Skip to content
agronom.cc cultivar database

Diseases

Scab

Scab is a group of crop diseases caused by fungi, actinomycetes, or plasmodiophoromycetes, manifesting as spots, ulcers, and deformations on vegetative and generative plant organs.

Mentioned in descriptions 12 064 varieties reference book.

Apple and pear scab affects leaves, flowers, ovaries, and fruits, manifesting as olive-colored spots with a velvety coating, which leads to fruit cracking and yield loss. In potatoes, several types of scab are distinguished: common scab, where ulcers appear on tubers, and powdery scab, characterized by the formation of warts that rupture into powdery ulcers, as well as root damage.

The development of the disease depends on environmental conditions: for fruit scab, high humidity and rainfall are favorable, while for potatoes, it depends on soil specifics (pH, temperature, and moisture). Varietal resistance is ensured by breeding based on major genes or their combinations. Absolutely immune varieties do not exist, so resistance often manifests as field resistance and depends on the climatic zone.

In variety trials, resistance is assessed visually using a scoring scale or in percentages under natural and artificial infection backgrounds. To increase the accuracy of breeding, molecular genetic marking is used, which allows for the detection of resistance genes by genotype, minimizing phenotypic evaluation errors.

Sources10

Breakdown by crop

Apple Scab 1 949 Potato Scab 1 000 Pear Scab 489 Apple Scab 238 Cucumber scab 197 Common Scab of Sugar Beet 34 Plum Scab 10 Peach Scab 9 Olive Leaf Spot 9 Pear Scab 8 Common Scab — Table Beet 8 Apricot Scab 7 Pear scab — Asian pear 7 Citrus Scab 5 Pear Scab — Asian Pear 5 Citrus Scab 3 Pecan Scab 3

Found in these crops

Apple 1 942 Potato 980 European pear 489 Cucumber 266 Apple 236 Sugar beet 33 European plum 10 Peach 9 Pear 8 Garden beet 8 Japanese pear 7 Apricot 7

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.

Virumgård

Active

Malus domestica (Suckow) Borkh. · Apple

1 record

Aneta

Withdrawn

Malus Mill. · Apple

SK
1 record

Aidared

Active

Malus domestica (Suckow) Borkh. · Apple

UA
1 record

Rosseau

Active

Malus Mill. · Apple

1 record

Rogo

Active

Malus domestica (Suckow) Borkh. · Apple

1 record

Amsel

Terminated

Solanum tuberosum L. · Potato

SK
1 record

Rival

Active

Malus domestica (Suckow) Borkh. · Apple

3 records

RGF 1

Active

Malus domestica (Suckow) Borkh. · Apple

1 record

Undine

Active

Malus domestica (Suckow) Borkh. · Apple

3 records

Jump to page 24 27 48 72 97 117 121 137 145