#Ecosia als standardsuchmaschine apple cracked#

Affected tissues eventually may become distorted and puckered, and leaf lesions become cracked and torn. Ontogenetic resistance of older leaves, however, usually results in smaller lesions or no visible symptoms. Scab lesions that form on young leaves may expand to more than 1 cm in diameter. Lesions increase in size and become olive-colored and velvety as a result of asexual spore production (conidia) ( Figures 2 and 3). Early lesions appear 10 days later as lighter green areas compared to the surrounding leaf tissue. Apple leaf and fruit symptomsĪpple scab infections are initiated in early spring on emerging and young leaves. Petioles, flowers, sepals, pedicels, young shoots, and bud scales can also become infected. Symptoms and SignsĪpple scab results in symptoms on most upper plant parts, most notably leaves and fruit.

It is most serious in areas that have cool, wet spring weather and may not be economically important in warm and/or dry climates. Typical “scabby” lesions are diagnostic symptomsĪpple scab occurs everywhere in the world where apples are grown and results in more losses than any other apple disease. However, the apple scab pathogen will not infect pear, and the pear scab pathogen will not infect apple.

Pear ( Pyrus spp.) is infected by a related fungus, Venturia pirina, which causes similar symptoms.

HOSTS: Apples and flowering crabapples ( Malus spp.), hawthorn ( Crataegus spp.), mountain ash ( Sorbus spp.), firethorn ( Pyracantha spp.), and loquat ( Eriobotrya japonica).