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 tuberosum L. · Potato
R.J. Mansholt's Veredelingsbedrijf
Solanum tuberosum L. · Potato
BERNARD KRIJGER
Malus Mill. · Apple
NIAB EMR (GB)
Solanum tuberosum L. · Potato
CYGNET POTATO BREEDERS
Solanum tuberosum L. · Potato
M HIGGINS LTD
Solanum tuberosum L. · Potato
DR. LUDWIG SIMON
Solanum tuberosum L. · Potato
SARL L.S.A.
Medicago sativa L. · Alfalfa
Tom Damin, Pasture Genetics Pty Ltd
Solanum tuberosum L. · Potato
Wageningen UR Plant Breeding
Solanum tuberosum L. · Potato
Teagasc Crops Research Department
Trifolium resupinatum L. · Persian clover
SEEDCO
Solanum tuberosum L. · Potato
Kmetijski inštitut, SI
Solanum tuberosum L. · Potato
Justus Böhm
Solanum tuberosum L. · Potato
Landbrugets Kartoffelfond, Foraedlst., DK-7184 Vandel
Solanum tuberosum L. · Potato
Station de Recherche du Comité Nord G.I.E.
Solanum tuberosum L. · Potato
Fobek B.V./A. de Nijs & Zonen. BV/Handelmaatschappij Pars B.V.
Medicago sativa L. · Alfalfa
CSIRO TROPICAL AGRICULTURE
Solanum tuberosum L. · Potato
Germicopa SAS, FR
Solanum tuberosum L. · Potato
Grocep S.I.C.A.
Solanum tuberosum L. · Potato
Station du Comite Nord (FR)
Capsicum annuum L. · Bell pepper
Clause Vegetable Seeds
Solanum tuberosum L. · Potato
Niederösterreichische Saatbaugenossenschaft reg.Gen.m.b.H.
Pisum sativum L. · Pea
Stegmark, Rolf