Apple Alternaria control

November 2021 | Stephen Tancred | Future Orchards® slides

Alternaria leaf blotch and fruit spot can become a serious problem in susceptible apple blocks, particularly when warm, wet conditions favour disease development. Stephen Tancred’s presentation focuses on an integrated approach rather than relying on a single fungicide response.

Management begins with reducing carry-over inoculum. Orchard sanitation, including breakdown or removal of infected leaves and pruning material, helps reduce the disease pressure entering the next season. Monitoring leaves through spring and summer is also important because early lesions can indicate whether additional protection is needed.

Fungicide timing should reflect disease risk, block history, cultivar susceptibility and weather. The broader Australian IPDM guidance associated with this topic recommends early protection where risk is high and consideration of late-season protection when pre-harvest fruit infection is a concern.

The resource also reinforces the importance of tree health and resistance management. Growers should use only currently registered products and follow label, withholding-period and mode-of-action guidance.

Australian guidance associated with the presentation also stresses that Alternaria management is multi-season work: lowering inoculum progressively and maintaining appropriate protection over several seasons is more realistic than expecting a single spray or single season to eradicate the problem.