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
LAND RHEINLAND OPPENHEIM| Land Rheinland-Pfalz, vertreten durch DLR Rheinhessen-Nahe-Hunsrueck Dienstsitz Oppenheim
Vitis vinifera L. · Common grape vine
IMIDRA - CCAA MADRID
Cucumis sativus L. · Cucumber
Yan Kulstra
Vitis vinifera L. · Common grape vine
Lykhovs`koi Volodymyr Volodymyrovych, Kotolovets` Zinaida Viktorivna, Poluliakh Alla Anatoliivna, Volynkin Volydymyr Oleksandrovych,
Lactuca sativa L. var. crispa L. · Leaf lettuce
OLAF ZONNEVELD
Humulus lupulus L. · Common hop
Chmelařský institut s.r.o. (CZ)
Lactuca sativa L. var. crispa L. · Leaf lettuce
Hellie Dodson
Helianthus annuus L. · Sunflower
Makov`eva Nadiia Petrivnav, Kusch Viacheslav Stepanovych, Herasymenko Oksana Oleksandrivna, Pershyna Liliia Vasylivna, Dymytrov Heorhii Demianovych, Skakun Vadym Mykhailovych,
Helianthus annuus L. · Sunflower
DAKOTA UNIV.
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Vitis vinifera L. · Common grape vine
N. Nedelchev, K. Stoev, M. Kondarev, Z. Zankov
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Helianthus annuus L. · Sunflower
INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE, FR
Vitis vinifera L. · Common grape vine
Institut National de la Recherche Agronomique (FR)/Sicarex Beaujolais (FR)
Vitis vinifera L. · Common grape vine
Dr. Norbert Becker im Staatl. Weinbauinstitut
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Lactuca sativa L. · Lettuce
Maraldi Sementi SRL (IT)
Lactuca sativa L. · Lettuce
Barb Neubert
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Humulus lupulus L. · Common hop
Herbert Ehrmaier
Vitis vinifera L. · Common grape vine
INCONNU (FR)
Cucumis melo L. · Melon
Ahmet Oktay Turhan
Humulus lupulus L. · Common hop
GMELCH| Franz Gmelch / EHRMAIER| Herbert Ehrmaier
Lactuca sativa L. · Lettuce
Gautier Semences SAS (FR)