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Diseases

Leaf spot 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.

Sources10

Breakdown by crop

Found in these crops

Varieties that feature this in their description

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.

Maimu

Active

Malus domestica (Suckow) Borkh. · Apple

EE
3 records

Ory

Active

Petroselinum crispum (Mill.) Nyman ex A. W. Hill · Parsley

RO
2 records

Orelia

Terminated

Brassica napus var. napus · Rapeseed

IT
2 records

Lucas

Active

Pyrus communis L. · European pear

SI
2 records

Lomosa

Active

Beta vulgaris Sugar Beet Group · Sugar beet

DE
2 records

MH Irén

Active

Hordeum vulgare L. · Barley

SK
2 records

Minjona

Active

Prunus domestica L. · European plum

LV
2 records

Leona

Terminated

Beta vulgaris Sugar Beet Group · Sugar beet

DK
2 records

MB-24

Active

Juglans regia L. · Persian walnut

SI
2 records

Merapido

Active

Lolium multiflorum Lam. · Italian ryegrass

DE
2 records

Mutsu

Application submitted

Malus Mill. · Apple

SK
2 records

Kvilda

Active

Beta vulgaris Sugar Beet Group · Sugar beet

CZ
3 records

Kupka

Active

Beta vulgaris Sugar Beet Group · Sugar beet

CZ
2 records

Beta vulgaris Sugar Beet Group · Sugar beet

RO
2 records

Murdoc

Active

Brassica oleracea L. (White Cabbage Group) · White cabbage

NL
2 records

Jukka

Active

Avena sativa L. · Oat

FI
3 records

Hordeum vulgare L. · Barley

CZ
5 records

Mašeka

Active

Ribes uva-crispa L. · Gooseberry

EE
3 records

Martinka

Active

Festuca arundinacea Schreb. · Tall fescue

CZ
2 records

x Triticosecale Wittm. ex A. Camus · Triticale

SK
3 records

Korok

Active

Avena sativa L. · Oat

CZ
3 records

Korino

Active

Brassica oleracea L. (White Cabbage Group) · White cabbage

CZ
2 records

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