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
UNICOPA (FR)/Clause Semences SA (FR)
Solanum tuberosum L. · Potato
NIEUW-VENNEP
Solanum tuberosum L. · Potato
Saka Pflanzenzucht GmbH Co KG
Solanum tuberosum L. · Potato
Y P VAN DER WERFF
Rubus idaeus L. · Red raspberry
Thomas Amrhein, Mario Aguas, José Lopez
Solanum tuberosum L. · Potato
TEAGASC OAK PARK RESEARCH CENTRE,CARLOW, CO-CARLOW
Solanum tuberosum L. · Potato
Lantmõnnen Seed B.V.
Solanum tuberosum L. · Potato
University of Maine System Board of Trustees
Solanum tuberosum L. · Potato
TPC Research BV
Solanum tuberosum L. · Potato
ROCUS PIETER GRAVELAND
Persea americana Mill. · Avocado
The Regents of the University of California
Persea americana Mill. · Avocado
The Regents of the University of California
Solanum tuberosum L. · Potato
SAKA| SaKa Pflanzenzucht GbR
Solanum tuberosum L. · Potato
SOCIETE CLAUSE
Solanum tuberosum L. · Potato
ZPC
Solanum tuberosum L. · Potato
Lantmännen SW Seed
Solanum tuberosum L. · Potato
KUIK G. (NL)
Solanum tuberosum L. · Potato
UNIPLANTA| Uniplanta - Saatzucht KG
Solanum tuberosum L. · Potato
Landbrugets Kartoffelfond, Foraedlst., DK-7184 Vandel
Glycine max (L.) Merr. · Soybean
University of Guelph (CA)
Glycine max (L.) Merr. · Soybean
Semences Prograin, CAN
Solanum tuberosum L. · Potato
SELECTIEBEDRIJF LUIDENBURG BV
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Simpson David
Solanum tuberosum L. · Potato
J.A. Crebas (NL)