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.
Cucumis sativus L. · Cucumber
Sakata Seed Corporation
Hordeum vulgare L. · Barley
SAATZUCHT JOSEF BREUN GmbH&Co.KG
Lolium perenne L. · Perennial ryegrass
PRODANA SEED A/S - DLF SEEDS A/S
Hordeum vulgare L. · Barley
Virágmag Kft., Szentgál
Beta vulgaris Sugar Beet Group · Sugar beet
Van der Have Sugarbeet (NL)
Hordeum vulgare L. · Barley
BUSCH AGRICULTURAL RESOUR
Beta vulgaris Sugar Beet Group · Sugar beet
MARIBO SEED INT. APS
Beta vulgaris Sugar Beet Group · Sugar beet
KWS Saat AG, DE
Beta vulgaris Sugar Beet Group · Sugar beet
Syngenta Crop Protection AG
Hordeum vulgare L. · Barley
Boreal Plant Breeding
Brassica napus var. napus · Rapeseed
Norddeutsche Pflanzenzucht Hans Georg Lembke KG,DE
Hordeum vulgare L. · Barley
Nordic Seed A/S
Daucus carota L. · Carrot
Bejo Zaden BV (NL)
Beta vulgaris Sugar Beet Group · Sugar beet
STRUBE HERMANN| Dr. Hermann Strube
Beta vulgaris Sugar Beet Group · Sugar beet
STRUBE GMBH AND CO. KG
Hordeum vulgare L. · Barley
Saatzucht Donau GmbH & Co.KG
Poa pratensis L. · Kentucky bluegrass
PRODANA| Prodana Seeds A/S
Brassica oleracea L. (Brussels Sprouts Group) · Brussels sprouts
Syngenta Seeds B.V. (NL)
Hordeum vulgare L. · Barley
Limagrain Europe S.A.S
Hordeum vulgare L. · Barley
SECOBRA RECHERCHES S.A.S
Cicer arietinum L. · Chickpea
Werner Horn
Hordeum vulgare L. · Barley
KWS MOMONT RECHERCHE SARL, FR
Allium porrum L. · Leek
Ger Beemsterboer
Helianthus annuus L. · Sunflower
Nicolae Boaghe, Elena Andreea Teodorescu