Resistances keys

Out of courtesy to its website visitors, Vilmorin-Mikado offers a list of pest organism Codes. The purpose of this section is to clarify the different codes by crop. It is intended for professional users. Vilmorin shall not be held liable for any reason regarding the information provided in this section.


Abbreviation Pathogen Disease
Ad Alternaria dauci Late leaf blight
Ay Aster yellow Aster yellow
Cc Cercospora carotae Early leaf blight, Cercospora leaf spot
Ps Pythium sulcatum Cavity spot
Pv Pythium Violae Cavity spot
Eh Erysiphe heraclei Powdery mildew
Xhc Xanthomonas ortorum pv. Carotae (ex Xanthomonas campestris pv. Carotae) Leaf spots, Bacterial blight
Pt Pyrenochaeta terrestris Pink root
Co Colletotrichum orbiculare (ex Colletotrichum lagenarium) Anthracnose
Fom Fusarium oxysporum f. sp. melonis Fusarium wilt
Fon Fusarium oxysporum f. sp. niveum Fusarium wilt
Gc Golovinomyces cichoracearum (ex Erysiphe cichoracearum Powdery mildew
Px Podosphaera Xanthii (ex Sphaerotheca fuliginea) Powdery mildew
Vd Verticillium dahliae Verticillium wilt
CMV Cucumber Mosaic Virus Cucumber mosaic
WMV Watermelon Mosaic Virus Watermelon mosaic
ZYMV Zucchini Yellow Mosaic Virus Zucchini yellows
Bl Bremia lactucae Downy mildew
Fol Fusarium oxysporum f. sp lactucae Fusarium wilt
Nr Fusariosi della lattuga Lettuce leaf aphid
Fol Fusarium oxysporum f. sp. lycopersici Fusarium wilt
For Fusarium oxysporum f. sp. radicis lycopersici Fusarium crown and root rot
Ff Fulvia fulva  
M Meloidogyne arenaria, M. incognita, M. javanica Root-knot
Ma Meloidogyne arenaria Root-knot
Mi Meloidogyne incognita Root-knot
Mj Meloidogyne javanica Root-knot
Pc Phytophtora capsici Phytophtora blight, Buckeye fruit and root rot
Pl Pyrenochaeta lycopersici Corky root rot
PMMoV Pepper mild mottle virus Pepper mottle
Pst Pseudomonas syringae pv. tomato Bacterial speck
PVY Potato Y virus Potato Virus Y
S Stemphylium floridanum, S. solani, S. botryosum f. sp. lycopersici Leaf spot disease
Sbl S. botryosum f. sp. lycopersici Leaf spot disease
Sl Stemphylium lycopersici Leaf spot disease
Ss Stemphylium solani Leaf spot disease
Tm (TMV) Tobacco Mosaic Virus Tomato mosaic / Tobacco mosaic / Pepper mild mottle
ToMV Tomato Mosaic Virus Tomato mosaic
TSWV Tomato Spotted Wilt Virus Tomato spotted wilt
TYLCV Tomato Yellow Leaf Curl Virus Tomato yellow leaf curl
V Verticillium dahliae, Verticillium albo-atrum Verticillium wilt
Va Verticillium albo-atrum Verticillium wilt
Vd Verticillium dahliae Verticillium wilt
Ac Albugo candida White rust, White blister
For Fusarium oxysporum f. sp. raphani Yellows/ damping off
Pp Peronospora parasitica Downy mildew



Disease resistance

Resistance is the ability of a variety to restrict the growth and development of a specified pest or pathogen and/or the damage it causes when compared to susceptible plant varieties under similar environmental conditions and pest or pathogen pressure. Resistant varieties may exhibit some disease symptoms or damage under heavy pest or pathogen pressure.


Two levels of resistance are defined:

  • High/standard resistance (HR): plant varieties that highly restrict the growth and development of the specified pest or pathogen under normal pest or pathogen pressure when compared to susceptible varieties. These plant varieties may, however, exhibit some symptoms or damage under heavy pest or pathogen pressure.
  • Moderate/intermediate resistance (IR): plant varieties that restrict the growth and development of the specified pest or pathogen, but may exhibit a greater range of symptoms or damage compared to HR varieties. IR varieties will still show less severe symptoms or damage than susceptible varieties when grown under similar environmental conditions and/or pest or pathogen pressure.