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Pierce’s Disease & Grape Leafroll Virus Management Options as Components of Vineyard IPM. Dan Horton, UGA, Entomology, Athens, GA. Pierces Disease and Leafhoppers are Endemic & Present on both Wild & Cultivated Grapes Across the Southeast
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Pierce’s Disease & Grape Leafroll Virus Management Options as Components of Vineyard IPM Dan Horton, UGA, Entomology, Athens, GA
Pierces Disease and Leafhoppers are Endemic & Present on both Wild & Cultivated Grapes Across the Southeast Pierce’s Disease Management is an Imperative On-going Effort to Minimize the Incidence of an Inevitable Malady P
Grape Leafroll Virus (GLRV) is the Most a Recent Insect-Vectored Disease to Threaten to Vineyard Health in SE Wine Grapes, However GLRV is not an Endemic Disease, that is Virus-Infected Wild Grapes are Not a Ubiquitous Threat & the Most Competent Mealybug Vector, Vine Mealybug is not yet Present
Grape Leafroll Virus Management If GLRV is not Present, Do Not Introduce It, If Available Plant Virus-Indexed Vines Recognize that Leaf-Hopper Suppression Programs will tend to Increase the Abundance of Previously Uncommon, Insignificant Phloem-Feeding Pests Such as Soft Scale or Mealybugs Should assume that Mealybugs or Soft Scale will Overwinter in the Vineyard and Implement Bud Swell Horticultural Oil Programs to Suppress MBs and/or Soft Scale, with As-Needed New Shoot treatments: Applaud, Venom, Assail imidacloprid, Movento …
Monitor for Mealybugs Under Bark in Dormant Season Incorporate examination of vines for mealybugs and/or honeydew part of your routine vineyard management practice If mealybugs are found/suspected take samples and get them to your County Agent Treat with either foliar applications or soil-applied neonicotinoids chlorpyrifos, diazinon Applaud Venom/Scoprion, Clutch imidacloprid, … Movento
Pseudococcus (P. longispinus, P. viburni or P. maritimus) would most likely be North GA’s key Leaf roll Virus Vectors (Greg Hodges, UFL, DPI) Longtailed Mealybug Pseudococcus longispinus Grape MealybugPseudococcus maritimus
Obscure MealybugPseudococcus obscurus Vine Mealybug *** Pseudococcus ficus
In CA Vineyards the Spread of Pierce’s Disease has been Slowed by LH Suppression With Insecticides Vector Suppression is More Complicated in the Verdant, but Droughty Southeast Soil-Applied Neonicotinoids: imidacloprid (Admire, Alias, other generics) or Venom/Scorpion can either languish if too dry or suffer reduced residual if too wet, wait until as late in the initial growth flush as rain patterns suggest Suggest LH Trapping as the Triggered for Foliar Applications, they are responsive, targeted and they complement neonicotinoids Foliar Treatments Should Alternate Applications of Pyrethroids-- cyfluthrin (Baythroid XL 1EC, Brigade/Fanfare/Tundra with Imidan @ 14-day Intervals
Neonicotinoids & Pyrethroids are Resistance-Prone & Inclined to Increase the Risk of Mites; Nicotinoids, Pyrethroids & Organophosphates (OP) are Injurious to Pollinators; A Balanced Program is More Likely to Suppress LH & MB Vectors while Avoiding or Delaying Insecticide Resistance
Leaf hopper Abundance in N GA is typically low during the Spring Vegetative Growth Flush,In vineyards with Low or No Pierce’s Disease Insecticidal Suppression Should Focus on the On- set of LHs in Vineyard, typically this will be Small Green Sharpshooters Soil-Applied Imidacloprid Should be Used in Concert with Foliar Pyrethroids/Imidan Program
2011 May Bring Two New, Exotic Stink Bugs to Many Southeastern Vineyards Brown Marmorated Stink Bug (BMSB) & Bean Plataspid (Kudzu Bug)
Bean Plataspid Greg Henderson, Edgefield County Agent, found bean plataspids on young peach trees in 2010 as late soybeans were being harvested. Hopefully this will prove to be of modest impact save for young orchards and vineyards where filling canopy is a priority.
Spotted Wing Drosophila may be Problematic Wine Grapes are not felt to be a Prime Host, but … SWD can successfully attack sound fruit, hence it should be regarded as a threat
Spotted Wing Drosophila (SWD) Trapping should be a Standard Operating Procedure, Augmented by Frequent Examination of Fruit SWD should be easily controlled, but it may well mandate a more aggressive, scheduled insecticide approach
Japanese Beetles are Significant Foliage Pests, and Modestly Important, Occasional Fruit Pests of Muscadine Grapes Japanese beetle populations get out of hand quickly, especially as soaking, drought-breaking rains prompt heavy, synchronous adult emergence Defoliation from Japanese beetle is more serious as grapes reach veraison, berry ripening, greater than 10% defoliation is probably injurious, but the key to managing Japanese beetles is to act before they become truly numerous
Japanese Beetle Insecticide Options in Muscadine acetamiprid (N) Assail 12-h/7-d ++++cyfluthrin (P) Baythroid, Tombstone 12-h/3-d++++bifenthrin (P) Fanfare, Tundra 12-h/30-d ++++carbaryl (C) 12-h/7-d++++diazinon (OP) 24-h/28-d +++dinotefuran (N) Venom 12-h/24-h*++++fenpropathrin (P) Danitol 24-h/21-d++++imidacloprid (N) Merit, Provado 12-h/DOH++++malathion (OP) 12-h/3-d12-h/3-d+++methomyl (C) 7-d/1 to 14-d+++phosmet (OP) Imidan 14-d/ 7 to 14-d++++