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
Lars Naested
Solanum lycopersicum L. · Tomato
UO «BELORUSSKAYA GOSUDARSTVENNAYA ORDENOV OKTYABRSKOJ REVOLYUCII I TRUDOVOGO KRASNOGO ZNAMENI SELSKOXOZYAJSTVENNAYA AKADEMIYA» GNU «INSTITUT GENETIKI I CZITOLOGII NAN BELARUSI»
Solanum tuberosum L. · Potato
Saatzucht Hergen Berding
hybrids between Prunus avium and Prunus pseudocerasus
National Seed Development Organisation Ltd / East Malling Research Station
Solanum tuberosum L. · Potato
Instytut Hodowli i Aklimatyzacji Roslin Panstwowy Instytut Badawczy
Solanum tuberosum L. · Potato
Johannes Martinus Kannegieter (J.M. Kannegieter)
Glycine max (L.) Merr. · Soybean
W.G. Thompson & Sons Ltd (CA)
Medicago sativa L. · Alfalfa
HORTAG SEED CO.
Solanum tuberosum L. · Potato
Grocep S.I.C.A.
Solanum lycopersicum L. · Tomato
PNOS
Solanum tuberosum L. · Potato
HERVE DUBREUIL_
Solanum tuberosum L. · Potato
Bretagne-plants (FR)
Solanum tuberosum L. · Potato
Heinrich Böhm
Solanum tuberosum L. · Potato
Bretagne-Plants S.C.I.C.A.
Solanum tuberosum L. · Potato
BRETAGNE PLANTS INNOVATION S.A.S./Germicopa Breeding SAS
Medicago sativa L. · Alfalfa
NORTH AMERICAN PLANT BREEDERS
Solanum tuberosum L. · Potato
Wolfgang Walter
Capsicum annuum L. · Bell pepper
Francisco Miguel Hernandez Valverde
Glycine max (L.) Merr. · Soybean
USDA MAINE
Solanum tuberosum L. · Potato
SCOTTISH CROP RESEARCH INSTITUTE
Solanum tuberosum L. · Potato
VERShININ BORIS MIHAJLOVICh
Solanum tuberosum L. · Potato
BOERHAVE VOF
Lactuca sativa L. · Lettuce
Rijk Zwaan, NL
Solanum tuberosum L. · Potato
CECAB (FR)/Bretagne-plants (FR)