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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.

Black Stallion

Application submitted

Lolium perenne L. · Perennial ryegrass

CZ
1 record

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

1 record

Avira

Withdrawn

Brassica napus var. napus · Rapeseed

DE
1 record

Sieger

Active

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

2 records

Sayra

Terminated

Hordeum vulgare L. · Barley

1 record

Rubin

Active

Fragaria x ananassa Duchesne ex Rozier · Garden strawberry

2 records

ROTET

Active

Ribes L. · Currants

1 record

Taylor

Active

Rubus idaeus L. · Red raspberry

2 records

ROSETTA

Active

Ribes L. · Currants

1 record

Adeline

Terminated

Brassica oleracea L. (Brussels Sprouts Group) · Brussels sprouts

NL
1 record

Juglans regia L. · Persian walnut

1 record

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