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.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Rubus idaeus L. · Red raspberry
Rubus idaeus L. · Red raspberry
Solanum tuberosum L. · Potato
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Solanum tuberosum L. · Potato
Solanum tuberosum L. · Potato
Solanum tuberosum L. · Potato
Solanum tuberosum L. · Potato
Capsicum annuum L. · Bell pepper
Medicago sativa L. · Alfalfa
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Citrus trifoliata L. · Trifoliate orange
Solanum tuberosum L. · Potato
University of Pannonia,Potato Research Centre (HU)
Solanum tuberosum L. · Potato
VERENIGDE KWEEKBEDRIJVEN (NL)
Solanum tuberosum L. · Potato
PRUMMEL (NL)
Solanum tuberosum L. · Potato
LAMSE J.J. (NL)
Solanum lycopersicum L. · Tomato
DE RUITER SEEDS
Solanum tuberosum L. · Potato
ZPC
Solanum tuberosum L. · Potato
SAS Bernard
Solanum lycopersicum L. · Tomato
ZERAIM GEDERA
Solanum tuberosum L. · Potato
Stephan Berger^^^JOSEF BERGER
Solanum lycopersicum L. · Tomato
keine Angabe
Solanum tuberosum L. · Potato
NIEHOFF| Dr. Karl-Heinrich Niehoff