Cultural control (Apple scab)

• Prune trees to allow good air circulation and rapid drying of leaves to reduce scab risk.
• Remove wood scab during winter pruning.
• After harvest and before leaf fall, apply a spray of 5% urea to the trees.  Urea encourages microflora that speed up leaf breakdown and increase the palatability of leaves to earthworms, which are mainly responsible for leaf litter disposal in orchards.
• Urea also directly affects the scab fungus by preventing formation of the sexual state.
• Earthworms remove leaf litter better from bare soil than from grass.  Therefore, keep the grass well mown to encourage earthworm activity.
• Mow leaves in autumn to macerate for more rapid leaf decomposition.  Maceration of leaves can decrease scab inoculum by up to 90%.
• Even where leaves are trapped in hedges maceration can reduce inoculum by 50-60%.
• Brushing machines can be used to sweep leaf litter from under trees into alley ways for maceration.
• Where leaf litter still remains in the spring or weather conditions have made action in the autumn impossible, mow to macerate leaves in spring.
• A spray of 5% urea to leaf litter in spring will also encourage leaf rotting and prevent ascospore release.