Seed potato certification is the process of assuring the quality of seed potatoes being marketed, usually done nationally according to regulated standards. Planting healthy seed potatoes is a key factor in maximizing the production of usable potatoes for consumption or processing. The
United Nations Economic Commission for Europe (UNECE) has drawn up an international-reference quality Standard for Seed Potatoes to help producers do exactly this.
The Standard sets out a common terminology and minimum requirements for certifying high-quality seed potatoes for international trade. It covers:
• varietal identity and purity
• genealogy and traceability
• diseases and pests
• external tuber quality and physiology
• sizing and labelling.
It is a marketing standard setting harmonized norms in quality requirements for seed potatoes. It supplements and supports other international seed potato phytosanitary standards and should be read in conjunction with, not in place of these; in particular ISPM 12 and ISPM 33.
The Standard defines minimum requirements at the exportcontrol point and prescribes tolerances for diseases, defects and faults in crop, lot or succeeding crop (direct progeny).

Contents

Introduction

Use of this Guide
Crop inspection procedures
Lot inspection procedures
UNECE classification scheme / Label colours

Fungal pathogens

Alternaria spp. / Early blight
Colletotrichum coccodes / Black dot
Fusarium spp. / Dry rot
Geotrichum candidum / Rubbery rot
Helminthosporium solani / Silver scurf
Phoma foveata / Gangrene (a dry rot)
Phytophthora erythroseptica / Pink rot
Phytophthora infestans / Late blight (foliage)
Phytophthora infestans / Late blight (tuber)
Polyscytalum pustulans / Skin spot
Pythium spp. / Watery wound rot (Leak)
Rhizoctonia solani / Stem canker / Black scurf
Sclerotinia sclerotiorum / White mould / Stalk break
Spongospora subterranea / Powdery scab
Synchytrium endobioticum / Wart disease
Verticillium spp. / Verticillium wilt

Viruses and viroids

Mild mosaic
Potato leafroll virus (PLRV)
Potato mop top virus / Spraing (PMTV)
Severe mosaic
Tobacco rattle virus / Spraing (TRV)
Tomato spotted wilt virus (TSWV)
PVYNTN / Potato Tuber Necrotic Ringspot Disease (PTNRD)
Potato spindle tuber viroid (PSTV)

Bacterial pathogens

Clavibacter michiganensis subsp. sepedonicus / Ring rot
Dickeya / Pectobacterium spp. / Blackleg
Ralstonia solanacearum / Brown rot
Streptomyces spp. / Common and netted scab
Potato stolbur
Witch’s broom
Zebra chip

Pests

Ditylenchus destructor / Root rot nematode
Globodera spp. / Potato cyst nematode (PCN)
Meloidogyne spp. / Root knot nematode
Agriotes / Tandonia / Arion spp. / Wireworms
Epitrix spp. / Potato flea beetle
Leptinotarsa decemlineata / Colorado beetle
Phthorimaea operculella / Tuber Moth

Other disorders

Chemical damage
Chilling injury / Frost damage
Growth cracks (present prior to harvest)
Damage
Misshapes / Secondary growth / Glassiness
Shrivelled tubers

Further reading

Download the book here 

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