GTBOP Ornamentals Industry Update 2024: Diseases and Insect Pests
Webinar Date: November 14, 2024
Speakers: Dr. Jean Williams-Woodward (UGA Plant Pathologist) & Dr. Shimat Joseph (UGA Entomologist)
Duration: 50:12
CEU Categories: 24, 27
SUMMARY:
Dr. Jean Williams-Woodward provides updates on vascular streak dieback (VSD) affecting redbuds and other deciduous trees, with research ongoing at Tennessee State University. She explains bot canker caused by Botryosphaeria fungi—organisms living endophytically that become problematic during water stress. Systemic fungicides including propiconazole and mefentrifluconazole (Cevya) with Pentra-Bark adjuvant show effectiveness.
The wet spring of 2024 caused severe anthracnose on Japanese maples, oaks, and London plane trees. Pruning dead branch tips removes overwintering inoculum. Boxwood blight research shows intensive management (biweekly fungicides, restricting pet access) can maintain infected landscapes, though most homeowners cannot sustain this effort. Dr. Williams-Woodward introduces hydrangea ringspot virus—a mechanically-transmitted virus spreading through pruning activities.
Dr. Shimat Joseph covers three invasive threats: box tree moth (not yet in Georgia but detected in Tennessee/South Carolina), spotted lanternfly (FIRST DETECTED IN GEORGIA in Fulton County, October 2024), and an invasive thrips species often misdiagnosed as broad mite damage.
TIMESTAMPS:
0:00 Introduction
1:42 Vascular Streak Dieback in Deciduous Trees
2:46 Bot Canker: Botryosphaeria Complex
4:27 Fungicide Treatments for Bot Canker
5:19 VSD Organism and Symptoms
7:04 Postiva Fungicide for VSD
9:31 Anthracnose Diseases
10:51 Pruning to Remove Overwintering Inoculum
13:28 Boxwood Blight Research
15:17 Boxwood Blight Symptoms
16:58 Pet Transmission of Boxwood Blight
21:34 Rose Rosette Virus Reminder
22:01 Hydrangea Ringspot Virus
24:22 Dr. Shimat Joseph: Entomology Update
25:40 Box Tree Moth Introduction
28:41 Box Tree Moth Larval ID
32:25 Box Tree Moth Management
33:26 Spotted Lanternfly
37:16 Georgia Detection Announcement
42:36 Spotted Lanternfly Management
44:16 Invasive Thrips Species
48:17 Thrips Management
49:40 Closing
Q&A HIGHLIGHTS:
Q: How does bot canker differ from vascular streak dieback?
A: Bot canker creates dark cambial discoloration entering through wounds; VSD shows vascular streaking when stems are cut vertically. Bot canker activates during water stress while VSD appears worse on light-colored redbud varieties.
Q: Can boxwood blight be managed without removing plants?
A: Yes, but it requires biweekly fungicide applications and restricting pet access. Korean boxwood types retain leaves better than American/English varieties when infected.
Q: What is spotted lanternfly’s status in Georgia?
A: First detected in Fulton County, October 2024. Spreads via egg masses on vehicles, trailers, and rail cars. Manage with systemic insecticides (imidacloprid, dinotefuran) as soil drenches or trunk injections.
Q: Why is the invasive thrips often misdiagnosed?
A: Damage resembles broad mite injury. When mite treatments fail, suspect thrips. Effective products include spinosad, Xxpire, Mainspring, and Sarisa.
PRODUCTS MENTIONED:
Fungicides: Propiconazole, Cevya, Postiva, Pentra-Bark
Insecticides: Spinosad, Xxpire, Acelepryn, Mainspring, imidacloprid, dinotefuran, Bt kurstaki
RESOURCES:
• Georgia Pest Management Handbook: online
• UGA Turf & Ornamental Pest Management Blog
• GA Dept of Agriculture pest updates
CEU CREDIT: Submit sign-in sheets to gtbop@uga.edu
Questions? Contact Dr. Williams-Woodward (diseases) or Dr. Shimat Joseph (insects) via UGA Extension.
gtbop uga plantpathology entomology boxwoodblight spottedlanternfly boxtreemoth ornamentals pestmanagement landscapeipm ceu georgia