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
VAN RIJN-KWS B.V.
Solanum tuberosum L. · Potato
Z.P.C. /F.G. VAN DER ZEE /G. VAN DER ZEE /P.J. VAN DER ZEE
Solanum tuberosum L. · Potato
Yosef Fohel`
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
UNIVERSITY OF FLORIDA, GULF COAST RESEARCH STATION
Malus Mill. · Apple
RUP «BRESTSKAYA OBLASTNAYA SELSKOXOZYAJSTVENNAYA OPYTNAYA STANCZIYA NAN BELARUSI»
Solanum tuberosum L. · Potato
VAN RIJN-KWS B.V.
Solanum tuberosum L. · Potato
PLANT BREEDING INTERNATIONAL CAMBRIDGE
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Simpson David
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
UNIVERSITY OF FLORIDA, GULF COAST RESEARCH AND EDUCATION CENTER
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
The Regents of the University of California
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
The Regents of the University of California
Solanum tuberosum L. · Potato
SOLANA GMBH & CO KG
Solanum tuberosum L. · Potato
Jacob Eising
Hybrids between Prunus cerasus and Prunus canescens
Werner Gruppe|Hanna Schmidt
Solanum tuberosum L. · Potato
The State of Oregon
Malus Mill. · Apple
Horticulture Research International
Solanum tuberosum L. · Potato
A.FINDLAY
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Raggi Giordano, Marchetti Enrico, Musacchi Dario, Bernardini Danilo,
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Siboni Adriana, Raggi Giordano, Marchetti Enrico, Bernardini Danilo,
Hybrids between Prunus cerasus and Prunus canescens
Werner Gruppe|Hanna Schmidt
Solanum tuberosum L. · Potato
University of Idaho, Office of Technology Transfer
Rubus idaeus L. · Red raspberry
Washington State University Puyallup Research and Extension Center
Rubus idaeus L. · Red raspberry
Marina Gambardella, Pilar Banados, Javiera Grez, Elida Contreras, Pontificia Universidad Catolica de Chile
Malus Mill. · Apple
Terence Robinson, James Cummins, Herbert Sanders A.