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.
Helianthus annuus L. · Sunflower
Posunko Anton Olehovych, Bushulian Oleh Volodymyrovych, Shatsman Dmytro Oleksandrovych,
Lactuca sativa L. · Lettuce
Syngenta Crop Protection AG
Allium cepa L. var. cepa · Onion
Seminis Vegetable Seeds
Nicotiana tabacum L. · Tobacco
Matiieha Ol`ha Omel`ianivna, Vasyliv Tamara Vasylivna, Savina Olena Ivanivna,
Lactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
Helianthus annuus L. · Sunflower
PIONEER HI-BRED INT
Pisum sativum L. · Pea
Yanivs`kyi Ihor Mykolaiovych, Bodnarenko Klavdiia Borysivna, Ukrainets` Viktor Valentynovych, Kaz`miruk Halyna Fedorivna, Stebnovs`ka Anzhela IAkymivna, Kaliuzhna Emiliia Al`oziivna, Kuz` Vasyl` Volodymyrovych, Rozvadovs`kyi Al`ozii Martynovych,
Lactuca sativa L. · Lettuce
Syngenta Crop Protection AG
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Allium cepa L. · Onion
Aiven Miller
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Impatiens walleriana Hook. f. · Busy Lizzie
Ball FloraPlant
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Allium fistulosum L. · Welsh onion
Shinji iioka
Cucumis sativus L. · Cucumber
Krylov Oleh Mykolaiovych, Borysov Oleksandr Volodymyrovych,
Vitis vinifera L. · Common grape vine
Dr. Bernd H.E. Hill c/o Staatl. Lehr-u.VA für Wein und Obstbau, Ref. Rebenzüchtung
Vitis L. · Grapevine
INCONNU (FR)
Lactuca sativa L. var. crispa L. · Leaf lettuce
Henk Driessen
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucumis sativus L. · Cucumber
Prutenskaia Nataliia Oleksiivna, Shamshyna Anna Viacheslavovna, Portiankin Alieksiei IEvhenovych, Havrysh Serhii Fedorovych,
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Helianthus annuus L. · Sunflower
Horbachenko Fedir Ivanovych
Vitis vinifera L. subsp. vinifera · Wine grape
Ivan D. Todorov
Spinacia oleracea L. · Spinach
Kees Reinink