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.
Corylus avellana L. · Common hazel
Rolf de Vries
Beta vulgaris Sugar Beet Group · Sugar beet
JOHANNES DIECKMANN
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GMBH and CO.KG
Beta vulgaris Sugar Beet Group · Sugar beet
Strube, D
Festuca arundinacea Schreb. · Tall fescue
Pickseed USA, Inc. & Rutgers, The State University of New Jersey
Phaseolus vulgaris L. · Common bean
Seminis Vegetable Seeds
x Festulolium Aschers. et Graebn. · Festulolium
DLF Seeds A/S
Hordeum vulgare L. · Barley
LIMAGRAIN
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Solanum lycopersicum L. · Tomato
Sakata Vegetables Europe, F
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Phleum pratense L. · Timothy grass
SCHUETZE| Dr. Ursula Schuetze in Fa. Saatzucht Leutewitz / POCIASK| Agr.Ing. M. Pociask c/o SHR Polanowice
Beta vulgaris Sugar Beet Group · Sugar beet
Stefaan Horemans
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Hordeum vulgare L. · Barley
KWS Lochow
Beta vulgaris Sugar Beet Group · Sugar beet
SESVANDERHAVE NV-SA, BE
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GMBH and CO.KG
Lolium perenne L. · Perennial ryegrass
WIJK| Dr. A.J.P. van Wijk c/o Limagrain Advanta Nederland B.V.
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Zea mays L. subsp. mays (Sweet Corn Group) · Sweet corn
MARK JONES
Hordeum vulgare L. · Barley
SECOBRA RECHERCHES S.A.S
Helianthus annuus L. · Sunflower
ZOLOTAREV KONSTANTIN MITROFANOVICh / YaKOVENKO ANATOLIJ ALEKSANDROVICh
Lactuca sativa L. · Lettuce
Rijk Zwaan Zaadteelt en Zaadhandel B.V.