UGA Extension Viticulture Blog

Sour Rot Management

After the meeting on Wednesday, there was a request for more information on sour rot management through use of insecticides for control of SWD.  I contacted Megan Hall, who conducted this research at Cornell.  She indicated that the 2016 research continued to support the use of MustangMaxx.  She states, “If a grower knows that they regularly see sour rot in a particular variety, I recommend beginning to spray at approximately 15 Brix using OxiDate and MustangMaxx weekly until harvest.” She still recommends the Oxidate, but she also indicated that the MustangMaxx is the heavy hitter.  Without MustangMaxx, the Oxidate product does nothing, according to Megan. Please realize that you will need to incorporate other SWD-active insecticides in a rotation with MustangMaxx, as you do not want to go to that well too often — resistance will develop. We hope to repeat and add to this research at some point in the future, but for now, this is the best information I have personally found to suggest that we can manage sour rot in any way.  See below for a poster that gives further details of this research and the results.

Sour Rot Poster