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.
Brassica oleracea L. (Savoy Cabbage Group) · Savoy cabbage
Syngenta Seeds B.V.
Medicago sativa L. · Alfalfa
SCHITEA MARIADRAGAN LENUTA
Fragaria L. · Strawberry
Robert Hureau c/o S.C. Darbonne
Trifolium subterraneum L. · Subterranean clover
WESTERN AUSTRALIA,DEP.AGR
Festuca arundinacea Schreb. · Tall fescue
Loft's Seed Inc. (US)
Festuca arundinacea Schreb. · Tall fescue
PURE SEED TESTING
Phaseolus vulgaris L. · Common bean
Pop Vriend Research B.V.
Brassica oleracea L. (Savoy Cabbage Group) · Savoy cabbage
Syngenta UK Ltd
Lactuca sativa L. · Lettuce
Syngenta Seeds B.V.
Phaseolus vulgaris L. · Common bean
HM.CLAUSE
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Brassica oleracea L. (Brussels Sprouts Group) · Brussels sprouts
Syngenta Seeds B.V.
Beta vulgaris Sugar Beet Group · Sugar beet
STRUBE UK LTD
Hordeum vulgare L. · Barley
SEMILLAS BATLLE, S.A.
Hordeum vulgare L. · Barley
ERHARDT EGER
Solanum lycopersicum L. · Tomato
Rijk Zwaan Zaadteelt en Zaadhandel BV (NL)
Hordeum vulgare L. · Barley
VASILESCU LILIANAPETCU EUGEN IULIANBUDE ALEXANDRU
Glycine max (L.) Merr. · Soybean
Sonets` Viktor Andriiovych, Pylypchenko Andrii Vasylovych, Tymchenko Viktor Naumovych, Marc Ham, Andre Letourneau, Alie Leturno,
Beta vulgaris Leaf Beet Group · Swiss chard
Rijk Zwaan Zaadteelt en Zaadhandel B.V.
Agrostis stolonifera L. · Creeping bentgrass
Texas Agricultural Experiment Station
Medicago sativa L. · Alfalfa
CRIADERO EL CENCERRO
Lolium perenne L. · Perennial ryegrass
Semences De France (FR)
Hordeum vulgare L. · Barley
Muranyi Istvan / Szalai Gyoergy / Harangi Laszlo
Brassica oleracea L. (Brussels Sprouts Group) · Brussels sprouts
A L TOZER LTD