Sunday, February 20, 2011

Plants, Pests, and Pathogens Webinar

We hope you can join us for Plants, Pests and Pathogens, Tuesday 2/22/2011 at 10am.

You can participate in this two-hour training opportunity for Master Gardeners and Horticulture Agents via your computer, or you can go to one the of downlink sitesTo participate from your computer:
  • Log In by 9:30 am. Include your county with your name and leave the password field blank
  • Take a few minutes ahead of time to visit the page on How to Use Elluminate. Check to be sure that you have downloaded the free software required to run the program.  There are one page reference guides and tutorials available.
In order to minimize interference, please keep your microphone turned off, except when you are speaking to the group.

Schedule for February 22 Session:
  • 10:05 am- Regional Update, Coastal Plains: Bob Filburn, Edgecombe County Horticulture, Apiculture, Local Foods Initiative, and Forestry-- Green Thumbs on Wheels
  • 10:10 am-Regional Update, Piedmont: David Goforth, Carbarrus County, Horticulture
  • 10:15 am- Regional Update, Mountain/Foothills: Cliff Ruth, Commerical Horticulture, Henderson and Transylvania Counties-- Weed Scouting Class
  • 10:20 am- Featured Speaker: Hannah Burrack, Assistant Professor of Entomology and Extension Specialist, tobacco and Small Fruits
  • 11:00 am- Entomology: David Stephan, NCSU PDIC, Insect Identification Specialist, 40 years experience
  • 11:35 am- Current Issues in Plant Pathology: Mike Munster, PDIC, Plant Pathologist and Diagnostician of Commercial Ornamentals 

Monday, February 14, 2011

Prime Weather for Paper Wasps

You aren't the only one heading outside to enjoy the beautiful weather... female paper wasps have started leaving their winter homes and may soon be seen swarming yours!
Paper wasps (Polistes spp.) eat a lot of insects and are usually considered beneficial to the landscape.  They are best known for their open, grey paper nests built under an open porch ceiling, window sill, or any type of overhang.  During their nesting phases, paper wasps can be defensive and are likely to sting you if you disturb their nests.  
During the cool/ cold times of the year, when their are no nests or young to protect, paper wasps show types of swarming behavior.  In the fall, this behavior is connected with mating.  Male wasps look for the best place to "hang out" and attract the females.  Dozens or even hundreds might be seen around the upper stories of buildings and other tall towers.  Males locate a good perch, camp out, and release odors (pheromones) to attract the pretty female wasps.  Some time after mating, the males die and the females seek a shelter for winter. 

During winter and early spring, on any warm day (like the one's we've been seeing this week!), these wasps become active.  If their shelter is inside a wall, chimney, or vent, they may follow the light into the inside of a structure rather than moving outside. The only risk is unknowingly coming into contact with the wasp and being stung. The future queens become active on warm days and start flying around, however they are not particularly defensive and are unlikely to attack.  This flying behavior disappears at the end of the day when temperatures drop and the wasps resettle.  
The best management and control of these wasps indoors is a rolled-up newspaper.  Aerosol pesticides work, but they cost money and aren't particularly necessary if you are able to whack the wasps with a paper or fly swatter.  

For more information on Paper Wasps click the link below:

Special Thanks to Steve Bambara and Michael Waldvogel for this great Insect Note!

Thursday, February 10, 2011

Elluminate Training Sessions: URL Links and Instructions

Below are the links for the Elluminate (interactive webinar) sessions on Plant Disease Diagnostic Training. 
February 23:
March 2:
March 9:

If you have never used Elluminate before, follow these instructions:
Our Elluminate session Plant Disease Diagnostic Training, is scheduled for the above dates. You can connect to the session by clicking the above links to the sessions.

Before connecting to Elluminate for the first time, make sure to complete the Configuration setup. You MUST do this at least 24 hours ahead of time. 

Please use the same location and equipment that you will use when you attend the actual Elluminate session(s) to complete the following steps:

  1. Go to
  2. Make sure Step 1 shows a checkmark or says that you have Java installed. If you do not see a checkmark, follow the instructions to obtain the latest version of Java.
  3. Enter the Configuration Room as outlined in Step 2. Follow the directions in the Configuration Room to test your audio setup.

If you have ANY PROBLEMS configuring Elluminate, call 866-388-8674, option 2. Elluminate Live! support is available 24 hours day, 7 days a week.

To join the session:
1. Go to the Elluminate meeting URL (links above).
2. Under section 2, "User Authentication", select "Guest." 
3. Type in your email address. 
4. Type in your name. 
5. Type in the session password if prompted. 
6. Click "Log In." 

