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
SAATZUCHT FRITZ LANGE KG, DE
Solanum tuberosum L. · Potato
R.P.GRAVELAND
Solanum tuberosum L. · Potato
Heinrich BOHM, DE
Solanum tuberosum L. · Potato
Teagasc Oak Park Research Centre
Solanum tuberosum L. · Potato
Gisele Lairy-Joly, Gisele Lairy-Joly, Germicopa Breeding, France
Solanum tuberosum L. · Potato
RICHARD MOOIJWEER
Solanum tuberosum L. · Potato
Winfried Lange, Frank Lange
Solanum tuberosum L. · Potato
LAIRY-JOLY Gisele
Solanum tuberosum L. · Potato
Station de Recherche du Comité Nord G.I.E.
Solanum tuberosum L. · Potato
Jan Boer
Solanum tuberosum L. · Potato
DOUGLAS HARLEY
Solanum tuberosum L. · Potato
Ytzen Pieter van der Werff^^^HZPC Holland B.V.
Solanum tuberosum L. · Potato
MARIEN WINTERS
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
The Regents of the University of California
Solanum tuberosum L. · Potato
UNICOPA/CLAUSE
Solanum tuberosum L. · Potato
Hodowla Ziemniaka Zamarte sp. z o.o. - Grupa IHAR
Solanum tuberosum L. · Potato
Selectiebedrijf KOOI (NL)
Solanum tuberosum L. · Potato
W. WEIBULL B.V.
Allium porrum L. · Leek
Bejo Zaden BV (NL)
Solanum tuberosum L. · Potato
Dunnet, J.
Solanum tuberosum L. · Potato
Soltau-Bergen eG
Solanum tuberosum L. · Potato
UNIPLANTA
Solanum tuberosum L. · Potato
UNICOPA (FR)/Clause Semences SA (FR)
Solanum tuberosum L. · Potato
VOGEL JOSEF