Guidelines on Potato Seed Certification

Legal basis and policy objective

The Order is issued pursuant to the Implementing Rules & Regulations of R.A. 7308, the Seed Industry Development Act of 1992, specifically Chapter III, Article II, Section 3.
The Order is adopted upon approval of the National Seed Industry Council, which authorizes adoption of the certification guidelines for potato seeds.
The objective is to assure that high quality planting materials of superior varieties are produced.
The objective requires planting materials with known genetic identity and varietal purity, and with freedom from known systemic pests and diseases.

Definitions and certification classes

The Seed Certifying Agency is the National Seed Quality Control Services (NSQCS) under the Bureau of Plant Industry, Department of Agriculture, sanctioned as the Seed Certifying Agency in the country under R.A. 7308.
Seed means a vegetatively propagated tuber used for reproduction of the potato rather than the true seed specially produced from potato flowers.
Field Lot means a field intended for seed production, multiplication and certification.
Seed Lot means a specific quantity of potatoes harvested from a certified field lot.
Seed Grower means an accredited seed potato producer who may be an individual, cooperative, or corporation, and who has satisfied requirements under Administrative Order No. 36, Series of 2000.
Seed Inspector means a qualified person authorized by the Seed Certifying Agency to conduct field inspection and other certification services to accredited seed potato growers.
Basic seed (Go) means seed potatoes harvested from greenhouse production directly controlled by the originating/sponsoring institution or individual.
Foundation Seed (F1) means progeny of Go harvested from seed multiplication field, handled to maintain genetic purity and disease free plant.
Certified Seed (C1) means progeny of F1 harvested from seed production area, handled to maintain genetic purity and identity, and certified by NSQCS.
CII means progeny of Certified I or earlier generation.
CIII means progeny of Certified II or earlier generation.
Roguing means the removal and destruction of all diseased or undesirable plants of tubers/potatoes produced thereon.

Eligibility, application, and seed varieties

Only duly approved and registered varieties by the National Seed Industry Council (NSIC) are eligible for certification.
Only accredited seed potato growers are eligible to apply for certification.
Certification forms are available at the nearest Seed Quality Control Services Office.
A seed grower shall plant only one potato variety for seed purposes on the same field at any one time.
Seed growers produce certified seed potatoes only if they adopt the rules and regulations for seed production and are either:
- members of the Seed Potato Growers' Association, or
- individual growers operating in accordance with instructions and under supervision of an authorized representative of the Seed Certifying Agency.
Seed potato classes and quality standards are based on the results of field inspections and laboratory analysis.
Seed potatoes of the same variety and class for multiplication must be planted in the same field.

Field requirements and geographic/area standards

The minimum area for seed production is at least 0.5 hectare.
Field suitability must follow A.O. No. 36 Series of 2000, Section 5 through these standards:
- The field must be free from potato cyst nematode (PCN) or root knot nematode (RKN), and must have a maximum of 10 colony forming unit (10 cfu) per seed lot of bacterial wilt organism.
- A Certificate of soil analysis for potato cyst nematode and bacterial wilt organism from authorized disease Indexing Laboratories must be attached with the application for accreditation.
- The field must have been rotated, preferably with corn or other cereal crops or other non-solanaceous vegetables, for at least two (2) cropping seasons.
- The field must be accessible to seed storage facilities.
- Agro-climatic conditions must be appropriate, requiring elevation of at least 900 meters above sea level in Mindanao and 1800 meters in the Cordillera Administrative Region (CAR).
Where only part of a field fails to meet standards for field inspection, the other parts may be considered for certification if the parts conform to the prescribed requirements.
A seed production field must meet isolation requirements based on seed class relationships (see next section for the required distances).

Crop inspection schedule and isolation distances

Seed potato crops require proper marking (labels) that are easy to be recognized by seed inspectors.
The field label must contain the following:
- Grower
- Variety
- Origin (Place)
- Seed Class Planted
- Date of Planning
- Area (ha.)
Isolation requirements must be met as follows (distance between fields):
- Basic-to-foundation (2 meters)
- Foundation–Certified Seed (C1) (20 meters)
- Certified Seed (CII)–Certified Seed (CIII) (50 meters)
Seed inspectors must inspect the field at least three times during the crop season.
The inspection schedule is:
- 1st within 20–30 days after planting
  - Roguing must be carried out by the farmer continuously as early as disease symptoms appear and continues until vines close on the rows to maintain seed stock quality.
  - Diseased plants and off-types must be removed and destroyed.
- 2nd within 40–50 days after planting
  - Diseased plants and off-types must be removed and destroyed.
- 3rd within 60–75 days after planting
  - Random fork testing of stunted plants must be undertaken to determine presence of Potato Cyst Nematode (PCN) and/or root knot nematode (RKN).
Additional field inspections must be conducted to follow up roguing requirements and disease occurrence.
Seed inspectors must prepare preliminary field inspection reports and submit them to the concerned NSQCS.
Tuber samples for laboratory analysis, including disease indexing, must be collected and submitted by the seed inspector only when the seed crop passed field standards.

