Diseases
Leaf spot diseases are a group of fungal, bacterial, or viral disorders manifesting as tissue necrosis in the form of spots of various shapes and colors. Pathogen development leads to a reduction in photosynthetic leaf area, tissue deformation, and significant yield losses.
Mentioned in descriptions 15 926 varieties reference book.
Leaf spot diseases represent a collective group of conditions caused by fungi, bacteria, or viruses. The primary diagnostic symptom is the formation of spots of various colors—brown, yellow, black, or gray—on the leaf blades, ranging from small dots to extensive necrotic lesions with or without margins. Infection often originates in the lower leaf canopy and, if allowed to develop, leads to premature defoliation and overall plant weakening.
Disease progression depends on a combination of favorable meteorological factors, such as moderately warm temperatures and high humidity, as well as the agrotechnical background. Improper crop rotation and the retention of crop residues in fields contribute to the accumulation of inoculum and intensive infection of crops in subsequent seasons. The severity of disease manifestation correlates directly with pathogen aggressiveness and the degree of cultivar susceptibility, which can lead to a 20–30% or greater reduction in crop productivity.
Cultivar resistance to leaf spots is a genetically determined ability to maintain productivity under disease pressure. It can be specific, targeting particular pathogen races, or non-specific polygenic, providing complex protection. Resistance mechanisms include physical barriers, such as waxy coatings, and biochemical responses. During variety testing, resistance is evaluated under natural and artificial inoculation conditions using scoring scales to record the degree of necrosis and pathogen development.
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.
Lolium multiflorum Lam. var. westerwoldicum Wittm. · Westerwolds Ryegrass
DLF Seeds A-S, DK
Beta vulgaris Sugar Beet Group · Sugar beet
Florimond Desprez Veuve et Fils, FR
Solanum lycopersicum L. · Tomato
Vilmorin SA (FR)
Lolium perenne L. · Perennial ryegrass
PICKSEED WEST INC
Solanum lycopersicum L. · Tomato
GRAINES GAUTIER, S.A.
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE & CO.KGAA
Begonia L. · Begonia
Rohde, Hans-Joachim|Nurtingen, Federal Republic of Germany
Beta vulgaris Sugar Beet Group · Sugar beet
SAS Florimond Desprez Veuve & Fils
Ribes nigrum L. · Blackcurrant
SAZONOV FEDOR FEDOROVICh
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Lenkijos sodininkystės ir gėlininkystės institutas
Beta vulgaris Sugar Beet Group · Sugar beet
STRUBE GmbH&Co.KG, DE
Beta vulgaris Sugar Beet Group · Sugar beet
RENROFFI
Brassica oleracea L. (Broccoli Group) · Broccoli
DIAMOND SEEDS S.L.
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Nicola D'Ercole (IT)/Walther FAEDI (IT)/Pasquale ROSATI (IT)
Brassica napus L. · Rapeseed
Norddeutsche Pflanzenzucht
Hordeum vulgare L. · Barley
ROTHWELL PLANT BREEDERS (GB)/Nickerson SA (FR)
Vicia faba L. var. minuta (hort. ex Alef.) Mansf. · Tick Bean
P.H. Petersen Saatzucht Lundsgaard GmbH (DE)
Beta vulgaris Fodder Beet Group · Mangelwurzel
KWS SAAT SE & CO.KGAA
Brassica napus var. napus · Rapeseed
Monsanto Technology LLC (US)/Norddeutsche Pflanzenzucht Hans-Georg Lembke KG (DE)
Beta vulgaris Sugar Beet Group · Sugar beet
Betaseed
Triticum aestivum L. · Bread wheat
Heinrich Busch^^^Bernd Schlieter
Beta vulgaris Sugar Beet Group · Sugar beet
SPPS
Beta vulgaris Sugar Beet Group · Sugar beet
Henning Friehe
Beta vulgaris Sugar Beet Group · Sugar beet
SESVanderhave NV