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
Tovarystvo z obmezhenoiu vidpovidalnistiu «IEvrosem»
Helianthus annuus L. · Sunflower
Borovs`ka Iryna IUriivna, Petrenkova Vira Pavlivna, Shepilov Borys Petrovych, Satarov Oleksandr Zainulovych, Syvenko Oleksandr Anatoliiovych, Kuzmyshena Nadiia Viktorivna, Veselyi Vitalii Oleksandrovych, Syvenko Valentyna Ivanivna, Kolomatska Valeriia Pav
Helianthus annuus L. · Sunflower
Interstate Seed Co.
Lactuca sativa L. · Lettuce
Syngenta Crop Protection AG
Lactuca sativa L. var. capitata L. · Head lettuce
Rijk Zwaan B.V.
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V. (NL)
Lactuca sativa L. var. crispa L. · Leaf lettuce
Henk Driessen
Helianthus annuus L. · Sunflower
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Helianthus annuus L. · Sunflower
Euralis Semences
Lactuca sativa L. · Lettuce
MERIDIEM SEEDS S.L.
Lactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
Brassica napus L. · Rapeseed
Andrew Easton
Helianthus annuus L. · Sunflower
NORTHRUP KING
Cucumis melo L. · Melon
SEMILLAS FITO, S.A.
Vitis L. · Grapevine
Instytut Sadownictwa i Kwiaciarstwa im. Szczepana Pieniążka
Brassica oleracea L. (Broccoli Group) · Broccoli
Hari Besels
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Helianthus annuus L. · Sunflower
Csikasz Tamas / Walz Ilona / Takacs Laszlo / Meszaros Laszlo
Brassica napus var. napus · Rapeseed
Vyshnevs`kyi Serhii Pavlovych, Liudva Valentyna Volodymyrivna, Romanenko Mykola Maksymovych, Korniichuk Oleksandr Vasylovych, Vyshnevs`kyi Pavlo Ivanovych,
Helianthus annuus L. · Sunflower
Rene Baratin
Humulus lupulus L. · Common hop
GMELCH| Franz Gmelch / EHRMAIER| Herbert Ehrmaier
Helianthus annuus L. · Sunflower
Asgrow France SA (FR)
Vitis vinifera L. · Common grape vine
ZIMMERMANN DR.| Dr. Johannes Zimmermann
Helianthus annuus L. · Sunflower
DAKOTA UNIV.