This is very early for first symptom development for these diseases and control measures are essential to protect fruit grown for the fresh fruit market. The most effective control of the summer disease complex including the pathogens causing decay is to apply protective fungicide sprays at intervals of not more than 14 days for complete sprays and 10 days for alternate side applications. In orchards with standard trees or trees that are difficult to thoroughly cover, it may be necessary to adjust sprayer ground speed, delivery rate per acre, or nozzle arrangement to assure complete coverage. Fruit susceptibility increases as the sugar content increases and the need for fungicidal protection increases as the interval to harvest decreases. One or two fungicidal applications during the harvest period may be needed if rain periods occur.
Brown rot is easier to control if inoculum levels are low.
Removing infected fruit from trees and orchard sites, especially on blocks of early varieties, is very beneficial for the more susceptible nectarines. There are many unanswered questions regarding the natural host range of PPV and whether aphids will naturally infect plants other than stone fruit. Since the beginning of summer we have been checking weed samples collected from sites adjacent to PPV infected orchards to determine if PPV has become naturally established in weeds. This information is essential to the success of the PPV eradication program. Alternatively, if eradication is not successful then it will be imperative to know which weeds can serve as natural virus reservoirs to develop an effective PPV management program.