RESISTANCE TERMINOLOGY AND CODES
Definitions of the terms describing the reaction of plants to pests1
In the information provided by the Seller, the following meaning is given to the terms below:• 'Susceptibility': the inability of a plant variety to restrict the growth and/or development of aspecified pest.
• 'Resistance': the ability of a plant variety to restrict the growth and/or development of a specified
pest and/or the damage it causes when compared to susceptible plant varieties under similar
environmental conditions and pest pressure.
Resistant varieties may exhibit some disease symptoms or damage under heavy pest pressure.
Two levels of resistance are defined:
i. High resistance (HR): plant varieties that highly restrict the growth and/or development of thespecified pest and/or the damage it causes under normal pest pressure when compared tosusceptible varieties. These plant varieties may, however, exhibit some symptoms or
damage under heavy pest pressure.
ii. Intermediate resistance (IR): plant varieties that restrict the growth and/or development of thespecified pest and/or the damage it causes, but may exhibit a greater range of symptoms or
damage compared to high resistant varieties. Intermediate resistant plant varieties will stillshow less severe symptoms or damage than susceptible plant varieties when grown undersimilar environmental conditions and/or pest pressure.
Varieties claiming the same level of resistance against a specific pest may exhibit a different
resistance response due to a different genetic background of a variety.
It is to be noted that if a resistance is claimed in a plant variety it is limited to the specified
biotypes, pathotypes, races or strains of the pest.
If no biotypes, pathotypes, races or strains are specified in the resistance claim for a variety, it isbecause no generally accepted or relevant classification of the biotypes, pathotypes, races or
strains of the cited pest exists. New biotypes, pathotypes, races or strains that may emerge are
not covered by the original resistance claim.
• 'Immunity': a plant variety is not subject to attack or infection by a specified pest.

1

FAO defines a pest as: any species, strain or biotype of plant, animal or pathogenic agent injurious to plants
or plant products.
Pathogens (microorganisms such as bacteria, viruses and fungi that cause a disease) are, therefore,included in the term ‘pest’.

Resistance codes
Resistances in our varieties are coded with a crop-specific resistance code (see the coding list on
this page for the explanations), unless indicated otherwise. In situations where a variety is resistant
to more than one pest, the individual resistance codes are separated by a semicolon (;).

