Clemson University scientists developed an agar-based assay to determine location-specific fungicide resistance profiles in Monilinia fructicola. It determines the sensitivity of local Monilinia populations to the four most commonly used fungicide classes (DMIs, BZIs, SDHIs and QoIs). Results are communicated with grower and county agents. The service helps growers to identify problem components in their spray program and improves preharvest and postharvest losses to disease. In addition, ‘Profile’ counteracts selection of pathogen populations for fungicide resistance, making disease management and the entire operation more sustainable for the future.
The situation in South Carolina is similar. Fungicide resistance is present in the main production areas. In 2009 we anticipated an epidemic from brown rot but it did not happen, likely because we identified high risk areas with the Profile kit and growers implemented crucial changes to their spray program, such as higher doses of fungicides or switching to a mode of action that works better. I would estimate that we would have lost about 10%-15% of our total production (includes pre and postharvest losses) if the Profile monitoring program had not been used. We total about $70 million annually, so the savings would be anywhere from $7 to $10.5 million (Dr. Guido Schnabel, Clemson University).
The service has since been applied to samples from Maryland and Pennsylvania.
Profile - An Agents Perspective: "The profile kit was very easy to use and provided a timely response to suspected resistance problems. Problems were easily identified by viewing the petri dishes. This past year we did have some trouble finding enough fruit to have an accurate sample. Bacterial contamination is a definite possibility if you are not careful in your procedure. Whatever you do, don't forget to check it on time. Some of the contaminants grow very quickly and can cloud results if not viewed when they are supposed to be. All in all the system works but will take up some of your time getting used to the procedure." -Andy Rollins, County Agent, Piedmont SC.