are unable to fulfill all of
the requirements during the first production year. This program should be valuable for an inexperienced seed grower who
would get the benefit of Potato Certification Service inspections and training before he would assume full responsibility for
selling certified seed. A prospective grower must contact the Potato Certification Service office prior to April 1 and outline
how he expects to eventually meet all requirements for certification. A review of progress will be made at the end of each
growing season to determine the feasibility of proceeding to full participation as a certified producer the next season.
Normal fees will be assessed for acreage entered into the grower entry program. In addition, a $3.00/acre fee will be assessed
on all acreage within the farming operation not entered in the grower entry program for a one time bacterial ring rot field
inspection. Since the seed produced under the Grower Entry program is not eligible for sale as certified, no tags or bulk
certificates will be issued, nor will seed lots be included in the Seed Directory until the grower has qualified for full
certification as per the Rules and Regulations.
The Memorandum of Understanding between the Colorado Certified Potato Growers' Association and the Colorado State
Board of Agriculture authorizes the Potato Certification Service to "cooperate with the Experiment Station in increasing and
releasing new varieties of potatoes developed by the Experiment Station," thus it becomes necessary to develop acceptable
guidelines for conducting the testing and seed increase program. In this respect, it is important to acknowledge the
unavoidable limitations to the visual inspection process encountered when the disease symptom expression of any potato
clone is unknown at the time a seed grower would like to enter it for certification. Therefore, the Experimental Seed Class
was established to expedite and facilitate field testing of numbered potato clones being considered for naming and official
release. Two categories of this Seed Class were established.
Category 1 will include only unnamed "Seedling" potato clones involved in the field testing phase of a potato cultivar
development program on which bacterial ring rot and/or leafroll virus symptom expression is unknown. Seed stocks of such
clones will not be eligible for certified tags or bulk certificates, nor will they be listed in the Seed Directory. Field plantings of
such clones will be inspected and a written report submitted to the Leader of the Cultivar Development Program. When
adequate field test data on disease expression and other performance characteristics has been collected to justify further
evaluation on seed growers farms, any given clone may be transferred to Category 2 of the Experimental Seed Class. This
decision will be made jointly by the Leader of the Cultivar Development Program, the Potato Certification Service and the
Seed Improvement Committee of the Colorado Certified Potato Growers' Association.
Category 2 seed lots will include only unnamed "Seedling" clones whose symptom expression of bacterial ring rot and
potato leafroll virus are known to be adequate under Colorado field conditions. Such seed lots will be eligible for entry into
the certification program on the following basis: There will be three years production allowed for Experimental Seed Class -
Non-Generation Category 2 stocks. At the end of three years, the status of these stocks will be reviewed and, where
possible, these stocks will be phased out and replaced with Limited Generation seed sources. If this is not possible, an
annual review will be conducted to verify the status of the stocks. All stocks which meet the criteria for certification will be
listed in the Seed Directory. The symbols "Exp 2-" followed by a number designating the years in the field after initial
release (i.e., Exp 2-1, Exp 2-2, etc.) will be printed both in the Seed Directory and on tags and bulk certificates. Limited
Generation sources of these stocks will carry the same designations with the exception that the symbols after "Exp 2-" will
reflect their status from the Limited Generation program, (i.e., Exp 2-G1, Exp 2-G2, etc.). Because of the limited knowledge
concerning potential disease reactions, and/or other problems in these seed stocks, the seed seller must obtain and submit
to the Potato Certification Service an affidavit signed by the seed buyer prior to seed shipment which states that the buyer
is willing to accept the risks involved with purchasing experimental seed.
This affidavit or its equivalent will be kept with the tag or bulk certificate order in the grower's Potato Certification Service
file. Also, it is understood that experimental seed stocks may be rejected at any time due to uncommon disease reactions.
Any seed grower/organization entering numbered potato selections for seed increase and evaluation in the potato
certification program also agrees to abide by an agreement with the Colorado State University Agricultural Experiment
Station, or to obtain written authorization from the potato breeding program from which the numbered potato selections
originate. The CSU agreement "Notice to Receivers of Experimental Potato Selections" consists in part of the following:
COLORADO STATE UNIVERSITY AGREES TO:
1. Supply seed stocks or grant permission to utilize these stocks for further propagation and evaluation to
the grower applicant.
