What is a Certified Seed Potato? Jeff McMorran Oregon Seed Certification Service What is it not?

Seed Certification (in general) Goal: “to provide a service to the public for the maintenance and increase of quality seed and propagating material of varieties grown and distributed in such a manner as to ensure varietal purity” Potato Seed Certification Goal: “to provide a service to the public for the maintenance and increase of quality seed and propagating material of varieties grown and distributed in such a manner as to ensure: (1) varietal purity (2) lot does not exceed tolerances for specified disease and other conditions

Limited Generation Program Greenhouse Production Field Production of Certified Seed Meristem Culture Tissue Culture and Testing Mini-tubers or Plantlets (Pre-Nuclear Generation)

Field Increase of Certified Seed

Seed Potato Certification: Limited Generation Program Pre-Nuclear Generation Greenhouse Production: Mini-tubers or Plantlets Nuclear Generation - First year in field Generation 1 Generation 2 Generation 3 Generation 4 Generation 5 - Last year of certified production NOTE: “Generation” denotes CLASS not Field Year!

Tolerances vary by: 1. Class (Nuclear, G1, G2 etc; or Foundation, Registered, Certified) 2. Type of inspection (field, latent virus test, winter Grow-out, Seed lab test) ✔ ✔ But…. Zero Tolerance ALWAYS means zero tolerance!

B. LIMITED GENERATION CERTIFIED SEED POTATOES Field Planting Equivalency Table 1 Prepared by the Certification Section of the PAA YEAR IN THE FIELD Agency AlaskaG1 3 G2G3G4G5G6G7G8 CaliforniaNG1G2G3G4G ColoradoG1G2G3G4G5G IdahoNG1G2G3G4G5G MaineFY1FY2FY3FY4FY5FY6 MichiganFY1 6 FY2FY3FY4FY5FY MinnesotaG1G2G3G4G5G6C MontanaNG1G2G3G Nebraska / WyomingNG1G2G3G4G NevadaNG1G2G3G4G New York 4 U (G1) U (G2) U (G3)G4G5G6 North DakotaNG1G2G3G4G5C OregonNG1G2G3G4G UtahN(G1)G2G3G4G5G WashingtonNG1G2G3G4G Wisconsin 5 FY1FY2FY3FY4FY5FY6C CanadaPEE1E2E3E4FC (G1)(G2)(G3)(G4)(G5)(G6)(G7)

Potato Seed Certification 5 STEP PROCESS 1.Verification 1.Verification 2. Inspections 2. Inspections 3. Latent Virus Testing 3. Latent Virus Testing 4. Winter Grow-outs 4. Winter Grow-outs 5. Tags & Certificates 5. Tags & Certificates

Seed Potato Certification Program 1.VERIFICATION - Variety Eligibility - Seed Stock Eligibility - Crop History Satisfied - Seed Farm Requirements

Seed Potato Certification Program 2. INSPECTIONS - Lab & Greenhouse - Field - Harvest

Seed Potato Certification Program 3. LATENT VIRUS TESTING CalWhite, Gem Russet, Shepody, all Russet Norkotah, Winema, etc! PVX, PVY, PVY strains (O, C, N, NO, NWi, NTN)

Seed Potato Certification Program 4. WINTER GROWOUTS & POST-HARVEST TESTING

Seed Potato Certification Program 5. TAGS and CERTIFICATES

What is a Certified Seed Potato? What is it not?

Q/A - VARIETY T/F: Certified seed means the variety is correct and there is no mix? True & False – Certified seed should match the basic description of the the variety specified (within tolerances for variety mix), Plant characteristics--i.e., height, growth habit, distinguishing stem, leaf and leaflet characteristics; flower color and abundance of inflorescence. Tuber characteristics--i.e., tuber skin and flesh color(s), tuber shape, eye distribution, and depth or prominence; Beyond the basic variety descriptions the agency must largely rely on the accuracy of the original certifying agency to attest that the lot is the correct variety.

Q/A - QUALITY T/F: Certified seed means it is guaranteed to grow well and have high yields? False – Certified seed only focuses on a specified set of criteria - certain tuber-born diseases, variety purity, and chemical injury that may affect subsequent crop. Other factors, such as proper handling, tuber dormancy/physiological age, diseases not scored by certification, physical damage, and proper variety selection for a particular environment, may have a more important impact on how a particular lot performs in your area. Buying certified seed is only part of answer to a profitable operation. - Look at the NAHC - Get a shipping point inspection if not required

Some Diseases Included in Certification Inspections POTATO: - Leafroll, Mosaic (PVY,PVA, PVX) - Other visible virus (AlfMV, TRV, PMTV, others) - Blackleg - Chemical Injury - Spindle Tuber Viroid - Bacterial Ring Rot - Root Knot, Nematode - Potato Cyst Nematode Q1: Why is the disease list for potato so long relative to other crops certified? Q2: Does the presence of these diseases mean the crop is not certified?

Q/A - DISEASE T/F: Certified seed means “disease-free seed”? False – means within tolerances for certain diseases. For example Generation 4 potatoes can have up to 1% mosaic found in the field inspections and 2% in the Winter Grow-out. However any Bacterial Ring Rot or RK Nematode found during any inspection will disqualify a lot. T/F: “Zero tolerance” means – none present? False = none found during normal inspection procedures What about you need a document that says “None Present”?

Q/A - Disease detection in seed certification is primarily based on: A. Lab testing B. Visual observation of plants C. Inspector’s hunches ✔ X Though this is changing!

- Seed-borne - Economic importance (thus not Silver Scurf in potato seed) - Increase market-ability (export, low mosaic, etc.) - Manageable using certification techniques (i.e., not Dry Rot) - Indigenous or potential threat to North America or production area (thus not a virus or disease only known to occur in S. America) Why are some disease listed in Standards and not others? What determines if a disease ‘makes the list’?

These are important potato diseases, why are they NOT generally listed in certification tolerance tables? PYVVPotato Wart Zebra ChipPSTV

T/F: If a disease is not listed the inspector would not score against it, nor do they need to recognize it? True and False: 1. Inspectors cannot ‘score’ (i.e. downgrade) against disease not on the list (i.e., Alternaria leaf spotting or White mold), …however we can decline certification if these diseases become so severe that they may mask other ‘score-able’ diseases or is a quarantinable disease 2. The Oregon standards state “Lots showing a disease new or uncommon to Oregon may have certification withheld pending further investigation”

What caused these? Why would a harvest inspector need to know what caused it?

Certified Seed = Quality Seed? Certified Seed is part of a Quality Seed Program