Plant Pathology Infobytes
March 4, 1998
Mummified Fruit Removal - Important Step in Peach Brown Rot Control
There's nothing like producing your own crop of peaches, plums, and other fruits. However, if that harvest bounty is to be enjoyed, diseases and other pests have to be controlled. A good example is brown rot of peaches, plums, and nectarines.
Brown rot is "public enemy number one" for these fruit crops, but this disease doesn't have to stand in the way of a successful harvest provided a recommended brown rot management program is followed through the season.
The brown rot fungus attacks blossoms, twigs, and even branches early in the season, but the real damage occurs later in the season as fruit begin to ripen. Ripe fruit are especially susceptible to brown rot, and unless fruit are protected through fungicides sprays, an entire crop can be lost to this disease within a few days. This is especially true in rainy seasons, when the brown rot fungus is more likely to cause problems.
Brown rot tends to start early in the season and fungicide sprays beginning bloom time are important steps in getting a handle on this disease. However, there's another important brown rot control step that's often overlooked and should be carried out before the bloom season arrives. This step is mummy removal.
Just what is a mummy? A mummy is nothing more than a dried up peach, plum, or nectarine fruit remaining from the previous season. Mummy removal is important because many of the brown rot fungus spores which kick off the disease cycle in the spring come from mummies. It is these spores which infect blossoms and other peach, plum, or nectarine susceptible tissues at the beginning of the season during periods of rainy weather.
Mummy removal is going to be important this season if the current wet weather pattern continues. Mummies should be raked from beneath trees (it may be necessary to use the rake handle to knock off a few that are still clinging to branches) and destroyed by burning or burial.
Removal of these structures is one of the single most important sanitation practices that can be carried out in home peach production, since it results in the removal of so much fungus inoculum from the orchard.
Peaches, plum, and nectarines aren't the only fruit crops which produce mummies, and dried-up apple and grape fruit from last season should also be removed from the orchard. This will reduce the amount of bitter rot and other fruit and foliage diseases, and removal of clinging bunch grape clusters from last season has been shown to help reduce black rot.
Of course mummy removal alone won't completely eliminate any of the fruit diseases previously mentioned, but used in conjunction with other control measures, it sure helps!
For the a complete listing of the steps which should be carried out in a control program for peach brown rot, as well as the disease of other orchard crops, check by your county Extension office and ask for publications on controlling disease and insect pests in home orchards. These publications are free and contain information which will increase your chances of producing higher quality fruit harvests.
Infobytes newsletter was written by the late Dr. Frank Killebrew, Extension Specialist.