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Weeds of Container Nurseries in the United States – Online ID Key

Weed control can be one of the most costly risks in the production of container-grown nursery crops. Any control program begins with the correct identification of the weeds present, along with an understanding of their life cycles and modes of reproduction and spread. Treated here are the most common weeds of outdoor container nurseries, as well as a selection of recently introduced species with the potential to spread. This work is based in large part on Weeds of Container Nurseries (Neal & Derr 2005), but builds on that treatment through the addition of multi-access keys, taxa, and images. The content is optimized for mobile use and should be accessible from standard browsers on nearly any device, whether desktop, tablet, or smartphone.

Access the key here:

Future. We consider this work a “living” resource and seek to continue to add images, tweak content, improve keys, etc. over time. Future versions will be identified by sequentially increasing version numbers.

Copyright. Re-use of any image in this work, for any purpose what-so-ever, is prohibited without the express written permission of the copyright owner. For permission to re-use any image, please contact the copyright owner directly.

Spraying Insecticide? There’s an App for That

U.S. Department of Agriculture (USDA) scientists have released two mobile phone applications, or “apps,” to make things easier for anyone who needs to adjust insecticide spray equipment.

The apps were developed by Agricultural Research Service (ARS) scientists Bradley Fritzand Wesley “Clint” Hoffmann at the agency’s Areawide Pest Management Research Unit in College Station, Texas. The apps are designed to ensure that aerial and ground-based crews can hit targets and minimize pesticide drift by keying in specifics on the type of equipment and pesticide they are using.
ARS is USDA’s principal intramural scientific research agency, and the research supports the USDA goal of promoting agricultural sustainability.
With dozens of manufacturers producing dozens of different types of spray technology—each with its own nozzle type, flow rate, and pressure setting range—the equipment setup can get pretty complicated. Aerial sprayers also must factor in wind speed, air temperature, flight speed and humidity.
The apps incorporate the latest science of spray technology, including “spray nozzle atomization” models developed by ARS at College Station. They can be used with a smartphone and accessed right from a field or the cabin of a small aircraft. More than half of all aerial applicators responding to a survey by the National Agricultural Aviation Association reported using smartphones. Data also can be saved for later use and e-mailed to colleagues.
One app is designed for ground-based spraying for mosquitoes and other threats to public health. It covers 60 different sprayers made by 19 manufacturers and was developed jointly with the Department of Defense‘s Navy Entomology Center of Excellence in Jacksonville, Fla. The user selects the appropriate sprayer and is guided through the process of selecting specific operational settings, such as the nozzle type, flow rate and spray pressure setting.
The other app, for aerial spraying, walks users through the process of adjusting nozzles and settings so pesticides are delivered at optimal droplet sizes. Droplet size is critical in aerial operations to ensure “on-target deposition” and minimize pesticide drift. The user specifies the nozzle manufacturer from a menu and is steered through a series of screens and prompts that, based on the specific operating conditions, helps him or her select the right size of the nozzle opening, spray pressure, nozzle orientation and airspeed.

The apps are available online through the Apple iTunes App Store and the Google Play Android Marketplace by searching for “Aerial Sprays” for the aerial application app and “Vector Sprays” for the ground-based sprayer app.

Read more about this research in the November/December 2012 issue of Agricultural Research magazine.

“Bringing Nature Home”, sponsored by the Georgia Exotic Pest Plant Council

Do you care about protecting our native plant habitats from invasive plants? How can you tell which plants are invasive? Do you want to know how you can help? First step is to come to the Georgia Exotic Pest Plant Council Annual Conference on November 8th.

The GA-EPPC, Georgia Exotic Pest Plant Council, is having its Annual Meeting and Conference on Thursday, November 8th, 2012, from 9am to 4pm. The conference will be held at Stuckey Conference Center, UGA 1109 Experiment Street Griffin, Georgia.

GA-EPPC’s goals are to focus attention on the adverse effects invasive plants have on the diversity of Georgia’s native plants and animals; the use of invasive plant management to prevent habitat loss; the socioeconomic impacts of these plants; changes in the seriousness of the different invasive plants over time and the need to exchange information to help land owners and managers set priorities for invasive plant management.

