Recently I attended the Southern Blueberry and Fruit Workers meeting in Atlanta, GA. It is held as part of the Southern Region of the American Society for Horticultural Science annual conference. Below are some new things I learned about at the meeting:
Ring nematode is prevalent in Georgia blueberry plantings
The nematode problem is worse in re-plant situations and may require fumigation
Southern highbush blueberries have more problems than Rabbiteyes, especially in re-plant situations
Using pine bark mulch appears to reduce nematode populations
The addition of humic acid to the soil does not appear to benefit blueberry plants
Botrytis resistance to fungicides has happened in GA. Use of Captan or Ziram is now recommended because of low resistance possibility
Mummy berry sprays should be applied starting at first sign of green tissue. Indar, Orbit, Pristine, and Proline (a new material) showed efficacy. Serenade, an organic product, also had some efficacy. Regalia, another organic product, had no effective control of the disease.
Exobasidium is becoming resistant to Pristine in GA. ‘Premier’ has high infection rates, as does Tifblue. A full Captan spray schedule is effective (about 8 sprays in GA), but not using Captan as a delayed dormant spray. Use Lime Sulfur or Sulforix for best control as a delayed dormant spray.
Xyllela (blueberry scorch) has been found in various states. In Rabbiteye’s it leads to chronic symptoms, but in Southern Highbush scorch symptoms are readily apparent. There may be different strains of this disease and more work is being done.
Blueberry Necrotic Ring Blotch is a non-systemic viral disease that is only in leaves. Mites spread it. It can lead to defoliation of the plant.
Broad mites have been found in blueberries and blackberries in Arkansas. Damage resembles Roundup injury. Leaves have a “silvery” look, with rosetting and stunting of plants, and necrosis of the petiole. It will kill shoot tips.
Blueberry rust is a problem in Gulf Coast areas of Alabama.
Foliar calcium spray trials in GA on rabbiteyes have shown no efficacy
Three new Southern Highbush blueberries are being released from UGA soon.
One new Rabbiteye cultivars is also being released from UGA – Krewer, an early, large fruited cultivar that should pair well with Titan