2. The term of this agreement will be for a one year period beginning upon seed grower/organization receipt
of the numbered stocks.
BY ACCEPTANCE OF SUCH POTATOES, THE SEED GROWER/ORGANIZATION AGREES TO:
1. Enter crop for certification. These stocks will be grown in accordance with the Rules and Regulations of
the seed potato certification program for the appropriate seed class using generally accepted cultural
practices.
2. Furnish land and labor, and meet all expenses involved in production and certification of the crop.
3. Permit representatives of the University to make observations and to obtain samples if desired.
4. Not to further propagate or distribute seed stocks of this (these) selections for propagation beyond the
terms of this agreement unless authorized by the University.
5. Dispose of any numbered selection discarded from the Potato Cultivar Development Program. These
stocks will not be eligible for entrance in any seed potato certification program unless authorized by the
University.
6. Special disposition instructions: As directed by Cultivar Development Program Leader.
7. A meeting between the Seed Grower(s)/Organization Representative(s), the Seed Improvement Committee
of the Colorado Certified Potato Growers' Association, the Potato Certification Service and the Project Leader
of the Potato Cultivar Development Program prior to January 1st to establish guidelines on price and method
of distribution of seed.
8. Not hold the University or its representatives financially liable for losses incurred as a result of production
and/or disposition of this seed.
IT IS MUTUALLY AGREED:
1. The proceeds from the crop produced under this agreement shall be the property of the Seed
Grower/Organization that submitted the stocks for certification.
2. That information derived from these evaluations shall be jointly shared by the parties to this agreement.
3. That the selections may be legally protected under the federal Plant Variety Protection Act or other
mechanisms that may require royalty payments before being grown commercially.
The following grade standards apply to all certified seed potatoes.
| Grade Defect for Tubers | All Seed Classes % Allowed |
| Stem end discoloration | 5.0 |
| Net Necrosis (Leafroll, after laboratory identification) | 0.5 |
| Net Necrosis (aster yellows) | 2.0 |
| Bacterial Ring Rot | 0 |
| Root Knot Nematode (visible tuber symptoms) | 0 |
Colorado Blue Tag Grade shall consist of potatoes which meet the requirements of the disease tolerances and grade
standards previously listed for CERTIFIED SEED POTATOES. In addition, they shall be graded to conform with the U.S.
No. 1 Seed Potatoes Grade as defined under U.S. Standards for Grades of Seed Potatoes (see pages 18-19) with the
following exceptions:
1. Not more than 1% of the potatoes shall be damaged by dry rot.
2. Size shall be 1-1/2" to 12 oz. unless a smaller maximum is specified on the tag or bulk certificate.
3. Not more than 3% of the potatoes in any lot may be below the specified size and, in addition, not more
than 8% may be above the specified size.
4. Physiological internal pigmentation shall not be considered a grade factor.
Colorado Yellow Tag Grade shall consist of potatoes which meet the requirements of the disease tolerances and grade
standards previously listed for CERTIFIED SEED POTATOES. This grade is intended to provide the buyer and seller an
opportunity to establish certain mutually agreed upon specifications not allowed in the Colorado Blue Tag Grade. The
potatoes must be graded to conform with the U.S. No. 1 Seed Potatoes Grade as defined under U.S. Standards for Grades of
Seed Potatoes (see pages 18-19) with the following exceptions:
1. Soft rot shall not exceed 1%.
2. Tuber size shall be specified on the tag or bulk certificate. Tolerances for specified size limits: Not more
than 3% of the potatoes in any lot may be below the stated minimum and, in addition, not more than 10%
may be above the stated maximum.
3. Tubers shall not be seriously damaged by external defects, or seriously misshapen unless otherwise
specified, and shall meet the tolerances for a U.S. No. 2 Grade.
4. Physiological internal pigmentation shall not be considered a grade factor.
Applications of Tolerances: The application of grade and size tolerances shall be as outlined
in the United States Standards for Potatoes, Section 51.3003.
U.S. Export "Seed Potatoes" shall consist of potatoes which meet the requirements, disease tolerances and grade standards
for international export as listed under the U.S. EXPORT "SEED POTATOES" STANDARDS, 12/95.