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.
Trifolium pratense L. · Red clover
Lietuvos agrarinių ir miškų mokslų centras
Linum usitatissimum L. · Common flax
GIE Linea Semences de lin (FR)
Festuca pratensis Huds. · Meadow fescue
Lietuvos agrarinių ir miškų mokslų centras
Beta vulgaris Sugar Beet Group · Sugar beet
STRUBE D and S GMBH
Cucumis sativus L. · Cucumber
Enza Zaden Beheer B.V.
Solanum tuberosum L. · Potato
Syndicat des Producteurs de Plants (SYNPLANTS)
Phaseolus vulgaris L. · Common bean
Syngenta Seeds B.V.
Oryza sativa L. · Rice
RISO GALLO S.P.A.
Festuca arundinacea Schreb. · Tall fescue
Barenbrug Holland BV (NL)
Allium porrum L. · Leek
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Spinacia oleracea L. · Spinach
Pop Vriend Research B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
Betaseed
Delosperma nubigenum (Schltr.) L. Bolus · Hardy yellow ice plant
Koichiro Nishikawa
Hordeum vulgare L. · Barley
Borana Dyulgerova, Darina Dimova, Marina Gramatikova, Dragomir Valchev, Toshka Popova
Hordeum vulgare L. · Barley
DEUTSCHE SAATVEREDELUNG AG
Solanum lycopersicum L. · Tomato
Paul Zamudio
Triticum aestivum L. · Bread wheat
Wiersum Plantbreeding B.V.
Fragaria L. · Strawberry
F.M.S. DE PAUW
Bromus sitchensis Trin. · Alaska brome
RAGT 2N S.A.S
Triticum aestivum L. · Bread wheat
Lietuvos agrarinių ir miškų mokslų centras
Solanum lycopersicum L. · Tomato
HAZERA SEEDS BV
Phleum pratense L. · Timothy grass
P.Berzins, Sk.Bumane, v.Stesele
Cucumis sativus L. · Cucumber
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
SAS FLORIMOND-DESPREZ Veuve et Fils