Apple scab (Venturia inaequalis): Preventive measures in organic pome fruit production (Biofruitnet Practice Abstract)

Summary in the original language of the document

Applying a combination of preventive, protective and curative measures during the ascospores phase in spring efficiently decreases the risk of infection.
Practical recommendations
Preventive measures to avoid risk of infection:
• Varieties: Use scab-resistant/tolerant apple varieties, such as e.g. Story/Inored, Topaz, Opal, Ladina, or Santana
• Good plant aeration/site selection: Apple scab depends on leaf moisture for successful infection. There-fore, it is important to allow quick drying of the plants with well-lit and air-permeable canopies and planting systems. To do so:
• Align rows towards the main wind direction;
• Space plants widely;
• Prune trees and roots to achieve steady growth and a loose canopy.
Preventive measures to reduce inoculum and reduce the risk of infection:
Promotion of foliage decomposition in autumn/spring reduces the ascospores potential for the upcoming season. You can promote this via:
• Mechanical shredding of infected plant parts (fallen leaves) by tillage;
• Use of Vinasse in autumn at leaf fall (single application);
• Use a leaf vacuum cleaner to actively remove infested leaves from the tree strips within the orchards