Diseases
Phytophthora infestans
Late blight is a dangerous disease of solanaceous crops caused by an oomycete, which manifests as the appearance of spots on leaves, stems, and tubers. The development of the disease is triggered by high humidity and moderate temperatures, which can lead to significant crop losses.
Mentioned in descriptions 6 798 varieties reference book.
Affected plants develop dirty-brown spots, often accompanied by a whitish mold on the underside of the leaf, while elongated dark-brown spots appear on the stems. Tubers show hard, sunken brown spots, and the internal tissue exhibits a characteristic rust-brown discoloration upon cutting.
Epiphytotics develop under conditions of high air humidity around 90% and alternating warm days with cool nights. The presence of free moisture, such as dew or fog, is a critical factor for rapid spore germination, which allows the infection to spread across the field in 10–15 days.
In breeding, a distinction is made between specific vertical resistance, controlled by R-genes, and field horizontal resistance, which is considered more reliable due to its polygenic nature and ability to slow down pathogen development. Varieties are evaluated using a 9-point scale; however, the resistance level of the foliage does not always coincide with that of the tubers, requiring comprehensive analysis during variety testing.
Selection based on the description text, not official resistance ratings: such data is not available in registers. Mention indicates that the trait is discussed in the variety's sources; see the variety's profile for details on what is specifically stated.
Solanum tuberosum L. · Potato
CALEDONIA POTATO HOLDINGS LTD
Solanum tuberosum L. · Potato
Station de Recherche du Comité Nord G.I.E.
Solanum tuberosum L. · Potato
Bretagne-Plants S.C.I.C.A.
Solanum tuberosum L. · Potato
Germicopa SAS, FR
Medicago sativa L. · Alfalfa
CRIADERO EL CENCERRO
Capsicum annuum L. · Bell pepper
Bayer Holland B.V.
Solanum tuberosum L. · Potato
CALEDONIA POTATO HOLDINGS LTD
Solanum tuberosum L. · Potato
SARPO KFT
Solanum tuberosum L. · Potato
Germicopa Breeding S.A.S
Glycine max (L.) Merr. · Soybean
Syngenta participation AG
Solanum tuberosum L. · Potato
Bavaria Saat GbR
Solanum tuberosum L. · Potato
IPR B.V.
Allium porrum L. · Leek
NAPOLEONSWEG 152
Solanum tuberosum L. · Potato
Mencke Landbouw B.V.
Solanum lycopersicum L. · Tomato
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Solanum tuberosum L. · Potato
Averis Seeds B.V.
Solanum tuberosum L. · Potato
Averis Seeds B.V.
Capsicum annuum L. · Bell pepper
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Capsicum annuum L. · Bell pepper
RIJK ZWAAN ZAADTEELT EN ZAADHANDEL B.V.
Solanum tuberosum L. · Potato
Averis Seeds B.V.
Solanum tuberosum L. · Potato
Bavaria Saat GbR
Solanum tuberosum L. · Potato
Averis Seeds B.V.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Bayer Holland B.V.
Solanum tuberosum L. · Potato
P.Y. OD WERFF