Experience and science have shown that maintaining good hygiene in the garden significantly reduces incidence of disease. Cutting out and destroying diseased tissue as soon as it appears. Removing diseased leaves that have fallen as soon as possible. If fungal or bacterial diseased fruit, leaves or wood is left on the tree or the soil surface it will very quickly and easily re-infect healthy tissue. The disease spores will also overwinter and infect pruning cuts or even healthy new growth in spring.
Apart from damaged wood or pruning cuts, another entry point for disease is leaf scars—the area where the leaves were attached following autumn leaf fall in pip and stone fruit trees. It is a good idea to commence winter clean up sprays in autumn soon after leaf fall commences. The first spray at about 30% leaf fall and the second at about 95% leaf fall. This provides protection to the leaf scars resulting in less over wintering infection. These two autumn sprays can be followed by one in late winter and another early spring just prior to bud burst.
Spray with a combination of Copper and Mineral oil for your winter clean up.
No one thing will control pests and diseases, but a combination of best practices will minimise pests & diseases.
Each one of the following practices will contribute. Use as many of these as applicable.