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
Niederösterreichische Saatbaugenossenschaft reg.Gen.m.b.H.
Solanum lycopersicum L. · Tomato
Domaine Public (FR)
Solanum lycopersicum L. · Tomato
BURPEE NL B.V.
Solanum lycopersicum L. · Tomato
Domaine Public (FR)
Solanum tuberosum L. · Potato
BACIU ANCA-MIHAELAMIKE LUIZA
Capsicum annuum L. · Bell pepper
Gautier Semences SAS (FR)
Solanum tuberosum L. · Potato
Hodowla Ziemniaka Zamarte sp. z o.o. - Grupa IHAR
Hybrids between Citrus x aurantium L. x Citrus trifoliata L.
Castanea sativa Mill. · Sweet chestnut
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Prunus x fontanesiana (Spach) C. K. Schneid.
Lyle A. BROOKS (US)
Solanum tuberosum L. · Potato
R H Johansen
Solanum tuberosum L. · Potato
Landbrugets Kartoffelfond
Solanum tuberosum L. · Potato
Hodowla Ziemniaka Zamarte sp. z o.o. - Grupa IHAR
Solanum lycopersicum L. · Tomato
NEUMAN Seed International (US)
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum lycopersicum L. · Tomato
Domaine Public (FR)
Solanum lycopersicum L. · Tomato
BURPEE NL B.V.
Solanum tuberosum L. · Potato
Vesa Velhartice a.s.
Solanum tuberosum L. · Potato
Pomorsko Mazurska Hodowla Ziemniaka Sp.z o.o. z siedziba w Strzekecinie
Solanum lycopersicum L. · Tomato
SEMILLAS FITO, S.A.
Solanum tuberosum L. · Potato
Hodowla Ziemniaka Zamarte sp. z o.o. - Grupa IHAR
Solanum tuberosum L. · Potato
004. Dept. of Agriculture, Ireland
Solanum tuberosum L. · Potato
BRETAGNE PLANTS INNOVATION S.A.S.
Allium cepa L. var. cepa · Onion
SAKATA SEED SUDAMERICA LTDA