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.
Vitis vinifera L. · Common grape vine
Miroslav Ivanov, Zdravko Nakov, Vanyo Haygarov
Cucumis sativus L. · Cucumber
Instytut Warzywnictwa im. Emila Chroboczka
Vitis vinifera L. · Common grape vine
BRUNEL Rene (FR)
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. · Common grape vine
ESTACION EXPERIMENTAL AGROPECUARIA INTA RAMA CAIDA (AR)
Helianthus annuus L. · Sunflower
Levchenko Valentyna Ivanivna, Shuhurova Nataliia Oleksiivna, Odynets` Serhii Ivanovych, Sereda Valentyna Oleksiivna, Shudria Larysa Ivanivna, Kutischeva Nataliia Mykolaivna,
Vitis vinifera L. · Common grape vine
Dr. Norbert Becker im Staatl. Weinbauinstitut
Allium cepa L. · Onion
Fesenko Ihor Valeriiovych, Pozniak Oleksandr Vasyl`ovych, Fesenko Liubov Petrivna,
Vitis vinifera L. · Common grape vine
Valentin Blattner-Haefeli und Frau Silvia
Helianthus annuus L. · Sunflower
Pryvatne Pidpryiemstvo "NASINNEVE"
Vitis vinifera L. · Common grape vine
HÖHERE BUNDESLEHRANSTALT UND BUNDESAMT FÜR WEIN UND OBSTBAU
Vitis vinifera L. · Common grape vine
Prof. Dr. H. Becker
Vitis vinifera L. · Common grape vine
Z. Nakov, V. Valchev, M. Ivanov, V. Tsvetkov, V. Haygarov, T. Yoncheva
Helianthus annuus L. · Sunflower
Pioneer Hi-Bred International Inc (US)
Helianthus annuus L. · Sunflower
PIONEER HI-BRED INTERNATIONAL
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Lactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
Lactuca sativa L. · Lettuce
Gautier Semences SAS (FR)
Lactuca sativa L. var. crispa L. · Leaf lettuce
Kees Reinink
Helianthus annuus L. · Sunflower
Amelia Bertero
Allium cepa L. · Onion
BEJO ZADEN
Lactuca sativa L. · Lettuce
RAMIRO ARNEDO, S.A.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucumis melo L. · Melon
PEOTEC SEEDS SRL