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.
Glycine max (L.) Merr. · Soybean
RAGT 2N S.A.S
Glycine max (L.) Merr. · Soybean
Saatzucht Gleisdort, A
Pisum sativum L. · Pea
Wilbur-Ellis Company
Helianthus annuus L. · Sunflower
Lidea France SAS, FR
Glycine max (L.) Merr. · Soybean
Patrice Jeanson
Helianthus annuus L. · Sunflower
PIONEER OVERSEAS CORPORATION
Helianthus annuus L. · Sunflower
RAGT 2N S.A.S
Helianthus annuus L. · Sunflower
Euralis Semences
Lactuca sativa L. · Lettuce
Rijk Zwaan (NL)
Allium cepa L. · Onion
Syngenta Seeds BV (NL)
Raphanus sativus L. var. sativus · Radish
Nunhems, NL
Lactuca sativa L. · Lettuce
Nickerson Zwaan, NL
Brassica oleracea L. (Broccoli Group) · Broccoli
Bejo Zaden B.V. (NL)
Cucumis sativus L. · Cucumber
DE RUITER ZONE
Brassica napus var. napus · Rapeseed
Monsanto Technology, USA
Brassica napus L. · Rapeseed
Deutsche Saatveredelung AG., Lippstadt DE
Helianthus annuus L. · Sunflower
Syngenta Participations AG., Basel CH
Helianthus annuus L. · Sunflower
Syngenta Seeds S.A.
Brassica oleracea L. (Red Cabbage Group) · Red cabbage
Hazera Seeds B.V.
Cucumis sativus L. · Cucumber
Syngenta Seeds B.V.
Spinacia oleracea L. · Spinach
SUJIT THA
Helianthus annuus L. · Sunflower
Semences Cargill SA (FR)
Brassica oleracea L. (Broccoli Group) · Broccoli
Royal Sluis BV, NL-1600 AA Enkhuizen
Helianthus annuus L. · Sunflower
Rustica Prograin Genetique SA (FR)