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 lycopersicum L. var. lycopersicum · Tomato
ISP QUEDLINBURG GERMANY
Solanum tuberosum L. · Potato
Federation des Syndicats Bretons (FR)
Solanum tuberosum L. · Potato
CHIRU SORIN CLAUDIUBOZESAN ION
Solanum tuberosum L. · Potato
APP Agroresursu un ekonomikas institūts
Solanum lycopersicum L. · Tomato
Thompson & Morgan (Ipswich) Ltd
Capsicum annuum L. · Bell pepper
UNITED GENETICS SEEDS CO
Solanum lycopersicum L. · Tomato
ARNDT| Dr. Hartmut Arndt
Capsicum annuum L. · Bell pepper
Bejo Zaden B.V.
Solanum tuberosum L. · Potato
Vilmorin SA (FR)
Solanum lycopersicum L. · Tomato
UNITED GENETICS SEEDS CO
Solanum tuberosum L. · Potato
Hodowla Ziemniaka Zamarte sp. z o.o. - Grupa IHAR
Cucumis sativus L. · Cucumber
Bayer Holland B.V.
Solanum lycopersicum L. · Tomato
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Solanum tuberosum L. · Potato
VOGEL JOSEF| Dr. Josef Vogel
Solanum tuberosum L. · Potato
J. Boer
Solanum tuberosum L. · Potato
Pomorsko Mazurska Hodowla Ziemniaka Sp.z o.o. z siedziba w Strzekecinie
Solanum lycopersicum L. · Tomato
ARCHE NOAH
Solanum lycopersicum L. · Tomato
Domaine Public (FR)
Solanum lycopersicum L. · Tomato
Daniela Ganeva, Stanislava Tileva, Galina Pevicharova
Solanum lycopersicum L. · Tomato
Graines Voltz (FR)
Solanum lycopersicum L. · Tomato
Gautier Semences SAS (FR)
Castanea sativa Mill. · Sweet chestnut
Solanum lycopersicum L. · Tomato
Vreugdenhil Breeding & Seeds B.V.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
VON SENGBUCH (DE)