Pecan scab continues to bear down on Georgia pecans, a result of soggy spring weather and plenty of inoculant left over in orchards from the crop's tough last year with the disease. But some recent University of Georgia trials show adding something to the fungicide mix could greatly reduce the disease.
According to a June 6 blog by UGA Extension pecan specialist Lenny Wells, early result of a fungicide trial show adding a surfactant to fungicides can make a difference:
“I visited with UGA plant pathologist Tim Brenneman for a while (June 5). … Dr. Brenneman’s results showed that adding a surfactant to the DMI/Strobilurin mix fungicide products like Absolute significantly reduces the incidence and severity of leaf scab over the fungicide alone. Similar results are expected with the effect on nut scab.
Dr. Brenneman used a 90/10 surfactant but expects the same results could be obtained with an 80/20 surfactant. Also, similar results would be expected with the other DMI/Strobi mix fungicides like Quadris Top and Quilt. The inclusion of a surfactant with DMI’s like Enable, Tebuconazole, Orbit, Propimax or Bumper mixed with Tin would likely be of benefit as well. Just be sure to jar test for compatibility when using any new tank mix.
With the at least temporary shortage of Elast, this provides us with another good tool to fight scab. DO NOT ADD A SURFACTANT WHEN USING ELAST due to the increased risk for burn.”