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
Pajbjergfonden
Hordeum vulgare L. · Barley
Sejet Planteforaedling I,S
Poa pratensis L. · Kentucky bluegrass
Jonathan Green and Sons, Inc. and Cascade International Seed Company
Hordeum vulgare L. · Barley
Syngenta UK Ltd
Beta vulgaris Sugar Beet Group · Sugar beet
Syngenta Crop Protection AG, CH
Poa pratensis L. · Kentucky bluegrass
PICKSEED WEST INC
Spinacia oleracea L. · Spinach
Henk Driessen
Brassica oleracea L. (Cauliflower Group) · Cauliflower
RIJK ZWAAN Zaadteelt en Zaadhandel B.V.
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V. (NL)
Hordeum vulgare L. · Barley
Syngenta UK Ltd
Hordeum vulgare L. · Barley
W WEIBULL
Lolium perenne L. · Perennial ryegrass
VEREDELINGSBERIJF
x Triticosecale Wittm. ex A. Camus · Triticale
SAATZUCHT DR H C HEGE GBRMBH
Hordeum vulgare L. · Barley
Syngenta Participations AG
Hordeum vulgare L. · Barley
Syngenta Crop Protection AG
Hordeum vulgare L. · Barley
Syngenta Crop Protection AG, CH
Hordeum vulgare L. · Barley
Syngenta Crop Protection AG, CH
Poa pratensis L. · Kentucky bluegrass
Agroscope Reckenholz
Phaseolus vulgaris L. · Common bean
Vilmorin SA (FR)
Hordeum vulgare L. · Barley
Nissilä, Eero
Brassica oleracea L. (Cauliflower Group) · Cauliflower
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Trifolium pratense L. · Red clover
RAGT 2N S.A.S
Lolium perenne L. · Perennial ryegrass
R 2n (FR)
Avena sativa L. · Oat
Nordsaat Saatzucht GmbH, D-38895 Langenstein, OT Bohnshausen