By Clint Thompson
University of Georgia (UGA) Extension advises grape producers to remain diligent with their fungicide applications.
Phil Brannen, UGA Extension fruit disease specialist, discussed disease management, with harvests slated to commence soon across the region.
“We’re starting to see some downy mildew coming out right now, so we are getting some disease as we’re looking towards the latter part of the season. It’s time for harvests to start very soon. In August will be some of the first ones, and they’ll go into September as well. We’re seeing some disease, but if they’re on a tight spray program and doing a good job of spraying, hopefully (the disease) will be less than it has been in the past,” Brannen said.
Vineyards in Georgia and Alabama are susceptible to downy mildew because of the humid and wet climate that is prevalent during the growing season. Spores can infect within hours when the leaves or fruit are wet. Dew counts for sufficient wetness.
Symptoms include “oil” spots on the upper leaf surface with white, fluffy spore formation on the underside of the leaf. The important factor for grape producers to consider is leaf protection. Plants don’t do well without leaves.
It is important to remember that fungicide rotation remains the best line of defense against a disease that’s not going away.