Diseases
Peronosporaceae
Downy mildew is a dangerous plant disease caused by oomycetes under high humidity conditions. It manifests as a characteristic growth on the underside of leaves and spotting, which leads to rapid death of vegetative mass and yield reduction.
Mentioned in descriptions 16 384 varieties reference book.
Downy mildew is a group of diseases caused by specialized oomycetes. The disease manifests as the appearance of yellowish or brown angular spots on the upper side of the leaves, delimited by veins. On the underside of the leaf, under humid conditions, a characteristic grey-violet, white, or bluish fuzzy growth forms. Pathogen development leads to yellowing and drying of leaves, stunting of plants, and deformation of fruits, which, in the case of high pathogen aggressiveness, can lead to crop death in a short period.
Disease development depends directly on meteorological conditions and agronomic practices. The pathogen prefers a cool, humid environment, with critical risk factors being heavy dew, fog, prolonged rain, high air humidity, and crop density. Optimal conditions for infection include nighttime temperatures in the range of +13…+20°C and the presence of droplet moisture on the leaf surface for more than 6 hours.
Assessment of variety resistance during variety testing is based on phytopathological recording of the degree of leaf damage, specialized screening of collection samples, and molecular analysis methods using DNA markers to find genetic donors of resistance. In production, a distinction is made between genetically resistant varieties possessing specific Dm-genes and tolerant forms capable of maintaining yield under infection due to active vegetative mass formation. Since new pathogen races can overcome genetic resistance, varieties require regular monitoring and renewal.
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.
Lactuca sativa L. var. capitata L. · Head lettuce
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Helianthus annuus L. · Sunflower
Koval`ov Volodymyr Hryhorovych, Zaitsev Oleksii Borysovych,
Beta vulgaris Leaf Beet Group · Swiss chard
KWS VEGETABLES B.V.
Helianthus annuus L. · Sunflower
Kapustian Maryna Viktorivna, Kapustian Volodymyr Vasylovych,
Cucumis sativus L. · Cucumber
Seminis Vegetable Seeds
Lactuca sativa L. · Lettuce
MARALDI SEMENTI S.r.l.
Daucus carota L. · Carrot
Khans Kole
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Allium cepa L. · Onion
Willem van Haerke
Lactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
Cucumis sativus L. · Cucumber
PLANTICO HODOWLA I NASIENNICTWO OGRODNICZE ZIELONKI SP. Z O.O.
Lactuca sativa L. · Lettuce
Rijk Zwaan France SARL (FR)
Lactuca sativa L. var. crispa L. · Leaf lettuce
Kees Reinink
Lactuca sativa L. · Lettuce
Levantia Seed Srl (IT)
Helianthus annuus L. · Sunflower
Brahin Oleksandr Mykolaiovych, Veselyi Vitalii Oleksandrovych, Kuzmysheva Nadiia Viktorivna, Syvenko Valentyna Ivanivna, Kolomatska Valeriia Pavlivna, Makliak Kateryna Mykolaivna, Kyrychenko Viktor Vasylovych,
Helianthus annuus L. · Sunflower
Borovs`ka Iryna IUriivna, Leonova Nina Mykolaivna, Syvenko Oleksandr Anatoliiovych, Kuz`myshena Nadiia Viktorivna, Syvenko Valentyna Ivanivna, Kolomats`ka Valeriia Pavlivna, Makliak Kateryna Mykolaivna, Kyrychenko Viktor Vasyl`ovych,
Vitis L. · Grapevine
Majer Janos / Gyoerffyne Dr. Jahnke Gizella / Knolmajerne Szigeti Gyoengyi / Nemeth Csaba
Vitis L. · Grapevine
Majer Janos / Gyoerffyne Dr. Jahnke Gizella / Knolmajerne Szigeti Gyoengyi / Nemeth Csaba
Helianthus annuus L. · Sunflower
KOIPESOL SEMILLAS, S.A.
Vitis vinifera L. · Common grape vine
LAND RHEINLAND OPPENHEIM| Land Rheinland-Pfalz, vertreten durch das DLR Rheinhessen-Nahe-Hunsrueck Dienstsitz Oppenheim
Lactuca sativa L. · Lettuce
Barb Neubert
Lactuca sativa L. · Lettuce
Levantia Seed Srl (IT)
Cucumis sativus L. · Cucumber
Barbara Khrzhanovs`ka, Yezhy Matchak, Tereza Bartlomiieschak,
Ocimum basilicum L. · Basil
LA SEMIORTO SEMENTI SRL