Regretable, there are not sprays available for this disease and crop at present.
Cultural practise can help minimize the problem for next year. At this time of year the disease is established on the tree. It will be important to clear up as many of the infected leaves and fruit during the Autumn, removing them from the tree area.
Next season in March, as growth starts again, apply granular Miracle Gro Rose & Shrub continuous release plant food over the root system. This is a balanced feed with lots of potash that will help produce strong early growth that will help resist the disease spores.
Avoid the tree becoming stressed during the growing season, keep the soil moist and apply a liquid feed such as Levington Tomorite over the roots when the crop is developing.
Once the crop is picked carry out the hygiene routine of removing infected leaves and fruits that fall.