Apple Scab Variety Comparison
Prepared by Frank Zalom, Emily Symmes, Mark Henderson and Mark Bell, July 2009 - UC Davis
Apple scab (Venturia inaequalis) occurs wherever apples are grown, but especially in areas with cool and moist climates. The fungal disease overwinters in leaf litter on the ground below trees. During spring rains, spores are released into the air and infect areas higher in the tree canopy. Leaves, petioles, twigs, and fruit may be infected. Leaves develop olive-green spots at the onset of infection; later spots appear dark green or black and velvety. Fruit spots become scab-like with age and fruit tissues may become misshapen.
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