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
SAKA PFLANZENZUCHT GMBH AND CO KG
Solanum tuberosum L. · Potato
R. L. J. MANSHOLT
Solanum tuberosum L. · Potato
GUUS HESELMANS
Solanum tuberosum L. · Potato
Teagasc Crops Research Centre
Solanum tuberosum L. · Potato
REITSMA BARTEL / JANSEN KLOMP MARTIN F.W.
Solanum tuberosum L. · Potato
Mr. J.J.H.M. Allefs
Solanum tuberosum L. · Potato
HESELMANS GUUS
Rubus idaeus L. · Red raspberry
The New Zealand Institute for Plant and Food Research
Vaccinium corymbosum L. · Highbush blueberry
Wagner L. Adam, Brazelton M. David
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
UNIVERSITY OF CALIFORNIA WOLFSKILL EXPERIMENTAL ORCHARD
Glycine max (L.) Merr. · Soybean
P. Jeanson
Solanum tuberosum L. · Potato
MR.E.A.BOERHAVE
Solanum tuberosum L. · Potato
Wolf Lange (DE)
Solanum tuberosum L. · Potato
OFFEREINS (NL)
Solanum tuberosum L. · Potato
The James Hutton Institute
Solanum tuberosum L. · Potato
P.I.J. VAN DER WERFF & COOP. DE Z.P.C.
Solanum tuberosum L. · Potato
SAKA-RAGIS PFLANZENZUCHT GBR
Solanum tuberosum L. · Potato
Veredelingsbedrijf B.V.
Solanum tuberosum L. · Potato
F.BRANDS
Solanum tuberosum L. · Potato
M. WINTENS_
Solanum tuberosum L. · Potato
Jack Dunnett
Solanum tuberosum L. · Potato
Wolfgang Walter
Solanum tuberosum L. · Potato
Heinrich Böhm
Solanum tuberosum L. · Potato
Saka Pflanzenzucht, D