If you have any problems logging in to the session or hearing the audio, call 866-388-8674, option 2.

Monday, February 7, 2011

County Agent Training in Plant Disease Diagnosis

The Plant Disease and Insect Clinic and the Department of Plant Pathology announce agent training in plant disease diagnosis. The training will consist of four one-hour Elluminate sessions covering the basics of plant disease diagnostics and one all-day hands-on session. In order to accommodate as many County Agents as possible, the hands-on session will be held twice, on the 18th and 25th of March. All County Agents are encouraged to participate in the Elluminate sessions. Seating is limited to 20 people for each of the hands-on workshops. There is no fee for this training.
The training sessions and dates are as follows:

 February 16, 2011, 10:00 a.m.

Introduction to Plant Disease Diagnosis: Types of plant problems; signs and symptoms of plant diseases; the diagnostic process

February 23, 2011, 10:00 a.m.
Using the Plant Disease and Insect Clinic: Sample collection and submission; using the database; interpreting diagnostic results; resources and information

March 2 and March 9, 2011, 10:00 a.m.  (participate in both sessions)
Tips for diagnosing common plant diseases of specific crops and ornamental plants; recognizing diseases that threaten North Carolina agriculture and landscapes

March 18, 2011 and March 25, 2011, 8:30 – 4:30 (attend one all-day session only)
Hands-on workshop in plant disease diagnosis.

Sessions are limited to 20 County Agents each, with priority given to agents hired in the past five years. These sessions will illustrate signs and symptoms on live material in the laboratory and in the landscape, will demonstrate simple techniques that can be used by County Agents in the field or at their office to make a diagnosis, or to provide preliminary information to a PDIC diagnostician or Extension Specialist. The session will also provide training in digital photography skills as they apply to plant disease diagnosis. Agents will tour the PDIC and will “walk through” the process of diagnosing a clinic sample. Lunch, breaks, educational materials, and reimbursement of travel expenses (breakfast and mileage) will be provided.

Contact Barbara Shew at for more information or to sign up for the all day sessions.

Friday, February 4, 2011

Geotrichum Sour Rot of Shrink Wrapped Sweetpotatoes

Recently, we received a sweetpotato sample in the clinic.  These sweetpotatoes were individually packaged in shrink wrap and ready to be microwaved up for dinner.   

There was only one problem… they looked like this and smelled even worse!

Geotrichum Soft Rot 

The Culprit??
Micrograph of Geotrichum candidum conidia
Geotrichum candidum causes a watery soft rot of sweetpotato.  Geotrichum soft rot has a distinctive fruit-alcohol-sour odor.  This disease requires conditions where oxygen is lacking and thrives at high temperatures.  This disease can begin in the field after flooding and can continue throughout postharvest storage in poorly ventilated areas.   

Signs of the pathogen include white tufts of mycelium on the outside of the roots.  The disease can be avoided by providing adequate drainage in the field and proper ventilation postharvest.  Roots should be packed dry because a thin film of water on the root surface can impede respiration and promote disease development. 

How is this a problem for shrink wrapped sweet potatoes??

Shrink- wrapped sweetpotato with white mycelium from Geotrichum candidum

The Sweetpotato Industry 

The majority of sweetpotatoes consumed in the US are purchased through retail fresh market outlets. Traditionally, sweetpotatoes have been marketed as individual roots stacked in bulk displays and priced per pound.  The times are changing and product convenience and ease of preparation are increasingly important to today’s consumers.  A new trend in shrink wrapping sweetpotatoes appeals to buyers that prefer microwaving to baking.  Individual roots are prewashed, dried, and heat sealed in plastic wrap.  Consumers can pop the packaged root in the microwave for 8 minutes and voilĂ , dinner on the table. 

Shrink-wrapping adds value to fresh market sweetpotatoes by enhancing the appearance, reducing weight loss, and allowing for individual labeling.  The downside to this is the potential for added postharvest spoilage.  Wrapping produce in plastic creates an ideal environment for microbes.  There is no way to completely remove surface microbes from sweetpotatoes and with the right environmental conditions you might have a sour rot problem on your hands.  Even though the roots are dried before packaging, fluctuations in storage temperatures can lead to condensation and moisture build up, which in turn creates a nice environment for pathogens like Geotrichum.  To avoid this problem, storage temperatures must be monitored closely.  

For more information on post harvest diseases of sweetpotatoes check out this link,