For more information please visit

Alternatives to Synthetic Herbicides for Weed Management in Container Nurseries

Weed management is one of the most critical and costly aspects for container nursery production. High irrigation and fertilization rates create a favorable environment for weed growth in addition to crop growth. Weeds can quickly out-compete the crop for light and other resources, reducing the rate and amount of crop growth as well as salability (Berchielli-Robertson et al., 1990; Norcini and Stamps, 1992). Weed management in nursery production is most effectively achieved by preventative practices, primarily with the use of pre-emergent herbicides (Gilliam et al., 1990; Gallitano and Skroch, 1993).

However, there are valid reasons for managing weeds using alternatives to synthetic herbicides (Sidebar 1). Ornamental crops encompass a wide array of species, and herbicide products must be tested on each for effective, safe and legal use. Even when a product is labeled for a crop, it may not be sufficiently effective for the weeds present or may induce crop damage under certain circumstances. Finally, use of synthetic herbicides in greenhouses and other enclosed structures is often prohibited on product labels.

Check out the entire publication here.


Free Webinar: Disease Management for Winter Annuals

Jean Williams-Woodward, University of Georgia Extension Plant Pathologist, will present common winter annual flower diseases, what to watch for, and how to control them. This Webinar is free to all Landscape Contractors and Extension Professionals.

A complete schedule and archive of Landscape Professional webinars may be found at

These webinars are easily viewed with a smart phone or iPad so you can be on the run.


Redheaded pine sawfly


The redheaded pine sawfly, Neodiprion lecontei, is a pest of pines in ornamental landscapes, nurseries, and plantations. Adults emerge in spring and a second generation occurs in mid summer.  Eggs are laid on many 2 and 3 needled pine species such as Jack pine, loblolly pine, and red pine.  Sawflies are not flies and the larvae do not turn into butterflies. They are non-stinging herbivorous wasps.  They can defoliate trees and bushes in the landscape. Since they are gregarious it is sometimes possible to prune off an infested branch and remove all the larvae.  Management for sawflies is similar as for caterpillars though not all the insecticides will work so check the label.  Horticultural oil is a good bet especially for small larvae. Formulations that contain azadirachtin or spinosad are also effective.  For sawflies and caterpillars, management of full grown caterpillars is generally not warranted;  the damage is already done and they are hard to kill.

For pictures of redheaded pine sawfly larvae and more information visit:


Yellownecked Caterpillars

Adult yellownecked caterpillars, Datana minstra, occur in June or July and lay eggs on deciduous shrubs and trees.  They will feed on many fruit and ornamental trees including birch, elm, oak, maple, Prunus spp., and others.  They feed gregariously in late summer.  They consume entire leaves except large mid-veins and can rapidly defoliate trees or cause significant damage. I found the caterpillars pictured below in the forest on a bush I couldn’t identify because every leaf was gone.  Scouting for small caterpillars can help reduce damage and improve control if it is needed.  Caterpillar management information is available here:

See pictures of this and other caterpillars on my blog here:


Coastal Green Educational Event – September 28, 2012 – Savannah, GA

This year, the 2012 Coastal Green will be held at the Coastal Gardens & Bamboo Farm in Savannah, Georgia on September 28, 2012. Registration is $50 per person until September 19 and $65 per person after September 19; registration includes breakfast, snacks, and lunch. To register, please visit this website. The agenda and driving directions for

Coastal Green details are below.

8:15 – 8:45 AM Registration

8:45 – 9:00 AM Welcome – GGIA Chapter 4 Leadership

9:00 – 10:00 AM Hot New Annuals and Perennials for the Landscape – Bodie Pennisi

10:00 – 10:15 AM Break

10:15 – 11:15 AM Non-Native Invasive Pests of Georgia – Mark Raines

11:15 – 12:15 PM Biological Control of Pests in the Landscape – Kris Braman

12:15 – 12:45 PM Lunch (included with registration fee)

12:45 – 1:45 PM Best Shrubs and Woodies for the Coast – Matthew Chappell

1:45 – 2:45 PM On-Site Consulting: A New Business Opportunity – Don Gardner

2:45 – 3:45 PM Pre-emergent and Post-Emergent Use, Safety, and New Products for the Landscape – Mark Czarnota,

3:45 – 4:30 PM Enjoy fellowship and networking.

