Wounds or breaks in the epidermis are necessary for the fungus to penetrate. They are then washed and rain-splashed to other parts of the tree throughout the summer. Apple fruits may become infected fairly early in the season, but rotting does not develop much until the fruit is almost mature. The development of Botryosphaeria canker and fruit rot is favored by any condition that reduces tree vigor. Control Control of white rot is best achieved through an integrated program of cultural practices and chemical control measures.
Sanitation is critical for effective control.
Piles of prunings are an important source of inoculum and should be removed from the perimeter of the orchard or burned. Prunings can be left on the orchard floor if they are chopped with a flail mower, which removes much of the bark and allows them to decompose faster. Removal of mummified apples and pruning out dead wood in the tree are important for reducing the inoculum within the tree. Pruning out current-season shoots infected with fire blight is also important, because they can be colonized and serve as an inoculum source during the same growing season. Any practice that helps to maintain trees in a healthy, vigorous condition is critical for controlling the canker phase of the disease.