Apple scab or Venturia inaequalis is a common fungus disease in Calgary, which affects trees in the Malus (apple) family. The disease causes yellow spots on fruits and twigs that turn black over time. Reinfestation takes place through wind and rain dispersal in the late spring after reproduction in the leaf litter over the winter.
Which of my trees should be inspected for Apple scab?
Apple Scab can affect all varieties in the Apple family – some are more prone to the disease than other varieties. Recently efforts are being made by fruit producers to create varieties that are more resistant to the disease.
Common symptoms linked to Apple scab are
Following pictures can help you determine if your tree is infected with Apple scab.
Can Apple scab be treated?
There are several measures that can be taken to control the affects of Apple scab.
Apple scab can be controlled by a wide variety of organic and non-organic chemicals. Applications should be done early in the year for optimum effect and minimal impact on birdlife and the environment.