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
HERMEZIU RADU
Solanum tuberosum L. · Potato
Potato Breeding & Consultancy (PBC)
Solanum tuberosum L. · Potato
Francis LEVIEIL (FR)
Solanum tuberosum L. · Potato
BRETAGNE PLANTS INNOVATION S.A.S.
Solanum tuberosum L. · Potato
IPR B.V.
Solanum tuberosum L. · Potato
Station de Recherche du Comité Nord G.I.E.
Solanum tuberosum L. · Potato
Pannon Egyetem Georgikon Mezőgazdaságtudományi Kar, Veszprém
Glycine max (L.) Merr. · Soybean
Semican INC (CA)
Prunus L. · Plum
GRASSELY| Charles Grassely c/o I.N.R.A. - Station de RecherchesFruitieres Mediterraneennes
Solanum tuberosum L. · Potato
JOGEVA PLANT BREEDING INSTITUTE
Glycine max (L.) Merr. · Soybean
UNIVERSITY OF INDIANA
Solanum tuberosum L. · Potato
Federation des Syndicats Bretons (FR)
Solanum tuberosum L. · Potato
Niederösterreichische Saatbaugenossenschaft reg.Gen.m.b.H.
Solanum tuberosum L. · Potato
Boerhave V.O.F.
Glycine max (L.) Merr. · Soybean
Syngenta participation AG
hybrids between Solanum lycopersicum L. and S. habrochaites S. Knapp & D.M. Spooner
VILMORIN, S.A.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
VARIOS OBTENTORES FRESA
Solanum tuberosum L. · Potato
Yosef Fohel`
Solanum tuberosum L. · Potato
Bretagne-Plants S.C.I.C.A.
Solanum tuberosum L. · Potato
van der Linden/Laurentius Gregorius Maria Hermus
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum tuberosum L. · Potato
Kmetijski Inštitut Slovenije (Agricultural Institute of Slovenia)
Solanum tuberosum L. · Potato
Selectiebedrijf Kooi B.V./Fobek B.V./P.K. Rispens
Glycine max (L.) Merr. · Soybean
Sylvain Legay