Furthermore, removal of remaining fruit after final picking separates the practice of removing mummies from spring pruning. Alternatively, direct a sprayer nozzle downward so that thinned fruit receive some fungicide. In spring, monitor for blossom infection and prune out any cankers and infected shoots. In spring, just prior to and during the blossom period, examine the orchard floor for apothecia. Their presence requires that blossoms be thoroughly protected with fungicide sprays during wet periods.
Fungicides are to be applied prior to fungal infection that occurs during rain periods.
Blossom infections are controlled with two or three fungicide sprays during the bloom period, with the number of sprays often varying from year to year depending upon the weather, the susceptibility of the stone fruit species, the length of the bloom period and the type of fungicide. Sweet cherry is generally more susceptible than sour cherry, and nectarines are more susceptible than peaches. The preharvest period for stone fruits is especially susceptible to brown rot infection. Begin preharvest sprays when the fruit begin to color, about 3 weeks before harvest. Controlling insects, especially those that directly injure fruit, will help prevent infection.