Leaf Spots in the Landscape

Elizabeth Little/Extension Specialist

Department of Plant Pathology, University of Georgia


Many areas in Georgia are experiencing warm, humid weather with frequent

thunderstorms this month. This is the perfect weather for fungal leaf spot

development in the landscape. Most leaf spots are benign and will not damage

the plant. Cercospora Leaf Spot of Hydrangea is an example of a leaf spot

disease that commonly occurs during prolonged wet weather or under sprinkler

irrigation. As with most leaf spots in the landscape, chemical treatment is rarely

needed. Some leaf spotting and leaf drop will not the harm the plant.

Management of leaf spot diseases involves removing sources of the disease and

protecting the plant. Start by selecting plants that will thrive where they are sited.

The fungi that cause these diseases mainly survive on the infected leaves that

fall to the ground, so removing and destroying diseased leaves can help lessen

the amount of disease next year. Stressed plants are more susceptible to

disease, so check the cultural conditions and optimize them with fertility

management and mulching. Good air circulation around plants will lower the

humidly and leaf wetness and reduce disease. Avoid wetting the leaves when

irrigating landscape plants.

If the plant is repeatedly defoliated each year or appears to be dying back

because of the disease, prune out the affected stems and use fungicides

preventatively (before the symptoms) to protect new growth.


FREE Book!!! – IPM for Select Deciduous Trees in Southeastern US Nursery Production

Southeastern nursery growers now have a new best friend when fighting pests and diseases. A new book, available in hard copy and iBook format for iPads, is now available, thanks to the Southern Nursery IPM Working Group.

The book—IPM for Select Deciduous Trees in Southeastern US Nursery Production—is a compilation of information about IPM for the major tree genera in nursery crop production in the southeast. The 320-page iBook covers sustainable management for insects, mites, disease, and weeds for the top-selling deciduous trees, as well as propagation and production information, genus by genus. The book demonstrates how each aspect of production can impact pest problems and management. Each chapter is centered on one crop, so answers to pest problems with “birch” or “dogwood” are easy to find.

The iBook includes movies illustrating techniques like grafting, hand-digging, and more as well as a custom glossary for terms specific to nursery production and pest management. While this resource is invaluable to nursery growers, landscapers, arborists, garden center owners, students and educators will also find it useful.

IPM for Select Deciduous Trees in Southeastern US Nursery Production was written by university Extension specialists in nursery production, plant pathology, entomology and weed science with partial support by the Southern Region IPM Center in Raleigh, NC.

Authors include extension specialists from the Southern Nursery IPM Working Group:

  • Craig Adkins, NC State University
  • S. Kris Braman, University of Georgia
  • Matthew Chappell, University of Georgia
  • Juang-Horng Chong, Clemson University
  • Jeffrey Derr, Virginia Tech
  • Winston Dunwell, University of Kentucky
  • Steven Frank, NC State University
  • Amy Fulcher, University of Tennessee
  • Frank Hale, University of Tennessee
  • William Klingeman, University of Tennessee
  • Gary Knox, University of Florida
  • Anthony LeBude, NC State University
  • Joseph Neal, NC State University
  • Mathews Paret, University of Florida
  • Nicole Ward, University of Kentucky
  • Sarah White, Clemson University
  • Jean Williams-Woodward, University of Georgia
  • Alan Windham, University of Tennessee
  • Jill Sidebottom, NC State University, guest author

To download the book to iTunes, search for IPM for Select Deciduous Trees in Southeastern US Nursery Production. To view or download the iBook chapter by chapter, go to

The iBook is formatted specifically for the iPad but can be downloaded as a pdf for viewing on any device. You can also view the book online from a computer or print it by chapter at the web address above. To request the book in hard copy, contact one of the authors or editors Amy Fulcher or Sarah for one of the limited print editions.