Laboratory sampling rules and field standards

Sampling must follow class-specific requirements.
Sample size and sampling procedures:
- Go
  - Sample size: not less than tubers per seed lot.
  - Tubers must be collected at random from each seed rack/bed.
  - Sample equals 1% of the population or not less than 50 tubers per seed lot, whichever is applicable.
- F1
  - Sample size: not less than 100 tubers per seed lot.
  - Tubers must be collected at random using a quadrant sampling scheme.
  - In each quadrant, a minimum of 25 tubers per quadrant must be collected.
  - Collection must pass through a Z-pattern to meet the required sample size.
- CI to CIII
  - Sample size: not less than 200 pieces of seed tubers per seed lot.
  - Tubers must be collected at random using a quadrant sampling scheme.
  - In each quadrant, a minimum of 50 tubers per quadrant must be collected.
  - Collection must pass through a Z-pattern to meet the required sample size.
Field standards use maximum permitted percentages for specific factors per class/inspection.
Maximum permitted varietal mixture is:
- For Go, F1, C1: 0 in 1st and 2nd inspections as shown in the table, and for C1 1st and 2nd as shown
- For C1 in 1st and 2nd inspections: 0.25 in the table, with the listed positions per inspection
- For CII and CIII: 0.75, 0.5, and 0 or 1.0, 0.5, 0.25 as shown for the 1st, 2nd, and 3rd inspections.
Maximum permitted values for other factors (including gap due to missing hills due to rouging, Rhizoctonia with rolling leaves, and severe virus diseases) follow the percentage caps stated in the tables for GO, F1, C1 (3 inspections) and for CII, CIII (1st/2nd/3rd inspections where shown).
The certification system includes inspection-based field standards for:
- Gap due to missing hills due to rouging
- Potato Cyst Nematode
- Root knot Nematode (RKN)
- Bacteria Wilt
- Black leg
- Rhizoctonia with rolling leaves
- Severe virus diseases

Post-harvest disease tolerance and seed size

Tuber samples from each field lot must be taken one week before harvest (when haulms are dried) by the seed inspector and must be submitted to the laboratory immediately for bacteria and virus testing.
Each sample must be accompanied by:
- a sample label
- the laboratory analysis report for bacteria and virus
- the final inspection report
Certified seed potato seed size must be 25–55 mm.
Post-harvest disease tolerance before storage end and before selling, expressed as percent by count per 100 tubers, must follow these limits:
- Dry rot/wet rot: 1
- External damages (cuts, bruises, insect damage, malformed tubers etc.): 5
- Scab (no more than 20% of tuber surface is attached): 5
- Black scurf (Rhizoctonia solani) (no more than 20% of tuber surface): 5
Seed tuber standards specify virus and bacterial tolerance requirements by class (Go, F1, CI, CII, CIII) including:
- Severe viruses (with named severe virus types PVLR and PVY and a listed category for mixed infections)
- Mild virus types including PVX, PVS, and PVM
- BW–Bacteria Wilt limits by class
- Nematodes: Cyst and or Root Knot limits by class
- Soft rot (Erwinia carotovora) limits by class
- Bacterial ring not (Clavibader michiganese) limits by class
- The tolerance percentages for each named virus/bacteria factor are set by class in the table.

Certification tags, verification, and seed fees

All seed stocks that pass certification must be officially tagged.
Tags serve as a guarantee of the seeds’ genetic identity, health condition, and varietal purity.
Certification tag color scheme is:
- Basic (Go): White
- Foundation (F1): Red
- Certified II (CII): Blue
- Certified III (CIII): Yellow
Certification tags must conform to standards set by the National Seed Industry Council, including color identification adopted in the country for all crops.
Tags must indicate:
- Crop/Variety
- Seed Grower Name
- Laboratory Name
- Lot Number
- Germination
- Date Tested
- Date Harvested
- Seed Inspector Name
NSQCS and accredited seed potato indexing laboratories provide services for which fees are payable by:
- seed growers
- farmer’s associations
- seed firms
Field inspection fees are based on a per unit area including 3 inspections during the cropping season:
- For 3 main field inspections
  - 0.5–1.0 ha: PHP 100.00
  - 1.0–1.5 ha: PHP 150.00
  - 1.5–2.0 ha: PHP 200.00
- Every additional field inspection: PHP 50.00
Certification fees include laboratory and tagging services:
- Laboratory analysis for Bacterial Wilt: PHP 200/sample
- Laboratory analysis for virus: PHP 300/sample
- Tags: PHP 2.00
The Seed Certifying Agency staff must conduct several field inspections during the cropping season to assure reliable field inspection work.
A representative of the Seed Certifying Agency must also check tagged seed stocks at unscheduled times before selling or distribution.

Compliance directive and transitory approvals

The Order requires compliance under a directive of “For your strict compliance.”
The guidelines are Adopted: 25 Oct. 2001.
BLO UMPAR ADIONG, Executive Director and Vice-Chairman, National Seed Industry Council, is shown as recommending approval.
The Order’s implementation is anchored on NSIC/NSQCS roles and on administrative guidance on certification, inspection, sampling, post-harvest standards, tagging, and fees.