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
University of Pannonia,Potato Research Centre (HU)
Fragaria L. · Strawberry
Ronald J. McNicol
Solanum tuberosum L. · Potato
QVFOODS FLEET ESTATE OFFICE
Solanum tuberosum L. · Potato
Winfried Lange, Frank Lange
Solanum tuberosum L. · Potato
NORIKA Nordring- Kartoffelzucht- und Ver
Solanum tuberosum L. · Potato
UNICOPA/CLAUSE
Solanum tuberosum L. · Potato
Wolfgang Walter
Solanum tuberosum L. · Potato
Heinrich Böhm
Solanum tuberosum L. · Potato
Kweekbedrijf-Zpc (NL)
Solanum tuberosum L. · Potato
Kweek- en Researchbedrijf Agrico B.V.
Solanum tuberosum L. · Potato
Heinrich Böhm
Solanum tuberosum L. · Potato
Teagasc
Solanum tuberosum L. · Potato
PLANTERA SEED BV
Solanum tuberosum L. · Potato
GERMICOPA S.A.S
Solanum tuberosum L. · Potato
Teagasc Crops Research Centre
Solanum tuberosum L. · Potato
PLANT BREEDING INTERNATIONAL CAMBRIDGE
Solanum tuberosum L. · Potato
STET Holland BV, Netherlands
Solanum tuberosum L. · Potato
van Loon, J.P.
Solanum tuberosum L. · Potato
Ludwig Simon
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Solanum tuberosum L. · Potato
ROBERT HOOPES
Solanum tuberosum L. · Potato
Germicopa Breeding S.A.S
Solanum tuberosum L. · Potato
Nilsson, Bengt
Solanum lycopersicum L. · Tomato
Steven Schroeder