American brown rot control in cherries
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
American brown rot management is becoming increasingly important as the sugar content in the fruit begins to build and cherries begin to color. Spore production is greater between 59°F and 74°F than at cooler temps, and the optimal temperature for infection is between 67°F and 77°F. Although injury to the fruit may lead to increased infection, the brown rot fungus readily infects when no wound or fruit-to-fruit contact is present. Under ideal conditions, spore production can occur within as few as three days, allowing for epidemic outbreaks after a very short period of time.
American brown rot management includes the application of a fungicide two to three weeks before harvest, with subsequent applications every five to ten days. The spray interval is highly dependent on weather conditions and inoculum level. The fungicides labeled for the control of brown rot are listed in the table below. Just a reminder, most of these fungicides are sterol inhibitors (with the exception of Pristine) and therefore do not have activity again cherry leaf spot.
Dr. Sundin's work is funded in part by MSU's AgBioResearch.