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.
Beta vulgaris Sugar Beet Group · Sugar beet
SESVanderhave NV
Helianthus annuus L. · Sunflower
RAGT 2N S.A.S
Beta vulgaris Sugar Beet Group · Sugar beet
Florimond Desprez Veuve et Fils, FR
Zea mays L. · Maize
NICKERSON| Nickerson S.A.
Solanum lycopersicum L. · Tomato
Seminis Vegetable Seeds
Hordeum vulgare L. · Barley
SECOBRA SAATZUCHT| SECOBRA Saatzucht GmbH
Veronica L. · Speedwell
POTTER| G.D. Potter c/o Rockhans-Nurseries
Trifolium hybridum L. · Alsike clover
Skriveri Research Centre
Phaseolus vulgaris L. · Common bean
Nunza B.V.
Triticum aestivum L. · Bread wheat
Lantmaennen ek foer
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Hordeum vulgare L. · Barley
Juha Uusitalo
Prunus salicina Lindl. · Japanese plum
WICKSON (US)
Hordeum vulgare L. · Barley
Unisigma GIE (FR)/Societe Europeenne de Semences NV/SA (BE)
Hordeum vulgare L. · Barley
NORDSAAT Saatzuchtgesellschaft mbH - Zuchtstation Gudow - Herrn Dr. Eberhard Laubach
Beta vulgaris Sugar Beet Group · Sugar beet
KWS SAAT SE and CO KGAA
Triticum aestivum L. · Bread wheat
Lietuvos agrarinių ir miškų mokslų centras
Brassica oleracea L. (Cauliflower Group) · Cauliflower
Vilmorin-Mikado
Capsicum annuum L. · Bell pepper
Enza Zaden Beheer B.V.
Brassica napus var. napus · Rapeseed
KWS SAAT SE&CO.KGaA, DE
Phaseolus vulgaris L. · Common bean
Syngenta Seeds
Hordeum vulgare L. · Barley
Plant Select Sro (CZ)
Beta vulgaris Sugar Beet Group · Sugar beet
Dietrich Hauer, Wolfgang Mechelke,
Hordeum vulgare L. · Barley
Hagberg, Arne