Cicero
ActiveSolanum tuberosum L. · Potato
Mme R.M. Schouten (NL)/J.A. Crebas (NL)
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
Mme R.M. Schouten (NL)/J.A. Crebas (NL)
Solanum tuberosum L. · Potato
VAN DER LEEST B^^^NAUTA J.G.
Solanum tuberosum L. · Potato
KWEEKBEDRIJF ROPTA ZPC
Solanum tuberosum L. · Potato
van der Zee, G. / van der Zee, Pieter
Solanum tuberosum L. · Potato
R.J. Mansholt's Veredelingsbedrijf
Solanum tuberosum L. · Potato
SOLANA DEUTSCHLAND GmbH
Solanum tuberosum L. · Potato
GERMIMCOPA BREEDING (GERMICOPA SAS)
Solanum tuberosum L. · Potato
J.P.M.Muijsers
Solanum tuberosum L. · Potato
KWEEEKBEDRYJF ROPTA-ZPC
Solanum tuberosum L. · Potato
VAN RIJN-KWS B.V.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
UNIVERSITY OF CALIFORNIA WOLFSKILL EXPERIMENTAL ORCHARD
Solanum tuberosum L. · Potato
WESTMAAS| Arie Westmaas
Solanum tuberosum L. · Potato
S.HARTMANS/C.MEIJER BV
Solanum tuberosum L. · Potato
Solana Agrarproducte GmbH & Co
Solanum tuberosum L. · Potato
P.G. KONSTZWAANSHOGK (AGRICO)
Solanum tuberosum L. · Potato
WOLF&WOLF
Solanum tuberosum L. · Potato
ROSEFIELD FARM
Solanum tuberosum L. · Potato
Teagasc Oak Park Research Centre
Solanum tuberosum L. · Potato
Solana Agrar Proukte GmBH & Co.
Solanum tuberosum L. · Potato
Meijer C. BV (NL)
Solanum tuberosum L. · Potato
Tjerk Krijthe
Solanum tuberosum L. · Potato
Germicopa SAS, FR
Rubus idaeus L. · Red raspberry
Promo-Fruit, CH
Solanum tuberosum L. · Potato
MARIEN WINTERS