Posts Tagged ‘Boxwood blight’

K. L. Ivors, L. W. Lacey, and M. Ganci

Dept. Plant Pathology, North Carolina State Univ.

455 Research Drive, Mills River, NC 28759

This trial evaluated the efficacy of several commercially available fungicides for preventive activity against boxwood blight caused by Cylindrocladium buxicola. Treatments were arranged in a randomized complete block design consisting of four replications of six 1-gal English boxwood plants per treatment on a container pad at the Mountain Horticultural Crops Research Station in Mills River, NC. Treatments were applied as foliar sprays until runoff with a CO2-pressurized backpack sprayer equipped with a handheld boom and a single, hollow-cone nozzle (TXVS-26) delivering 50-60 psi. Treatments were applied on 13 Sep, 28 Sep, and 13 Oct. Inoculum was prepared by flooding Petri-dishes of 10 day cultures of the pathogen growing on PDA. Plants were spray inoculated with 5,000 spores per ml until runoff one day post treatment on 14 Sep, and again on 30 Sep, two days after the second fungicide treatment with 8,000 spores per ml until run-off. Disease assessments were conducted on 1, 16 and 26 Oct. Percent leaf area diseased was recorded using the standard Horsfall-Barratt scale. Disease pressure was not high enough to evaluate percent leaf drop or percent stem streaking. AUDPC for percent leaf area diseased across the entire timeframe of the trial was calculated. Air temperatures during the trial was suboptimal for high rates of infection with average daily high and low temperatures of 77.7 and 55.4°F for Sept; and 66.3 and 43.5°F for Oct.

For the entire article – click here.

By: Steve Frank – Assistant Professor and Extension Specialist, Department of Entomology, North Carolina State University; and

Kelly Ivors – Associate Professor and Extension Specialist, Department of Plant Pathology, North Carolina State University

The National IPM Webinar series was started in 2011 by Dr. Scott Ludwig at Texas A&M but is now run by Drs. Kelly Ivors and Steve Frank at NC State.  The webinar series is designed to provide timely information to the green industry through monthly seminars on the production and maintenance of ornamental plants.  The webinar series invites extension specialists from around the county to speak on topics important to the nursery greenhouse, and landscape industry with particular emphasis on issues relevant to the Southeast.  This provides an opportunity for green industry professionals to learn in-depth information from the specialists conducting research on a particular pest or horticultural issue.

The webinars are live presentations in which the presenter speaks while showing power point slides on screen.  The webinars last about 40 minutes then audience members can ask questions through a microphone (if they have one) or by typing their question.  The webinars are presented on a level that is instructive to growers, extension agents, and even specialists that need to learn about a particular topic.  Since just one topic is covered, specialists have the time to cover topics more thoroughly than in other extension outlets.  In addition, since the presenters are active researchers, the audience may hear about efficacy data or other management information that is not published and thus would not be available to specialists who normally give presentations in their state.

In the inaugural webinar held January 5, 2012 Kelly Ivors discussed the new boxwood disease Box Blight on which she is the US expert (http://go.ncsu.edu/box_blight_webinar).  Kelly had nearly 300 people participate in her seminar and 2400 more access the webinar since then.  The February webinar was about new research in the management of ambrosia beetles given by Steve Frank (http://go.ncsu.edu/ambrosia_beetle_webinar).  Both webinars were attended by growers, industry personnel, county extension agents, and extension specialists.  The March Webinar titled “‘Bark with a Bite’ Bark handling and what to watch out for”will be presented by Dr. Ted Bilderback March 8th at 11 am EST.

Webinars are typically scheduled for the first Thursday of each month starting at 11 am EST.  Announcements are sent out via a listserve.  This is not a discussion list. It is only used to send out information about  the webinar series.  You can sign up for the list serve by going to http://go.ncsu.edu/IPM_webinar_signup.  Simply enter your email address in the field at the bottom of the screen and click subscribe. Past webinars are posted online with audio so you can watch them at your convenience.  Links will be sent out via the list serve prior to each session.

To participate in a webinar click on the link sent out via the list serve (e.g. http://go.ncsu.edu/box_blight_webinar).  You will be able to enter the session starting at 10 am EST on the day it occurs.  This allows time for trouble shooting if necessary but the actual webinar will not start until 11 am EST.  You do not need any special software just an up-to-date browser and internet connection.  In order to test that your system requirements are acceptable, visit the Configuration Room linked on http://go.ncsu.edu/elluminate_config.

This new series provides a great opportunity to get up-to-date and timely information relevant to improving IPM in your business.  I hope you will consider joining webinar sessions that are pertinent to your business or accessing online at your convenience.  These webinars could also make good tools for training employees.  Due to budget cuts and new technology the nature of extension is changing.  At North Carolina State University we are staying ahead of the curve so you can too.

The IPM Webinar Series received initial sponsorship from many state organizations including:

.           Alabama Nursery and Landscape Association

.           Louisiana Nursery and Landscape Association

.           North Carolina Nursery and Landscape Association

.           North Carolina Commercial Flower Growers Association

.           Northeast Texas Nursery Growers Association

.           South Carolina Greenhouse Growers Association

.           South Carolina Nursery & Landscape Association

.           Southeast Texas Nursery Growers Association

.           Texas Nursery and Landscape Association

.           The Tennessee Nursery and Landscape Association

.           Virginia Flower Growers Association

Norm Dart1, Virginia State Plant Pathologist 

Mary Ann Hansen1 and Elizabeth Bush1, Extension Plant Pathologists 

Virginia Department of Agriculture and Consumer Services1, Virginia Tech2 

Boxwood blight (also called “box blight” in Europe), caused by the fungal pathogen Cylindrocladium buxicola, was reported for the first time in the U.S. at two North Carolina production nurseries in October, 2011. Boxwoods originating from an infected block of plants at one of the North Carolina nurseries were planted in two production fields in Virginia. The Virginia Department of Agriculture and Consumer Services and the North Carolina Department of Agriculture and Consumer Services are developing and implementing mitigation strategies aimed at aggressively removing the pathogen from infested fields and stopping the spread of this disease.

Read more at: http://www.ppws.vt.edu/~clinic/alerts/11-04-11_boxwood_blight_alert.pdf