Phil Brannen

  • As I have reported over the last 2-3 years, we are observing warming winter temperatures, and as a result, we are also observing increasing levels of Pierce’s disease (PD). With colder winter temperatures, the bacteria that causes PD, Xylella fastidiosa, can actually be “cured” from the vine. With warmer temperatures, the bacteria survives and kills…

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  • In Georgia and the Southeast as a whole, we grow vinifera, muscadine and other native grapes, and various hybrids. The acid profiles of these grapes are highly variable, and they will contribute to the quality of wines produced. Dr. Abhinav Mishra (UGA Food Science Department) will be conducting some preliminary experiments to explore the acid…

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  • Fungicide Resistance Testing in Georgia

    We do now have an option for fungicide resistance testing of several pathogens of wine grapes. These include pathogens associated with powdery mildew, downy mildew, ripe rot, and Botrytis. Now is a good time to test, as pathogens are being observed in some vineyards, and testing now can allow you to switch fungicide classes to…

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  • Pesticide Redistribution Fact Sheet

    You may find the attached resource to be of use as you try to understand your pesticides and how they move within or on the plant. I am particularly interested in the fungicide aspect. Plant growth that occurs rapidly in grape vines can quickly provide unprotected tissues relative fungicides. Some materials can redistribute or volatilize,…

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  • Just as an update from my last blog post, we are now finding Pierce’s disease (PD) symptomatic Crimson Cabernet vines in our Horticulture Farm trial in Watkinsville, GA — just outside of Athens. Shane Breeden, a Ph.D. student in the Plant Pathology Department identified symptoms last week, and Kendall Johnson, another Ph.D. student from the…

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  • End-of-Season Pierce’s Disease Observations

    We continue to see quite a bit of Pierce’s disease (PD) in our vineyards this year, to include our northern Georgia sites. I am convinced that bacterial titer drives this disease, and bacterial levels in the plant are determined by the vectors (type and number of sharpshooters involved), winter temperatures, and possible alternative hosts. I…

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  • Blanc du Bois Review

    For those growing or interested in Blanc du Bois, the following review may be of interest to you. This has been submitted for development as a UGA publication, so consider this a “sneak peak.” We still need more research-based information on this cultivar and others we are growing in Georgia, but this provides you with…

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  • New Grape Rot Reference

    See attached for a new open-access journal article on grape rots. We get all of these rots, so this review article may be a helpful reference for you. Enjoy.

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  • Captan Registration Review

    Captan is currently under review by the EPA. The review document is below, and it can be perused for the impact of EPAs potential actions on grape disease management. EPA is proposing several mitigations for the continued use of Captan. Any responses are currently due by 27 June, but you can request an extension for…

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  • Botrytis Testing for Fungicide Resistance

    Clemson University has picked up the resistance testing for Botrytis. This is not a free service at this time. However, it is very useful and worth the funds to determine which Botryticides are working. See the attached form for information needed. Additional information from Dr. Guido Schnabel. I worked with our plant and pest diagnostic…

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