SPC00240E / v. 61/3

Asparagus

CodeScientific nameEnglish common name

Pa

Puccinia asparagiRust

Bc

Botrytis cinerea

Botrytis blight

Sv

Stemphylium vesicarium

Purple spot

Xcc

Xanthomonas campestris pv. campestrisBlack rotAc

Albugo candida

White rust

FocFusarium oxysporum f. sp. conglutinans

Fusarium yellows

Hb

Hyaloperonospora brassicae

Downy mildew

Pyb

Pyrenopeziza brassicae

Light leaf spot

Mb

Mycosphaerella brassicicola

Ring spot

Ss

Sclerotinia sclerotiorum

White moldPb

Plasmodiophora brassicae

Clubroot

Vd

Verticillium dahliae

Verticillium wilt

Vl

Verticillium longisporum

Verticillium wilt

TtThrips tabaciThrips

Ad

Alternaria dauciAlternaria leaf blightAr

Alternaria radicina

Black rot

Cc

Cercospora carotae

Cercospora leaf blight

EhErysiphe heraclei

Powdery mildew

Ma

Mycocentrospora acerina

Liquorice rot

Ps

Pythium sulcatum

Cavity spot

Pv

Pythium violae

Cavity spot

Rc

Rhexocercosporidium carotae

Black spot

CtRLV

Carrot red leaf virus

Carrot red leaf

CMoV

Carrot mottle virus

Carrot mottle

Foa

Fusarium oxysporum f. sp. apii

Fusarium yellows and wilt

Sa

Septoria apiicola

Late blightVirus

CeMV

Celery mosaic virus

Celery mosaicVirus

TSWV

Tomato spotted wilt virus

Tomato spotted wilt

BCMNV

Bean common mosaic necrosis virus

Bean common mosaic necrosis

SBMVSouthern bean mosaic virus

Southern bean mosaic

BCMV

Bean common mosaic virus

Bean common mosaic

EpErysiphe polygoni

Powdery mildew

CMV

Cucumber mosaic virus

Cucumber mosaic

PRSV

Papaya ringspot virus

Papaya ringspot

WMV

Watermelon mosaic virus

Watermelon mosaic

ZYMV

Zucchini yellow mosaic virus

Zucchini yellows

Psl

Pseudomonas syringae pv. lachrymans

Angular leaf spot

CABYV

Cucurbit aphid borne yellows virus

Cucurbit aphid borne yellows

CMV

Cucumber mosaic virus

Cucumber mosaic

CVYV

Cucumber vein yellowing virus

Cucumber vein yellowing

CYSDV

Cucurbit yellow stunting disorder virus

Cucurbit yellow stunting disorder

PRSV

Papaya ringspot virus

Papaya ringspot

ZYMV

Zucchini yellow mosaic virus

Zucchini yellows

WMV

Watermelon mosaic virus

Watermelon mosaicCcu

Cladosporium cucumerinum

Scab and gummosis

Cca

Corynespora cassiicola

Corynespora blight and target spot

Gc

Golovinomyces cichorarearum

Powdery mildewPcu

Pseudoperonospora cubensis

Downy mildew

Px

Podosphaera xanthii

Powdery mildew

Fungi
Bacteria

Brassicas

Fungi

InsectFungi
CarrotVirus

Celery, Celeriac
Chicory (Radicchio
Rosso / Green Hearted
Chicory / Endive

Climbing Bean

Fungi

Virus
Fungi

Courgette (Zucchini)

Viruses

Bacteria

Viruses

Cucumber, Gherkin

Fungi

SPC00240E / v. 62/3

Leek, (Bunching) Onion,
Shallot

Code

Scientific nameEnglish common name

ApAlternaria porri

Purple blotch

FocFusarium oxysporum f. sp. cepae

Basal rot

Pd

Peronospora destructor

Downy mildew

Pp

Phytophthora porriWhite tip of leek

Pa

Puccinia allii

RustPtPyrenochaeta terrestris

Pink root

Tt

Thrips tabaci

ThripsBlBremia lactucae

Downy mildew

FolFusarium oxysporum f. sp. lactucae

Fusarium wilt

LMV

Lettuce mosaic virus

Lettuce mosaic

TBSV

Tomato bushy stunt virus

Lettuce die-backInsectNr

Nasonovia ribisnigri

Lettuce leaf aphid

FungusFungus

FomPc

Fusarium oxysporum f. sp. melonis
Plasmopara crustosa

Fusarium wilt
Downy mildew

Bacteria

Xcv

Xanthomonas campestris pv. vesicatoria

Bacterial spot

FungusPc

Phytophthora capsici

Phytophthora blightCMVCucumber mosaic virus

Cucumber mosaic

PVY

Potato Y virus

Potato YBPMoV*Bell pepper mottle virus

Bell pepper mottle

PaMMV*

Paprika mild mottle virus

Paprika mild mottle

PMMoV *

Pepper mild mottle virus

Pepper mild mottle

TMGMV*

Tobacco mild green mosaic virus

Tobacco mild green mosaic

TMV*

Tobacco mosaic virus

Tobacco mosaic

ToMV*Tomato mosaic virus

TmTobamo = viruses marked with *Ac

Albugo candida

Tomato mosaic
variety is resistant to specified
Tm codesWhite rust/blister

ForFusarium oxysporum f. sp. raphani

YellowsHb

Hyaloperonospora brassicae

Downy mildew

BNYVV
CMV

Beet necrotic yellow vein virus
Cucumber mosaic virus

Rhizomania
Cucumber mosaicCv

Cladosporium variabile

Leaf spotPfs
Pst
TLCV
TMV
ToMV

Peronospora farinosa f. sp. spinaciae
Pseudomonas syringae pv. tomato
Tomato leaf curl virus
Tobacco mosaic virus
Tomato mosaic virus

Downy mildew
Bacterial speck
Tomato leaf curl
Tobacco mosaic
Tomato mosaic

TSWV

Tomato spotted wilt virus

Tomato spotted wilt

TYLCV

Tomato yellow leaf curl virus

Tomato yellow leaf curl

Pf (ex Ff)

Passalora fulva (ex Fulvia fulva)

Leaf mold

Fol

Fusarium wilt

Pi

Fusarium oxysporum f. sp. lycopersici
Fusarium oxysporum f. sp. radicislycopersici
Phytophthora infestans

SsStemphylium solani

Gray leaf spot

Va

Verticillium albo-atrum and/or Verticillium
dahliaVerticillium wilt

Ma

Meloidogyne arenaria

Root-knot nematodeMi

Meloidogyne incognita

Root-knot nematode

Mj

Meloidogyne javanica

Root-knot nematode

Fon

Fusarium oxysporum f. sp. niveum

Fusarium wilt

Fungi

Insects
Fungi
LettuceMelon(Rooted) Parsley

Hot and Sweet PepperViruses

Viruses

Virus group code

RadishRed Beet
Spinach

Fungi
Virus
Virus
Fungi

VirusesTomatoFor
Fungi

Nematodes
Watermelon

SPC00240E / v. 6

Fungi

Crown and root rot
Late blight

3/3