Planning an orchard
When planning a new orchard, integrate measures which can reduce the incidence of apple scab in the long term, such as:
- Select less susceptible varieties.
- Plant more tolerant varieties in areas where tree foliage is likely to take longer to dry.
- Choose row directions to encourage foliage to dry quickly after rain.
- Avoid overhead irrigation systems.
- Choose a training/pruning system which allows for good air flow and spray penetration through the canopy.
- Avoid over-vigorous rootstocks.
- Avoid excessive application of nitrogen fertilisers.
- Design rows to allow the use of sweepers and flail mowers for orchard clean-up over winter.
Be aware that bird or hail netting can increase foliage drying time.
Organic orchards
Good orchard hygiene practices significantly reduce the incidence of primary infections in commercial organic orchards where apple scab is endemic. When planning an organic orchard, follow the recommendations listed above.
Diagnosis
DDLS - Plant pathology services (Tel: +61 (0)8 9368 3351) provides an identification service for apple scab and other diseases. Please note that this is a user pays service.
Samples collected in the field will keep under refrigeration for a few days with sheets of absorbent paper, in a sealed plastic bag.
Acknowledgements
This article is adapted from Farmnote 551 'Managing apple scab', written by Martine Combret and Paul Murphy.