Diseases
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.
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.
Solanum tuberosum L. · Potato
Victorian Department of Natural Resources and Environment
Malus domestica (Suckow) Borkh. · Apple
Purdue Research Foundation (US)
Solanum tuberosum L. · Potato
Real Potatoes Ltd
Solanum tuberosum L. · Potato
Christoph Gämperli
Malus domestica (Suckow) Borkh. · Apple
INCONNU (FR)
Malus domestica (Suckow) Borkh. · Apple
Station de Recherche York (US)
Malus Mill. · Apple
Cripps, John E.|Florent Park, Australia
Solanum tuberosum L. · Potato
G&C SCHAT - FOBEK
Malus domestica (Suckow) Borkh. · Apple
Plants for Europe Ltd
Solanum tuberosum L. · Potato
Josef Schwarzfischer^^^Adolf Kellermann
Malus domestica (Suckow) Borkh. · Apple
Lane W. David|Summerland, CA
Solanum tuberosum L. · Potato
SIMON BRUNIA
Solanum tuberosum L. · Potato
W. WEIBULL B.V.I.O.
Solanum tuberosum L. · Potato
KWEEKBEDRIJF ROPTA ZPC
Solanum tuberosum L. · Potato
Svalof Weibull AB
Solanum tuberosum L. · Potato
ZPC Portugal
Solanum tuberosum L. · Potato
ROCUS PIETER GRAVELAND
Solanum tuberosum L. · Potato
JANSEN A.
Solanum tuberosum L. · Potato
SAKA-RAGIS PFLANZENZUCHT GBR
Solanum tuberosum L. · Potato
RIAN STEKELENBURG / F. BORN_ / MARTIN F. W. JANSEN KLOMP
Solanum tuberosum L. · Potato
Kweekbedrijf D. Biemond B.V.
Solanum tuberosum L. · Potato
S.BRUNIA
Solanum tuberosum L. · Potato
ZPC
Solanum tuberosum L. · Potato
RIAN STEKELENBURG / F. BORN_ / MARTIN F. W. JANSEN KLOMP