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.
Hordeum vulgare L. · Barley
NORDSAAT Saatzucht GmbH Frau Dr. Lissy Kuntze
Hordeum vulgare L. · Barley
Claus Einfeldt
Lolium perenne L. · Perennial ryegrass
Ampac Seed company (US)
Cucumis sativus L. · Cucumber
SYNGENTA SEEDS B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
STRUBE D and S GMBH
Beta vulgaris Leaf Beet Group · Swiss chard
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
DLF Beet Seed APS
Phaseolus vulgaris L. · Common bean
Seminis Vegetable Seeds
Beta vulgaris Sugar Beet Group · Sugar beet
Lindroos Erik
Solanum lycopersicum L. · Tomato
Syngenta Crop Protection AG
Festuca arundinacea Schreb. · Tall fescue
PICKSEED WEST INC
Spinacia oleracea L. · Spinach
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Solanum lycopersicum L. · Tomato
Monsanto, NL
Beta vulgaris Sugar Beet Group · Sugar beet
Dr. Herman Strube
Trifolium pratense L. · Red clover
M. Strukcinskas, A. Svirskis,
Brassica napus var. napus · Rapeseed
M A Pickford
Hordeum vulgare L. · Barley
ROBERTSON| M.A. Robertson c/o Nickerson (UK) Limited
Hordeum vulgare L. · Barley
SECOBRA Saatzucht GmbH Herrn Hubert Bluemel - Betriebsstaette -
Lolium perenne L. · Perennial ryegrass
Barenbrug Holland B.V.
Cydonia Mill. · Quince
Cucumis sativus L. · Cucumber
RIJK ZWAAN ZAADTEELT EN ZAADHANDEL B.V.
Hordeum vulgare L. · Barley
Eberhard Laubach
Fragaria x ananassa Duchesne ex Rozier · Garden strawberry
Shahrokh Khanizadeh
Hordeum vulgare L. · Barley
Saatzucht Dr.J. Ackermann (DE)